Research

Research in to PROS

This page is dedicated to research that has been undertaken in to PROS.

Explanations of PROS:

Research papers in to PROS (PIK3CA Related Overgrowth Spectrum)

Drug Trials for PROS (PIK3CA Related Overgrowth Spectrum)

  • The various cells in our bodies usually follow a particular lifespan, this is the same for the growth gene PIK3CA. A normal cell will undergo a rapid death should anything become altered or damaged.
  • However, if through mutation this PIK3CA gene does not die or “switch off” they become known as “oncogenes.”
  • This means that the gene has the potential to cause cancer & tumour progression. however, this does not seem to be common place in PROS patients.
  • This link to cancer has led to an increase in research to find potential (non-invasive) treatment for cancer patients, but which could also benefit PROS patients.

2016: Cancer drug could treat blood vessel deformities

  • Conclusion of the study suggests that “Rapamycin is a drug that blocks a signalling process that happens downstream of PIK3CA, so it stops one of PIK3CA’s effects but does not block it at source,” explains lead author Dr Sandra Castillo (UCL Cancer Institute). “When we gave rapamycin to the mice, it showed clinical benefit, but in patients it can have serious side-effects and compromise the immune system”.

2017: ArQule Announces First Patient Dosed in Company Sponsored Phase 1/2 Trial of AKT Inhibitor, ARQ 092, for Rare Overgrowth Diseases

  • ArQule announced that the first patient has been dosed in a company sponsored phase 1/2 trial with its AKT inhibitor, ARQ 092, in patients with Overgrowth Diseases driven by genetic alterations of the PI3K/AKT1 pathway. ARQ 092 is an orally available, selective pan-AKT inhibitor.

2017: Study of ARQ 092 in Subjects With PIK3CA-related Overgrowth Spectrum and Proteus Syndrome (MOSAIC)

  • Details of the study: “this is an open label, Phase 1/2 study of oral ARQ 092 (Miransertib) administered to subjects at least 2 years of age with PIK3CA-related Overgrowth Spectrum (PROS) and Proteus syndrome (PS) (MOSAIC)”.

2017/2018: Severe PI3Kinase Overgrowth Syndrome Treated with the AKT Inhibitor Miransertib

  • Results indicated as follows: “calculated volumes of fatty overgrowth declined by approximately 15% on treatment. The patient has now completed 25 months of therapy with clinically stable disease and clear radiological improvement. Miransertib was well tolerated with no significant toxicities other than hyperlipidaemia comparable to lipid profile derangement previously noted on sirolimus therapy”.

2017: Trial of Taselisib in Overgrowth (TOTEM)

  • “Taselisib is a selective inhibitor of class I PI3Ks and has direct inhibitory activity of the p110α isoform with a Kiapp value of 0.29 nmol/l”. Unfortunately the trial was: “Terminated (In accordance with the protocol, following the occurrence of two SUSARs, the TOTEM trial was stopped early for safety reasons.)”

2018: In vitro efficacy of ARQ 092, an allosteric AKT inhibitor, on primary fibroblast cells derived from patients with PIK3CA-related overgrowth spectrum (PROS)

  • Results from the trial suggest: “we demonstrated the following: (a) that PROS cells are dependent on AKT; (b) the advantage of inhibiting the pathway immediately downstream of PI3K to circumventing problems depending on multiple classes a PI3K kinases; and (c) that PROS patients benefit from inhibition of AKT rather than mTOR. Clinical development of ARQ 092 in PROS patients is on going in these patients.”
 
  • Results showed: “BYL719 was used to treat nineteen patients with PROS. The drug improved the disease symptoms in all patients. Previously intractable vascular tumours became smaller, congestive heart failure was improved, hemihypertrophy was reduced, and scoliosis was attenuated. The treatment was not associated with any substantial side effects. In conclusion, this study provides the first direct evidence supporting PIK3CA inhibition as a promising therapeutic strategy in patients with PROS.
  • Results from this study offer the following thoughts: “This study suggests that low-dose sirolimus can modestly reduce overgrowth, but cautions that the side-effect profile is significant, mandating individualized risk–benefit evaluations for sirolimus treatment in PROS.”
  • As a side note, I (Mandy Sellars) began taking Rapamycin a number of years ago with amazing results. Along with a combination of exercise & healthy eating, my overgrowth stopped & began to shrink. I lost around 4/5 stone in weight from my affected areas. Unfortunately my body became tolerant of the dosage I was taking & it was recommended not to increase the dose. Therefore, sadly I had to stop taking the medication & my overgrowth started to increase again.
  • An overview of research in the UK from Professor R Semple.

2019: Managed Access Program (MAP) to Provide Alpelisib (BYL719) for Patients With PIK3CA-Related Overgrowth Spectrum (PROS)

    • The purpose of the study is “to allow access to alpelisib for patients diagnosed with PIK3CA-Related Overgrowth Spectrum (PROS) who fulfill certain eligibility criteria as specified in this document. The patient’s Treating Physician should follow the suggested treatment guidelines and comply with all local health authority regulations.”
    • To reiterate, this drug is available on “compassionate use” only. Please speak to your specialist/consultant who will hopefully be able to help you with this.
    • You can also contact Novartis for more information: mailto:novartis.email@novartis.com

2020: Retrospective Chart Review Study of Patients With PIK3CA-Related Overgrowth Spectrum Who Have Received Alpelisib (EPIK-P1)

  • This retrospective study aims to determine the effectiveness & safety of the drug Alpelisib. This was administered to patients through the “compassionate use” scheme for the treatment of PROS (PIK Related Overgrowth Spectrum)
  • Results of this study should be available July/August 2020. Should the results be favourable, this could hopefully lead to medical trials of Alpelisib for PROS patients.

2020: https://www.sciencedirect.com/science/article/pii/S0006291X2030886X

  • PIK3CA-related overgrowth spectrum is characterized by increased cell proliferation.
  • Strong activation of HSF1 is found in PIK3CA-related overgrowth spectrum fibroblasts.
  • AKT inhibitors reduces HSF1 activation and HSF1-dependent gene transcription.
  • HSF1 inhibition blocks the PIK3CA-related overgrowth spectrum proliferation.
  • As there is currently no curative treatment for PIK3CA-related overgrowth spectrum, our results identify HSF1 as a new potential therapeutic target.

2020: Novartis receives Piqray approval in Europe – the first and only targeted medicine for HR+/HER2- advanced breast cancer with a PIK3CA mutation

  • Piqray (alpelisib) is the only treatment approved specifically to address PIK3CA mutation
  • This is very promising for those living with a PIK3CA mutation that is causes overgrowth, trials are in the pipeline.

2020: https://www.fiercepharma.com/pharma/esmo-novartis-posts-long-awaited-survival-data-for-breast-cancer-blockbuster-hopeful-piqray

  • Novartis has an ambitious development plan for the drug going forward. It’s preparing to file for approval in patients with a rare disorder called PIK3CA overgrowth syndrome.

2020: https://clinicaltrials.gov/ct2/show/NCT04409145

  • VT30-101 is a 2-part first-in-human trial of topically administered VT30 to subjects with cutaneous venous malformations, lymphatic malformations, or mixed venolymphatic malformations associated with PIK3CA or TEK mutations.
  • VT30 is a PI3K-inhibitor prodrug, formulated as a topical gel and dispensed from a metered dose pump; administration is once or twice daily, applied to target-treatment area(s) on the skin.

2020: https://clinicaltrials.gov/ct2/show/NCT04589650?cond=PIK3CA+Related+Overgrowth+Spectrum&draw=2&rank=2

  • This is a prospective Phase II multi-center study with an upfront 16-week, randomized, double-blind, placebo-controlled period, and extension periods, to assess the efficacy, safety and pharmacokinetics of alpelisib in pediatric and adult participants with PIK3CA-related overgrowth spectrum (PROS).
  • Study start date: February 2, 2021
  • For further information: mailto:novartis.email@novartis.com

2020: What is Apelisib

2020: Characterization and Childhood Tumor Risk Assessment of Genetic and Epigenetic Syndromes Associated With Lateralized Overgrowth

  • We suspect that it is likely that the overall risk falls below 1%
  • There is a clear need for further publication of known cases and collaboration among institutions, so the denominator of patients with PROS can be further adjusted to understand true WT risk in this population.
  • In terms of current recommendations, tumor screening should be performed at the discretion of the provider based on the genetic change and clinical features of the PROS presentation, as well as the family perspective.

2021: https://link.springer.com/article/10.1007/s00109-020-02030-6#Fig1

  • Recently, this drug was used by us for one such case, that of a 29-year-old Canadian woman, and led to a spectacular response.
  • During the last years, moreover, ~ 60 patients were treated for PROS with this drug under the care of Dr. Guillaume Canaud at NeckerEnfants Malades Hospital, and all have experienced regression over their overgrowths.

2021: https://comptes-rendus.academie-sciences.fr/biologies/articles/10.5802/crbiol.50/

  • PIK3CA-related overgrowth spectrum: animal model and drug discovery
  • This review recapitulates the recent knowledge accumulation on overgrowth syndrome related to gain of function of the phosphoinositide3 kinase (PI3K)-alpha. These disorders, known as PIK3CA related overgrowth syndromes (PROS) are caused by somatic PIK3CA mutation occurring during embryogenesis. We summarize here the currently available animal models and new treatments undergoing development.

2021: https://ojrd.biomedcentral.com/articles/10.1186/s13023-021-01929-8

  • A review of mechanisms of disease across PIK3CA-related disorders with vascular manifestations.

  • PIK3CA-related disorders include vascular malformations and overgrowth of various tissues that are caused by postzygotic, somatic variants in the gene encoding phosphatidylinositol-3-kinase (PI3K) catalytic subunit alpha. These mutations result in activation of the PI3K/AKT/mTOR signaling pathway. The goals of this review are to provide education on the underlying mechanism of disease for this group of rare conditions and to summarize recent advancements in the understanding of, as well as current and emerging treatment options for PIK3CA-related disorders.
  • Management of patients with PIK3CA-related disorders requires a multidisciplinary approach. Further results from ongoing clinical studies of agents targeting the PI3K pathway are highly anticipated.

2021: A standard of care for individuals with PIK3CA-related disorders: an international expert consensus statement

  • Growth promoting variants in PIK3CA cause a spectrum of developmental disorders, depending on the developmental timing of the mutation and tissues involved. These phenotypically heterogeneous entities have been grouped as PIK3CA-Related Overgrowth Spectrum disorders (PROS). Deep sequencing technologies have facilitated detection of low-level mosaic, often necessitating testing of tissues other than blood. Since clinical management practices vary considerably among healthcare professionals and services across different countries, a consensus on management guidelines is needed. Clinical heterogeneity within this spectrum leads to challenges in establishing management recommendations, which must be based on patient-specific considerations. Moreover, as most of these conditions are rare, affected families may lack access to the medical expertise that is needed to help address the multi-system and often complex medical issues seen with PROS. In March 2019, macrocephaly-capillary malformation (M-CM) patient organizations hosted an expert meeting in Manchester, United Kingdom, to help address these challenges with regards to M-CM syndrome. We have expanded the scope of this project to cover PROS and developed this consensus statement on the preferred approach for managing affected individuals based on our current knowledge.

2021: Novartis announces findings from a real-world study of alpelisib

  • Novartis announces findings from a real-world study of alpelisib demonstrating clinical benefit in people with PIK3CA-Related Overgrowth Spectrum (PROS)

  • PROS is a spectrum of rare disorders caused by PIK3CA mutations and is characterized by atypical, visible overgrowths and anomalies in blood vessels, the lymphatic system and other tissues.
  • At 24 weeks, 38% of patients achieved ≥20% reduction in the volume of the PROS lesions assessed in the primary endpoint analysis; no patients experienced disease progression or death.
  • Alpelisib is the first potential treatment to specifically address the root cause of PROS conditions.

2021: https://www.science.org/doi/10.1126/scitranslmed.abg0809#.YV54vSeHixo.twitter

  • Gain-of-function mutations in the PIK3CA gene cause lymphatic malformations (LMs), genetic disorders characterized by vascular abnormalities causing pain, inflammation, and deformities. To identify potential treatments able to prevent LMs, Delestre et al. developed a genetic mouse model that recapitulates the main features of LMs and showed that the approved drug PIK3CA inhibitor alpelisib, used in oncology, prevented LMs, and increased survival. Alpelisib administration in six patients refractory to previous pharmacological or surgical approaches improved symptoms and reduced the volume of LMs. Although two patients developed adverse events potentially related to the treatment, the results suggest that inhibiting PIK3CA could be effective in treating LMs.

2021:  Positive correlation between transcriptomic stemness and PI3K/AKT/mTOR signaling scores in breast cancer, and a counterintuitive relationship with PIK3CA genotype

  • A PI3Kα-selective inhibitor has recently been approved for use in breast tumors harboring mutations in PIK3CA, the gene encoding p110α. Preclinical studies have suggested that the PI3K/AKT/mTOR signaling pathway influences stemness, a dedifferentiation-related cellular phenotype associated with aggressive cancer. However, to date, no direct evidence for such a correlation has been demonstrated in human tumors. In two independent human breast cancer cohorts, encompassing nearly 3,000 tumor samples, transcriptional footprint-based analysis uncovered a positive linear association between transcriptionally-inferred PI3K/AKT/mTOR signaling scores and stemness scores. Unexpectedly, stratification of tumors according to PIK3CA genotype revealed a “biphasic” relationship of mutant PIK3CA allele dosage with these scores. Relative to tumor samples without PIK3CA mutations, the presence of a single copy of a hotspot PIK3CA variant was associated with lower PI3K/AKT/mTOR signaling and stemness scores, whereas the presence of multiple copies of PIK3CA hotspot mutations correlated with higher PI3K/AKT/mTOR signaling and stemness scores. This observation was recapitulated in a human cell model of heterozygous and homozygous PIK3CAH1047R expression. Collectively, our analysis (1) provides evidence for a signaling strength-dependent PI3K-stemness relationship in human breast cancer; (2) supports evaluation of the potential benefit of patient stratification based on a combination of conventional PI3K pathway genetic information with transcriptomic indices of PI3K signaling activation.

2022:  Treatment of two infants with PIK3CA-relatedovergrowth spectrum by alpelisib.

  • PIK3CA-related overgrowth spectrum (PROS) includes rare genetic conditions due to gain-of-function mutations in the PIK3CA
    There is no approved medical therapy for patients with PROS, and alpelisib, an approved PIK3CA inhibitor in oncology,
    showed promising results in preclinical models and in patients. Here, we report for the first time the outcome of two infants
    with PROS having life-threatening conditions treated with alpelisib (25 mg) and monitored with pharmacokinetics. Patient
    1 was an 8-mo-old girl with voluminous vascular malformation. Patient 2 was a 9-mo-old boy presenting with asymmetrical
    body overgrowth and right hemimegalencephaly with West syndrome. After 12 mo of follow-up, alpelisib treatment was
    associated with improvement in signs and symptoms, morphological lesions and vascular anomalies in the two patients. No
    adverse events were reported during the study. In this case series, pharmacological inhibition of PIK3CA with low-dose alpelisib
    was feasible and associated with clinical improvements, including a smaller size of associated complex tissue malformations
    and good tolerability.

2022: PIK3CA mutation correlates with mTOR pathway expression but not clinical and pathological features in Fibfibroipose vascular anomaly (FAVA)

  • There was no significant association between the presence of PIK3CA mutations and the clinicopathological features of FAVA, suggesting that the PIK3CA gene is not necessarily involved in the onset of FAVA. FAVAs lacking PIK3CA mutations may be caused by other gene mutations that activate 4EBP1 and S6K1.

2022: Genotypes and phenotypes heterogeneity in PIK3CA-related overgrowth spectrum and overlapping conditions: 150 novel patients and systematic review of 1007 patients with PIK3CA pathogenetic variants

  • We confirm that (1) molecular diagnostic yield increases when multiple tissues are tested and by enriching NGS panels with genes of overlapping ‘vascular’ phenotypes; (2) strongly activating PIK3CA variants are found in affected tissue, rarely in blood: conversely, weakly activating mutations more common in blood; (3) weakly activating variants correlate with CNS involvement, strong variants are more common in cases without; (4) patients with vascular malformations overlapping those of PROS can harbour variants in genes other than PIK3CA.

2022: Alpelisib to treat CLOVES syndrome, a member of the PIK3CA-related overgrowth syndrome spectrum

  • CLOVES syndrome is a rare congenital overgrowth disorder caused by mutations in the phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) gene. It is part of the PIK3CA-related overgrowth syndrome (PROS) spectrum and its treatment is challenging. PROS malformations have traditionally been treated by surgery, but research into pharmacological treatments capable of blocking the PIK/AKT/mTOR pathway has increased over the past decade. The results have been promising and suggest that compassionate use of these treatments in patients with PROS disorders could have clinical benefits. Another promising drug is alpelisib (BYL719), which is a selective inhibitor that competitively binds to the p110a subunit of PIK3 in the intracellular PI3K/AKT signalling pathway. Compassionate use of low-dose alpelisib had striking effects in an uncontrolled case series of 19 PROS patients, several with life-threatening complications. Moreover, there were few adverse effects and the treatment did not impair linear growth, despite the young age of many of the patients. We present the case of a patient with CLOVES syndrome who was started on compassionate treatment with alpelisib after surgical debulking of a cystic lymphangioma and treatment with sirolimus. This promising drug significantly reduced the size of the lymphangioma and prevented progression of the tissue overgrowth in the gluteal region. This case suggests that low-dose PI3K inhibition may provide collateral benefits that extend beyond mitigation of disease-specific features of PROS.

2022: FDA approves Novartis Vijoice® (alpelisib) as first and only treatment for select patients with PIK3CA-Related Overgrowth Spectrum (PROS)

  • Vijoice is first approved treatment to specifically address the root cause of PROS conditions in select patients 2 years of age and older1
  • PROS is a spectrum of rare conditions and is characterized by atypical overgrowths and anomalies in blood vessels, the lymphatic system and other tissues2,3  
  • Approval based on real-world data from EPIK-P1 study, which showed patients treated with Vijoice experienced reduction in the size of PROS lesions and improvement of PROS-related signs and symptoms
  • Novartis to offer robust patient support program that includes assistance to access medication, financial resources for eligible patients and continued education

2022: Sexual Function and Fertility in Males With Vascular Malformations of the Genitourinary Tract and Pelvis

  • Males with VM involving or not involving the GU system may experience problems with sexual function and satisfaction. While prospective studies are needed to clarify the prevalence and extent of these symptoms, providers should be aware that such symptoms can occur in this patient population.

2022: Clinical Response to PI3K-α Inhibition in a Cohort of Children and Adults With PIK3CA-Related Overgrowth Spectrum Disorders

Objective:

The goal of this report is to describe, through a series of 5 cases, the clinical response and safety of alpelisib (BYL719) use in children and adults with PIK3CA-related overgrowth spectrum (PROS) disorders at our center.

Methods:

We reviewed clinical records of 5 patients from October 2019 through September 2021 followed by the pediatric hematology and multidisciplinary vascular anomalies teams at the Monroe Carell Jr. Children’s Hospital at Vanderbilt (MCJCHV). All patients carried a clinical or genetic diagnosis of PROS and were treated with alpelisib provided by a Novartis managed access program.

Results:

We highlight improvement in reported symptoms, objective overgrowth measurements, and quality of life to varying degrees in all patients. We note dose-dependent hyperglycemia and gastrointestinal side effects in 2 of the 5 patients. No patients experienced any serious side effects.

Conclusion:

This case series reports on the real-world use of PI3K-α inhibition in the management of PROS. Ongoing clinical trials will provide efficacy and safety data as these drugs become more widely used in patients with vascular anomalies and syndromes secondary to somatic PIK3CA mutations.

2022: At a crossroads: how to translate the roles of PI3K in oncogenic and metabolic signalling into improvements in cancer therapy

  • Numerous agents targeting various phosphatidylinositol 3-kinase (PI3K) pathway components, including PI3K, AKT and mTOR, have been tested in oncology clinical trials, resulting in regulatory approvals for the treatment of selected patients with breast cancer, certain other solid tumours or particular haematological malignancies. However, given the prominence of PI3K signalling in cancer and the crucial role of this pathway in linking cancer growth with metabolism, these clinical results could arguably be improved upon. In this Review, we discuss past and present efforts to overcome the somewhat limited clinical efficacy of PI3Kα pathway inhibitors, including optimization of inhibitor specificity, patient selection and biomarkers across cancer types, with a focus on breast cancer, as well as identification and abrogation of signalling-related and metabolic mechanisms of resistance, and interventions to improve management of prohibitive adverse events. We highlight the advantages and limitations of laboratory-based model systems used to study the PI3K pathway, and propose technologies and experimental inquiries to guide the future clinical deployment of PI3K pathway inhibitors in the treatment of cancer.

2022: Alpelisib to Treat PIK3CA-Related Overgrowth Syndrome (PROS)

  • Video from Guillaume Canaud, MD, PhD, of the Paris Descartes University, describes the clinical studies that led to the approval of alpelisib to treat persons with PiK3CA-related overgrowth syndrome (PROS).

2022: Mapping the PIK3CA-related overgrowth spectrum (PROS) patient and caregiver journey using a patient-centered approach

  • PROS disorders are driven by somatic, gain-of-function mutations in PIK3CA that result in hyperactivation of the phosphatidylinositol-3-kinase (PI3K) signaling pathway. PROS encompasses a broad spectrum of overlapping phenotypes (including overgrowth and vascular malformations) that vary significantly in their severity; every case is unique, leading to different, complex experiences. Here, we aim to describe the PROS experience from the patients’ and caregivers’ points of view, from onset to diagnosis to treatment and support.

2022: PIK3CA-related overgrowth with an uncommon phenotype: case report

  • Megalencephaly-capillary malformation syndrome is a rare multiple-malformation syndrome secondary to somatic activating mutations in the PI3K-AKT-MTOR pathway. This is included in a heterogeneous group of disorders, now defined “PIK3CA-related overgrowth spectrum”.

2022: Treating Alpelisib-Induced Hyperglycemia with Very Low Carbohydrate Diets and Sodium-Glucose Co-Transporter 2 Inhibitors: A Case Series

  • Alpelisib is a α-selective phosphatidylinositol 3-kinase (PI3K) inhibitor approved for treatment of postmenopausal women, and men, with hormone receptor positive (HR+), human epidermal growth factor receptor 2 negative (HER2–), PIK3CA-mutated, advanced breast cancer (ABC). Hyperglycemia is a common, on-target adverse effect that impairs treatment efficacy and increases the rate of treatment delays, dose reductions, and discontinuation. Currently, there are no clear guidelines on how to manage hyperglycemia due to alpelisib when metformin is not effective. In this case series, we review 3 subjects with ABC that developed hyperglycemia during alpelisib-fulvestrant therapy and were successfully managed with dietary and pharmacologic interventions. These cases provide anecdotal evidence to support the use of sodium-glucose co-transporter-2 inhibitors (SGLT2i) and very low carbohydrate diets to minimize hyperglycemia during alpelisib therapy.

2022: 4 questions for professor Guillaume Canaud

2022: Undergrowth Of First Toe In PiK3CA-Related Overgrowth Spectrum (PROS)

  • PIK3CA-related overgrowth syndrome (PROS) include a heterogeneous group of disorders characterized by segmental overgrowth secondary to somatic mosaic activating variants in PIK3CA. Segmental undergrowth is more uncommon and has been less studied but pathogenic variants in PIK3CA have also been found. With this in mind, we have noticed a group of patients with PROS that present an undergrowth component associated with their focal overgrowth.

2022: Vijoice & PIK3CA Related Overgrowth Spectrum (PROS)

2022: When, where and which PIK3CA mutations are pathogenic in congenital disorders

  • PIK3CA encodes the class I PI3Kα isoform and is frequently mutated in cancer. Activating mutations in PIK3CA also cause a range of congenital disorders featuring asymmetric tissue overgrowth, known as the PIK3CA-related overgrowth spectrum (PROS), with frequent vascular involvement. In PROS, PIK3CA mutations arise postzygotically, during embryonic development, leading to a mosaic body pattern distribution resulting in a variety of phenotypic features. A clear skewed pattern of overgrowth favoring some mesoderm-derived and ectoderm-derived tissues is observed but not understood. Here, we summarize our current knowledge of the determinants of PIK3CA-related pathogenesis in PROS, including intrinsic factors such as cell lineage susceptibility and PIK3CA variant bias, and extrinsic factors, which refers to environmental modifiers. We also include a section on PIK3CA-related vascular malformations given that the vasculature is frequently affected in PROS. Increasing our biological understanding of PIK3CA mutations in PROS will contribute toward unraveling the onset and progression of these conditions and ultimately impact on their treatment. Given that PIK3CA mutations are similar in PROS and cancer, deeper insights into one will also inform about the other.

2022: Alpelisib for the treatment of PIK3CA-related head and neck lymphatic malformations and overgrowth

  • Purpose: PIK3CA-related overgrowth spectrum (PROS) conditions of the head and neck are treatment challenges. Traditionally, these conditions require multiple invasive interventions, with incomplete malformation removal, disfigurement, and possible dysfunction. Use of the PI3K inhibitor alpelisib, previously shown to be effective in PROS, has not been reported in PIK3CA-associated head and neck lymphatic malformations (HNLMs) or facial infiltrating lipomatosis (FIL). We describe prospective treatment of 5 children with PIK3CA-associated HNLMs or head and neck FIL with alpelisib monotherapy.

2022: Alpelisib Displays Clinical Benefit in Pediatric PIK3CA-Related Overgrowth Spectrum Disease

  • Alpelisib decreased the need for surgery and led to improvements in performance status and disease-related signs and symptoms in pediatric patients with PIK3CA-related overgrowth spectrum disease who received treatment with the PI3K inhibitor under compassionate use.

2022: Clinical and genetic analyses of patients with lateralized overgrowth

Background

The genetic features and treatment strategies of lateralized overgrowth have been elusive. We performed this study to analyze the genetic characteristics and treatment results of propranolol- or alpelisib-treated patients with lateralized overgrowth.

Methods

Fifteen patients with lateralized overgrowth were involved. Clinical characteristics and whole-body magnetic resonance imaging (WB-MRI) findings were evaluated. Targeted exome sequencing with a gene panel of affected tissue and peripheral white blood cells was performed. Propranolol was administered and treatment results were evaluated. The PIK3CA inhibitor alpelisib was prescribed via a managed access program.

Results

The identified mutations were PIK3CA (n = 7), KRAS (n = 2), PTEN (n = 1), MAP2K3 (n = 1), GNAQ (n = 1), TBC1D4 (n = 1), and TEK (n = 1). Propranolol was prescribed in 12 patients, and 7 experienced mild improvement of symptoms. Alpelisib was prescribed in two patients with a PIK3CA mutation, and the reduction of proliferated masses after 1 year of treatment was proved by WB-MRI.

Conclusions

Targeted exome sequencing identified various genetic features of lateralized overgrowth. Propranolol could be applied as an adjuvant therapy for reducing vascular symptoms, but a PIK3CA inhibitor would be the primary therapeutic strategy for PIK3CA-related overgrowth syndrome.

2022: Clinical and genetic analysis of patients with segmental overgrowth features and somatic mammalian target of rapamycin (mTOR) pathway disruption: Possible novel clinical issues

  • Segmental overgrowth syndromes include a group of clinical entities, all characterized by the abundant proliferation of tissues or organs in association with vascular abnormalities. These syndromes show a wide spectrum of severity ranging from limited involvement of only small areas of the body to complex cases with impressive distortions of multiple tissues and organs. It is now clear that somatic mutations in genes of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway (in brief “mTOR pathway”) are responsible for such entities. Not all the cells of the body carry the same causative mutation, which is mosaic, appearing from two (or more) distinct cell lineages after fertilization. In this article, we reconsider the clinical spectrum and surveillance programs of patients with segmental overgrowth syndromes, based on the features of six patients with diverse clinical forms of overgrowth and pathogenic variants in genes of the mTOR pathway.

2022: PIK3CA gain-of-function mutation in adipose tissue induces metabolic reprogramming with Warburg-like effect and severe endocrine disruption

  • PIK3CA-related overgrowth syndrome (PROS) is a genetic disorder caused by somatic mosaic gain-of-function mutations of PIK3CA. Clinical presentation of patients is diverse and associated with endocrine disruption. Adipose tissue is frequently involved, but its role in disease development and progression has not been elucidated. Here, we created a mouse model of PIK3CA-related adipose tissue overgrowth that recapitulates patient phenotype. We demonstrate that PIK3CA mutation leads to GLUT4 membrane accumulation with a negative feedback loop on insulin secretion, a burst of liver IGFBP1 synthesis with IGF-1 sequestration, and low circulating levels. Mouse phenotype was mainly driven through AKT2. We also observed that PIK3CA mutation induces metabolic reprogramming with Warburg-like effect and protein and lipid synthesis, hallmarks of cancer cells, in vitro, in vivo, and in patients. We lastly show that alpelisib is efficient at preventing and improving PIK3CA-adipose tissue overgrowth and reversing metabolomic anomalies in both animal models and patients.

2023: Response to sirolimus in capillary lymphatic venous malformations and associated syndromes: Impact on symptomatology, quality of life, and radiographic response

  • Capillary lymphatic venous malformations (CLVM) and associated syndromes, including Klippel–Trenaunay syndrome (KTS) and congenital lipomatous overgrowth, vascular malformation, epidermal nevi, skeletal, and spinal syndrome (CLOVES), are underrecognized disorders associated with high morbidity from chronic pain, recurrent infections, bleeding, and clotting complications. The rarity of these disorders and heterogeneity of clinical presentations make large-scale randomized clinical drug trials challenging. Identification of PIK3CA (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha [gene]) mutations in CLVM has made targeted medications, such as sirolimus, attractive treatment options. The aim of this study was to investigate the safety and efficacy of sirolimus therapy in CLVM.

2023: Ultrasound-Guided Percutaneous Intercostal Cryoneurolysis for Acute-on-Chronic Pain in CLOVES Syndrome

  • Cryoneurolysis is an analgesic method that has been shown to provide extended pain relief in postoperative patients. However, to date, this method has not been described in nonsurgical inpatients with chronic pain experiencing an acute exacerbation. This analgesic modality has the potential to provide pain relief for patients whose expected duration of severe acute pain would outlast that of other regional anesthetic techniques while avoiding opioid escalation and facilitating discharge.

    We present a patient with acute exacerbation of chronic pain from breast ulcerations caused by congenital lipomatous overgrowth, vascular malformations, epidermal nevis, spinal/skeletal anomalies/scoliosis (CLOVES) syndrome that was successfully treated as an inpatient with a portable cryoneurolysis device.

    This is the first reported use of cryoneurolysis in an inpatient setting to treat acute-on-chronic pain in a nonsurgical patient. The authors recommend regional anesthesiologists and acute pain specialists to utilize this technique to provide analgesia in patients with complex pain to facilitate hospital throughput.

2023: The VASCERN-VASCA Working Group Diagnostic and Management Pathways for Venous Malformations

  • Objective(s): 

    To elaborate expert consensus patient pathways to guide patients and physicians toward efficient diagnostics and management of patients with venous malformations.

    Methods: 

    VASCERN-VASCA (https://vascern.eu/) is a European network of multidisciplinary centers for Vascular Anomalies. The Nominal Group Technique was used to establish the pathways. Two facilitators were identified: one to propose initial discussion points and draw the pathways, and another to chair the discussion. A dermatologist (AD) was chosen as first facilitator due to her specific clinical and research experience. The draft was subsequently discussed within VASCERN-VASCA monthly virtual meetings and annual face-to-face meetings.

    Results: 

    The Pathway starts from the clinical suspicion of a venous type malformation (VM) and lists the clinical characteristics to look for to support this suspicion. Strategies for subsequent imaging and histopathology are suggested. These aim to inform on the diagnosis and to separate the patients into 4 subtypes: (1) sporadic single VMs or (2) multifocal, (3) familial, multifocal, and (4) combined and/or syndromic VMs. The management of each type is detailed in subsequent pages of the pathway, which are color coded to identify sections on (1) clinical evaluations, (2) investigations, (3) treatments, and (4) associated genes. Actions relevant to all types are marked in separate boxes, including when imaging is recommended. When definite diagnoses have been reached, the pathway also points toward disease-specific additional investigations and recommendations for follow up. Options for management are discussed for each subtype, including conservative and invasive treatments, as well as novel molecular therapies.

    Conclusion: 

    The collaborative efforts of VASCERN-VASCA, a network of the 9 Expert Centers, has led to a consensus Diagnostic and Management Pathways for VMs to assist clinicians and patients. It also emphasizes the role of multidisciplinary expert centers in the management of VM patients. This pathway will become available on the VASCERN website (http://vascern.eu/)

2023: Condition causing big feet is ruining girl’s life
          A young girl’s feet are so big that she is forced to use a wheelchair. But now a new drug has given her hope.
 
 
  • Abstract : Background
  • Facial infiltrating lipomatosis (FIL) is a rare congenital disorder characterized by unilateral facial swelling, for which surgery is the prevailing therapeutic option. Several studies have shown that the development of FIL is closely associated with PIK3CA mutations. This study aimed to further identify rare clinical features and underlying molecular variants in patients with FIL.
  • Results:
  • Eighteen patients were included in this study, and all patients presented with infiltrating adipose tissues confirmed by magnetic resonance imaging. Macrodactyly, polydactyly, hemimegalencephaly and hemihyperplasia were also observed in patients with FIL. In total, eight different PIK3CA mutations were detected in tissues obtained from sixteen patients, including the missense mutations p.His1047Arg (n = 4), p.Cys420Arg (n = 2), p.Glu453Lys (n = 2), p.Glu542Lys (n = 2), p.Glu418Lys (n = 1), p.Glu545Lys (n = 1), and p.His1047Tyr (n = 1) and the deletion mutation p.Glu110del (n = 3). Furthermore, the GNAQ mutation p.Arg183Gln was detected in the epidermal nevus tissue of one patient. Imaging revealed that several patients carrying hotspot mutations had more severe adipose infiltration and skeletal deformities.
  • Conclusions:
  • The abundant clinical presentations and genetic profiles of FIL make it difficult to treat. PIK3CA mutations drive the pathogenesis of FIL, and PIK3CA hotspot mutations may lead to more extensive infiltration of lipomatosis. Understanding the molecular variant profile of FIL will facilitate the application of novel PI3K-targeted inhibitors.

2023: Alpelisib for Treatment of Patients With PIK3CA-Related Overgrowth Spectrum (PROS)

  • Abstract

    PURPOSE

    PROS encompasses several rare conditions resulting from activating variants in PIK3CA. Alpelisib, a PI3Kα-selective inhibitor, targets the underlying etiology of PROS, offering a novel therapeutic approach to current management strategies. This study evaluated the safety and efficacy of alpelisib in pediatric and adult patients with PROS.

    METHODS

    EPIK-P1 (NCT04285723) was a non-interventional, retrospective chart review of 57 patients with PROS (≥2 years) treated with alpelisib through compassionate use. Patients had severe/life-threatening PROS-related conditions and confirmed PIK3CA pathogenic variant. The primary endpoint assessed patient response to treatment at Week 24 (6 months).

    RESULTS

    Twenty-four weeks (6 months) after treatment initiation, 12/32 (37.5%) patients with complete case records included in the analysis of the primary endpoint experienced a ≥20% reduction in target lesion(s) volume. Additional clinical benefit independent from lesion volume reduction was observed across the full study population. Adverse events (AEs) and treatment-related AEs were experienced by 82.5% (47/57) and 38.6% (22/57) of patients, respectively; the most common treatment-related AEs were hyperglycemia (12.3%) and aphthous ulcer (10.5%). No deaths occurred.

    CONCLUSIONS

    EPIK-P1 provides real-world evidence of alpelisib effectiveness and safety in patients with PROS and confirms PI3Kα as a valid therapeutic target for PROS symptom management.

2023: Klippel–Trenaunay Syndrome, Segmental/Focal Overgrowth Malformations: A Review

  • Abstract
    Klippel–Trenaunay syndrome is an uncommon, infrequent, congenital disorder characterized by a triad of capillary malformation, varicosities, and tissue and bone hypertrophy. The presence of two of these three signs is enough to obtain the diagnosis. Capillary malformations are usually present at birth, whereas venous varicosities and limb hypertrophy become more evident later. The syndrome has usually a benign course, but serious complications involving various organs, such as gastrointestinal and genitourinary organs, as well as the central nervous system, may be observed. Recently, Klippel–Trenaunay syndrome has been included in the group of PIK3CA-related overgrowth spectrum (PROS) disorders. In terms of this disorder, new results in etiopathogenesis and in modalities of treatment have been advanced. We report here a review of the recent genetic findings, the main clinical characteristics and related severe complications, differential diagnoses with a similar disorder, and the management of patients with this complex and uncommon syndrome.
     

2023: Targeted next-generation sequencing for detection of PIK3CA mutations in archival tissues from patients with Klippel–Trenaunay syndrome in an Asian population

  • Abstract

        Background

Klippel–Trenaunay syndrome (KTS) is a rare slow-flow combined vascular malformation with limb hypertrophy. KTS is thought to lie on the PIK3CA-related overgrowth spectrum, but reports are limited. PIK3CA encodes p110α, a catalytic subunit of phosphatidylinositol 3-kinase (PI3K) that plays an essential role in the PI3K/AKT/mammalian target of rapamycin (mTOR) signaling pathway. We aimed to demonstrate the clinical utility of targeted next-generation sequencing (NGS) in identifying PIK3CA mosaicism in archival formalin-fixed paraffin-embedded (FFPE) tissues from patients with KTS.

Results

Participants were 9 female and 5 male patients with KTS diagnosed as capillaro-venous malformation (CVM) or capillaro-lymphatico-venous malformation (CLVM). Median age at resection was 14 years (range, 5–57 years). Median archival period before DNA extraction from FFPE tissues was 5.4 years (range, 3–7 years). NGS-based sequencing of PIK3CA achieved an amplicon mean coverage of 119,000x. PIK3CA missense mutations were found in 12 of 14 patients (85.7%; 6/8 CVM and 6/6 CLVM), with 8 patients showing the hotspot variants E542K, E545K, H1047R, and H1047L. The non-hotspot PIK3CA variants C420R, Q546K, and Q546R were identified in 4 patients. Overall, the mean variant allele frequency for identified PIK3CA variants was 6.9% (range, 1.6–17.4%). All patients with geographic capillary malformation, histopathological lymphatic malformation or macrodactyly of the foot had PIK3CA variants. No genotype–phenotype association between hotspot and non-hotspot PIK3CA variants was found. Histologically, the vessels and adipose tissues of the lesions showed phosphorylation of the proteins in the PI3K/AKT/mTOR signaling pathway, including p-AKT, p-mTOR, and p-4EBP1.

Conclusions

The PI3K/AKT/mTOR pathway in mesenchymal tissues was activated in patients with KTS. Amplicon-based targeted NGS could identify low-level mosaicism from low-input DNA extracted from FFPE tissues, potentially providing a diagnostic option for personalized medicine with inhibitors of the PI3K/AKT/mTOR signaling pathway.

2023: Whole mount of adult ear skin as a model to study vascular malformations

  • Abstract

    Background

    Genetic analysis in human patients has linked mutations in PIK3CA, the catalytic subunit of PI-3′Kinase, to sporadic incidences of vascular malformations.

    Methods

    We have developed a mouse model with inducible and endothelial-specific expression of PIK3CAH1047R, resulting in the development of vascular malformations. Systemic induction of this mutation in adult mice results in rapid lethality, limiting our ability to track and study these lesions; therefore, we developed a topical and local induction protocol using the active metabolite of tamoxifen, 4OH-T, on the ear skin of adults.

    Results

    This approach allows us to successfully model the human disease in a mature and established vascular bed and track the development of vascular malformations. To validate the utility of this model, we applied a topical rapamycin ointment, as rapamycin is therapeutically beneficial to patients in clinical trials. We found that the induced ear lesions showed significant attenuation after treatment, which was easily quantified.

    Conclusions

    These data collectively provide evidence of a new model to study vascular malformations in adult tissues, which should be particularly useful in environments lacking specialized small-animal imaging facilities.

2023: Gastrointestinal involvement in Klippel-Trénaunay syndrome: pathophysiology, evaluation, and management

  • Abstract

    Klippel-Trénaunay syndrome is typically a complex combined capillary-lymphatic-venous malformation in lower limb. Gastrointestinal involvement is not infrequent in Klippel-Trénaunay syndrome. Rectal bleeding is the most common complication. In recent years, this condition has been increasingly reported. However, most authors simply described extreme manifestations or various combinations of clinical observations. The underlying pathophysiology of gastrointestinal involvement in Klippel-Trénaunay syndrome has been underrecognized. Pathophysiologically, some seemingly adequate managements are pitfalls in treatment. Anorectosigmoid vascular malformations in KTS have distinct and more complicated pathophysiologies than anorectal vascular malformation. Once understanding the pathophysiology, some patients can be successfully managed with a staged plan in our practice. Therefore, recognizing the pathophysiologies of gastrointestinal involvement is needed to evaluate, prevent pitfalls, and determine adequate managements for practitioners. Because of the complexity and rarity of this condition, prospective controlled study or a large cohort of patients is impossible. Based on literature review and our practice, we discuss pathophysiologies, evaluation, pitfalls, and treatment strategies for gastrointestinal involvement in Klippel-Trénaunay syndrome.

2023: Hemifacial myohyperplasia: a study describes the mechanism of this rare facial malformation and proposes a medicinal treatment

  • Hemifacial myohyperplasia (HFMH) is a rare cause of asymmetry involving exclusively the facial muscles. This disorder is reported in very few patients in the literature. The genetic causes and mechanisms of progression of HFMH have hitherto been unknown.

    To date, its management has been punctuated by diagnostic errors and inadequate strategies, including aggressive attempts at surgical correction (muscle remodelling surgery). The results were always disappointing, with significant sequelae.

    The recent discovery of the role played by somatic mutation of genes activating the PIK3CA/AKT/mTOR pathway has opened up new therapeutic prospects for patients.

    In particular, gain-of-function PIK3CA mutations explain the vast majority of proliferation syndromes.

    Canaud and Khonsari research teams and clinicians hypothesised that the PIK3CA/AKT/mTOR pathway was abnormally affected in patients with HFMH.

    Five patients with HFMH were included in this study.

    A gain-of-function mutation in the PIK3CA gene was found in the facial muscles of these five patients. It resulted in striated muscle cell hypertrophy, mitochondrial dysfunction and hypoglycaemia with low circulating insulin levels.

    To understand the pathophysiology of muscle hypertrophy, Prof Canaud’s research team created a mouse model specifically carrying a PIK3CA mutation in skeletal muscle.

    Treatment with alpelisib, an approved PIK3CA inhibitor, was able to prevent and reduce muscle hypertrophy in the mouse model with correction of the endocrine abnormalities.

    Pr Canaud’s team obtained authorisation to treat the five patients with alpelisib and observed a clear improvement in muscle hypertrophy in all patients, associated with progressive symmetrisation of the face. Response to treatment was assessed and confirmed using innovative imaging methods, including 3D photography and analysis of 2D photographs using artificial intelligence. These morphological approaches were confirmed by cellular and molecular methods which demonstrated that alpelisib had a positive and prolonged action on the effects of the PIK3CA gene mutation.

    These results mean that we finally have a genetic explanation for patients with haemifacial myohyperplasia, an understanding of the mechanisms of the disease and the prospect of an effective therapeutic approach.

2023: Article on Alpelisib

  • Article looks at what is Alpelisib, what is PI3K & PIK3CA, how does Alpelisib work, side effects & more.

2023: Oliwia_Mruk_Seeing_the_zebras_among_the_horses

2023: Low risk of embryonic and other cancers in PIK3CA ‐related overgrowth spectrum: Impact on screening recommendations

  • The PIK3CA ‐related overgrowth spectrum (PROS) encompasses various conditions caused by mosaic activating PIK3CA variants. PIK3CA somatic variants are also involved in various cancer types. Some generalized overgrowth syndromes are associated with an increased risk of Wilms tumor (WT). In PROS, abdominal ultrasound surveillance has been advocated to detect WT. We aimed to determine the risk of embryonic and other types of tumors in patients with PROS in order to evaluate surveillance relevance. We searched the clinical charts from 267 PROS patients for the diagnosis of cancer, and reviewed the medical literature for the risk of cancer. In our cohort, six patients developed a cancer (2.2%), and Kaplan Meier analyses estimated cumulative probabilities of cancer occurrence at 45 years of age was 5.6% (95% CI = 1.35%–21.8%). The presence of the PIK3CA variant was only confirmed in two out of four tumor samples. In the literature and our cohort, six cases of Wilms tumor/nephrogenic rests (0.12%) and four cases of other cancers have been reported out of 483 proven PIK3CA patients, in particular the p.(His1047Leu/Arg) variant. The risk of WT in PROS being lower than 5%, this is insufficient evidence to recommend routine abdominal imaging. Long‐term follow‐up studies are needed to evaluate the risk of other cancer types, as well as the relationship with the extent of tissue mosaicism and the presence or not of the variant in the tumor samples.

2023: PI3K signaling through a biochemical systems lens

  • Following 3 decades of extensive research into PI3K signaling, it is now evidently clear that the underlying network does not equate to a simple ON/OFF switch. This is best illustrated by the multifaceted nature of the many diseases associated with aberrant PI3K signaling, including common cancers, metabolic disease, and rare developmental disorders. However, we are still far from a complete understanding of the fundamental control principles that govern the numerous phenotypic outputs that are elicited by activation of this well-characterized biochemical signaling network, downstream of an equally diverse set of extrinsic inputs. At its core, this is a question on the role of PI3K signaling in cellular information processing and decision making. Here, we review the de-terminants of accurate encoding and decoding of growth factor signals and discuss outstanding questions in the PI3K signal relay network. We emphasize the importance of quantitative
    biochemistry, in close integration with advances in single-cell time-resolved signaling measurements and mathematical modeling.

2023: New Insight Into Hyperglycemia Risk With PI3K Inhibitor for Breast Cancer

  • Severe hyperglycemia has emerged as a common side effect among patients with PIK3CA-mutated breast cancer treated with the PI3K inhibitor alpelisib (Piqray), especially patients treated outside a clinical trial, a retrospective study showed.

2023: Mutant PIK3CA is a targetable driver alteration in histiocytic neoplasms

  • Activation of PI3K signaling is sufficient to induce a histiocytosis-like disease in vivo at the monocyte/dendritic cell precursors level.

  • The PI3Kα-specific inhibitor alpelisib shows promising clinical efficacy in PIK3CA-mutant Langerhans cell histiocytosis.
Key Points:

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm characterized by the accumulation of clonal mononuclear phagocyte system cells expressing CD1a and CD207. In the past decade, molecular profiling of LCH, as well as other histiocytic neoplasms demonstrated that these diseases are driven by MAP kinase (MAPK) activating alterations, with somatic BRAFV600E mutations in >50% of LCH patients, and clinical inhibition of MAPK signaling has demonstrated remarkable clinical efficacy. At the same time, activating alterations in kinase-encoding genes such as PIK3CA, ALK, RET, and CSF1R which can activate mitogenic pathways independent from the MAPK pathway have been reported in a subset of histiocytic neoplasms with anecdotal evidence of successful targeted treatment of histiocytoses harboring driver alterations in RET, ALK, and CSF1R. However, evidence supporting the biological consequences of expression of PIK3CA mutations in hematopoietic cells has been lacking, and whether targeted inhibition of PI3K is clinically efficacious in histiocytic neoplasms is unknown. Here, we provide evidence that activating mutations in PIK3CA can drive histiocytic neoplasms in vivo using a conditional knock-in mouse expressing mutant PIK3CAH1047R in monocyte/dendritic cell progenitors. In parallel, we demonstrate successful treatment of PIK3CA-mutated, multisystemic LCH using alpelisib, an inhibitor of the alpha catalytic subunit of PI3K. Alpelisib demonstrated a tolerable safety profile at a dose of 750mg/week and clinical and metabolic complete remission in a PIK3CA-mutated LCH patient. These data demonstrate PIK3CA as a targetable non-canonical driver of LCH and underscore the importance of mutational analysis-based personalized treatment in histiocytic neoplasms.

2023: Successful Treatment of Hypoglycemia With Alpelisib in Pediatric Patients With PIK3CA-Related Overgrowth Spectrum

  • Activating mutations in the PIK3CA gene, causing phosphoinositide 3-kinase (PI3K) hyperactivation, are rare causes of hypoglycemia. We report the novel use of alpelisib (a PI3K inhibitor) for the treatment of hypoketotic, hypoinsulinemic hypoglycemia in 2 children with PIK3CA-related overgrowth spectrum (PROS). Patient 1 was a 7-month-old girl who presented with a hypoglycemic seizure. Despite nutritional management including continuous feeds, she continued to have frequent hypoglycemia. At age 2.8 years, alpelisib was started at 50 mg daily and titrated to 100 mg daily. She was weaned off nocturnal continuous feeds by 8 months. She developed colitis when the alpelisib dose was increased to 125 mg, but this resolved with a dose decrease and medical management. At age 5.3 years, she was doing well with rare hypoglycemia. Her accelerated growth stabilized. Patient 2 was a 3-year-old boy who developed hypoglycemia in early infancy. Alpelisib 50 mg daily was started due to recurrent hypoglycemia despite nutritional management. He came off continuous feeds after 4 months, with decreased hypoglycemia frequency. At age 4.5 years, he had not experienced side effects from treatment. In conclusion, alpelisib appears to be effective in decreasing PROS-related hypoglycemia frequency and severity and should be considered for refractory hypoglycemia in this condition.

2023: PI3K signaling through a biochemical systems lens

  • Following 3 decades of extensive research into PI3K signaling, it is now evidently clear that the underlying network does not equate to a simple ON/OFF switch. This is best illustrated by the multifaceted nature of the many diseases associated with aberrant PI3K signaling, including common cancers, metabolic disease, and rare developmental disorders. However, we are still far from a complete understanding of the fundamental control principles that govern the numerous phenotypic outputs that are elicited by activation of this well-characterized biochemical signaling network, downstream of an equally diverse set of extrinsic inputs. At its core, this is a question on the role of PI3K signaling in cellular information processing and decision making. Here, we review the determinants of accurate encoding and decoding of growth factor signals and discuss outstanding questions in the PI3K signal relay network. We emphasize the importance of quantitative biochemistry, in close integration with advances in single-cell time-resolved signaling measurements and mathematical modeling.

2023: Fibro-adipose vascular anomaly (FAVA) – diagnosis, staging and management

Background

The diagnosis and treatment of fibro-adipose vascular anomaly (FAVA) of the limb remains challenging since this entity is rare and complex. This paper is aimed to describe the clinical and imaging features, staging and management of this underrecognized disease of the limb.

Material and method

Patients diagnosed with FAVA and managed between September 2019 and May 2022 in department of pediatric surgery & vascular anomalies of Xi’an international medical center hospital were retrospectively reviewed. Data extracted include age at presentation, previous diagnosis, affected muscles, symptoms, previous treatment, our management, and follow-up.

Results

Thirty-two patients with FAVA were diagnosed and managed in our center. There was a female sex predominance, with 23 female (72%) and 9 male (28%) in the cohort. Only one lesion was noticed during infancy; the remaining presented at age 1 to 20 years (median, 7 years). The most commonly involved muscles were gastrocnemius (14/32, 44%) and soleus (13/32, 40%). Swelling (mass), pain and contractures were the most common presentations. MRI featured a heterogeneous and ill-defined intramuscular high signal intensity. Diseases were staged according to clinical features: stage I (pain stage, n = 4), stage II (contracture stage, n = 20) and stage III (deformity stage, n = 8). Patients with stage I disease underwent radical resection and obtained a cure. Patients with stage II disease received radical resection and possible Achilles lengthening, having an outcome of cure. Personalized treatment was required in patients with stage III disease, including radical/partial/staged resection, Achilles lengthening/tenotomy, joint capsulotomy, neurolysis/neurectomy, tendon transfer, stretching exercises, and oral sirolimus/alpelisib. Significant improvement of symptoms was achieved in most.

Conclusion

The most distinct features of FAVA include enlarging mass, severe pain and contracture. Based on distinct clinical and radiologic features, it is not difficult to make the diagnosis of FAVA. Earlier awareness of this disease can reduce misdiagnoses. Surgery-based comprehensive management can typically improve pain and contracture. Oral sirolimus or alpelisib plays an important role in treatment of unresectable lesions and major nerve involvement. Surgery alone can be curative in early stage FAVA.

2023: Preliminary results of the European multicentric phase III trial regarding sirolimus in slow-flow vascular malformations

  • BACKGROUND. Slow-flow vascular malformations frequently harbor activating mutations in the PI3K/AKT/mTOR cascade. Phase II trials pinpointed sirolimus effectiveness as a drug therapy. Efficacy and safety of sirolimus thus need to be evaluated in large prospective phase III trials.

    METHODS. The Vascular Anomaly-Sirolimus-Europe (VASE) trial, initiated in 2016, is a large multicentric prospective phase III trial (EudraCT 2015-001703-32), which evaluates efficacy and safety of sirolimus for 2 years in pediatric and adult patients with symptomatic slow-flow vascular malformations. In this interim analysis, we studied all patients enrolled up to October 2021 who received sirolimus for 12 or more months or who prematurely stopped the treatment.

    RESULTS. Thirty-one pediatric and 101 adult patients were included in this analysis; 107 completed 12 or more months of sirolimus, including 61 who were treated for the whole 2-year period. Sirolimus resulted in a clinical improvement in 85% of patients. The efficacy appeared within the first month for the majority of them. Grade 3–4 adverse events were observed in 24 (18%) patients; all resolved after treatment interruption/arrest. Sirolimus increased feasibility of surgery or sclerotherapy in 20 (15%) patients initially deemed unsuitable for intervention. Among the 61 patients who completed the 2-year treatment, 33 (54%) reported a recurrence of symptoms after a median follow-up of 13 months after sirolimus arrest. While there was no difference in efficacy, clinical improvement was faster but subsided more rapidly in PIK3CA-mutated (n = 24) compared with TIE2-mutated (n = 19) patients.

    CONCLUSION. Sirolimus has a high efficacy and good tolerance in treatment of slow-flow vascular malformations in children and adults.

2023: Oncogenic PIK3CA corrupts growth factor signaling specificity

  • Abstract

    Pathological activation of the PI3K/AKT pathway is among the most frequent defects in human cancer and is also the cause of rare overgrowth disorders. Yet, there is currently no systematic understanding of the quantitative flow of information within PI3K/AKT signaling and how it is perturbed by disease-causing mutations. Here, we develop scalable, single-cell approaches for systematic analyses of signal processing within the PI3K pathway, enabling precise calculations of its information transfer for different growth factors. Using genetically-engineered human cell models with allele dose-dependent expression of PIK3CAH1047R, we show that this oncogene is not a simple, constitutive pathway activator but a context-dependent modulator of extracellular signal transfer. PIK3CAH1047Rreduces information transmission downstream of IGF1 while selectively enhancing EGF-induced signaling and transcriptional responses. This leads to a gross reduction in signaling specificity, akin to “blurred” signal perception. The associated increase in signaling heterogeneity promotes phenotypic diversity in a human cervical cancer cell line model and in human induced pluripotent stem cells. Collectively, these findings and the accompanying methodological advances lay the foundations for a systematic mapping of the quantitative mechanisms of PI3K/AKT-dependent signal processing and phenotypic control in health and disease.

    One-sentence summary Single-cell signaling and information theoretic analyses reveal that oncogenic PI3K/AKT activation leads to a gross reduction in signaling specificity, context-dependent EGF response amplification as well as increased phenotypic heterogeneity.

2023: BRIEF REPORT Improving genetic diagnostic yield in a large cohort of children with rare vascular anomalies or PIK3CA- related overgrowth spectrum

  • Purpose: Drugs that attenuate hyperactivation of the phosphatidylinositol 3-kinase-Akt and Ras-mitogen-activated protein kinase signaling pathways are emerging treatments for children with rare, intractable vascular anomalies or PIK3CA-related overgrowth spectrum (PROS) with an eligible genetic diagnosis. However, access to genetic testing remains a barrier to genetic diagnosis. Here, we implement a targeted molecular diagnostic strategy for vascular anomalies or PROS.
  • Methods: We applied a novel genetic testing strategy to children with vascular anomalies or PROS using a tiered approach of (1) droplet digital PCR, (2) Sanger sequencing, (3) high-depth exome sequencing, and (4) reanalysis of existing clinical exome data.
  • Results: We applied this strategy to 60 individuals detecting pathogenic somatic variants in 33 of 60 (55%). This included 26 individuals with slow-flow lesions with variants in PIK3CA, TEK, GNAQ, GNA11, BRAF, or PIK3R1, 4 individuals with fast-flow lesions with variants in KRAS or
    MAP2K1, 1 individual with a PIK3CA variant and a mixed phenotype, and 2 individuals with PIK3CA variants and PROS without vascular anomalies.
  • Conclusion: We demonstrate an effective genetic diagnostic strategy for children with vascular anomalies or PROS identifying somatic variants in 55% of individuals. Increasing genetic diagnostic yield extends the clinicogenetic spectrum and may provide access for those with intractable disease to therapeutic drug trials.

2023: Rare Case of Abdominal Aortic and Multiple Visceral Aneurysms in a Pediatric Patient With PIK3CA Mutation and Vasculitis

  • Abstract

    Abdominal aortic aneurysms (AAA) are most commonly observed in elderly male patients and are particularly rare in children. Among the pediatric population, they are usually diagnosed in the context of connective tissue disorders, genetic mutations, or vasculitis. The same is true of visceral arteries aneurysms. This case report describes the staged management of an 11-year-old patient presenting PIK3CA mutation and a 5.8 cm infrarenal AAA associated with bilateral common iliac arteries and multiple visceral aneurysms, the largest observed in the superior mesenteric artery (SMA = 3.2 cm). After careful evaluation, decision was made to first approach the most life-threatening lesion (the infrarenal AAA due to the large diameter) and the remaining aneurysms in secondary procedures, with special attention to the SMA aneurysm. The patient underwent a staged repair, with the first phase consisting of an aortobi-iliac graft with the distal anastomosis made at the left common iliac artery and right external iliac artery. The right hypogastric artery was ligated. The second procedure consisted of SMA aneurysm repair with a plication technique, as 7 branches were visualized coming off the aneurysm sac. Postoperative pathology analysis of the aortic and SMA aneurysms sac revealed vasculitis with a mixed inflammatory pattern and a COL3A1 gene heterozygote variant. He is currently in his 18th month after the last surgical intervention, receiving immunomodulatory therapy, with a planned follow-up by the interdisciplinary team to monitor the medications’ side effects and the diameter of the remaining visceral aneurysms.

2023: Work-Up and Treatment Strategies for Individuals with PIK3CA-Related Disorders: A Consensus of Experts from the Scientific Committee of the Italian Macrodactyly and PROS Association

  • Abstract

    PIK3CA-related disorders encompass many rare and ultra-rare conditions caused by somatic genetic variants that hyperactivate the PI3K-AKT-mTOR signaling pathway, which is essential for cell cycle control. PIK3CA-related disorders include PIK3CA-related overgrowth spectrum (PROS), PIK3CA-related vascular malformations and PIK3CA-related non-vascular lesions. Phenotypes are extremely heterogeneous and overlapping. Therefore, diagnosis and management frequently involve various health specialists. Given the rarity of these disorders and the limited number of centers offering optimal care, the Scientific Committee of the Italian Macrodactyly and PROS Association has proposed a revision of the most recent recommendations for the diagnosis, molecular testing, clinical management, follow-up, and treatment strategies. These recommendations give insight on molecular diagnosis, eligible samples, preferable sequencing, and validation methods and management of negative results. The purpose of this paper is to promote collaboration between health care centers and clinicians with a joint shared approach. Finally, we suggest the direction of present and future research studies, including new systemic target therapies, which are currently under evaluation in several clinical trials, such as specific inhibitors that can be employed to downregulate the signaling pathway.

2023: Molecular characterization of 13 patients with PIK3CA-related overgrowth spectrum using a targeted deep sequencing approach

Abstract

Activating variants in the PIK3CA gene cause a heterogeneous spectrum of disorders that involve congenital or early-onset segmental/focal overgrowth, now referred to as PIK3CA-related overgrowth spectrum (PROS). Historically, the clinical diagnoses of patients with PROS included a range of distinct syndromes, including CLOVES syndrome, dysplastic megalencephaly, hemimegalencephaly, focal cortical dysplasia, Klippel-Trenaunay syndrome, CLAPO syndrome, fibroadipose hyperplasia or overgrowth, hemihyperplasia multiple lipomatosis, and megalencephaly capillary malformation-polymicrogyria (MCAP) syndrome. MCAP is a sporadic overgrowth disorder that exhibits core features of progressive megalencephaly, vascular malformations, distal limb malformations, cortical brain malformations, and connective tissue dysplasia. In 2012, our research group contributed to the identification of predominantly mosaic, gain-of-function variants in PIK3CA as an underlying genetic cause of the syndrome. Mosaic variants are technically more difficult to detect and require implementation of more sensitive sequencing technologies and less stringent variant calling algorithms. In this study, we demonstrated the utility of deep sequencing using the Illumina TruSight Oncology 500 (TSO500) sequencing panel in identifying variants with low allele fractions in a series of patients with PROS and suspected mosaicism: pathogenic, mosaic PIK3CA variants were identified in all 13 individuals, including 6 positive controls. This study highlights the importance of screening for low-level mosaic variants in PROS patients. The use of targeted panels with deep sequencing in clinical genetic testing laboratories would improve diagnostic yield and accuracy within this patient population.

2023: Alpelisib for treatment of patients with PIK3CA-related overgrowth spectrum (PROS)

Abstract

Purpose

PIK3CA-related overgrowth spectrum (PROS) encompasses several rare conditions resulting from activating variants in PIK3CA. Alpelisib, a PI3Kα-selective inhibitor, targets the underlying etiology of PROS, offering a novel therapeutic approach to current management strategies. This study evaluated the safety and efficacy of alpelisib in pediatric and adult patients with PROS.

Methods

EPIK-P1 (NCT04285723) was a non-interventional, retrospective chart review of 57 patients with PROS (≥2 years) treated with alpelisib through compassionate use. Patients had severe/life-threatening PROS-related conditions and confirmed PIK3CA pathogenic variant. The primary end point assessed patient response to treatment at Week 24 (6 months).

Results

Twenty-four weeks (6 months) after treatment initiation, 12 of 32 (37.5%) patients with complete case records included in the analysis of the primary end point experienced a ≥20% reduction in target lesion(s) volume. Additional clinical benefit independent from lesion volume reduction was observed across the full study population. Adverse events (AEs) and treatment-related AEs were experienced by 82.5% (47/57) and 38.6% (22/57) of patients, respectively; the most common treatment-related AEs were hyperglycemia (12.3%) and aphthous ulcer (10.5%). No deaths occurred.

Conclusion

EPIK-P1 provides real-world evidence of alpelisib effectiveness and safety in patients with PROS and confirms PI3Kα as a valid therapeutic target for PROS symptom management.

2024: Genomic dissection and mutation-specific target discovery for breast cancer PIK3CA hotspot mutations

Abstract

Background: Recent advancements in high-throughput genomics and targeted therapies have provided tremendous potential to identify and therapeutically target distinct mutations associated with cancers. However, to date the majority of targeted therapies are used to treat all functional mutations within the same gene, regardless of affected codon or phenotype.

Results: In this study, we developed a functional genomic analysis workflow with a unique isogenic cell line panel bearing two distinct hotspot PIK3CA mutations, E545K and H1047R, to accurately identify targetable differences between mutations within the same gene. We performed RNA-seq and ATAC-seq and identified distinct transcriptomic and epigenomic differences associated with each PIK3CA hotspot mutation. We used this data to curate a select CRISPR knock out screen to identify mutation-specific gene pathway vulnerabilities. These data revealed AREG as a E545K-preferential target that was further validated through in vitro analysis and publicly available patient databases.

Conclusions: Using our multi-modal genomics framework, we discover distinct differences in genomic regulation between PIK3CA hotspot mutations, suggesting the PIK3CA mutations have different regulatory effects on the function and downstream signaling of the PI3K complex. Our results demonstrate the potential to rapidly uncover mutation specific molecular targets, specifically AREG and a proximal gene regulatory region, that may provide clinically relevant therapeutic targets. The methods outlined provide investigators with an integrative strategy to identify mutation-specific targets for the treatment of other oncogenic mutations in an isogenic system.

2024: Klippel-Trenaunay Syndrome: To Be or Not to Be Afraid

Klippel-Trenaunay syndrome (KTS) is a rare genetic syndrome comprising an abnormal development of soft tissues and the lymphovascular system with bony overgrowth, venous malformation, and port wine stains. We present an interesting case of a three-year-old child brought to our hospital with a swollen limb and raised skin lesions associated with bleeding from minor trauma. Most of the clinical characteristics of KTS were seen in our patient, including arteriovenous, soft tissue, capillary, and lymphatic abnormalities. The diagnosis of KTS is based on clinical examinations and imaging investigations. He had gross hypertrophy of the left lower limb with measurable lengthening compared to the opposite limb. Ultrasonography of the left limb revealed soft tissue hypertrophy with abnormal venous communication. The management of KTS is mainly symptomatic and should be approached conservatively if the patient has functional limbs without edema, bleeding, ulceration, or pain.

2024: PIK3CA regulates development of diabetes retinopathy through the PI3K/Akt/mTOR pathway

Abstract

Objective

To explore their association with the development of diabetes retinopathy (DR), single nucleotide polymorphism (SNP) mutations were screened out by high-throughput sequencing and validated in patients diagnosed with DR. To understand the role of PIK3CA in the pathogenesis of DR and explore the relationship between PIK3CA,phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR),and DR, the effect of PIK3CA.rs17849079 mutation was investigated in a DR cell model.

Methods

Twelve patients diagnosed with DR at the Qinghai Provincial People’s Hospital from September 2020 to June 2021 were randomly selected as the case group, while 12 healthy subjects of similar age and gender who underwent physical examination in Qinghai Provincial People’s Hospital physical examination center during the same period were randomly selected as the control group. Blood samples (2 mL) were collected from both groups using EDTA anticoagulant blood collection vessels and frozen at −20°C for future analysis. SNP mutations were detected by high-throughput sequencing, and the shortlisted candidates were subjected by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The detected SNP candidates were verified by expanding the sample size (first validation: 56 patients in the case group and 58 controls; second validation: 157 patients in the case group and 96 controls). A lentivirus vector carrying mutated or wild-type PIK3CA.rs17849079 was constructed. ARPE-19 cells were cultured in a medium supplemented with 10% fetal bovine serum (FBS) to establish a DR cell model. PIRES2-PIK3CA-MT and PIRES2-PIK3CA-WT vectors were transfected into DR model cells, which were categorized into control, mannitol, model, empty vector, PIK3CA wild-type, and PIK3CA mutant-type groups. Cell activity was detected by the cell counting kit (CCK)-8 assay, and cellular apoptosis was evaluated by flow cytometry. Glucose concentration and levels of cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β were detected using enzyme-linked immunosorbent assay kits. The expression of PIK3CA, AKT1, mTOR, and VEGF genes was detected by real-time quantitative polymerase chain reaction (RT-qPCR), while the expression of PI3K, p-PI3K, AKT1, p-AKT1, mTOR, p-mTOR, and VEGF proteins was detected by western blotting.

Results

The mutated SNPs were mainly enriched in the PI3K/AKT pathway, calcium ion pathway, and glutamatergic synaptic and cholinergic synaptic signaling pathways. Seven SNPs, including PRKCE.rs1533476, DNAH11.rs10485983, ERAP1.rs149481, KLHL1.rs1318761, APOBEC3C.rs1969643, FYN.rs11963612, and KCTD1.rs7240205, were not related to the development of DR. PIK3CA.rs17849079 was prone to C/T mutation. The risk of DR increased with the presence of the C allele and decreased in the presence of the T allele. High glucose induced the expression of PIK3CA and VEGF mRNAs as well as the expression of PI3K, p-PI3K, p-AKT1, p-mTOR, and VEGF proteins in ARPE-19 cells, which led to secretion of inflammatory factors TNF-αand IL-1, cell apoptosis, and inhibition of cell proliferation. The PIK3CA.rs17849079 C allele accelerated the progression of DR. These biological effects were inhibited when the C allele of PIK3CA.rs17849079 was mutated to T allele.

Conclusion

The mutated SNP sites in patients with DR were mainly enriched in PI3K/AKT, calcium ion, and glutamatergic synaptic and cholinergic synaptic signaling pathways. The rs17849079 allele of PIK3CA is prone to C/T mutation where the C allele increases the risk of DR. High glucose activates the expression of PIK3CA and promotes the phosphorylation of PI3K, which leads to the phosphorylation of AKT and mTOR. These effects consequently increase VEGF expression and accelerate the development of DR. The C to T allele mutation in PIK3CA.rs17849079 can play a protective role and reduce the risk of DR.

2024: PIK3CA-Related Disorders: From Disease Mechanism to Evidence-Based Treatments

Recent advances in genetic sequencing are transforming our approach to rare-disease care. Initially identified in cancer, gain-of-function mutations of the gene are also detected in malformation mosaic diseases categorized as -related disorders (PRDs). Over the past decade, new approaches have enabled researchers to elucidate the pathophysiology of PRDs and uncover novel therapeutic options. In just a few years, owing to vigorous global research efforts, PRDs have been transformed from incurable diseases to chronic disorders accessible to targeted therapy. However, new challenges for both medical practitioners and researchers have emerged. Areas of uncertainty remain in our comprehension of PRDs, especially regarding the relationship between genotype and phenotype, the mechanisms underlying mosaicism, and the processes involved in intercellular communication. As the clinical and biological landscape of PRDs is constantly evolving, this review aims to summarize current knowledge regarding and its role in nonmalignant human disease, from molecular mechanisms to evidence-based treatments.

2024: Recurrent Cellulitis as Clinical Presentation of Klippel–Trénaunay Syndrome: A Case Report

A 32-year-old man presented with a history of recurrent cellulitis since his teenage together with nonpitting unilateral edema of the left leg. Further clinical examination and imaging studies revealed port-wine stains along the torso with extrathoracic capillary, lymphatic, and venous malformations. A diagnosis of Klippel–Trénaunay syndrome was established, and the patient was treated with complex decompression therapy. After 7 months, the left leg volume was reduced by more than half, and he was able to reinitiate physical activity with no new recurrences. This case highlights the importance of considering subjacent causes in patients with recurrent cellulitis episodes and lymphedema.

2024: A cystic and bullous lung disease associated with a PIK3CA related overgrowth syndrome

2024: Alpelisib-related adverse events: The FDA Adverse Event Reporting System Database (FAERS) pharmacovigilance study

Background

Alpelisib was approved for treatment of breast cancer. We assessed the safety signals associated with alpelisib by data mining the FDA pharmacovigilance database.

Methods

Data from the second quarter of 2019 to the fourth quarter of 2022 had been retrieved from the FAERS database. Disproportionality analysis by reporting odds ratio were used to evaluate the potential association between adverse events (AEs) and alpelisib.

Results

A total of 5,980,090 reports were extracted, 18,149 of them were chosen with alpelisib as the suspected drug. After combining the same PRIMARYID, 5647 patients remained. We observed 10 system organ classes (SOCs) with a reported number >50 and associated with alpelisib as gastrointestinal disorders, general disorders and administration site conditions, metabolism and nutrition disorders, skin and subcutaneous tissue disorders, investigations and neoplasms benign, malignant and unspecified (incl cysts and polyps), immune system disorders, nervous system disorders, psychiatric disorders, eye disorders. The median time to AEs in these patients was 13 days, with an IQR (Interquartile Range) of 7–70 days. 61.12% AEs happened within the initial month of alpelisib usage.

Conclusion

Our study provided a more in-depth and extensive understanding of AEs that may be associated with alpelisib, which will help to reduce the risk of AEs in the clinical treatment of alpelisib. AEs with novel preferred term (PTs) were constipation, dysphagia, diabetic ketoacidosis, feeding disorder, urticaria, eye disorders and vision blurred. 61.12% of cases developed AEs within 30 days after taking alpelisib.

2024: EMA pins lack of long-term data as rationale for Novartis’ failed Vijoice bid

2024: Lymphatic malformations: mechanistic insights and evolving therapeutic frontiers

The lymphatic vascular system is gaining recognition for its multifaceted role and broad pathological significance.
Once perceived as a mere conduit for interstitial fluid and immune cell transport, recent research has unveiled its active
involvement in critical physiological processes and common diseases, including inflammation, autoimmune diseases, and
atherosclerosis. Consequently, abnormal development or functionality of lymphatic vessels can result in serious health
complications. Here, we discuss lymphatic malformations (LMs), which are localized lesions that manifest as fluid-filled cysts
or extensive infiltrative lymphatic vessel overgrowth, often associated with debilitating, even life-threatening, consequences.
Genetic causes of LMs have been uncovered, and several promising drug-based therapies are currently under investigation
and will be discussed.

2024: Improving genetic diagnostic yield in a large cohort of children with rare vascular anomalies or PIK3CA-related overgrowth spectrum

Abstract

Purpose

Drugs that attenuate hyperactivation of the phosphatidylinositol 3-kinase-Akt and Ras-mitogen-activated protein kinase signaling pathways are emerging treatments for children with rare, intractable vascular anomalies or PIK3CA-related overgrowth spectrum (PROS) with an eligible genetic diagnosis. However, access to genetic testing remains a barrier to genetic diagnosis. Here, we implement a targeted molecular diagnostic strategy for vascular anomalies or PROS.

Methods

We applied a novel genetic testing strategy to children with vascular anomalies or PROS using a tiered approach of (1) droplet digital PCR, (2) Sanger sequencing, (3) high-depth exome sequencing, and (4) reanalysis of existing clinical exome data.

Results

We applied this strategy to 60 individuals detecting pathogenic somatic variants in 33 of 60 (55%). This included 26 individuals with slow-flow lesions with variants in PIK3CA, TEK, GNAQ, GNA11, BRAF, or PIK3R1, 4 individuals with fast-flow lesions with variants in KRAS or MAP2K1, 1 individual with a PIK3CA variant and a mixed phenotype, and 2 individuals with PIK3CA variants and PROS without vascular anomalies.

Conclusion

We demonstrate an effective genetic diagnostic strategy for children with vascular anomalies or PROS identifying somatic variants in 55% of individuals. Increasing genetic diagnostic yield extends the clinicogenetic spectrum and may provide access for those with intractable disease to therapeutic drug trials.
 

Abstract

Activating mutation of PIK3CA is linked with cases of overgrowth syndromes and belongs to the PIK3CA-related overgrowth spectrum (PROS). Mutations in this gene are associated with vascular malformations, brain abnormalities, and an increased risk for certain tumors. We report the case of a newborn girl, preterm at 34 weeks of gestation, referred to our center for atypical necrotizing enterocolitis (NEC). At laparotomy, the appearance of the intestinal tract was described as puffy, cauliflower-like with a dark purplish coloration. Subsequently, the colostomy was described as having a consistent proliferative appearance. Medical treatment with sirolimus resulted in minimal improvement. There are no reported cases in the literature of association between NEC and PIK3CA mutation. It is possible that PIK3CA mutation, including the related vascular anomalies, plays a role in the pathogenesis of NEC with this condition.

2024: Dermato-Radiological Evaluation of Congenital Limb Overgrowth Vascular Syndromes

Abstract

International Society for the Study of Vascular Anomalies classification defines Congenital Limb Overgrowth Vascular Syndromes (CLOS) as a subset of vascular syndromes with other abnormalities that present with unilateral limb overgrowth. It includes Klippel–Trenaunay Syndrome, Parkes–Weber Syndrome, CLOVES (Congenital Lipomatous Overgrowth, Vascular Malformations, Epidermal Nevi, Spinal/Skeletal Anomalies/Scoliosis) Syndrome, Proteus Syndrome, PTEN Hamartomatous Syndrome, and Fibroadipose Vascular Anomaly. Due to their rare and complex nature, a multidisciplinary approach to diagnosis and treatment is required. A thorough clinical and radiological workup can go miles in reflecting on the patient’s outcome. Here we report five cases of CLOS with their detailed dermato-radiological profiles.

2024: Targeted treatment in complex lymphatic anomaly: a case of synergistic efficacy of trametinib and sirolimus

Abstract Repurposing anticancer drugs to vascular malformations has significantly improved patient outcomes. Complex Lymphatic Anomalies (CLA) are part of the spectrum of lymphatic malformations (LMs) that share similar oncogenic mutations to cancer. We report the case of a young patient with highly symptomatic CLA who was initially treated with sirolimus, due to the frequent involvement of the PI3K-AKT-mTOR pathway in CLA pathogenesis. Despite an initial reduction in symptoms, sirolimus progressively lost its effectiveness. After an unsuccessful attempt with trametinib alone, sirolimus was added to trametinib and resulted in a significant, rapid and sustained improvement in symptoms. This suggests that, contrary to current dogmas, combination therapy using sub-therapeutic doses targeting both the PI3K and RAS pathways retains efficacy without generating the toxicity known for combination therapies, and is beneficial in the management of CLAs and potentially other vascular anomalies.

2024: Concurrent PIK3CA and IDH1 variants in facial infiltrating lipomatosis with intracranial lesions

Facial infiltrating lipomatosis (FIL) is a congenital disorder caused by the hyperproliferation of adipose and skeletal tissue within the facial region. Infiltration of mature adipose tissue into adjacent structures is a hallmark pathologic finding. In addition to the aesthetic implications, patients may suffer from impaired facial function, including difficulty in swallowing and breathing, sleep disturbances, and visual field displacement. FIL is associated with phosphatidylinositol 3kinase catalytic subunit alpha (PIK3CA) variants. PIK3CA variants were detected in over85% of FIL cases, spanning numerous tissue types. Prior research has indicated that PIK3CA hotspot variants may result in a more severe phenotype. However, identical PIK3CA variants can lead to varying degrees of phenotypic severity. This highlights the need for further exploration into the potential contribution of other pathogenic factors. In this study, we reported the cooccurrence of PIK3CA and isocitrate dehydrogenase 1 (IDH1) variants in two patients with FIL and intracranial lesions for the first time. Our study expands the genetic landscape of FIL and provides a view that variants in genes other than PIK3CA may be involved in the pathogenesis of overgrowth disorders.

2024: Gene-Disease Associations and Recommendations for Genetic Testing for Somatic Variants in Vascular Anomalies

The field of vascular anomalies is undergoing a transformative phase, with genetic insights leading the way to more accurate diagnoses and targeted treatments. The VASCERN Vascular Anomalies Working Group’s recent study, Assessment of gene-disease associations and recommendations for genetic testing for somatic variants in vascular anomalies by VASCERN-VASCA, offers valuable recommendations to optimize genetic testing for these complex conditions.

Vascular anomalies include a wide range of disorders characterized by abnormal blood vessel formation. These conditions can vary significantly, both clinically and genetically, often presenting unique diagnostic challenges. Somatic (postzygotic) variants are a common cause of these anomalies. However, differences in testing methods across laboratories can lead to varying results, affecting the sensitivity and accuracy of these tests.

Genetic testing has become an integral part of the diagnostic process for vascular anomalies, complementing clinical, radiological, and histopathological evaluations. Despite its importance, access to genetic testing isn’t always consistent, and different labs use different methods. This can result in discrepancies in test results, impacting patient care and treatment plans.

Physicians and laboratory specialists from 11 multidisciplinary European centers came together to address these challenges. This team reviewed current knowledge and practices related to genes involved in non-hereditary vascular malformations. Their findings included:

  • Core Gene List: A list of 24 key genes was identified based on current practices, existing classifications, and scientific literature.
  • Gene-Phenotype Associations: The study evaluated the relationship between genes and specific conditions, categorizing these associations as:
    • 16 definitive
    • 16 strong
    • 3 moderate
    • 7 limited
    • 3 with no current evidence

The study provides important recommendations for improving genetic testing, particularly in knowing both the gene-phenotype relationships and the strength of the associations. This will greatly help laboratories in data interpretation and eventually in the clinical diagnosis, leading to better patient outcomes.

For detailed information on the study and its findings, click here.

2024: PIK3CA inhibition in models of proliferative glomerulonephritis and lupus nephritis

Abstract

Proliferative glomerulonephritis is a severe condition that often leads to kidney failure. There is a significant lack of effective treatment for these disorders. Here, following the identification of a somatic PIK3CA gain-of-function mutation in podocytes of a patient, we demonstrate using multiple genetically engineered mouse models, single-cell RNA sequencing, and spatial transcriptomics the crucial role played by this pathway for proliferative glomerulonephritis development by promoting podocyte proliferation, dedifferentiation, and inflammation. Additionally, we show that alpelisib, a PI3Kα inhibitor, improves glomerular lesions and kidney function in different mouse models of proliferative glomerulonephritis and lupus nephritis by targeting podocytes. Surprisingly, we determined that pharmacological inhibition of PI3Kα affects B and T lymphocyte populations in lupus nephritis mouse models, with a decrease in the production of proinflammatory cytokines, autoantibodies, and glomerular complement deposition, which are all characteristic features of PI3Kδ inhibition, the primary PI3K isoform expressed in lymphocytes. Importantly, PI3Kα inhibition does not impact lymphocyte function under normal conditions. These findings were then confirmed in human lymphocytes isolated from patients with active lupus nephritis. In conclusion, we demonstrate the major role played by PI3Kα in proliferative glomerulonephritis and show that in this condition, alpelisib acts on both podocytes and the immune system.

2024: Targeted therapy for capillary-venous malformations

Abstract

Sporadic venous malformations are genetic conditions primarily caused by somatic gain-of-function mutation of PIK3CA or TEK, an endothelial transmembrane receptor signaling through PIK3CA. Venous malformations are associated with pain, bleedings, thrombosis, pulmonary embolism, esthetic deformities and, in severe cases, life-threatening situations. No authorized medical treatment exists for patients with venous malformations. Here, we created a genetic mouse model of PIK3CA-related capillary venous malformations that replicates patient phenotypes. We showed that these malformations only partially signal through AKT proteins. We compared the efficacy of different drugs, including rapamycin, a mTORC1 inhibitor, miransertib, an AKT inhibitor and alpelisib, a PI3Kα inhibitor at improving the lesions seen in the mouse model. We demonstrated the effectiveness of alpelisib in preventing vascular malformations’ occurrence, improving the already established ones, and prolonging survival. Considering these findings, we were authorized to treat 25 patients with alpelisib, including 7 children displaying PIK3CA (n = 16) or TEK (n = 9)-related capillary venous malformations resistant to usual therapies including sirolimus, debulking surgical procedures or percutaneous sclerotherapies. We assessed the volume of vascular malformations using magnetic resonance imaging (MRI) for each patient. Alpelisib demonstrated improvement in all 25 patients. Vascular malformations previously considered intractable were reduced and clinical symptoms were attenuated. MRI showed a decrease of 33.4% and 27.8% in the median volume of PIK3CA and TEK malformations respectively, over 6 months on alpelisib. In conclusion, this study supports PI3Kα inhibition as a promising therapeutic strategy in patients with PIK3CA or TEK-related capillary venous malformations.

2024: Magnetic resonance imaging of fetal vascular malformations

Abstract
Vascular anomalies develop during fetal life and can be detected on prenatal ultrasonography and fetal magnetic resonance
imaging. Diagnosis of lymphatic, venous, and arteriovenous malformations, as well as congenital hemangiomas and other
congenital vascular tumors, may be challenging. The benign vascular anomalies may be difficult to differentiate from malig-
nancies with a similar appearance. In this manuscript, we present a succinct overview of the congenital vascular anomalies
that may present in fetal or neonatal life.

2024: Venous Anomalies in Overgrowth Syndromes

Overgrowth syndromes, particularly within the PIK3CA-related overgrowth syndrome (PROS) spectrum, are commonly associated with venous anomalies. The anomalies include spongiform venous malformations and persistent embryonic veins, such as the lateral marginal vein (of Servelle). The anomalous veins pose a significant risk of thromboembolic disease and should be occluded, preferably earlier in life. A thorough understanding of the conditions, anatomy, and interdisciplinary treatment of these complex anomalies is essential for optimal management. This review explores the clinical and imaging diagnosis of overgrowth syndromes and techniques for assessing and treating associated venous anomalies, particularly the endovenous closure of anomalous veins.

2024: PA04 Germline activating variants in PIK3CA result in a diffuse overgrowth phenotype characterized by macrocephaly, cardiovascular and renal anomalies: recommendations for screening and monitoring

Abstract

Somatic activating mutations in PIK3CA cause a wide spectrum of clinical phenotypes characterized by mosaic pattern overgrowth of tissues. These are grouped under the umbrella term ‘PIK3CA-related overgrowth syndrome’ (PROS). Mosaic PROS has a reported prevalence of 1 in 28 000 live births. However, germline heterozygous PIK3CA variants leading to an overgrowth phenotype are extremely rare, reported in fewer than 20 cases to date. Here we report three new patients with germline PI3KCA variants and present this in the context of the existing literature, highlighting key clinical findings with recommendations for baseline evaluation and monitoring. Patient 1, an 11-year-old girl, was diagnosed antenatally with a single umbilical artery and presented with multiple congenital cardiac anomalies: dysplastic pulmonary valve, multiple apical muscular ventricular septal defects, patent ductus arteriosus, and secundum atrial septal defects. Other features noted include marked hypotonia, developmental delay, digit abnormalities, cutaneous capillary malformations, and bilateral duplex kidneys. Macrocephaly has been prominent throughout childhood, but with normal cranial imaging. Patient 2, a 6-year-old boy, presented with macrosomia, macrocephaly (normal cranial imaging) and subtle left-sided overgrowth with one small area of capillary malformation. He has mild developmental delay. Patient 3, a 20-month-old girl, presented with macrocephaly, left-sided capillary malformations and mild gross motor developmental delay with hypermobility. Magnetic resonance imaging findings include macrocephaly with polymicrogyria, thick corpus callosum and large cerebellum. Including our three patients, 21 patients with germline PIK3CA variants have been reported to date. Macrocephaly was a predominant feature in 95% (20 of 21), as was developmental delay 100% (9 of 9), where data were available. Importantly, of those with available data, 33% of patients had renal anomalies (3 of 9) and 71% had cardiac or vascular anomalies (10 of 14), neither of which are frequently observed in mosaic PROS. Germline heterozygous activating PIK3CA variants cause diffuse overgrowth, forming a rare but distinct part of PROS. We characterize here a cohort of patients, adding three new cases to the existing literature. Macrocephaly and developmental delay are observed almost universally in this cohort, and in contrast to mosaic PROS there is a high proportion of renal and cardiovascular anomalies. Clinicians should be alerted to these salient features and perform baseline neurological, cardiac and renal imaging at diagnosis, and ensure close neurodevelopmental monitoring. Unlike mosaic PROS, where the risk of passing the variant to offspring is small, in rare cases of gonadal mosaicism, inheritance of germline PIK3CA variants will follow an autosomal dominant pattern, thus referral to clinical genetics for counselling is critical for this cohort.

2024: Delineation of the phenotypes and genotypes of PIK3CA-related overgrowth spectrum in East asians

PIK3CA-related overgrowth spectrum (PROS) is an umbrella term to describe a diverse range of developmental disorders. Research to date has predominantly emerged from Europe and North America, resulting in a notable scarcity of studies focusing on East Asian populations. Currently, the prevalence and distribution of PIK3CA variants across various genetic loci and their correlation with distinct phenotypes in East Asian populations remain unclear. This study aims to elucidate the phenotype-genotype correlations of PROS in East Asian populations. We presented the phenotypes and genotypes of 82 Chinese patients. Among our cohort, 67 individuals carried PIK3CA variants, including missense, frameshift, and splice variants. Six patients presented with both PIK3CA and an additional variant. Seven PIK3CA-negative patients exhibited overlapping PROS manifestations with variants in GNAQ, AKT1, PTEN, MAP3K3, GNA11, or KRAS. An integrative review of the literature pertaining to East Asian populations revealed that specific variants are uniquely associated with certain PROS phenotypes. Some rare variants were exclusively identified in cases of megalencephaly and diffuse capillary malformation with overgrowth. Non-hotspot variants with undefined oncogenicity were more common in CNS phenotypes. Diseases with vascular malformation were more likely to have variants in the helical domain, whereas phenotypes involving adipose/muscle overgrowth without vascular abnormalities predominantly presented variants in the C2 domain. Our findings underscore the unique phenotype-genotype patterns within the East Asian PROS population, highlighting the necessity for an expanded cohort to further elucidate these correlations. Such endeavors would significantly facilitate the development of PI3Kα selective inhibitors tailored for the East Asian population in the future.

2024: Genetic insights into the mechanisms of proliferative glomerulonephritis

Glomerular visceral epithelial cells (i.e., podocytes) are an essential component of the tripartite glomerular filtration barrier. Healthy podocytes are terminally differentiated cells with limited replicative capacity; however, inappropriate cell cycle reentry can be induced in podocytes by various injurious stimuli. In this issue of the JCI, Yamaguchi et al. report on a somatic mosaic gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic α subunit (p110α, encoded by PIK3CA). The study reveals that activating mutations of p110α can drive podocyte proliferation in PIK3CA-related overgrowth syndrome (PROS). They also showed that selective, small-molecule inhibitors of p110 may be useful for the treatment of proliferative glomerulonephritis.

2024: PIK3CA mutations enhance the adipogenesis of ADSCs in facial infiltrating lipomatosis through TRPV1

Abstract

Facial infiltrating lipomatosis (FIL) is a congenital disorder. The pathogenesis of FIL is associated with PIK3CA mutations, but the underlying mechanisms remain undetermined. We found that the adipose tissue in FIL demonstrated adipocytes hypertrophy and increased lipid accumulation. All adipose-derived mesenchymal stem cells from FIL (FIL-ADSCs) harbored PIK3CA mutations. Moreover, FIL-ADSCs exhibited a greater capacity for adipogenesis. Knockdown of PIK3CA resulted in a reduction in the adipogenic potential of FIL-ADSCs. Furthermore, WX390, a dual-target PI3K/mTOR inhibitor, was found to impede PIK3CA-mediated adipogenesis both in vivo and in vitro. RNA sequencing (RNA-seq) revealed that the expression of transient receptor potential vanilloid subtype 1 (TRPV1) was upregulated after PI3K pathway inhibition, and overexpression or activation of TRPV1 both inhibited adipogenesis. Our study showed that PIK3CA mutations promoted adipogenesis in FIL-ADSCs and this effect was achieved by suppressing TPRV1. Pathogenesis experiments suggested that WX390 may serve as an agent for the treatment of FIL.

2024: Radiation-Induced Angiosarcoma in a Patient With Klippel-Trenaunay Syndrome: A Case Report

Abstract

Background. Klippel-Trenaunay syndrome (KTS) is a rare vascular disorder that typically presents in the lower limb with unilateral port-wine discoloration of the skin due to capillary malformations, varicose veins, and soft tissue and bone overgrowth. Radiation-induced angiosarcoma (RIAS) is a rare vascular malignancy that develops as a long-term complication secondary to radiation therapy. While there is no well-established direct relationship between KTS and development of angiosarcoma, there is literature that suggests a logical association between the 2 disorders. The present case report highlights the importance of further research into a potential connection between KTS and RIAS.

Methods. A 51-year-old female with a history of KTS was referred to the plastic surgery clinic for delayed breast reconstruction following RIAS of the left breast. It was decided that a 2-stage left latissimus dorsi musculocutaneous flap reconstruction with silicone implant would best achieve her goal of symmetry. 

Results. The patient reported here had an unremarkable postoperative course. Of note, this patient experienced severe body dysmorphia after her mastectomy and RIAS excision due to the absence of her left breast juxtaposed with her prior large right breast augmentation. The choice of 2-stage combined autologous/implant reconstruction likely contributed to her satisfactory cosmetic outcome.

Conclusions. While RIAS and KTS are distinct conditions, a link may exist between the two. More research is needed to investigate this possible relationship. Aggressive treatment of RIAS is crucial for patient recovery, and a 2-stage combined autologous/implant reconstruction is an optimal choice for post-RIAS reconstruction, especially in patients hoping to achieve a large breast size.

2024: Targeted Treatments for Vascular Malformations: Current State of the Art

Abstract

Vascular malformations, which arise from anomalies in angiogenesis, encompass capillary, lymphatic, venous, arteriovenous and mixed malformations, each affecting specific vessel types. Historically, therapeutic options such as sclerotherapy and surgery have shown limited efficacy in complicated malformations. Most vascular malformations stem from hereditary or somatic mutations akin to oncogenic alterations, activating the PI3K-AKT-mTOR, RAS-MAPK-ERK, and G-protein coupled receptor pathways. Recognizing the parallels with oncogenic mutations, we emphasize the potential of targeted molecular inhibitors in the treatment of vascular malformations by repurposing anticancer drugs. This review delves into the recent development and future use of such agents for the management of slow- and fast-flow vascular malformations, including in more specific situations, such as prenatal treatment and the management of associated coagulopathies.

2024: Information on an ongoing Alpelisib drug trial

2024: A class I PI3K signalling network regulates primary cilia disassembly in normal physiology and disease

Primary cilia are antenna-like organelles which sense extracellular cues and act as signalling hubs. Cilia dysfunction causes a heterogeneous group of disorders known as ciliopathy syndromes affecting most organs. Cilia disassembly, the process by which cells lose their cilium, is poorly understood but frequently observed in disease and upon cell transformation. Here, we uncover a role for the PI3Kα signalling enzyme in cilia disassembly. Genetic PI3Kα-hyperactivation, as observed in PIK3CA-related overgrowth spectrum (PROS) and cancer, induced a ciliopathy-like phenotype during mouse development. Mechanistically, PI3Kα and PI3Kβ produce the PIP3 lipid at the cilia transition zone upon disassembly stimulation. PI3Kα activation initiates cilia disassembly through a kinase signalling axis via the PDK1/PKCι kinases, the CEP170 centrosomal protein and the KIF2A microtubule-depolymerising kinesin. Our data suggest diseases caused by PI3Kα-activation may be considered ‘Disorders
with Ciliary Contributions’, a recently-defined subset of ciliopathies in which some, but not all, of the clinical manifestations result from cilia dysfunction.

2024: PIK3CA-Related Disorders: From Disease Mechanism to Evidence-Based Treatments

ABSTRACT
 

Recent advances in genetic sequencing are transforming our approach to rare-disease care. Initially identified in cancer, gain-of-function mutations of the gene are also detected in malformation mosaic diseases categorized as -related disorders (PRDs). Over the past decade, new approaches have enabled researchers to elucidate the pathophysiology of PRDs and uncover novel therapeutic options. In just a few years, owing to vigorous global research efforts, PRDs have been transformed from incurable diseases to chronic disorders accessible to targeted therapy. However, new challenges for both medical practitioners and researchers have emerged. Areas of uncertainty remain in our comprehension of PRDs, especially regarding the relationship between genotype and phenotype, the mechanisms underlying mosaicism, and the processes involved in intercellular communication. As the clinical and biological landscape of PRDs is constantly evolving, this review aims to summarize current knowledge regarding and its role in nonmalignant human disease, from molecular mechanisms to evidence-based treatments.

2024: Dysfunctional mechanotransduction regulates the progression of PIK3CA-driven vascular malformations

Abstract

Somatic activating mutations in PIK3CA are common drivers of vascular and lymphatic malformations. Despite common biophysical signatures of tissues susceptible to lesion formation, including compliant extracellular matrix and low rates of perfusion, lesions vary in clinical presentation from localized cystic dilatation to diffuse and infiltrative vascular dysplasia. The mechanisms driving the differences in disease severity and variability in clinical presentation and the role of the biophysical microenvironment in potentiating progression are poorly understood. Here, we investigate the role of hemodynamic forces and the biophysical microenvironment in the pathophysiology of vascular malformations, and we identify hemodynamic shear stress and defective endothelial cell mechanotransduction as key regulators of lesion progression. We found that constitutive PI3K activation impaired flow-mediated endothelial cell alignment and barrier function. We show that defective shear stress sensing in PIK3CAE542K endothelial cells is associated with reduced myosin light chain phosphorylation, junctional instability, and defective recruitment of vinculin to cell-cell junctions. Using 3D microfluidic models of the vasculature, we demonstrate that PIK3CAE542K microvessels apply reduced traction forces and are unaffected by flow interruption. We further found that draining transmural flow resulted in increased sprouting and invasion responses in PIK3CAE542K microvessels. Mechanistically, constitutive PI3K activation decreased cellular and nuclear elasticity resulting in defective cellular tensional homeostasis in endothelial cells which may underlie vascular dilation, tissue hyperplasia, and hypersprouting in PIK3CA-driven venous and lymphatic malformations. Together, these results suggest that defective nuclear mechanics, impaired cellular mechanotransduction, and maladaptive hemodynamic responses contribute to the development and progression of PIK3CA-driven vascular malformations.

2024: PIK3CA-Related Overgrowth Spectrum: Exploring Brain Growth From Fetal to Infant

Abstract

Background

Megalencephaly-capillary malformation-polymicrogyria syndrome (MCAP) is a rare neurological disorder characterized by abnormal brain size, vascular malformations, and body overgrowth. MCAP is caused by somatic mosaicism of PIK3CA, a crucial gene in regulation of cell growth and survival, and is one of the disorders in the PIK3CA-related overgrowth spectrum.

Methods

We present a unique clinical report of a male infant diagnosed with MCAP from prenatal stages to age 12 months. Prenatal imaging unveiled ventricular asymmetry, later confirmed postnatally as megalencephaly. Genetic analysis identified a PIK3CA mutation. The patient underwent early interventions, including ventriculoperitoneal shunt placement and posterior fossa decompression.

Results

Despite early interventions, the patient developed progressive macrocrania, hydrocephalus, and significant neurodevelopmental delay. Multidisciplinary management and continuous neuroimaging were crucial in addressing complications associated with the disorder.

Conclusions

This case underscores the critical need for multidisciplinary care and continual neuroimaging surveillance to effectively navigate the progressive complications associated with PIK3CA-related overgrowth spectrum. The diagnostic hurdles and management challenges intrinsic to the disorder’s natural course are elucidated. Although current treatments manage symptoms, emerging therapies hold promise for improving patient outcomes.

2024: Treatment for Overgrowth of a Finger Owing to Vascular Malformations: A Case Report

Abstract

Treatment for mild macrodactyly with only overgrowth of the solitary finger caused by vascular malformations (VMs) is rarely reported. We encountered a case of right middle finger overgrowth resulting from a VM in a seven-year-old girl. The length of her middle finger was 7.7 mm longer than her left middle finger. In order to control additional overgrowth, epiphysiodesis was planned when the finger reached the same length as that of her mother’s finger. At the age of 12, her right middle finger length reached the same length as her mother’s finger, and epiphysiodesis was performed. The length of her middle finger was 9.4 mm longer than her left middle finger. No additional overgrowth of the right finger occurred after surgery; however, the normal left finger stopped growing earlier than expected, maintaining a left-right difference of approximately 10 mm. No functional disorders were observed at a follow-up of 2.5 years. The timing of epiphysiodesis should be determined through a comprehensive assessment of multiple factors, not only the length of the parents’ fingers.

2024: Epik-P2: A Phase 2 Study of Alpelisib (ALP) in Pediatric and Adult Patients (pts) with PIK3CA-Related Overgrowth Spectrum (PROS)

Conclusions: EPIK-P2 showed durable radiological responses in a meaningful proportion of pts treated with ALP, and the tx was well tolerated in both adult and pediatric pts, although the prespecified efficacy boundary was not crossed. These data support further prospective investigation of approved dosing of ALP in pts with PROS.

2024: Rapid Response to Sirolimus in Patients with PIK3CA-Related Overgrowth Spectrum

Abstract

PIK3CA-related overgrowth spectrum (PROS) is an umbrella term used to unify a heterogenous group of vascular overgrowth disorders by a shared genetic cause. Given that patients with PROS have a known, or likely, gene mutation in the PI3K/AKT/mTOR cascade, we hypothesize they experience a rapid response to inhibitors of this pathway, including sirolimus. In the following case series, we describe 3 patients with PROS and their response to sirolimus therapy. Despite their unique clinical presentations, insight into the genetic origin of their vascular overgrowth allowed for their successful treatment with the same medication.

2024: Klippel-Trenaunay Syndrome: A Case Study of Severe Anemia in a Rare Vascular Disorder

Abstract

Klippel-Trenaunay syndrome (KTS) is a rare congenital vascular disorder involving varicosities, cutaneous vascular malformations, and hypertrophy of soft tissues and bones. It is often linked to PIK3CA gene mutations. It affects the lymphatic, capillary, and venous systems. The diagnosis is usually based on clinical presentation, supplemented by magnetic resonance imaging (MRI) and computed tomography (CT) imaging. This case involves a 43-year-old male diagnosed with KTS after presenting with severe anemia (hemoglobin 2.5 g/dL) and left lower limb swelling with varicosities. Investigations revealed hepatosplenomegaly, hemangiomas, rectosigmoid malformations, an enlarged inferior vena cava (IVC), and vascular congestion. MRI confirmed an extensive veno-lymphatic malformation in the left lower limb. The case highlights KTS’s complex presentation, emphasizing the importance of timely diagnosis, multidisciplinary care, and ongoing monitoring to manage its complications. Further research is needed to enhance treatment strategies for this rare condition.

2024: Oncogenic PIK3CA corrupts growth factor signaling specificity

Abstract
Technical limitations have prevented understanding of how growth factor signals are encoded in distinct activity patterns of the phosphoinositide 3-kinase (PI3K)/AKT pathway, and how this is altered by oncogenic pathway mutations. We introduce a kinetic, single-cell framework for precise calculations of PI3K-specific information transfer for different growth factors. This features live-cell imaging of PI3K/AKT activity reporters and multiplexed CyTOF measurements of PI3K/AKT and RAS/ERK signaling markers over time. Using this framework, we found that the PIK3CAH1047R oncogene was not a simple, constitutive activator of the pathway as often presented. Dose-dependent expression of PIK3CAH1047R in human cervical cancer and induced pluripotent stem cells corrupted the fidelity of growth factor-induced information transfer, with preferential amplification of epidermal growth factor receptor (EGFR) signaling responses compared to insulin-like growth factor 1 (IGF1) and insulin receptor signaling. PIK3CAH1047R did not only shift these responses to a higher mean but also enhanced signaling heterogeneity. We conclude that oncogenic PIK3CAH1047R corrupts information transfer in a growth factor-dependent manner and suggest new opportunities for tuning of receptor-specific PI3K pathway outputs for therapeutic benefit.
 
 

 

Abstract

We report a rare case of partial prenatal diagnosis of congenital lipomatous overgrowth, vascular malformations, epidermal nevi, and skeletal anomalies (CLOVES) syndrome in a fetus presenting extensive dorsal lymphatic malformation, bilateral polydactyly and syndactyly, hypertrophy on the left foot, and suspected cryptorchidism. Amniocentesis with comparative genomic hybridization (CGH) and trio-exome sequencing did not reveal any pathogenic variant. Postnatal clinical examination and imaging confirmed the malformations, including a multilocular macrocystic lymphatic malformation with retroperitoneal extension. Sirolimus therapy was initiated, resulting in a modest reduction in the volume of the dorsal mass within the first two months of treatment. This report underscores key prenatal features that may raise suspicion for CLOVES syndrome, helping clinicians to differentiate it from other overgrowth disorders such as Proteus syndrome and conditions within phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-related overgrowth spectrum (PROS), supporting improved diagnosis and counseling during pregnancy.

2025: Safety findings from the phase 1/2 MOSAIC study of miransertib for patients with PIK3CA-related overgrowth spectrum or Proteus syndrome

Abstract

Background

PIK3CA-related overgrowth spectrum (PROS) and Proteus syndrome are associated with mosaic tissue overgrowth of varying severity that commonly presents in childhood. The multicenter, open-label, phase 1/2 MOSAIC study (NCT03094832) was designed to evaluate the clinical efficacy and safety of the selective pan-AKT inhibitor miransertib for participants with PROS or Proteus syndrome.

Methods

Participants ≥ 2 years of age with PROS with documented somatic PIK3CA mutations or Proteus syndrome with documented somatic AKT1 mutations were enrolled to receive oral miransertib at a starting dose of 15 mg/m2 every day for the first 3 cycles (1 cycle = 28 days) and miransertib 25 mg/m2 every day thereafter, provided no clinically significant drug-related toxicities were observed. The initial primary objective of the study was to assess clinical response to miransertib. Due to study design and data collection limitations, evaluating efficacy was no longer considered feasible and the primary objective was updated in 2021 to evaluate the safety and tolerability of miransertib.

Results

Between May 16, 2017 and January 25, 2021, 49 participants were enrolled and received ≥ 1 dose of study drug, comprising the safety analysis population. Forty-five participants had a diagnosis of PROS and four had a diagnosis of Proteus syndrome. The median (range) age at enrollment was 7 years (2–41). Median (range) duration of treatment was 20.5 months (9.9–45.6). A total of 23 (46.9%) participants had a drug-related adverse event, most commonly decreased neutrophil count (n = 6, 12.2%), increased blood insulin (n = 5, 10.2%), and stomatitis (n = 5, 10.2%). One (2.0%) participant experienced a grade 3 drug-related adverse event (deep vein thrombosis). No drug-related adverse events led to early study discontinuation or death. Laboratory assessment values remained generally stable throughout the study.

Conclusion

Miransertib was safe and tolerable in participants with a confirmed diagnosis of PROS or Proteus syndrome. Future investigations are needed to determine whether patients receive measurable clinical benefit from miransertib.

2025: Analysis of the application value of endovascular interventional technology in the diagnosis and treatment of vascular malformations with limb hypertrophy

Abstract

This study aims to retrospectively analyze the clinical data of children diagnosed with vascular malformations associated with limb hypertrophy, treated at the General Surgery department of Liangjiang Branch of the Children’s Hospital Affiliated to Chongqing Medical University. Additionally, it seeks to explore the diagnostic and therapeutic value of endovascular interventions for this condition. This study conducts a retrospective analysis of the medical records of children with vascular malformations accompanied by limb hypertrophy who received treatment in our department. We summarize their medical history characteristics, clinical manifestations, auxiliary examinations, DSA (Digital Subtraction Angiography) results, intraoperative treatment methods, and follow-up data collected at least 1 year post-surgery to evaluate the diagnostic and therapeutic value of these interventions. This study included a total of 19 children, comprising 10 females and 9 males. The average age was 4 years, while the median age was 3 years and 1 month. The primary site of onset was the lower extremities. The disease types predominantly included arteriovenous malformation (AVM), Klippel–Trenaunay syndrome (KTs), and Parkes-Weber syndrome (PWs). All children underwent digital subtraction angiography (DSA) surgery. During the operation, they were categorized into high-flow and low-flow groups based on their blood flow characteristics, and distinct treatment plans were implemented for each group. Postoperative follow-up revealed a significant decrease in limb skin temperature in the high-flow group before and after treatment (t = 9.266, p = 0.000), while the limb circumference in the low-flow group also decreased significantly (t = 5.701, p = 0.002). Additionally, differences were observed in the relief of symptoms such as limb limping, skin plaques, pain, and pruritus between the two groups. During the postoperative follow-up period, only one child with AVM experienced recanalization 1 year after the operation and subsequently underwent reoperation. Vascular malformations associated with limb hypertrophy are relatively rare in clinical practice. Therefore, it is essential to enhance our understanding of these conditions to facilitate early diagnosis and treatment. Endovascular interventional therapy offers significant advantages for the diagnosis and treatment of this disease, making it worthy of wider adoption in clinical settings. Furthermore, treatment plans should be tailored to the specific clinical characteristics of each patient.

2025: Capillary Venous Malformation With Undergrowth and Activating PIK3CA Variant: An Underrecognized Phenotype

Abstract

Congenital vascular malformations associated with segmental overgrowth and PIK3CA variants are well-documented and are classified within the PIK3CA-related overgrowth spectrum (PROS), yet PIK3CA-associated segmental undergrowth is a less understood entity. We present a case of a patient with a capillary venous malformation (CVM) and limb undergrowth associated with a pathogenic PIK3CA variant (p.Glu453Lys). An updated classification system should be considered to more broadly encompass variable phenotypic presentations of PIK3CA-related disorders, including segmental undergrowth. We propose novel terminology such as PIK3CA-related altered growth spectrum (PRAGS).

2025: PIK3CA-Related Overgrowth Spectrum With Progressive Neurological Manifestations: A Rare Case Report

Abstract

PIK3CA-related overgrowth spectrum (PROS) disorders present complex management challenges due to their multisystem involvement. We describe a teenage male with a genetically confirmed PROS disorder (PIK3CA c.353G>A mutation), specifically megalencephaly-capillary malformation-polymicrogyria (MCAP) syndrome, who developed a unique constellation of neurological symptoms. Initially presenting with fetal macrocephaly, seizures, and developmental delay, he underwent surgical interventions including Chiari decompression and ventriculoperitoneal shunt placement. Concurrent progression of scoliosis and gait instability suggested syrinx progression, though obtaining follow-up imaging proved challenging due to insurance barriers. This case uniquely demonstrates the diagnostic complexity of differentiating between primary neurological symptoms, mechanical complications from structural abnormalities, and vascular phenomena in PROS disorders. Management required coordinated care across multiple subspecialties including neurology, neurosurgery, ophthalmology, and orthopedics. The case highlights multiple learning points: 1) the importance of serial monitoring in PROS/MCAP due to the progressive nature of complications, and 2) the challenge of characterizing episodic symptoms in the context of multiple potential underlying mechanisms.

2025: A Phase 2 Study of Mutant-selective PI3Kα Inhibitor, RLY-2608, in Adults and Children With PIK3CA Related Overgrowth Spectrum and Malformations Driven by PIK3CA Mutation

2025: Multisite Involvement in Klippel-Trénaunay Syndrome Using Photon-counting CT

A 34-year-old man presented with swelling and pain in the left lower limb that had persisted for 3 years. Physical examination revealed a light cutaneous port-wine stain of the left lower limb accompanied by mild swelling and superficial varicosities. CT angiography of the lower-limb arteries was unremarkable. Subsequent CT venography using photon-counting CT revealed extensive varicose veins and venous aneurysms in the left lower limb accompanied by reduced muscle density (Fig 1A), bone hyperplasia (Fig 2), and diffuse abnormal hypertrophy of the subcutaneous soft tissue in the left side of the abdomen, scrotum, and lower limb (Fig 1B). Based on the clinical presentation and the triad of cutaneous port-wine capillary malformations, hemihypertrophy of bone and soft tissues, and presence of varicose veins, the patient was diagnosed with Klippel-Trénaunay syndrome. Cinematic rendering vividly depicted the typical unilateral involvement, venous malformations, and connective tissue proliferation (Fig 1C, Movie). Clinical evaluation indicated that the patient’s condition was stable, with no functional impairment or cosmetic concerns. The patient was advised to wear compression stockings and to undergo oral administration of mTOR (mechanistic target of rapamycin) inhibitor sirolimus to mitigate disease progression. Regular follow-up was conducted to monitor the clinical course.

2025: Isolated Hemihyperplasia in Adolescence: A Case Report

Abstract

Isolated hemihyperplasia is a rare condition characterized by asymmetric overgrowth of the body that is not associated with overgrowth syndromes. We report the case of a 16-year-old adolescent with isolated congenital hemihyperplasia affecting the left hemibody, who had never undergone specific evaluation for this condition, as the clinical manifestations were mild and did not result in significant alterations beyond the observable asymmetry. Notable findings included slightly finer and thinner scalp hair texture on the contralateral side to the hemihyperplasia, as well as bilateral brachymetatarsia of the third toes. Clinical criteria and molecular testing were essential for establishing an accurate diagnosis.

Given the association between hemihyperplasia and tumor risk, screening for neoplasms using abdominal ultrasound and serum alpha-fetoprotein testing is recommended. This condition presents a clinical challenge, as coordinated intervention by specialists in orthopedics, nephrology, and genetics is required to ensure effective clinical management.

2025: Vascular malformations: Advancements, Debates and Consensus

2025: Relay Therapeutics’ Promising Phase 2 Study on RLY-2608: A Potential Game-Changer in Targeted Therapy

2025: Pregnancy and PIK3CA-Related Overgrowth Spectrum: New Insights from Alpelisib Treatment

A recent article published in the European Journal of Human Genetics brings new perspective to an important, yet rarely addressed, question: Can young patients with PIK3CA-related overgrowth spectrum (PROS) safely conceive and carry pregnancies while being treated with targeted therapies like alpelisib? “An article with some positives but also with some thoughts to consider for patients.”

2025: An Extremely Preterm Infant With PIK3CA-Related Overgrowth Spectrum (PROS): Alpelisib Treatment and Outcome

Abstract

Phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-related overgrowth spectrum (PROS) is a group of rare genetic asymmetric and atypical overgrowth disorder syndromes. Affecting skin, adipose and connective tissues, brain, bone, and vasculature and severity influenced by the gestational age at which the change occurred, PROS is phenotypically heterogeneous. This paper shares the case report of a former extremely preterm infant diagnosed with a subtype of PROS, megalencephaly-capillary malformation/megalencephaly-capillary malformation polymicrogyria (MCAP) syndrome, for whom treatment with alpelisib was initiated at 10 months of age (7 months corrected age). To our knowledge, this patient is the third and youngest to be included in this expanded access program for compassionate use for patients under 2 years of age.

 
 
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