According to a recent press release, the FDA has recently granted approval to Vijoice – also known under the generic name alpelisib – for the treatment of PIK3CA-related overgrowth spectrum (PROS) patients who require treatment with systemic therapy. This approval fills an unmet need within the rare disease community, as PROS patients did not previously have any treatment options specific to them and approved by the FDA. Now, they have a drug that offers improvement in target lesion volumes alongside disease manifestations and symptoms.

FDA Approval of Vijoice

FDA approval hinges on data from EPIK-P1, which was a retrospective chart review study. This research produced the following results:

• 27% of study participants treated with Vijoice experienced a confirmed treatment response
  • Confirmed treatment response is defined as a minimum of 20% reduction in the sum of PROS target lesion volume
• 74% of participants demonstrated a reduction in target lesion volume in some way
  •  The mean reduction was 13.7%
• At the time of the primary analysis (24 weeks), no participants experienced disease progression
• Improvements were seen across the following symptoms:
  • Limb asymmetry
  • Pain
  • Vascular malformation
  • Fatigue
  • Disseminated intravascular coagulation
• The most common adverse events (AEs) included diarrhea, hyperglycemia, and stomatitis
  • In terms of grade 3/4 AEs, the most common was cellulitis

This data is extremely positive and is ultimately what led to FDA approval. Vijoice is also under the Accelerated Approval Program, meaning that continued approval is possible if confirmatory data is given that affirms the drug’s clinical benefit.

About PROS

According to NORD, PIK3CA-related overgrowth spectrum is an umbrella term for a group of rare conditions characterized by overgrowth of different parts of the body. Examples include CLOVES syndrome, hemimegalencephaly, and fibroadipose hyperplasia. The symptoms vary depending on which specific disorder one has, but they can include:

• Megalencephaly
• Intellectual disability
• Seizures
• Hypotonia
• Focal overgrowth
  • Note: this means that one part of the body grows larger than the others
• Changes in the vascular system
• Segmental overgrowth
  • Note: this means that more than one part of the body grow larger than the others

As the name suggests, mutations in the PIK3CA gene cause PROS. This mutation is typically only present in some of the cells throughout the body, and it it not usually inherited.