There are numerous ways to find treatments for rare diseases, with the major method that springs into everyone’s minds being clinical trials starting from scratch. However, in many cases, drugs that have already received FDA approval are repurposed to treat new diseases. For example, Vijoice – which was originally approved for metastatic breast cancer – has now received the green light for PIK3CA-related overgrowth spectrum (PROS).
About PROS
First, let’s dive into what this rare disease is. 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.
FDA Approval of Vijoice
Also known under its generic name, alpelisib, Vijoice is a PI3K inhibitor that first received approval to treat HER2-negative, HR-positive metastatic breast cancer with PI3K mutations. Despite the fact that it had only received that one approval, a number of PROS patients were allowed to take it under a compassionate use program.
Novartis, the drug developer, then took and analyzed data from 57 PROS patients being treated with Vijoice in a study titled EPIK-P1. Their investigation revealed that PROS symptoms improved, and PROS lesions shrank as well. It was these data that led the FDA to green-light the drug under its accelerated approval pathway.
Looking Forward
Under the rules of the accelerated approval pathway, Novartis is obligated to conduct confirmatory trials, which will be two phase II studies. The first will be referred to as EPIK-P2 and evaluate the safety, pharmacokinetics, and efficacy of the drug, while the second will be EPIK-P3 and assess the long-term efficacy and safety in the participants of the EPIK-P1 study.
Want to read more about this approval? Head here!
