RecruitingPhase 2Drug trialEPIK-P4: A Phase II Single-arm Study to Assess the Efficacy, Safety and Pharmacokinetics of Alpelisib (BYL719) in Pediatric and Adult Patients With PIK3CA-related Overgrowth Spectrum (PROS)This study is designed to demonstrate the efficacy and assess safety and tolerability of oral daily alpelisib in participants with PIK3CA-related overgrowth spectrum (PROS).