Study Assessing Long-term Safety and Efficacy of Alpelisib in Patients With PIK3CA-Related Overgrowth Spectrum (PROS) Who Previously Participated in Study CBYL719F12002 (EPIK-P1)

The study will enroll male and female participants aged 2 years or older who previously participated in the EPIK-P1 study (NCT04285723) and continued to receive alpelisib after the EPIK-P1 data cut-off date of 09 March 2020. The study consists of an initial retrospective period followed by a prospective period. The retrospective, non-interventional period began on 10 March 2020, one day after the EPIK-P1 data cut-off date, and ended the day before the participant received the first interventional dose of alpelisib in the prospective period. Safety and efficacy data collected during routine medical practice were longitudinally abstracted from participants' medical records. The prospective, interventional period began on the day the participant received the first interventional dose of alpelisib. Safety and efficacy data are being collected according to a structured assessment plan common to all participants. The prospective period will end after all participants have completed at least 5 years of treatment or discontinued treatment earlier, whichever occurs first.