OBJECTIVES: PIK3CA-related overgrowth spectrum (PROS) is a rare condition with diverse clinical manifestations caused by activating PIK3CA mutations. OrphaNET and NIH Genetics have estimated its prevalence to 14 patients per 1 million persons. However, confirming the epidemiology and burden of PROS remains challenging due to the lack of specific medical coding. Although today no treatment is approved in Europe for PROS, alpelisib has demonstrated significant improvement in treating patients with severe forms of PROS (EPIK-P1 study). This study assesses the epidemiology and hospital-related resource utilization of patients with multiple PROS-related hospitalizations to support alpelisib assessment by French HTA.

METHODS: Retrospective analyses of the French national claims hospital database (PMSI) were conducted from January 2017 to December 2022. Patients were identified using a combination of inclusion (e.g., malformations commonly associated with PROS) and exclusion (e.g., hemangioma diagnosis) criteria based on ICD-10-CM and technical procedure codes at time of hospitalization. Hospitalizations and external technical procedures and visits (ACE) rates were estimated per person-year (PPY) in the sub-population (SP) of patients with multiple PROS-related hospitalizations.

RESULTS: 3,605 patients were identified (mean age 30.1 (±19.9) years, 52% female), corresponding to a yearly prevalence rate of 9 hospitalized PROS-patients per 1 million persons. 923 patients (SP) (mean age 23.6 (±18.0), 49% female) had multiple PROS-related hospitalizations during the follow-up period, indicating more intensive and ongoing need for hospital care. Over an average follow-up period of 20.5 months (±17.7), SP patients required 5.86 [95%CI 5.73; 5.98] all-cause ACE and 2.28 [95%CI 2.21; 2.26] hospitalizations PPY, including 1.59 [95%CI 1.53; 1.66] PROS-related hospitalizations.

CONCLUSIONS: This study introduces an innovative method for identifying patients with PROS in a claims database. It provides insights on the epidemiology and hospital management of patients with PROS in France.