LGG-53. PNOC001 (NCT01734512): A PHASE II STUDY OF EVEROLIMUS FOR RECURRENT OR PROGRESSIVE PEDIATRIC LOW-GRADE GLIOMAS (pLGG)

Abstract

OBJECTIVETo estimate the 6-month Progression Free Survival (PFS6) associated with everolimus for progressive/recurrent pLGGs and to determine if activated PI3K/Akt/mTOR pathway as measured by positive phosphorylated-ribosomal protein S6 (p-RPS6) status was associated with response. METHOD: Patients 3–21 years of age with recurrent or progressive pLGG were enrolled. Everolimus was administered orally at 5 mg/m2 daily. Tissue availability for molecular analysis was mandatory. Immunohistochemistry (IHC) for p-RPS6 was performed centrally. An adaptive Simon two-stage design was employed based on p-RPS6 status. Based on results of the first stage, enrollment in the second stage was either limited to pathway activated patients or open to all subjects.RESULTSFrom December 2012 to July 2019 a total of 65 subjects enrolled [median age 9 years (range 3–19); 43% female]. As of December 15, 2019 median number of treatment cycle is 8 (range 1–24); 7 patients remain on treatment. Toxicity profile is similar to published reports with rash and elevated lipid profiles as most common adverse events. PFS6 for the entire cohort is 63%; PFS6 is 64% for the activated and 61% for the non-activated patients. Central imaging review (n=52) revealed 1 partial response, 1 complete response, 33 stable disease, and 17 progressive disease at the end of study treatment. Initial molecular analysis identified BRAF alterations in 35/65 patients.CONCLUSIONEverolimus is well tolerated and active in a subset of pLGGs. Ongoing analyses will assess predictive biomarkers of response and will be reported at the meeting.