Phase Ib Study Of Bgj398 In Combination With Byl719 In Patients (Pts) With Select Advanced Solid Tumors.

2500Background: Phosphatidylinositol-3-kinase (PI3K) and fibroblast growth factor receptor (FGFR) pathway dysregulation can co-occur in tumors. In this study (NCT01928459), safety, tolerability, and preliminary activity of the pan-FGFR (BGJ398) + α-specific PI3K (BYL719) inhibitors were evaluated and maximum tolerated dose (MTD) was established in pts w/ advanced solid tumors w/ PI3K catalytic subunit (PIK3CA) mutations ± FGFR alterations. Methods: Pts w/ solid tumors received once-daily (QD) BGJ on D1-D21 of each 28-D cycle (C) and BYL continuously during escalation (PIK3CA-mutant ± FGFR-altered) and expansion (arm 1, PIK3CA-mutant [n = 15]; arm 2, PIK3CA-mutant + FGFR-altered [n = 10]; arm 3, PIK3CA-mutant + FGFR-altered breast cancer [n = 10]). Results: Of 62 pts enrolled, 44% had ≥ 4 prior therapies. The MTD, 125 BGJ + 300 BYL, was determined based on 32 evaluable pts’ data during escalation. C1 dose-limiting toxicities (DLTs) occurred in 4 pts (table). During expansion, 24 pts in arms 1 (n = 12), 2 (...