Phase I dose-escalation study of the dual PI3K-mTORC1/2 inhibitor gedatolisib in combination with paclitaxel and carboplatin in patients with advanced solid tumors

Purpose: This phase I study evaluated safety, tolerability, pharmacokinetics, and preliminary activity of the PI3K/mTORC1/2 dual inhibitor gedatolisib combined with carboplatin and paclitaxel. Patients and Methods: Patients with advanced solid tumors treated with ≤ 2 prior chemotherapies received intravenous gedatolisib on days 1, 8, 15, and 22 (95, 110, or 130 mg according to dose level); carboplatin (AUC5) on day 8 (day 1 following protocol amendment); and paclitaxel at 80 mg/m2 on days 8, 15, and 22 (1, 8, and 15 after amendment), every 28 days. Patients without progressive disease after cycle 6 received maintenance gedatolisib until progression. Results: Seventeen patients were enrolled [11 ovarian (10 clear cell ovarian cancer, CCOC), 4 endometrial, 2 lung cancers]. Median number of prior chemotherapies was 1 (range, 0–2). Median number of administered cycles was 6 (range, 2–16). Dose-limiting toxicities occurred in 4 patients: 2 (cycle 2 delay due to G2–G3 neutropenia) at 110 mg leading to a change in the treatment schedule, 2 at 130 mg (G2 mucositis causing failure to deliver ≥ 75% of gedatolisib at cycle 1). The recommended phase II dose is gedatolisib 110 mg on days 1, 8, 15, and 22 with carboplatin AUC5 on day 1 and paclitaxel 80 mg/m2 on days 1, 8, and 15. The most frequent ≥G3 treatment-related adverse events were neutropenia (35%), anemia (18%), and mucositis (12%). The overall response rate was 65% (80% in CCOC). Pharmacokinetic parameters of gedatolisib were consistent with single-agent results. Conclusions: Gedatolisib combined with carboplatin and paclitaxel is tolerable, and preliminary efficacy was observed especially in CCOC.