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.

A phase I study to assess the safety, pharmacokinetics (PK), pharmacodynamics (PD) and antitumor activities of BAL101553, a novel tumor checkpoint controller (TCC), administered as 48-hour infusion in adult patients with advanced solid tumors

TPS2602

Background: BAL101553 (prodrug of BAL27862), is a novel TCC that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 has shown potent antitumor activity in diverse preclinical tumor models, including models refractory to standard therapies. In a completed Phase 1 study using 2-h IV infusions (Days 1, 8, 15, q28d, NCT01397929 , CDI-CS-001, Lopez et al. JCO 34, 2016 suppl; 2525) dose-limiting vascular effects were observed and appeared Cmax related. The recommended Phase 2 dose for 2-h IV BAL101553 is 30 mg/m2. Vascular toxicity was not observed in an ongoing study with oral BAL101553 (NCT02490800, CDI-CS-002) at daily doses up to 30 mg (QD). Preclinical data suggest that antiproliferative effects of BAL101553/27862 are driven by exposure (AUC); thus vascular toxicity and antitumor activity are mediated by different PK drivers. BAL27862 has a half-life of ~15 h. Based on PK-modeling, extending the infusion from 2 h to 48 h was expected to result in ~4-fold higher AUC at a given Cmaxlevel and thereby improve the therapeutic window. Methods: This is an ongoing multicenter, open-label, Phase 1 dose-escalation study (NCT02895360, CDI-CS-003/SAKK67/15) using a 3+3 design to determine the MTD, characterize dose-limiting toxicities and assess the PK, PD and antitumor activities of 48-h infusions of BAL101553 in consecutive 28-day cycles at a starting dose of 30 mg/m2 administered on Day 1, 8 and 15 (q28d). The dose escalation scheme foresees up to ~ 50% dose increments depending on observed toxicities. During cycle 2, patients receive 7 days oral (QD) BAL101553 (Day 15–21) instead of the weekly IV infusion to assess absolute oral bioavailability. Patients with histologically-confirmed advanced or recurrent solid tumors are eligible for enrollment. Adverse events are assessed using CTCAEv4; tumor response by RECIST 1.1 (every 2 cycles). PD assessments include optional tumor biopsies and circulating tumor cells. PK profiles are assessed during the first 2 cycles. Two dose cohorts (30 and 45 mg/m2) have completed without DLTs or signs of vascular toxicity. Clinical trial information: NCT02895360.