A phase 1b study of crenigacestat (LY3039478) in combination with gemcitabine and cisplatin or gemcitabine and carboplatin in patients with advanced or metastatic solid tumors

Background: Notch signaling plays an integral role in development and tissue homeostasis. Inhibition of Notch signaling has been identified as a reasonable target for oncotherapy. Crenigacestat (LY3039478) is a potent Notch inhibitor that decreases Notch signaling and its downstream biologic effects. Methods: I6F-MC-JJCD was a multicenter, nonrandomized, open-label, phase 1b study with 5 separate, parallel dose escalations in patients with advanced or metastatic cancer from a variety of solid tumors followed by a dose-confirmation phase in pre-specified tumor types. This manuscript reports on 2 of 5 groups. The primary objective was to determine the recommended phase 2 dose of crenigacestat combined with other anticancer agents (gemcitabine/cisplatin or gemcitabine/carboplatin). Secondary objectives included evaluation of safety, tolerability, preliminary efficacy, and pharmacokinetics. Results: Patients (N = 31) received treatment between November 2016 and July 2019. Dose-limiting toxicities occurred in 6 patients. The recommended phase 2 dose for crenigacestat was 50 mg TIW in Part 1 (combined with gemcitabine/cisplatin) and not established in Part 2 (combined with gemcitabine/carboplatin) due to poor tolerability. Patients had at least one treatment-emergent adverse event (TEAE), and most had Grade ≥ 3 TEAEs. Over 50% of the patients experienced gastrointestinal disorders (Grade ≥ 3). No patient had complete response; 5 patients had a partial response. Disease control rates were 62.5% (Part 1) and 60.0% (Part 2). Conclusion: This study demonstrated that the Notch inhibitor, crenigacestat, combined with different anticancer agents (gemcitabine, cisplatin, and carboplatin) was poorly tolerated and resulted in disappointing clinical activity in patients with advanced or metastatic solid tumors. Clinicaltrials.gov Identification Number: NCT02784795.