Safety and clinical activity of the Notch inhibitor, crenigacestat (LY3039478), in an open-label phase I trial expansion cohort of advanced or metastatic adenoid cystic carcinoma.

Background Deregulated Notch signaling is implicated in multiple cancers. The phase I trial (I6F-MC-JJCA) investigated the safety and anti-tumor activity of crenigacestat (LY3039478), a selective oral Notch inhibitor, in an expansion cohort of patients with adenoid cystic carcinoma (ACC) who received the dose-escalation-recommended phase 2 dose (RP2D), established previously (Massard C, et al., Annals Oncol 2018, 29:1911-17). Methods Patients with advanced or metastatic cancer, measurable disease, ECOG-PS ≤1, and baseline tumor tissue were enrolled. Primary objectives were to identify a safe RP2D, confirm this dose in expansion cohorts, and document anti-tumor activity. Secondary objectives included safety and progression-free survival (PFS). The ACC expansion cohort received the RP2D regimen of 50 mg crenigacestat thrice per week in a 28-day cycle until disease progression or other discontinuation criteria were met. Results Twenty-two patients with ACC were enrolled in the expansion cohort (median age of 60 years). Median treatment duration was 3 cycles with 6 patients remaining on treatment. There were no objective responses; 1 (5%) patient had an unconfirmed partial response. Disease control rate was 73% and 4 patients had stable disease ≥6 months. Median PFS was 5.3 months (95%CI: 2.4-NE)) for the 22 patients; and 7.7 months (95%CI: 4.0-NR) and 2.4 months (95%CI: 1.1-NE) in the subgroup of patients in second-line (n = 7) or ≥ third-line (n = 9), respectively. Frequent treatment-related-adverse events (all grades) included diarrhea, fatigue, vomiting, decreased appetite, dry mouth, and dry skin. There were no new safety signals. Conclusion The crenigacestat RP2D regimen induced manageable toxicity and limited clinical activity, without confirmed responses, in heavily pretreated patients with ACC.

Notch pathway inhibition with LY3039478 in soft tissue sarcoma and gastrointestinal stromal tumours.

BACKGROUND: LY3039478 is an orally bioavailable selective Notch inhibitor. This phase 1a/b trial evaluated the safety, pharmacokinetics and antitumour activity of LY3039478 in patients with soft tissue sarcoma (STS) and gastrointestinal stromal tumour (GIST). METHODS: This multipart, phase 1 trial enrolled patients with refractory advanced/metastatic STS and GIST, measurable disease, Eastern Cooperative Oncology Group ≤1 and baseline tumour tissue. Eligible patients received LY3039478 50mg/75 mg three times per week, for 28-day cycle until disease progression. Safety assessments were based on Common Terminology Criteria for Adverse Events, V4.0. Tumour responses were assessed using Response Evaluation Criteria in Solid Tumours (RECIST 1.1) and Choi criteria. Primary objectives were to confirm the recommended phase 2 dose of LY3039478 and document the antitumour activity. Secondary objectives were safety and toxicity, pharmacokinetics (PK), progression-free survival (PFS) and overall survival (OS). RESULTS: Sixty-nine patients were enrolled and received LY3039478 (27 males, 42 females; median age 58, range 31-78). 16/37 (43%) patients with evaluable samples were positive for Notch 1 immunohistochemistry. Per RECIST 1.1, in leiomyosarcoma (LMS) group (n = 29), ten (36%) had stable disease (SD) and one (4%) had unconfirmed partial response (PR). In GIST group (n = 13), four (31%) had SD. Among other STS subtypes (n = 27), one patient with angiosarcoma had unconfirmed PR, six (21%) had SD. Median PFS was 1.9 months (95% confidence interval:1.6-3.3) for LMS, 1.9 months (0.3-6.1) for GIST and 1.7 months (1.4-2.2) for other STS groups. Median OS was 7.4 months (4.3-non-evaluable [NE]) for LMS, 16.5 months (3.9-16.5) for GIST and 5.6 months (3.4-NE) for other STS groups. Most common adverse events were diarrhoea, nausea, vomiting and decreased appetite. CONCLUSION: LY3039478 suggested a modest clinical activity in patients with STS and GIST and had a manageable safety profile.