Abstract CT090: DAREON™-7: A phase 1, open-label, dose escalation and expansion cohort trial of the delta-like ligand (DLL3)-targeting T-cell engager BI 764532, plus first-line platinum-based chemotherapy in patients with DLL3-positive (+) neuroendocrine carcinomas

Abstract

Abstract Background Neuroendocrine carcinomas (NECs) have limited treatment options. DLL3 is highly expressed in NECs and is a promising treatment target. In an ongoing phase 1 trial (NCT04429087), BI 764532, a DLL3/CD3 IgG-like T-cell engager, was tolerable with clinical activity in patients with DLL3-positive (+) tumors, including those with small cell lung cancer and other NECs. Purpose DAREON™-7 (NCT06132113), a phase 1, open-label, dose-escalation (Part A) and dose-expansion (Part B) trial, aims to determine the maximum tolerated dose (MTD), recommended dose for expansion (RDE)/recommended phase 2 dose (RP2D), and the safety and efficacy of BI 764532 + platinum and etoposide in patients with DLL3+ NEC. Experimental design Part A: ~25 patients will receive intravenous BI 764532 (target dose after step-in dosing) plus carboplatin/etoposide (CE) until intolerable toxicity, or progression per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1, or for a maximum of 36 months. BI 764532 dose escalation will be guided by a Bayesian logistic regression model with overdose control. Part B: 2 cohorts (~15 patients each) will receive BI 764532 at the RDE/RP2D + CE or cisplatin/etoposide (carboplatin/etoposide or cisplatin/etoposide are the most-used standard of care [SOC] regimens). Key inclusion criteria: patients must have no prior systemic treatment for DLL3+ locally advanced or metastatic NEC (extrapulmonary or unknown primary) or large cell NEC of the lung except for 1 cycle of standard platinum/etoposide regimen as first-line treatment prior to entering the treatment period of the trial; patients with localized NEC or resectable disease who received prior adjuvant therapy can participate in the trial if they experienced a treatment-free interval of >6 months prior to the diagnosis of metastatic disease; and patients must have at least 1 measurable lesion as defined per RECIST v1.1. Patients must be adequate candidates to receive platinum/etoposide as the SOC treatment. Primary endpoints: occurrence of dose-limiting toxicities (DLTs) in the MTD evaluation (Part A) and on-treatment (Part B) periods. Secondary endpoints: occurrence of DLTs and adverse events during the on-treatment period (Part B), and efficacy measured by objective response and duration of response (Part B). Enrollment is ongoing. Citation Format: Jaume Capdevila, Timon Vandamme, Patricia Niccoli, Saori Mishima, Ken Kato, Yiyuan Ma, Ping Sun, Lijiang Geng, Ulrich M. Lauer. DAREON™-7: A phase 1, open-label, dose escalation and expansion cohort trial of the delta-like ligand (DLL3)-targeting T-cell engager BI 764532, plus first-line platinum-based chemotherapy in patients with DLL3-positive (+) neuroendocrine carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT090.