A phase Ia/Ib, dose-escalation/expansion study of BI 907828 in combination with BI 754091 and BI 754111 in patients (pts) with advanced solid tumors.

Abstract

TPS3660 Background: Preclinical data show that the combination of a murine double minute 2–tumor protein 53 (MDM2–TP53) antagonist with anti-PD-1 and anti-LAG3 antibodies produces an anti-tumor effect in multiple tumor types. This Phase Ia/Ib study aims to determine the safety, recommended dose for expansion (RDE), and preliminary efficacy of BI 907828, a MDM2–TP53 antagonist, with BI 754091, an anti-PD-1 antibody, and BI 754111, an anti-LAG-3 antibody, in a variety of TP53 wild-type cancers. Methods: In Phase Ia (dose escalation), ~30 pts with a confirmed diagnosis of any unresectable, advanced/metastatic solid tumor, irrespective of TP53 mutation status, will be enrolled. Pts will receive one dose of BI 907828 every 21 days (Q3W), at a starting dose of 10 mg orally, plus BI 754091 and BI 754111 (240 mg and 600 mg, respectively, Q3W, intravenously). Dose escalation will be guided by a Bayesian Logistic Regression Model with overdose control. The primary endpoint is the maximum-tolerated dose of BI 907828 based on dose-limiting toxicities (DLTs) during the first treatment cycle. Secondary endpoints include pharmacokinetics and DLTs in the treatment period (to determine the RDE). In Phase Ib (dose expansion), pts with previously treated, unresectable, advanced/metastatic TP53 wild-type tumors with ≥1 measurable target lesion will be enrolled into four expansion cohorts (1: NSCLC; 2: melanoma; 3: well-differentiated/dedifferentiated liposarcoma or undifferentiated pleomorphic sarcoma; 4: hepatocellular carcinoma). The RDE of BI 907828 will be administered with fixed doses of BI754091 and BI 754111 (Q3W). In the NSCLC cohort only, pts will be randomized to one of three arms: RDE of BI 907828 + 240 mg BI 754091 + 600 mg BI 754111 (arm A, 32 pts); 240 mg BI 754091 + 600 mg BI 754111 (arm B, 32 pts); RDE of BI 907828 + 240 mg BI 754091 (arm C, 16 pts). The primary endpoint is objective response (OR, per RECIST 1.1). Secondary endpoints include OR (per iRECIST), disease control (per RECIST 1.1 and iRECIST), progression-free survival (PFS), PFS rate at 12 and 24 weeks (cohort 3), and safety. Phase Ib will include at least 140 evaluable pts (80 pts in cohort 1 and 20 pts each in cohorts 2–4). Clinical trial information: NCT03964233 .