Abstract CT033: KontRASt-01: A phase Ib/II, dose-escalation study of JDQ443 in patients (pts) with advanced, KRAS G12C-mutated solid tumors

Background: KRAS G12C oncogenic mutations occur in ~13% of non-small cell lung cancers (NSCLCs) and up to 4% of other solid tumors. JDQ443 is a selective, covalent, orally bioavailable, investigational KRASG12C inhibitor that irreversibly traps KRASG12C in the inactive, GDP-bound state. JDQ443 is structurally unique and forms novel interactions with KRAS in the switch II pocket. Methods: KontRASt-01 (NCT04699188) is a Phase Ib/II, open-label, multicenter, dose-escalation and dose-expansion trial of JDQ443 as monotherapy or in combination with TNO155 (SHP2 inhibitor) and/or tislelizumab (anti-PD-1 monoclonal antibody). Primary objectives of dose escalation are to assess safety and tolerability, and identify the maximum tolerated doses (MTDs) and/or recommended doses (RDs) and regimens for future studies. The primary objective of dose expansion is to assess efficacy. Key inclusion criteria: advanced, KRAS G12C-mutated solid tumors; previous standard-of-care treatment; age ≥18 yrs; ECOG PS 0-1. Key exclusion criteria for the JDQ443 monotherapy arm: active brain metastases, prior KRASG12C inhibitor treatment. Here, we present preliminary results for JDQ443 monotherapy dose escalation. Results: As of Nov 3, 2021, 39 pts were treated with JDQ443 PO continuously across 4 dose levels: 200 mg once daily (QD) (n=10), 400 mg QD (n=11), 200 mg twice daily (BID) (n=11), and 300 mg BID (n=7). Median age was 60 yrs (range 26-76), median prior lines of therapy was 3 (range 1-7), and indications included NSCLC (n=20) and colorectal cancer (CRC) (n=16). Median duration of exposure was 9.1 wks (range 0.9-21), with ongoing treatment in most pts (61.5%) at the time of cut-off. Treatment-related adverse events (TRAEs) occurred in 25 (64.1%) pts. Most TRAEs were Grade (Gr) 1-2. Four Gr 3 TRAEs occurred in 4 (10.3%) separate pts; there were no Gr 4-5 TRAEs. The most common TRAEs (occurring in ≥10% of pts) were fatigue (25.6%), nausea (15.4%), edema (12.8%), pruritus (10.3%), and vomiting (10.3%). There was one DLT (Gr 3 fatigue) and one treatment-related serious AE (Gr 3 photosensitivity reaction), each in separate pts treated at 300 mg BID. TRAEs led to dose reduction in 1 pt and discontinuation in 1 pt. A MTD was not reached. The RD was declared as 200 mg BID. At the RD, PK and PD modeling for JDQ443 predicted average KRASG12C target occupancy of >90% in >82% of pts. Using an efficacy cut-off date of Dec 13, 2021, for the 20 pts with NSCLC among the same 39 pts, the ORR (confirmed complete response or partial response) by RECIST 1.1 was 30.0% (6/20) across dose levels and 43.0% (3/7) at the RD. Additional data will be available at the time of presentation. Conclusions: JDQ443 demonstrates an acceptable safety and tolerability profile, with early signs of clinical activity in pts with NSCLC. Enrollment is ongoing to NSCLC and CRC dose-expansion groups for JDQ443 monotherapy at the RD, and to JDQ443 + TNO155 dose escalation. Citation Format: Daniel S. Tan, Toshio Shimizu, Benjamin Solomon, Rebecca S. Heist, Martin Schuler, Maria J. De Miguel Luken, Anas Gazzah, Martin Wermke, Christophe Dooms, Herbert H. Loong, Neeltje Steeghs, Enriqueta Felip, Conor E. Steuer, Eric van Cutsem, Ross A. Soo, Ashley C. Jaeger, Jaeyeon Kim, Kun Xu, Xueying Chen, Xiaoming Cui, Heather Burks, Anna Farago, Philippe A. Cassier. KontRASt-01: A phase Ib/II, dose-escalation study of JDQ443 in patients (pts) with advanced, KRAS G12C-mutated solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT033.