Abstract CT008: Long-term outcomes with sotorasib in pretreated KRASp.G12C-mutated NSCLC: 2-year analysis of CodeBreaK100

Introduction: Sotorasib, a first-in-class KRASG12C inhibitor, has been FDA-approved for adults with KRAS p.G12C-mutated locally advanced or metastatic NSCLC who received prior systemic therapies based on the Phase 1/2 global, single-arm CodeBreaK100 trial. We will report the longest follow-up for a KRASG12C inhibitor, including 2-year survival, safety, and genomic profiles associated with durable clinical benefit. Methods: Sotorasib was administered orally at 960 mg once daily to patients who progressed on prior therapies and had KRAS p.G12C-mutated locally advanced, metastatic NSCLC. Primary endpoint was objective response rate (ORR) assessed by central review. Key secondary endpoints included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. In an exploratory analysis, baseline tumor tissue and/or plasma samples were collected and analyzed for genomic alterations. Tumor samples were analyzed for PD-L1 levels to evaluate correlates with prolonged tumor response, defined as patients with PFS ≥ 12 months, in comparison with those with PFS ≤ 3 months. Results: In the first analysis of the combined Phase 1 and Phase 2 study (N=174), the median number of prior lines of therapy was 2.0 (range 1-4+). 90.2% received prior anti-PD1 or anti PD-L1 treatment; 82.8% received both prior platinum-based chemotherapy and anti-PD1/PD-L1. Updated ORR by central review was 40.7% (95% CI: 33.2, 48.4) and median DOR was 12.3 months (7.1, 14.6). Median PFS and OS was 6.3 months (95% CI: 5.3, 8.2) and 12.5 months (10.0, 17.8). One and two-year OS was 50.8% and 30.3%. Sotorasib was well-tolerated in the long-term with mild and manageable toxicities, and no new safety signals emerged. Prolonged tumor response was observed across PD-L1 expression, including in tumors with low PDL-1 expression and STK11 co-mutation that may derive less benefit from immunotherapy. Conclusions: In the longest follow-up of any KRASG12C inhibitor, sotorasib continued to demonstrate a favorable safety profile and durable efficacy, including a 2-year OS observed in 30% of patients. Current analyses continue to support long-term clinical benefit across subgroups in patients with KRAS p.G12C-mutated NSCLC, and additional biomarker data will be presented. Citation Format: Grace K. Dy, Ramaswamy Govindan, Vamsidhar Velcheti, Gerald S. Falchook, Antoine Italiano, Juergen Wolf, Adrian G. Sacher, Toshiaki Takahashi, Suresh S. Ramalingam, Christophe Dooms, Dong-Wan Kim, Alfredo Addeo, Jayesh Desai, Martin Schuler, Pascale Tomasini, Qui Tran, Simon Jones, Agnes Ang, Abraham Anderson, Antreas A. Hindoyan, David S. Hong, Bob T. Li. Long-term outcomes with sotorasib in pretreated KRASp.G12C-mutated NSCLC: 2-year analysis of CodeBreaK100 [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 CT008.