KRYSTAL-1: Activity and preliminary pharmacodynamic (PD) analysis of adagrasib (MRTX849) in patients (Pts) with advanced non-small cell lung cancer (NSCLC) harboring KRASG12C mutation
Riely GJ, Ou SHI, Rybkin I, Spira A, Papadopoulos K, Sabari JK, Johnson M, Heist RS, Bazhenova L, Barve M, Pacheco JM, Velastegui K, Cilliers C, Olson P, Christensen JG, Kheoh T, Chao RC, and Janne PA. KRYSTAL-1: Activity and preliminary pharmacodynamic (PD) analysis of adagrasib (MRTX849) in patients (Pts) with advanced non-small cell lung cancer (NSCLC) harboring KRASG12C mutation. J Thorac Oncol 2021; 16(4):S751-S752.
J Thorac Oncol
Background: KRAS, the most frequently mutated oncogene in cancer, is a key mediator of the RAS/MAPK signaling cascade that promotes cellular growth and proliferation. KRASG12C mutations occur in approximately 14% of NSCLC (adenocarcinoma). Adagrasib, an investigational agent, is a potent, covalent inhibitor of KRASG12C that irreversibly and selectively binds to KRASG12C, locking it in its inactive state and was optimized for favorable PK properties, including oral bioavailability, long half-life (∼24 h), and extensive tissue distribution.
Methods: KRYSTAL-1 (NCT03785249) is a multi-cohort phase I/II study evaluating adagrasib in pts with advanced or metastatic solid tumors, including NSCLC, harboring a KRASG12C mutation previously treated with chemotherapy and an anti-PD-(L)1. Exploratory endpoints include correlative analysis of co-occurring genetic alterations in tumor tissue at baseline and evaluation of the modulation of PD markers, including transcriptomics, in pretreatment and on-study biopsies.
Results: As of 30 August 2020, 79 pts with pretreated NSCLC were treated with adagrasib 600 mg BID (phase I/Ib and phase II). Most commonly reported (>20%) TRAEs included: nausea (54%), diarrhea (48%), vomiting (34%), fatigue (28%), and increased ALT (23%). Among the 51 pts evaluable for clinical activity, 45% (23/51) had a partial response (PR) and 26 pts had stable disease (SD). In a subpopulation of pts with STK11-comutations, ORR was 64% (9/14). Preliminary PD and mechanistic biomarker analyses on pre- and posttreatment tumor NSCLC biopsies (n = 3) demonstrate own regulation of KRAS/MAPK pathway genes including DUSP6 and SPRY4. In pts with tumors harboring STK11-comutations, there was minimal expression of immune transcripts (eg, CD4 and CD8) at baseline and these transcripts were increased after treatment with adagrasib suggesting a potential immune response to therapy.
Conclusions: Adagrasib is tolerable and has demonstrated clinical activity in pts with previously treated KRASG12C-mutant NSCLC. Additional PD and mechanistic data will be presented.