Adagrasib in KRYSTAL-12 has Not Broken the KRAS G12C Enigma Code of the Unspoken 6-Month PFS Barrier in NSCLC

Abstract

Mutations in KRAS G12C are among the more common oncogenic driver mutations in non-small cell lung cancer (NSCLC). In December 2022, the US Food and Drug Administration (FDA) granted accelerated approval to adagrasib, a small molecule covalent inhibitor of KRAS G12C, for the treatment of patients with locally advanced or metastatic KRAS G12C mutant NSCLC who received at least one prior systemic therapy based on promising results from phase 1 and 2 trials wherein adagrasib demonstrated a median PFS of 6.5 months. Results from the phase 3 KRYSTAL-12 trial were recently presented, showing benefit with adagrasib compared to docetaxel, with participants in the adagrasib group demonstrating a PFS of 5.5 months compared to 3.8 months in the docetaxel group. However, these results fall short of the 6-month PFS benchmark that had seemed achievable from what had been seen in phase 1 and 2 trials, mirroring similarly disappointing results from the CodeBreaK 200 trial wherein sotorasib, the first-in-class KRAS G12C inhibitor, also failed to meet the 6-month benchmark also thought to be possible when examining earlier trials. These results raise the question of adagrasib's true value in the second-line treatment setting and compel us to explore more potent novel therapies, combination therapies, and more as we seek to break the 6-month PFS barrier in the treatment of KRAS G12C mutant NSCLC.

Keywords: Kirsten rat sarcoma viral oncogene homolog gene; docetaxel; sotorasib.