Sotorasib (960 mg or 240 mg) once daily in patients with previously treated KRAS G12C-mutated advanced NSCLC

Background: Sotorasib 960 mg once daily is approved to treat KRAS G12C-mutated locally advanced or metastatic non-small cell lung cancer (NSCLC). Sotorasib exhibits non-dose proportional pharmacokinetics and clinical responses at lower doses; therefore, we evaluated the efficacy and safety of sotorasib 960 mg and 240 mg. Methods: In this phase 2, randomized, open-label study, adults with KRAS G12C-mutated advanced NSCLC received sotorasib 960 mg or 240 mg once daily. Primary endpoints were objective response rate (ORR) and safety. Secondary endpoints included disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and pharmacokinetics. The study was not powered for formal statistical hypothesis testing. Results: In the 960 mg group (n = 104), ORR was 32.7 % and DCR was 86.5 %. In the 240 mg group (n = 105), ORR was 24.8 % and DCR was 81.9 %. Median PFS was 5.4 months (960 mg) and 5.6 months (240 mg). At a median follow-up of 17.5 months, median OS was 13.0 months (960 mg) and 11.7 months (240 mg). AUC_{0–24 h} and C_max were 1.3-fold numerically higher with the 960 mg dose. Treatment-emergent adverse events (TEAEs, ≥10 %) for 960 mg and 240 mg doses, respectively, were diarrhea (39.4 %; 31.7 %), nausea (23.1 %; 19.2 %), increased alanine aminotransaminase (14.4 %; 17.3 %), and increased aspartate aminotransferase (13.5 %; 13.5 %). Conclusions: Patients treated with sotorasib 960 mg once daily had numerically higher ORR and DCR, and longer DOR and OS, than patients treated with 240 mg in this descriptive analysis. TEAEs were manageable with label-directed dose modifications.