ASCO 2021 | Overall survival in the Phase II CodeBreaK 100 trial in NSCLC

The Phase II CodeBreak 100 trial is evaluating sotorasib in about 126 patients with KRAS G12C mutant lung adenocarcinoma. These are patients who have failed multiple prior lines of treatment, have had previous chemotherapy and immunotherapy. And this is an open label, multicenter study enrolling patients with KRAS G12C positive lung adenocarcinoma. The primary endpoint for the study was centrally assessed objective response rate and after 126 patients in all the across 11 countries, 120 patients had centrally valuable lesions by resist at baseline. The confirmed objective response rate in the trial was 77.1% with four patients out of the 120 achieving a complete response. And 42 patients achieved confirmed partial response with a greater than 30% tumor reduction. This is consistent with previously reported study of sotorasib in a phase one study at 960 milligram daily dosing. So the duration of response was 11.1 months and 80% of the patients achieved disease control with sotorasib.

The median PFS was 6.8 months and median overall survival was 12.5 months. In addition, the safety and tolerability of sotorasib at the 960 mg daily dosing was consistent with previously reported study from a phase one study for sotorasib at that dose. The most common treatment related adverse event were all grade one, two fatigue, nausea, diarrhea, and increase in liver enzymes. About 5% of the patients treated with sotorasib had grade three transaminitis. 20% of patients required dose reduction of sotorasib. And there were no life threatening side effects noted with sotorasib in the trial and there were no treatment related deaths observed in the trial.