Kim DW, Gadgeel S, Gettinger SN, Riely GJ, Oxnard GR, Mekhail T, Schmid P, Dowlati A, Heist RS, Wozniak AJ, Singh J, Cha E, Spahn J, and Ou SI. Brief Report: Safety and Antitumor Activity of Alectinib Plus Atezolizumab From a Phase 1b Study in Advanced ALK-Positive NSCLC. JTO Clin Res Rep 2022; 3(8):100367.
JTO Clin Res Rep
INTRODUCTION: Alectinib is a preferred first-line treatment option for advanced ALK-positive NSCLC. Combination regimens of alectinib with immune checkpoint inhibitors are being evaluated for synergistic effects.
METHODS: Adults with treatment-naive, stage IIIB/IV, or recurrent ALK-positive NSCLC were enrolled into a two-stage phase 1b study. Patients received alectinib 600 mg (twice daily during cycle 1 and throughout each 21-d cycle thereafter) plus atezolizumab 1200 mg (d8 of cycle 1 and then d1 of each 21-d cycle). Primary objectives were to evaluate safety and tolerability of alectinib plus atezolizumab. Secondary objectives included assessments of antitumor activity.
RESULTS: In total, 21 patients received more than or equal to 1 dose of alectinib or atezolizumab. As no dose-limiting toxicities were observed in stage 1 (n = 7), the starting dose and schedule were continued into stage 2 (n = 14). Median duration of follow-up was 29 months (range: 1-39). Grade 3 treatment-related adverse events occurred in 57% of the patients, most often rash (19%). No grade 4 or 5 treatment-related adverse events were reported. Confirmed objective response rate was 86% (18 of 21; 95% confidence interval [CI]: 64-97). Median progression-free survival was not estimable (NE) (95% CI: 13 mo-NE), neither was median overall survival (95% CI: 33 mo-NE).
CONCLUSIONS: The combination of alectinib and atezolizumab is feasible, but increased toxicity was found compared with the individual agents. With small sample sizes and relatively short follow-up, definitive conclusions regarding antitumor activity cannot be made.