Atezolizumab Improves Response Among Certain Patients With NSCLC

The BIRCH study assessed the efficacy of atezolizumab, a humanized anti-programmed death-ligand 1 (PD-L1) monoclonal antibody, across different lines of therapy and found it was effective at improving the objective response rate and overall survival among patients with advanced non-small-cell lung cancer (NSCLC).

In the study, researchers enrolled participants with advanced-stage NSCLC with PD-L1 tumors and no central nervous system metastases. Patients were divided into 3 cohorts based on the line of therapy they were on when they received atezolizumab. A total of 139 received atezolizumab as first line therapy, 286 received atezolizumab as second line therapy, and 252 received atezolizumab as third line therapy or higher. Atezolizumab was administered intravensouly every 3 weeks at a dose of 1200 mg. Objective response rate (ORR) was assessed as the primary endpoint, and median duration of response, progression-free survival, and overall survival (OS) were assessed as the secondary endpoints.
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Overall, the BIRCH trial met its primary objective by demonstrating that atezolizumab had a significant ORR compared with historical controls. All 3 cohorts had an ORR of 18% to 22% after a minimum of 12 months of follow-up. Patients identified with PD-L1 expressing tumor cells (TC) 3 and expressing tumor-infiltrating immune cells (IC) 3 had an ORR of 26% to 31%. Responses occurred regardless of EGFR or KRAS mutation status.

For patients who received atezolizumab as first line therapy, the median OS from an updated analysis with a minimum of 20 months of follow-up was 23.5 months and 26.9 months for patients with TC3 or IC3. The median OS for patients who received atezolizumab as second line therapy was 15.5 months and the median OS for patients who received atezolizumab as third line therapy was 13.2 months.

In addition, the safety profile of atezolizumab was similar across all cohorts and consistent with previous studies assessing atezolizumab as a monotherapy.

“BIRCH demonstrated responses with atezolizumab monotherapy in patients with PD-L1–selected advanced NSCLC, with good tolerability,” the researchers concluded. “PD-L1 status may serve as a predictive biomarker for identifying patients most likely to benefit from atezolizumab.”

—Melissa Weiss

Reference:

Peters S, Gettinger S, Johnson ML, et al. Phase II trial of atezolizumab as first-line or subsequent therapy for patients with programmed death-ligand 1-selected advanced non-small-cell lung cancer (BIRCH) [published online before print June 13, 2017]. J Clin Oncol. doi:10.1200/JCO.2016.71.9476.