Introduction: The programmed death-ligand 1 inhibitor atezolizumab improves progression-free survival (PFS) and overall survival (OS) for patients with previously treated advanced NSCLC. Preclinical studies indicate that targeting CD38-positive cells with daratumumab may synergistically enhance atezolizumab's antitumor activity by increasing the effector T-cell activity.
Methods: This phase 1b-2 study included a safety run-in (one cycle of daratumumab plus atezolizumab) and randomized phases (daratumumab plus atezolizumab versus atezolizumab alone). The primary objective of the randomized phase was to compare overall response rates. The secondary objectives included evaluations of safety, clinical benefit rate (stable disease or better), PFS, OS, and pharmacokinetics.
Results: In total, 99 patients were enrolled (safety run-in, n = 7; randomized, n = 46 per arm). In the randomized phase, the overall response rate was 4.3% for daratumumab plus atezolizumab and 13.0% for atezolizumab alone (OR: 0.30; 95% confidence interval: 0.03-1.92). The respective clinical benefit rates were 52.2% and 43.5%. No improvements were observed in the median PFS or median OS for combination therapy. The study was terminated because of the limited efficacy of daratumumab plus atezolizumab.
Conclusions: Daratumumab plus atezolizumab therapy did not improve efficacy versus atezolizumab monotherapy for patients with previously treated advanced NSCLC.
Keywords: Atezolizumab; Combination immunotherapy; Daratumumab; Non‒small cell lung cancer.
© 2020 The Authors.