Atezolizumab significantly improved overall survival compared with docetaxel and was well tolerated in patients with previously treated non-small cell lung cancer (NSCLC), a study published in the journal The Lancet has shown.1
For the international, open-label, phase 2 study, researchers enrolled 144 patients with NSCLC who progressed on postplatinum chemotherapy. Patients were randomly assigned 1:1 to receive atezolizumab 1200 mg IV or docetaxel 75 mg/m2 IV once every 3 weeks. In addition to evaluating the safety and efficacy of this immunotherapeutic agent, researchers sought to analyze whether baseline PD-L1 expression of tumor cells and tumor-infiltrating immune cells is a prognostic marker.
Results showed that median overall survival was 12.6 months (95% CI: 9.7-16.4) with atezolizumab compared with 9.7 months (95% CI: 8.6-12.0) with docetaxel (HR, 0.73; 95% CI: 0.53-0.99; P=.04).
Further, researchers found that improvement in survival correlated with PD-L1 immunohistochemistry expression on tumor cells and tumor-infiltrating immune cells. This suggests that PD-L1 expression is predictive for atezolizumab benefit.
The study also demonstrated that patients with preexisting immunity, defined by high T-effector–interferon-γ-associated gene expression, had improved overall survival with atezolizumab.
In terms of safety, 8% of patients receiving atezolizumab discontinued treatment due to adverse events compared with 22% of patients in the docetaxel arm. Eleven percent and 39% of patients in the atezolizumab and docetaxel groups, respectively, experienced treatment-related grade 3 to 4 adverse events.
Of note, 1 patient in the atezolizumab group and 3 in the docetaxel group died as a result of a treatment-related adverse event.
1. Fehrenbacher L, Spira A, Ballinger M, et al. Atezolizumab versus docetaxel for patients with previously treated non-small-cell lung cancer (POPLAR): a multicentre, open-label, phase 2 randomised controlled trial [published online ahead of print March 9, 2016]. Lancet. doi:10.1016/S0140-6736(16)00587-0.