The FDA granted priority review to a supplemental biologics license application that seeks approval of durvalumab for previously untreated extensive-stage small cell lung cancer.
Durvalumab (Imfinzi, AstraZeneca) is a human monoclonal antibody that binds to PD-L1. It is approved in the United States for treatment of patients with unresectable stage III non-small cell lung cancer, as well as for previously treated patients with advanced bladder cancer.
The FDA based the new priority review designation on results of the randomized phase 3 CASPIAN trial, which included 805 patients with treatment-naive extensive-stage small cell lung cancer. All patients had WHO performance status of 0 to 1, and those who had asymptomatic or treated and stable brain metastases were eligible.
Researchers assigned patients 1:1:1 to one of three treatment arms: 1,500 mg durvalumab plus chemotherapy for up to four cycles followed by 1,500 mg durvalumab every 4 weeks until disease progression; chemotherapy every 3 weeks for up to six cycles followed by optional prophylactic cranial irradiation; or 1,500 mg durvalumab plus 75 mg tremelimumab (CP-675, AstraZeneca) with chemotherapy every 3 weeks for up to four cycles followed by 1,500 mg durvalumab every 4 weeks until disease progression. Chemotherapy in each arm consisted of 80 mg/m2 to 100 mg/m2 etoposide with either carboplatin area under the curve 5 to 6 or 75 mg/m2 to 80 mg/m2 cisplatin.
OS served as the study’s primary endpoint. Secondary endpoints included PFS, objective response rate, safety and tolerability, and health-related quality of life.
As HemOnc Today previously reported, results showed durvalumab in combination with standard chemotherapy conferred a statistically significant OS benefit (median, 13 months vs. 10.3 months; HR = 0.73; 95% CI, 0.59-0.9). More patients assigned durvalumab survived 1 year (53.7% vs. 39.8%) and 18 months (33.9% vs. 24.7%).