Durvalumab in Unresectable NSCLC: Are Outcomes Affected by PD-L1 Expression?
Posted: Wednesday, May 6, 2020
The monoclonal antibody durvalumab appears to improve progression-free survival regardless of tumor PD-L1 expression in patients with unresectable stage III non–small cell lung cancer (NSCLC), according to exploratory analyses of the PACIFIC trial published in Annals of Oncology. Additionally, durvalumab significantly improved overall survival and the time to death or distant metastasis compared with placebo in most subgroups.
“Although PACIFIC was not designed to evaluate durvalumab based on archival tumor PD-L1 expression, the results of these exploratory analyses support treatment benefit with durvalumab versus placebo irrespective of archival, prespecified tumor PD-L1 expression status,” stated Luis G. Paz-Ares, MD, PhD, of the Hospital Universitario 12 de Octubre, Madrid, and colleagues.
The double-blind phase III trial enrolled 713 patients who were randomly assigned 2:1 to durvalumab at 10 mg/kg intravenously every 2 weeks or placebo. The exploratory analyses included 451 study patients with known PD-L1 status; 35% had at least 25% PD-L1 expression, 32% had 1% to 24% PD-L1 expression, and 33% had less than 1% PD-L1 expression.
Durvalumab improved progression-free survival compared with placebo across all exploratory subgroups: ≥ 25% PD-L1 expression (17.8 vs. 3.7 months), < 25% expression (16.9 vs. 6.9 months), ≥ 1% expression (17.8 vs. 5.6 months), and < 1% expression (10.7 vs. 5.6 months). Overall survival was also improved in most subgroups—but not in the subgroup with less than 1% PD-L1 expression (33.1 vs. 45.6 months). The safety profile of durvalumab across PD-L1 subgroups was consistent with previous studies.
“Prospectively planned studies to assess outcomes with immunotherapies in patients with different levels of tumor PD-L1 expression are warranted, since the PACIFIC trial was not designed to do so,” concluded the authors.
Disclosure: For full disclosures of the study authors, visit sciencedirect.com.