Positive results have been announced from the ongoing phase 3 PACIFIC trial, a randomized, double-blind, placebo-controlled evaluation of durvalumab (Imfinzi, AstraZeneca/MedImmune) as sequential treatment in patients with locally advanced, unresectable (stage III) non–small-cell lung cancer (NSCLC) who had not progressed after standard platinum-based chemotherapy administered concurrently with radiation therapy.
A planned interim analysis conducted by an independent data monitoring committee concluded that the study has already met a primary endpoint by showing statistically significant and clinically meaningful progression-free survival in patients treated with durvalumab compared with those given placebo. The ongoing trial will also evaluate overall survival, a coprimary endpoint.
Durvalumab, a human monoclonal antibody directed against programmed death ligand 1 (PD-L1), blocks PD-L1 interaction with programmed death 1 (PD-1) and CD80 proteins on T cells, countering the tumor’s immune-evading tactics and inducing an immune response.
Durvalumab is also being studied as monotherapy in the first-line treatment of patients with NSCLC in the MYSTIC and PEARL trials. In addition, it is being developed in combination with tremelimumab, a checkpoint inhibitor that targets CTLA-4, as part of the MYSTIC, NEPTUNE, and POSEIDON studies.
Durvalumab recently received accelerated approval from the FDA for use in previously treated patients with advanced bladder cancer.
Source: AstraZeneca; May 12, 2017.