• Three-year overall survival update from the PACIFIC trial

      de Wit, M.; Gray, J. E.; Villegas, A.; Daniel, D.; Vicente, D.; Murakami, S.; Hui, R.; Kurata, T.; Chiappori, A.; Lee, K. H.; et al. (2019)
      Background: In the PACIFIC study of patients with unresectable, St. III NSCLC without progression after chemoradiotherapy (CRT), durvalumab demonstrated significant improvements versus placebo in the primary endpoints of progression-free survival (HR, 0.52; 95% CI, 0.42-65; P< 0.0001) and overall survival (HR, 0.68; 95% CI, 0.53-0.87; P=0.00251). Safety was similar and durvalumab had no detrimental effect on patient- reported outcomes. Here, we report 3-year OS rates for all patients randomized in the PACIFIC study. Methods: Patients with WHO PS 0/1 who received ?2 cycles of platinum- based CRT were randomized (2:1), 1-42 days following CRT, to receive durvalumab 10 mg/kg i.v. every 2 weeks or placebo, up to 12 months, and stratified by age, sex, and smoking history. OS was analyzed using a stratified log-rank test in the ITT population. Medians and OS rates at 12, 24 and 36 months were estimated by Kaplan-Meier method. Results: In total, 713 patients were randomized of whom 709 received treatment (durvalumab, n=473; placebo, n=236). The last patient had completed the protocol-defined 12 months of study treatment in May 2017. As of Jan 31, 2019 (data cutoff), 48.2% of patients had died (44.1% and 56.5% in the durvalumab and placebo groups, respectively). The median duration of follow-up was 33.3 months (range, 0.2-51.3). Updated OS remained consistent with that previously reported (stratified HR 0.69, 95% CI, 0.55-0.86), with the median not reached (NR; 95% CI, 38.4 months-NR) with durvalumab versus 29.1 months (95% CI, 22.1-35.1) with placebo. The 12-, 24- and 36-month OS rates with durvalumab and placebo were 83.1% versus 74.6%, 66.3% versus 55.3%, and 57.0% versus 43.5%, respectively. After discontinuation, 43.3% and 57.8% in the durvalumab and placebo groups, respectively, received subsequent anticancer therapy (9.7% and 26.6% subsequently received immunotherapy). OS subgroup results will be presented. Conclusions: Updated OS data from PACIFIC, including 3-year survival rates (ITT & PD-L1 ?1% subgroup), underscore the long-term clinical benefit with durvalumab following CRT and further establish the PACIFIC regimen as the standard of care in this population.