Non-pneumonitis immune-mediated adverse events (imAEs) with durvalumab in patients with unresectable stage III NSCLC (PACIFIC)

Abstract

Background: The phase 3 PACIFIC trial established durvalumab (durva) after chemoradiotherapy (CRT) as SoC for pts with unresectable stage III NSCLC. We report exploratory analyses to characterize non-pneumonitis (np) imAEs that occurred with durva in PACIFIC. Methods: PACIFIC was a double blind trial of pts without disease progression after platinum-based concurrent CRT (?2 cycles). Pts were randomized 2:1 to receive durva 10 mg/kg or placebo (pbo) IV q2w for ?12 months, stratified by age, sex and smoking history. We characterized the time to onset, duration, and management/outcomes of np imAEs and their association with (1) baseline pt/disease factors and (2) AEs (excluding all-cause pneumonitis). Results: Of 709 treated pts, 19% and 11% experienced imAEs and np imAEs of any grade, respectively; proportionally more had np imAEs with durva (71/475; 15%) vs pbo (5/234; 2%). Thyroid disorders (54/475; 11%), rash/dermatitis (9/475; 2%), and diarrhea/colitis (5/475; 1%) were the most common np imAEs with durva; rash/dermatitis had the shortest time to onset (Table). Among durva treated pts with np imAEs, 11% had grade 3/4 np imAEs, 41% had np imAEs that resolved, and none had fatal np imAEs; interventions included endocrine replacement therapy (73%), systemic corticosteroids (34%), high dose corticosteroids (16%), and discontinuation (10%). There were no apparent differences in baseline factors between pts with or without np imAEs. Durva had a broadly manageable safety profile irrespective of the occurrence of np imAEs. However, a higher proportion of durva treated pts with vs without np imAEs experienced all-cause, grade 3/4 events (41% vs 29%); none were fatal (excl. pneumonitis). Conclusions: Np imAEs occurred infrequently in PACIFIC, but were more common with durva vs pbo; thyroid disorders and rash/dermatitis were the most common np imAEs. Of durva treated pts with np imAEs, 11% experienced np imAEs of grade 3/4. Overall, np imAEs were broadly manageable and did not lead to high rates of discontinuation, and no association with baseline factors was seen, suggesting this should not deter use of durva in eligible pts.