Durvalumab Post Concurrent Chemoradiotherapy in Japanese Patients With Limited‐Stage Small‐Cell Lung Cancer in the Phase 3 ADRIATIC Trial

ABSTRACT At the first interim analysis of the global, randomized, phase 3, double‐blind ADRIATIC trial in patients with limited‐stage small‐cell lung cancer (LS‐SCLC) not progressing after concurrent chemoradiotherapy (cCRT), consolidation durvalumab significantly improved overall survival (OS; hazard ratio HR 0.73) and progression‐free survival (PFS) by blinded independent central review (BICR; HR 0.76) versus placebo (dual primary endpoints). We report an exploratory analysis in patients enrolled in Japan. Patients received durvalumab 1500 mg ( N = 264), durvalumab+tremelimumab 75 mg (4 doses, N = 200; arm remained blinded), or placebo ( N = 266) every 4 weeks for ≤ 24 months. Prior cCRT ± prophylactic cranial irradiation (PCI) was per local standards of care. In the Japan subgroup, 19 and 31 patients received durvalumab and placebo, respectively; prior cCRT comprised cisplatin‐etoposide/carboplatin‐etoposide in 94.7/5.3% and 87.1/12.9% and once‐daily/twice‐daily radiotherapy in 10.5/89.5% and 0/100%; 52.6% and 58.1% received PCI. Median OS was not reached versus 44.9 months (3‐year OS 67.4% versus 58.1%; HR 0.67, 95% CI 0.24–1.62). Median PFS by BICR was 44.2 versus 29.4 months (24‐month PFS 59.6% vs. 58.6%; HR 1.05, 95% CI 0.44–2.36); median PFS by investigator assessment (sensitivity analysis) was 44.2 versus 19.7 months (24‐month PFS 65.6% vs. 47.0%; HR 0.68, 95% CI 0.28–1.51). With durvalumab and placebo, 21.1% and 19.4% had maximum grade 3–4 adverse events (AEs), 21.1% and 9.7% had AEs leading to treatment discontinuation, and 52.6% and 45.2% had pneumonitis/radiation pneumonitis (grade 3–4: 0% and 6.5%). In conclusion, consolidation durvalumab demonstrated a favorable risk/benefit profile in Japanese patients with LS‐SCLC post cCRT. Trial Registration: ClinicalTrials.gov identifier: NCT03703297.