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

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.