Durvalumab Plus Platinum-Etoposide in Extensive-Stage Small-Cell Lung Cancer: Outcomes in Age, Sex, and Platinum Subgroups From the Phase 3 CASPIAN Study

Abstract

Introduction: In the phase 3 CASPIAN study, first-line durvalumab plus etoposide combined with either carboplatin or cisplatin (EP) significantly improved overall survival (OS) versus EP alone in treatment-naïve extensive-stage small-cell lung cancer (ES-SCLC). We report exploratory subgroup analyses from CASPIAN.

Methods: Patients with untreated ES-SCLC were randomized to durvalumab plus EP or EP alone. We analyzed OS and safety in subgroups defined by age, sex, and planned platinum agent, and patient-reported outcomes (PROs) by age.

Results: Of 537 patients (durvalumab plus EP: n = 268; EP alone: n = 269), 80.6% versus 19.4% were aged <70 versus ≥70 years; 69.6% versus 30.4% were male versus female; and planned platinum was cisplatin versus carboplatin in 25.1% versus 74.9%. The OS HRs for durvalumab plus EP versus EP were 0.71 (95% CI, 0.58-0.88) versus 0.74 (95% CI, 0.49-1.11) for patients aged <70 versus ≥70 years; 0.76 (95% CI, 0.62-0.95) versus 0.60 (95% CI, 0.42-0.84) for males versus females; and 0.65 (95% CI, 0.45-0.94) versus 0.74 (95% CI, 0.60-0.91) for planned cisplatin versus carboplatin. With durvalumab plus EP, rates of grade 3/4 adverse events (AEs) were similar across subgroups; serious AEs were more frequent in patients aged ≥70 versus <70 years; and immune-mediated AEs were more common in females versus males. Adding durvalumab to EP had no detrimental effect on PROs in either age subgroup.

Conclusions: These findings support the use of durvalumab plus EP as first-line standard of care for ES-SCLC. Additional trials focused on elderly populations would be informative.

Keywords: Immune checkpoint inhibitor; Patient-reported outcomes; Safety; Subgroup analysis; Survival.