Camrelizumab Plus Apatinib in Extensive-Stage SCLC (PASSION): A Multicenter, Two-Stage, Phase 2 Trial

Treatment options in the second-line extensive-stage SCLC (ED-SCLC) setting are limited. The PASSION study (ClinicalTrials.gov identifier: NCT03417895) was a phase 2 study of camrelizumab plus apatinib in ED-SCLC after platinum-based chemotherapy.

In stage I of the study, patients were randomized (1:1:1) to receive camrelizumab 200 mg every 2 weeks plus apatinib 375 mg once daily (QD), 5 days on and 2 days off, or 7 days on and 7 days off (six patients each cohort). On the basis of tolerability during the first 28-day cycle and efficacy data at stage I, one cohort was chosen to expand to 45 patients at stage II. The primary end point was objective response rate (ORR).

From April 20, 2018 to March 12, 2019, a total of 59 patients were enrolled, with 47 patients in the QD cohort. In the QD cohort, confirmed ORR reached 34.0% (95% confidence interval: 20.9‒49.3), the median progression-free survival was 3.6 months, and the median overall survival was 8.4 months. Chemotherapy-sensitive and chemotherapy-resistant patients (defined as patients with disease relapse at ≥90 and <90 d after platinum-based chemotherapy, respectively) had comparable confirmed ORR (37.5% versus 32.3%), median progression-free survival (3.6 versus 2.7 mo), and median overall survival (9.6 versus 8.0 mo). Treatment-related adverse events of grade 3 or higher were reported in 43 of 59 patients (72.9%). Five patients (8.5%) discontinued because of treatment-related adverse events.

Camrelizumab plus apatinib exhibited potential antitumor activity in patients with both chemotherapy-sensitive and chemotherapy-resistant ED-SCLC who had failed platinum-based chemotherapy with an acceptable toxicity profile. This phase 2 data warrant further clinical studies of camrelizumab plus apatinib in SCLC.