CAPTAIN-1st

Background

Phase III double-blind RCT (CAPTAIN-1st). N=236 patients with recurrent or metastatic NPC (R/M NPC), no prior systemic chemotherapy for R/M disease. Enrolled 2018–2020 at 16 Chinese institutions. Camrelizumab is an anti-PD-1 monoclonal antibody. Tested first-line IO + chemotherapy vs placebo + chemotherapy in R/M NPC. Stratified by prior palliative radiotherapy, liver metastasis, and ECOG PS.

Interventions and follow up

Arm A: Camrelizumab 200 mg q3wk + gemcitabine 1000 mg/m² D1,D8 + cisplatin 80 mg/m² D1 q3wk × 6 cycles → camrelizumab maintenance
Arm B: Placebo + gemcitabine + cisplatin × 6 cycles → placebo maintenance
Primary endpoint: PFS (investigator-assessed)
mFollow up: 24.0 month

Results

mPFS: 9.7 vs 6.9 months, HR 0.54 (95% CI 0.39–0.76), P<.0001
OS: HR 0.55 (95% CI 0.35–0.85), P=.007 — significant; 2-year OS 76.8% (camrelizumab) vs 59.5% (placebo)
ORR: 87.3% vs 80.8%

Adverse events

Main adverse events: Grade ≥3 AEs: 83.5% (camrelizumab) vs 75.4% (placebo). Unique to camrelizumab: reactive cutaneous capillary endothelial proliferation (RCCEP, "blood blisters") in 79.6% (grade 3: 0.8%) — a class effect of camrelizumab. Grade 3 anemia 36.4%, neutropenia 30.5%, thrombocytopenia 16.1% (chemotherapy-related).

Conclusions

Camrelizumab + GP significantly improved PFS (HR 0.54) and OS (HR 0.55) vs placebo + GP as first-line treatment for R/M NPC. CAPTAIN-1st was the first phase III trial to demonstrate OS benefit for an anti-PD-1 agent in R/M NPC, establishing PD-1 inhibition + GP as a new standard of care.

Key Limitations

Key Limitations: Conducted exclusively in China; EBV-positive endemic NPC — results may not generalize to non-endemic NPC. Camrelizumab is not globally approved; RATIONALE-309 (tislelizumab + GP) and KEYNOTE-122 (pembrolizumab) have also been studied. RCCEP is a unique and visible toxicity of camrelizumab that requires patient counseling. PD-L1 was not used for patient selection; no biomarker subgroup analysis presented. GP alone is a less toxic and effective regimen for R/M NPC even without IO (ORR ~85% with GP).

Clinical Context

CAPTAIN-1st (camrelizumab), RATIONALE-309 (tislelizumab), and JUPITER-02 (toripalimab + GP) are three positive phase III trials establishing PD-1 + GP as the new first-line standard for R/M NPC. In Asia, any approved anti-PD-1 + GP is preferred over GP alone. In Western markets, pembrolizumab data are more relevant (KEYNOTE-122 showed PFS benefit). NCCN and ESMO recommend first-line platinum-based chemotherapy + PD-1 inhibitor for R/M NPC.

References

References: Yang Y et al, Lancet Oncol 2021 (primary)