First-Line Pembrolizumab Plus Chemotherapy for Advanced Biliary Tract Cancer: China Subgroup Analysis of the Randomized Phase 3 KEYNOTE-966 Study.

INTRODUCTION

In the global phase 3 KEYNOTE-966 study (NCT04003636), pembrolizumab plus gemcitabine and cisplatin (pembrolizumab group) showed a statistically significant, clinically meaningful improvement in overall survival (OS) versus placebo plus gemcitabine and cisplatin (placebo group) without any new safety signals in participants with advanced biliary tract cancer (BTC). This analysis focused on the subgroup of participants from KEYNOTE-966 enrolled in China.

METHODS

Adults with previously untreated advanced BTC were randomly assigned (1:1) to receive pembrolizumab 200 mg or placebo intravenously every 3 weeks plus gemcitabine 1000 mg/m2 and cisplatin 25 mg/m2 intravenously on days 1 and 8 of every 3-week cycle. Primary endpoint was OS. Secondary endpoints were progression-free survival (PFS), objective response rate (ORR), and duration of response (DOR), all per RECIST v1.1 by blinded independent central review, and safety.

RESULTS

One hundred fifty-eight participants were enrolled in China (75, pembrolizumab group; 83, placebo group). Median time from randomization to data cutoff (December 15, 2022) was 20.5 (range, 15.0-28.8) months. Median OS was 14.1 (95% CI, 10.4-17.7) months in the pembrolizumab group versus 9.9 (95% CI, 8.6-13.0) months in the placebo group (HR, 0.74; 95% CI, 0.51-1.08); median PFS was 5.6 (95% CI, 3.2-7.4) months versus 5.7 (95% CI, 4.4-6.9; HR, 0.83 [95% CI, 0.58-1.19]) months; ORR was 36.0% (95% CI, 25.2-47.9) versus 28.9% (95% CI, 19.5-39.9); median DOR was 10.2 (range, 1.2+ to 20.6) months versus 5.7 (range, 1.4+ to 18.2) months. Grade 3 or 4 treatment-related adverse events occurred in 53 participants (71.6%) in the pembrolizumab group versus 58 (70.7%) in the placebo group; no treatment-related grade 5 events occurred.

CONCLUSION

Consistent with the KEYNOTE-966 global population, first-line pembrolizumab plus gemcitabine and cisplatin provided a numeric improvement in OS versus placebo plus gemcitabine and cisplatin and no new safety signals in participants enrolled in China.

TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT04003636, NCT04924062.