Clinical Summary: 

• Design/Population: In this randomized phase 2 trial, patients with locoregionally advanced nasopharyngeal carcinoma  who had a suboptimal response to induction chemotherapy received adjuvant sintilimab plus capecitabine or capecitabine alone following concurrent chemoradiotherapy.
• Key Outcomes: The addition of sintilimab to capecitabine did not improve progression-free survival compared with capecitabine alone. 
• Clinical Relevance: These findings do not support routine intensification of adjuvant therapy with sintilimab after a suboptimal response to induction chemotherapy.

Results from a randomized phase 2 trial demonstrated that adding sintilimab to adjuvant capecitabine did not significantly improve progression-free survival (PFS) among patients with locoregionally advanced nasopharyngeal carcinoma who experienced a suboptimal response to induction chemotherapy.

These results were presented by Lin-Quan Tang, PhD, Sun Yat-sen University Cancer Center, Guangzhou, China, at the American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.

In this open-label study, 150 previously untreated patients with nonkeratinizing locally advanced nasopharyngeal carcinoma and detectable Epstein-Barr virus DNA and/or stable or progressive disease following platinum-based induction chemotherapy were randomized 1:1 after concurrent chemoradiotherapy to receive 200 mg of sintilimab on days 1 and 14, followed by once every 3 weeks 28 days after chemoradiotherapy, plus 100 mg/m² of twice daily capecitabine on days 1 through 14 of an every-21-day cycle for up to 8 cycles. The primary end point was progression-free survival (PFS). A key secondary end point was safety. 

At a median follow-up of 41 months, the 2-year PFS rate was 88.2% in the sintilimab plus capecitabine arm and 87.8% in the capecitabine monotherapy arm (hazard ratio [HR], 0.85; 90% confidence interval [CI], 0.43 to 1.70; P = .77). 

Grade 3/4 adverse events were reported in 34% of patients in the sintilimab plus capecitabine arm and 31% of patients in the capecitabine monotherapy arm, and most frequently included hand-foot mouth syndrome. Grade 3 immune-related myocarditis was reported in 3% of patients in the sintilimab plus capecitabine arm. No treatment-related deaths were reported. 

“Future studies are warranted to focus on biomarker-driven patient selection and optimization of immunotherapy sequencing with conventional treatments,” concluded Dr Liu. 

Source: 

Liu LT, Mai HQ, Chen QY, et al. Adjuvant sintilimab-capecitabine versus capecitabine alone in locoregionally advanced nasopharyngeal carcinoma with suboptimal response to induction chemotherapy: An open-label, randomized, controlled, phase 2 trial. Presented at the ASCO Annual Meeting. May 29 - June 2, 2026. Chicago, Illinois. LBA6005.