Efficacy and safety of immune checkpoint inhibitor consolidation after chemoradiation in patients of Asian ethnicity with unresectable stage III non-small cell lung cancer: Chinese multicenter report and literature review.

Background The PACIFIC study has defined a new standard of care for patients with unresectable stage III non-small cell lung cancer (NSCLC) in the form of immune checkpoint inhibitor (ICI) consolidation therapy. However, there is little specific data pertaining to the safety and efficacy of this approach in Chinese NSCLC patients. Methods This was a prospective multicenter cohort study. Between September 2018 and January 2020, patients with unresectable stage III NSCLC that had undergone chemoradiation therapy (CRT) and ICI consolidation treatment were enrolled in this study. The short-term safety, tolerability, and efficacy of ICI combination with CRT were evaluated in these patients. Results Of the 20 Chinese patients eligible for inclusion, 17 (85.0%) underwent concurrent CRT treatment. In these patients, a median period of 40.5 days (range: 1-85 days) passed between the end of CRT and initiation of consolidation therapy. Pneumonitis occurred in 80.0% of patients, with seven (35.0%) being diagnosed with grade 1 pneumonitis and nine (45.0%) with grade 2 pneumonitis. No patients experienced grade 3 or higher pneumonitis or other ICI-related toxicities. Lung V20 >= 20% was associated with higher grade 2 pneumonitis (77.8%; >= 20% vs. 18.2%; <20%,P= 0.027). The overall response rate (ORR) in these patients was 95.0%. Over a median follow-up period of 11.3 months (range: 6.2-21.8 months), 12-month PFS of these patients were 89.5% (95% CI: 76.7-100.0%), and 12 months OS was 100.0%. Conclusions These data indicate that ICI consolidation therapy can achieve favorable short-term efficacy, while exhibiting good safety and acceptable toxicity profiles in Chinese patients with unresectable stage III NSCLC. Key pointsSignificant findings of the study This is the first report evaluating the safety and efficacy of ICI consolidation therapy after chemoradiotherapy in China. Our results indicate that ICI consolidation is associated with favorable efficacy and no severe pneumonitis incidence in Chinese patients undergoing both anti-PD-1 and anti-PD-L1 monoclonal antibody consolidation. What this study adds Post-hoc analysis of the Japanese subgroup in the PACIFIC study suggested that consolidation therapy may be associated with increased pneumonitis incidence in Asian patients. However, our findings indicate that consolidation therapy is safe and tolerable in Chinese patients with unresectable stage III NSCLC.