Efficacy of immune checkpoint inhibitor therapy in patients with pulmonary sarcomatoid carcinoma in clinical practice

Objective: Studies have suggested the potential efficacy of immune checkpoint inhibitors (ICIs) for pulmonary sarcomatoid carcinoma. This multicenter observational study was conducted to evaluate the efficacy of systemic ICI therapy and chemoradiation followed by durvalumab therapy for pulmonary sarcomatoid carcinoma. Methods: We analyzed the data of patients with pulmonary sarcomatoid carcinoma who received systemic ICI therapy or chemoradiation followed by durvalumab therapy between 2016 and 2022. Results: In this study, data of a total of 22 patients who received systemic ICI therapy and four patients who received chemoradiation followed by durvalumab therapy were analyzed. In the patients who received systemic ICI therapy, the median progression-free survival after initiation of therapy was 9.6 months, and the overall survival did not reach the median. The 1-year progression-free survival rate and overall survival rate were estimated to be 45.5% and 50.1%, respectively. Although the log-rank test revealed no significant association between the tumor expression level of programmed death ligand-1 (tumor proportion score evaluated using 22C3 antibody: ≥50% vs. <50%) and the survival duration, the majority of patients showing long-term survival showed a tumor proportion score of ≥50%. Of four patients treated with chemoradiation followed by durvalumab therapy, two patients showed an overall survival of ≥30 months, whereas the remaining two patients died within 12 months. Conclusion: The progression-free survival of patients who received systemic ICI therapy was 9.6 months, suggesting that ICI therapy might be effective in patients with pulmonary sarcomatoid carcinoma.