Remarkable response to pembrolizumab with platinum-doublet in PD-L1-low pulmonary sarcomatoid carcinoma: A case report.

Pulmonary sarcomatoid carcinoma (SC) is an aggressive subtype of lung cancer that exhibits resistance to cytotoxic chemotherapy. Although programmed cell death 1 (PD-1) inhibitors have been reported to show antitumor effects in patients with high programmed death-ligand 1 (PD-L1) expressing SC, the efficacy of combined therapy with PD-1 inhibitor plus cytotoxic chemotherapy has not previously been clarified. We herein report a case of SC with low expression of PD-L1 and few pre-existing tumor-infiltrating lymphocytes which showed a remarkable response to pembrolizumab plus cytotoxic chemotherapy as first-line treatment. Our findings suggest that combined treatment might enhance the immunogenic response, even in immunologically ignored SCs.