Evaluation of the Effectiveness and Safety Profile of First-Line Immune Checkpoint Inhibitors Combined with Chemotherapy in Pulmonary Sarcomatoid Carcinoma.

Background: Pulmonary sarcomatoid carcinoma (PSC) represents a rare subtype of non-small cell lung cancer (NSCLC), and it has poor pathologic differentiation, aggressive progression, and early metastasis. Conventional antitumor therapies demonstrate limited efficacy against PSC, which is frequently associated with unfavorable clinical outcomes. Methods: We conducted an open-label, single-arm Phase II trial. This study has been registered with Clinical Trials (ChiCTR2000031478). Patients received immune checkpoint inhibitor (ICI) combination with chemotherapy, the treatment continued until disease progression, unacceptable toxicity, patient withdrawal, or death. The primary endpoint was objective response rate (ORR), with secondary endpoints comprising progression-free survival (PFS), disease control rate (DCR), overall survival (OS), and treatment-emergent adverse events. Results: From March 2021 through August 2023, a total of 38 patients were enrolled. The study comprised predominantly male participants (91%, n=34) with a median age of 65.4 years. Notably, 86.8% (n=33) had smoking histories. The ORR and DCR were 73.7% and 94.7%, respectively. The median PFS was 13.3 months (95% CI, 10.2-15.7) and median OS was not reached. The most common immune-related adverse events were pneumonitis, the incidence of which was 13.2%. The majority of observed AEs were grades 1 or 2 and all AEs were manageable. Only two patients discontinued treatment due to grade 3 immune-related pneumonitis during the study. Conclusion: In our trial, we found that ICI combination with chemotherapy showed robust efficacy alongside acceptable toxicity in advanced-stage PSC. Taken together, ICI combination with chemotherapy could be a better option for PSC.