Efficacy of first-line immune checkpoint inhibitors in pulmonary sarcomatoid carcinoma.

Background: Pulmonary sarcomatoid carcinomas (PSC) are notorious for their poor prognosis and resistance to chemotherapy. The literature suggests that immunotherapy might be effective against this aggressive tumor. This study aims to evaluate the efficacy of immunotherapy, either alone or combined with chemotherapy, as first-line treatment for PSC patients. Methods: In a retrospective, multicentric, real-world study conducted between July 2017 and April 2021, patients with stage III (ineligible for surgery or radio-chemotherapy) or stage IV PSC were enrolled. These patients received their first-line treatment with immunotherapy and were categorized into two groups based on their treatment modality: the immuno-chemotherapy (IO CT) group or the immunotherapy-alone (IO) group. Results: This study analyzed a population of 34 patients from eight different hospital centers. In this cohort, the objective response rate (ORR) was 56%, median duration of response was 20.5 months, median progression-free survival (PFS) was 5.11 months, and median overall survival (OS) 13.9 months. Demographic characteristics remained consistent among the treatment groups except for the age (54.0- and 71.0-year-old in the IO CT and IO group, respectively, P=0.02). The IO CT group demonstrated an ORR of 64.0%, a median PFS at 8.72 months, and a median OS of 16.08 months, while the IO group displayed respective values of 52.0%, 3.45 months, and 13.11 months. Conclusions: This study showed the potential efficacy of immunotherapy as a first-line treatment for PSC. While acknowledging the retrospective nature of the study, our findings suggest a trend favoring the combination of IO CT over IO alone in these patients.