Management of Metastatic Pulmonary Spindle Cell Carcinoma With Upfront Pembrolizumab‐Chemotherapy and Subsequent Ipilimumab–Nivolumab Salvage Therapy: A Case Report

Sarcomatoid carcinoma is a heterogeneous and rare subset of non–small cell lung cancers (NSCLCs), comprising pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, pulmonary blastoma, and carcinosarcoma. Pulmonary spindle cell carcinoma accounts for less than 1% of all NSCLC cases. Studies have shown a poor response to chemotherapy and radiotherapy, whereas immunotherapy with or without chemotherapy has shown variable responses in this subtype, and no consensus standard of care currently exists. We present the case of a woman diagnosed with pulmonary spindle cell carcinoma with metastases to the brain and bilateral adrenal glands. She underwent Gamma Knife radiosurgery for brain metastases and received chemoimmunotherapy with carboplatin, paclitaxel, and pembrolizumab, followed by maintenance pembrolizumab, achieving a complete radiologic response. Upon disease recurrence, she showed no response to chemotherapy rechallenge. Subsequently, combination immune checkpoint blockade with the anti–PD‐1 agent nivolumab and the anti–CTLA‐4 agent ipilimumab resulted in a partial response. She remains on combination immunotherapy and maintains an ECOG performance status of 0. This case highlights the potential role of dual immune checkpoint blockade as an effective salvage therapy following progression on PD‐1–based regimens in pulmonary spindle cell carcinoma, a setting for which data are extremely limited.