Long-Term Disease Control With Second-Line Nivolumab Monotherapy in Malignant Pleural Mesothelioma: A Case Report

Nivolumab is recommended as second-line therapy for malignant pleural mesothelioma (MPM); however, durable responses remain uncommon. In addition, combination immune checkpoint inhibitors are frequently limited by immune-related adverse events. A 72-year-old man with epithelioid MPM underwent extrapleural pneumonectomy followed by adjuvant chemotherapy with cisplatin and pemetrexed. After recurrence, additional platinum-based chemotherapy was administered, followed by disease progression. Nivolumab monotherapy was then initiated as second-line therapy, resulting in a sustained radiological response. The patient has maintained progression-free survival for 24 months without severe immune-related adverse events, allowing long-term treatment continuation. This case highlights that nivolumab monotherapy may achieve durable disease control with a favorable safety profile in selected patients with MPM.