Efficacy of pembrolizumab in patients with chemotherapy-resistant gestational trophoblastic neoplasia, a case report.

Gestational trophoblastic neoplasia (GTN) is a rare malignancy that can develop following a hydatidiform mole or a non-molar pregnancy and often presents with metastasis. Although conventional chemotherapy achieves remission in over 90% of metastatic cases some patients develop resistance. I report a 36-year-old woman with metastatic GTN after prolonged uterin bleeding and elevated β-hCG levels. Despite multiple chemotherapy regimens, including cisplatin/etoposide and EMA-CO, the patient did not achieve remission. After the failure of conventional chemotherapy, pembrolizumab, an immune checkpoint inhibitor, was introduced. This treatment resulted in a rapid decrease in β-hCG levels and a complete biochemical response. The treatment was well tolerated, only minor immune-related adverse events. After eight cycles of pembrolizumab, she remained in remission for one year. This case highlights the potential role of immunotherapy in managing chemoresistant metastatic GTN and underscores the need for further studies to establish its effectiveness in such situations.