Combined chemotherapy and pembrolizumab salvages multi-chemotherapy agent and avelumab resistant choriocarcinoma: A case report

INTRODUCTION: Gestational trophoblastic neoplasia (GTN) including choriocarcinoma (CC) frequently requires multi-agent chemotherapy to achieve cure. In chemotherapy-resistant GTN, immunotherapy with the checkpoint inhibitors pembrolizumab, avelumab and camrelizumab are potential new treatment options previously described in small case series, phase 2 trials and case reports. CASE DESCRIPTION: A 32-year-old woman was diagnosed with gestational choriocarcinoma (FIGO score 5). Prior administered therapy regimes included methotrexate, actinomycin-D followed by open hysterectomy with bilateral salpingectomy (histology without GTN) as well as multi-agent chemotherapy and avelumab single-agent. After detection of a suspicious pulmonary mass video- assisted thoracoscopic left lung segmentectomy was performed confirming CC. The patient experienced an intracerebral haemorrhage and was treated with an emergency decompressive craniotomy. The cerebrospinal fluid showed an increased ratio of hCG compared to serum. Therapy with combined escalated etoposide and cisplatin with pembrolizumab was commenced followed by maintenance pembrolizumab achieving a complete hCG response and negative PET CT. DISCUSSION: In the management of multi drug- resistant GTN, application of checkpoint inhibitor pembrolizumab is a new therapeutic strategy. In this heavily pre-treated patient incorporation of pembrolizumab resulted in complete long-term response in a patient who had also failed avelumab therapy.