Metastatic germ cell tumor showing a durable response to the anti-PD-1 antibody toripalimab

The outcome for patients with recurrent and metastatic germ cell tumors can be dismal, and novel salvage therapies are required for these patients. Here we describe a case of metastatic germ cell tumor in which 30% of cells were positive for PD-L1. This tumor achieved a durable response to toripalimab, a monoclonal anti-PD-1 antibody. Follow-up for 36 months post-treatment confirmed no disease progression. Continuous remission was maintained even when treatment was interrupted after 18 months because of an immune-related adverse event (allergic rhinitis). Thus, toripalimab may be an alternative choice for salvage therapy in patients with recurrent and metastatic germ cell tumors. Plain language summaryRescue treatment for recurrent and metastatic germ cell tumors is limited. Immune checkpoint inhibitors have shown certain efficacy and safety in the treatment of a variety of tumors. Here we describe a case of metastatic germ cell tumor in which 30% of cells were positive for PD-L1. This tumor achieved a durable response to toripalimab, a monoclonal anti-PD-1 antibody. Follow-up for 36 months post-treatment confirmed no disease progression. We not only report the first use of toripalimab for the treatment of a metastatic germ cell tumor but also describe a patient with the longest sustained remission with an anti-PD-1 antibody to date.