Successful Pregnancy and Cancer Outcomes With Ipilimumab and Nivolumab for Metastatic Renal Cell Carcinoma: Case Report and Review of the Literature.

Pregnancy and cancer share CTLA-4 and PD-1/PD-L1 as some of the immunomodulatory pathways that reshape the immune system from a destructive response to a state of tolerance to the fetus and the tumor, respectively. Ipilimumab (anti-CTLA-4 inhibitor) and nivolumab (anti-PD-1 inhibitor) are used in combination for the treatment of metastatic renal cell carcinoma, and their use could theoretically result in an immune response against the fetus. Furthermore, these immune checkpoint inhibitors are immunoglobulin G antibodies that transfer from the mother to the fetus and may cause a direct toxicity.