ubamatamab + cemiplimab

Ubamatamab + cemiplimab is a combination of two monoclonal antibodies investigated for the treatment of cancers expressing MUC16 (CA-125), especially ovarian cancer, endometrial cancer, epithelioid sarcoma, and renal medullary carcinoma. **Ubamatamab** (REGN4018) is a humanized hinge-stabilized IgG4 bispecific antibody that binds **Mucin 16 (MUC16)**, an antigen overexpressed in many ovarian and some other epithelial cancers, and **CD3**, a component of the T-cell receptor, redirecting cytotoxic T cells against MUC16-expressing tumor cells. **Cemiplimab** is a fully human IgG4 monoclonal antibody targeting **programmed cell death protein 1 (PD-1)**, functioning as an immune checkpoint inhibitor to enhance antitumor immune responses. The combination promotes potent T-cell–mediated cytotoxicity through dual mechanisms (direct redirection via ubamatamab and checkpoint blockade via cemiplimab). Primary clinical development has been in recurrent ovarian cancer, endometrial cancer, renal medullary carcinoma (RMC), and epithelioid sarcoma (ES)[1][2][3][5].