8 May 2019 - - The first patient has been dosed in XmAb23104-01 (DUET-3), a Phase 1 clinical study to evaluate the safety and tolerability of XmAb23104, a bispecific antibody that simultaneously targets the immune receptors PD-1 and ICOS, for the treatment of patients with advanced solid tumors, US-based biopharmaceutical company Xencor, Inc. (NASDAQ: XNCR) said.

DUET-3 is a Phase 1, multiple-dose, dose-escalation study that will characterize the safety and tolerability, pharmacokinetics, pharmacodynamics, immunogenicity and preliminary anti-tumor activity of intravenous administration of XmAb23104 in patients with selected advanced solid tumors.

XmAb23104 is a bispecific antibody that simultaneously targets PD-1, an immune checkpoint receptor, and ICOS, an immune co-stimulatory receptor, and is designed to promote tumor-selective T-cell activation.

Xencor's XmAb bispecific Fc domain serves as the scaffold for these two antigen binding domains and confers long circulating half-life, stability and ease of manufacture.

XmAb bispecific Fc domains have been engineered to eliminate Fc gamma receptor binding, with the intent to prevent activation and/or depletion of T cells via engagement by FcγR-expressing cells. XmAb23104 is being evaluated in XmAb23104-01 (DUET-3), a Phase 1 study for the treatment of advanced solid tumors.

Xencor is a clinical-stage biopharmaceutical company developing engineered monoclonal antibodies for the treatment of cancer, autoimmune diseases, asthma and allergic diseases.

Currently, 13 candidates engineered with Xencor's XmAbtechnology are in clinical development internally and with partners.

Xencor's XmAb antibody engineering technology enables small changes to the structure of monoclonal antibodies resulting in new mechanisms of therapeutic action.