Gilead Sciences Inc. agreed to acquire a license to access Xencor Inc.'s Xtend and Cytotoxic XmAb technologies for developing and commercializing its experimental HIV infection treatment GS-9722.

Under the agreement, Gilead will have an exclusive license to use the technologies for GS-9722, or elipovimab, and up to three additional HIV treatments. Xencor retains the right to grant licenses for other antibodies directed to the target.

Xencor will receive an up-front payment and is eligible to receive milestone payments and royalties on developing and commercializing these products.

Financial details of the agreement were not disclosed.

Foster City, Calif.-based Gilead will be responsible for all development, regulatory and commercial activities. The biotech is evaluating GS-9722 in a phase 1 trial.

GS-9722 is a broadly neutralizing anti-HIV antibody that can potentially reduce or eliminate the number of HIV infected immune cells by killing them.

Xencor's Xtend technology helps increase binding capacity of the antibodies with certain cells lining the blood vessels, which protect antibodies from degradation. This helps improve antibody performance and results in longer drug exposure.

Cytotoxic XmAb technology improves immune system functions for eliminating tumors and other diseased cells.