Alligator Bioscience and Aptevo Therapeutics announced further details of the companies' collaboration on ALG.APV-526, a bispecific antibody targeting 4-1BB and a tumor antigen, now identified as 5T4, which is found on various types of cancer cells.
5T4 is a protein predominantly expressed on tumor cells. It is present at very low levels or not at all in normal tissue. This enables the immune-activating effect of ALG.APV-527 to be targeted specifically to the tumor and not against normal tissue, the goal being effective tumor-directed immune activation with minimal side effects. The 5T4 tumor antigen is present on a number of different solid tumors, including breast, cervical, non-small-cell-lung, prostate, renal, gastric, colorectal and bladder cancers, indicating that ALG.APV-527 may be used for the treatment of several different types of cancer.
By combining a tumor-binding and an immunomodulatory antibody in one molecule, Alligator and Aptevo have created a drug candidate whose effect is localized to the tumor area, activating the tumor-specific immune cells present there.
ALG.APV-527 is a bispecific antibody (4-1BB x 5T4) intended for tumor-directed treatment of solid cancers. The ALG.APV-527 antibody consists of two parts, one part activating tumor-specific T cells through the co-stimulatory receptor 4-1BB (CD137), the other part binding to the 5T4 protein expressed on the surface of tumor cells.