ALG.APV-527: A tumor-binding and immunomodulatory antibody in the same molecule

4-1BB has the ability to stimulate the immune cells (antitumor-specific T cells) involved in tumor control, making 4-1BB a particularly compelling target for cancer immunotherapy. The tumor-binding function of ALG.APV-527 targets the 5T4 tumor-associated antigen. 5T4 is a protein expression in multiple tumor types, as well as certain types of aggressive tumor cells (tumor-initiating cells), but at low levels or not at all in normal tissue, making 5T4 a compelling target molecule for cancer therapy.

1. ALG.APV-527 is seeking the tumor area and binds to the target molecule 5T4 on the surface of tumor cells.
2. In the tumor area, ALG.APV-527 simultaneously binds to 4-1BB on the surface of T cells.
3. The beneficial T cells are activated to kill tumor cells.


In May 2018, new preclinical data for ALG.APV-527 were presented at several scientific conferences – the 2018 PEGS Summit, the Annual Meeting of the American Association of Immunologists (AAI) and the Annual Meeting of the Association for Cancer Immunotherapy (CIMT). New data show that ALG.APV527 has the potential to selectively stimulate and strengthen the T cell response in the tumor without stimulating the immune
system in the rest of the body. The findings support its overall potential to evoke an effective tumor-targeting immune response with fewer adverse events.

A preclinical data package is currently being compiled with the aim to submit an application for Clinical Trial Authorization (CTA) in the second half of 2019.

In July 2017, Aptevo Therapeutics and Alligator Bioscience signed an agreement regarding the co-development of ALG.APV-527. The antibody is based on Alligator’s original bispecific drug candidate ATOR-1016. Under the agreement, the companies will equally own and finance the development of the drug candidate through Phase II clinical trials.