These product candidates – two GITR agonists and a CTLA-4 antagonist – target cell-surface checkpoint proteins that control immune responses. They are part of Agenus’ recent acquisition of 4-Antibody AG and the result of several years of intensive collaborative efforts between 4-Antibody and Ludwig Cancer Research.
The parties also have ongoing programs to discover and develop other immune checkpoint modulator antibodies, including OX40 agonists and antagonists of LAG-3, TIM-3 and PD-1.
Agenus chief scientific officer Dr Robert B Stein noted GITR, a checkpoint protein on T-lymphocytes, plays an important role in amplifying specific cellular immune responses, including those against tumors.
"We are encouraged to have identified high-quality agonist antibodies for this very competitive target, something that has proven difficult for many other companies.
"Furthermore, it is rational to combine CPMs such as CTLA-4 and PD-1 antagonists with anti-cancer vaccines, and we are collaborating on an on-going Phase 2 trial exploring Prophage and Yervoy® (CTLA-4 antagonist) in patients with metastatic melanoma. Intelligently designed translational studies may improve the odds of success for our CPMs and accelerate their clinical development," Dr Stein added.
In collaboration with its translational research partner Ludwig Cancer Research, Agenus and 4-Antibody plan to advance the emerging portfolio of CPMs as single agents and in optimized combinations, including potential combinations with the company’s anti-cancer vaccine and other agents.
CPMs like CTLA-4 and PD-1 antagonists make cancer more vulnerable to immune attack by releasing the brakes on the anti-cancer immune response and neutralizing the defenses cancer cells use to fend off that attack.
Cancer vaccines, meanwhile, are designed to enhance the immune system’s recognition of cancer cells as abnormal based on mutant proteins that they display. Scientists reason that, together, these strategies should deliver a one-two punch against cancer that could have a durable therapeutic impact.