EQS-News

Israeli Ministry Of Health Clears Way For Human Trials Of AllocetraTM, A Proprietary Off-the-Shelf Immunotherapy For Solid Tumors - Seite 2

Because cancer can trick macrophages into defending tumors instead of attacking them, other immunotherapies, including checkpoint inhibitors like Merck & Co. Inc.’s (NYSE: MRK) Keytruda or Bristol-Myers Squibb Co.’s (NYSE: BMY) YERVOY, struggle to bypass the cancer’s new defenders.

This challenge has resulted in response rates as low as 13% to these novel treatments. That figure is disappointing because, in theory, checkpoint inhibitors are extremely promising. Checkpoints like PD-1 and CTLA-4, the ones blocked by Keytruda and YERVOY, respectively, are “off switches” that help the immune system recognize and avoid attacking the body’s own cells.

Just as cancer can trick macrophages into coming to its defense, it can use those checkpoints to trick the immune system into believing the cancer cell is a normal cell. By blocking those checkpoints, the cancer is no longer able to escape detection in this way.

However, even when those checkpoints are blocked and the immune system kicks into action to fight the cancer cells it can now recognize, dysregulated macrophages form a kind of protective layer on top of a tumor that prevents the immune system from effectively attacking it.

It’s that last layer of defense that researchers think may play a role in the low response rate of checkpoint inhibitors. Enlivex hopes that AllocetraTM’s potential to reprogram those macrophages will help remove that protective barrier so that when the checkpoint inhibitor gets rid of the cancer’s “off switch,” the patient’s immune system won’t have any obstacles in its way to attacking that tumor.

The Phase I/II Clinical Trial Will Study AllocetraTM Alone and in Combination with a Checkpoint Inhibitor

The recent MOH approval paves the way for Enlivex to enroll up to 48 patients with advanced solid tumors in a multicenter, open-label trial that will include two stages. In stage one, patients will receive escalating doses of AllocetraTM by itself. The intravenous injections will be administered once a week for three weeks.

In stage two, patients will receive three injections of AllocetraTM in combination with an anti-PD1 checkpoint inhibitor. In preclinical studies, this combination resulted in 50% survival probability for mice with ovarian cancer, compared to 15% or less for anti-PD1 checkpoint inhibitors on their own.