ost-503

OST-503, formerly known as ADXS-503, is an investigational, off-the-shelf immunotherapy being developed by OS Therapies for the treatment of solid tumors. [18, 19] It is based on an attenuated Listeria monocytogenes (Lm) bacterial vector that has been bioengineered to elicit potent T-cell responses against 22 tumor antigens commonly found in non-small cell lung cancer (NSCLC), which include 11 hotspot mutations and 11 tumor-associated antigens (TAAs). [1, 3, 16] The drug is designed to stimulate the immune system to recognize and attack cancer cells. [8, 12] OST-503 has been evaluated in a Phase 1/2 clinical trial (NCT03847519) both as a monotherapy and in combination with the checkpoint inhibitor pembrolizumab for patients with metastatic NSCLC. [2, 5, 6] The asset was originally developed by Advaxis and was acquired by OS Therapies from Ayala Pharmaceuticals following a merger between Advaxis and Ayala.

Other names

Lm immunotherapy