AUSTIN, TX, USA I March 09, 2023 I Molecular Templates, Inc. (Nasdaq: MTEM, “Molecular Templates,” or “MTEM”), a clinical-stage biopharmaceutical company focused on the discovery and development of proprietary targeted biologic therapeutics, engineered toxin bodies (“ETBs”), to create novel therapies with potent differentiated mechanisms of action for cancer, has received clearance by the United States Food and Drug Administration (“FDA”) following review of its Investigational New Drug Application (“IND”) to proceed for clinical testing of its novel MT-8421 ETB program targeting CTLA-4 in patients with relapsed/refractory solid tumors previously exposed to checkpoint inhibitors.

“MT-8421 represents a novel approach to target CTLA-4 in a wholly distinct manner from the current monoclonal antibody approaches. MT-8421 was designed to eliminate CTLA-4-expressing Tregs in the tumor microenvironment (“TME”) through a direct cell-kill mechanism independent of the effector cell presence that antibodies rely upon while not effecting Tregs in the periphery, the major mechanism of antibody-mediated autoimmune toxicity,” said Eric Poma, Chief Executive Officer and Chief Scientific Officer of MTEM.

Preclinical data from MT-8421 showed that in a transgenic mouse model expressing human CTLA-4 and bearing syngeneic subcutaneous tumors, MT-8421 treatment depleted immune suppressive Tregs in the TME but not in the periphery. MT-8421 was well tolerated in a non-human GLP primate toxicology study and achieved serum levels well-above projected IC50 concentrations for Tregs in the TME. MTEM expects to initiate a first-in-human phase I study with MT-8421 by mid-year 2023 at a starting dose of 32 mcg/kg.

About Molecular Templates
Molecular Templates is a clinical-stage biopharmaceutical company focused on the discovery and development of targeted biologic therapeutics. Our proprietary drug platform technology, known as engineered toxin bodies, or ETBs, leverages the resident biology of a genetically engineered form of Shiga-like Toxin A subunit to create novel therapies with potent and differentiated mechanisms of action for cancer.

SOURCE: Molecular Template