Molecular Templates Announces the FDA Removal of Partial Clinical Hold in the Phase 1 Clinical Trial for MT-0169 and Focuses on Extramedullary Myeloma

AUSTIN, Texas, June 01, 2023 (GLOBE NEWSWIRE) -- 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, announced today that the U.S. Food and Drug Administration (“FDA”), after reviewing safety data on the program, has removed the partial clinical hold on patient enrollment for its MT-0169 trial, allowing Molecular Templates to proceed with its plan to evaluate the efficacy of MT-0169, one of its ETBs, which specifically targets CD38, a validated target in Multiple Myeloma. The FDA placed the Phase I study for MT-0169 on a partial clinical hold in April 2023, based on previously disclosed asymptomatic and fully reversible cardiac adverse events (“AEs”) noted in two patients dosed at 50 mcg/kg which prompted the dose reduction to 5 mcg/kg last year.

“We are pleased that the FDA has removed the partial clinical hold,” said Eric Poma, Ph.D., Chief Executive and Chief Scientific Officer of MTEM. “MT-0169 represents a novel approach to myeloma that is demonstrating good safety with early signs of potential clinical benefit, particularly in the extramedullary setting, where we have seen a stringent Complete Response in a patient who remains on study for 10 months.”

MTEM will be focusing development of MT-0169 on extramedullary myeloma, a form of myeloma that is less responsive to current therapies and carries a worse overall prognosis. Up to 20% of patients with relapsed/refractory multiple myeloma have extramedullary disease.

About MT-0169
MT-0169 was designed to destroy CD38+ tumor cells through internalization of CD38 and cell destruction via a novel mechanism of action (enzymatic ribosomal destruction and immunogenic cell death). The MT-0169 study completed the 5 mcg/kg dose escalation cohort (N=4) and the 10 mcg/kg dose escalation cohort (N=3) without any cardiac AEs or dose-limiting toxicities. A stringent Complete Response was seen in a patient with extramedullary IgA myeloma dosed with MT-0169 at 5 mcg/kg. The patient had a marked reduction in IgA serum protein, conversion from immunofixation positive to negative, and resolution of uptake on bone scan of skeletal lesions. The patient’s disease was quad-agent refractory including CD38-targeting, proteosome inhibitor, IMiD, and a BCMA bispecific antibody. The patient continues on study for 10 months. To date, no instances of capillary leak syndrome or other manifestations of innate immunity have been observed with any next-generation ETB.