JERSEY CITY, N.J., June 12, 2025 – Mitsubishi Tanabe Pharma America, Inc. (MTPA) today announced the first patient dosed in its first in human, multicenter, open-label, Phase I/II study (NCT06943521) that evaluates safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of MT-4561 in patients with advanced solid tumors. MT-4561 is a novel BRD4 degrader with potential for inducing anti-tumor effects in patients with advanced solid tumors.
“This first-in-oncology study of our internally-developed MT-4561 marks a significant step in expanding MTPA’s pipeline of innovative therapies for difficult-to-treat diseases,” said Bijan Nejadnik M.D., Chief Medical Officer, MTPA. “We are forging a new path for patients whose tumors have progressed on conventional therapies, and we are grateful to START Midwest for their collaboration in this important clinical study.”
START Midwest is one of the clinical trial sites for the study and is where the first patient was dosed. “We are proud to work with MTPA on this important trial and to dose the first patient,” said Manish R. Sharma, MD, Co-Director of START Midwest. “MT-4561’s novel mechanism of action offers the potential to address the unmet needs of patients with various solid tumors.”
The clinical trial for MT-4561 will be conducted in 3 parts, across several sites, with the first part consisting of an intravenous infusion of MT-4561 once every week in a 28-day cycle that evaluates the number of patients with adverse events and the incidence of dose limiting toxicities (DLT). The study details and doses of Part 2 (dose-optimization) and Part 3 (Drug-Drug Interaction) will be available after review of applicable Part 1 results.
About MT-4561
MT-4561 is a novel BRD4 degrader that exerts continuous anti-tumor effects in various cancer xenograft models and patient derived cells. BRD4 is responsible for promoting transcription of cancer related genes and degradation of BRD4 can result in rapid induction of apoptosis and death of transcriptionally addicted cancers. MTPA is developing MT-4561 as a potential treatment option for advanced solid tumors.
About MT-4561 Clinical Trial
The clinical trial for MT-4561 will be conducted in 3 parts. Part 1 consists of an intravenous infusion of MT-4561 once every week in a 28-day cycle and is aimed at evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics of MT-4561 and determining the Maximum Tolerated Dose (MTD) using the Bayesian Optimal Interval (BOIN) design. The study details and doses of Part 2 (dose-optimization) and Part 3 (Drug-Drug Interaction) will be available after review of applicable Part 1 results. Primary endpoints for Part 1 include the number of patients with adverse events and the incidence of dose limiting toxicities (DLT), which are defined as any event meeting the DLT criteria at least possibly related to MT-4561 for Cycle 1 (i.e., DLT monitoring window is approximately 28 days).
About Mitsubishi Tanabe Pharma America, Inc.
Based in Jersey City, N.J., Mitsubishi Tanabe Pharma America, Inc. (MTPA) is a wholly-owned subsidiary of Mitsubishi Tanabe Pharma Corporation (MTPC). It was established by MTPC to develop and advance our pipeline as well as commercialize approved pharmaceutical products in North America. For more information, please visit www.mt-pharma-america.com or follow us on X (formerly Twitter), Facebook and LinkedIn.
About Mitsubishi Tanabe Pharma Corporation
Mitsubishi Tanabe Pharma Corporation (MTPC) is one of the oldest pharmaceutical companies in the world, founded in 1678, and focusing on ethical pharmaceuticals. MTPC is headquartered in Doshomachi, Osaka, the birthplace of Japan’s pharmaceutical industry. MTPC sets the MISSION of “Creating hope for all facing illness”. To that end, MTPC is working on the disease areas of central nervous system, immuno-inflammation, diabetes and kidney, and cancer. MTPC is focusing on “precision medicine” to provide drugs with high treatment satisfaction by identifying patient populations with high potential for efficacy and safety. In addition, MTPC is working to develop “around the pill solutions” to address specific patient concerns based on therapeutic medicine, including prevention of diseases, pre-symptomatic disease care, prevention of aggravation and prognosis. For more information, go to https://www.mt-pharma.co.jp/e/.
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