Imbrium Therapeutics Announces FDA Orphan Drug Designation for Tinostamustine for the Treatment of T-cell Prolymphocytic Leukemia

Imbrium Therapeutics L.P., a clinical-stage biopharmaceutical company and operating subsidiary of Purdue Pharma L.P., in conjunction with Mundipharma EDO GmbH, announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation (ODD) to its investigational drug tinostamustine, a potentially first-in-class alkylating deacetylase inhibiting molecule being studied in early phase clinical trials, for the treatment of T-cell prolymphocytic leukemia (T-PLL).

T-PLL is an extremely rare and aggressive T-cell leukemia that is characterized by out of control growth of mature T-cells. There are very limited effective treatment options for T-PLL. The disease typically progresses rapidly and does not respond well to standard multi-agent chemotherapy.

“This orphan drug designation represents an important step not just for Imbrium and the development of tinostamustine, but also for the patients suffering from T-PLL who do not currently have sufficient treatment options,” said Richard Fanelli, PhD, head of Regulatory Affairs, Imbrium Therapeutics.

The FDA grants ODD status to medicines intended for the treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the United States. Orphan drug designation is intended to facilitate drug development for rare diseases and may provide certain incentives to drug developers.1,2 T-PLL is an extremely rare and typically aggressive blood cancer. It is so rare that healthcare professionals may only see one case of T-PLL every five to 10 years.3 Due to its rarity, T-PLL can be misdiagnosed, resulting in poor patient outcomes with a median survival of around one year. 3,4 There is no guarantee that tinostamustine, an investigational agent, will successfully complete clinical development or gain FDA approval.

Craig Landau, MD, president and CEO, Purdue Pharma L.P. added, “This marks the second orphan drug designation we have received from the U.S. FDA in just the last two months and demonstrates our commitment to rapidly advancing our pipeline of oncology chemotherapeutics for rare and difficult to treat cancers.”

In addition to T-PLL, Imbrium Therapeutics has initiated the early phase clinical development of tinostamustine in a range of rare and difficult-to-treat blood cancers and advanced solid tumors.