March 28, 2019 Press Release

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

STAMFORD, Conn. – March 28, 2019 – Imbrium Therapeutics L.P., a clinical-stage biopharmaceutical company and operating subsidiary of Purdue Pharma L.P., in conjunction with Mundipharma EDO GmbH, today 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.

About T-cell prolymphocytic leukemia

T-cell prolymphocytic leukemia (T-PLL) affects approximately 2 percent of all patients with mature lymphocytic leukemias.5 It is characterized by the out of control growth of mature T-cells (T-lymphocytes). T-cells are a type of white blood cell that protects the body from infections.6 The majority of patients present with hepatosplenomegaly and generalized lymphadenopathy, with skin infiltration, anemia and thrombocytopenia often seen.5 T-PLL affects older adults with a median age at diagnosis of 61 years, and it is more common in men than in women.6

T-PLL typically has rapid progression and does not respond well to standard multi-agent chemotherapy.

About tinostamustine

Tinostamustine (EDO-S101), is a novel multi-action therapy in Phase 2 clinical development for a range of rare and difficult-to-treat blood cancers and advanced solid tumors.

Preclinical studies have shown that tinostamustine has the potential to improve access to the DNA strands within cancer cells, break them, and counteract damage repair.7,8,9,10 The preclinical data also suggest that these complementary and simultaneous modes of action have the potential to overcome resistance toward some other cancer treatments.7,8,9,10

Tinostamustine is currently being studied in multiple myeloma, Hodgkin lymphoma, peripheral T-cell lymphoma, cutaneous T-cell lymphoma, T-cell prolymphocytic leukemia, soft tissue sarcoma, small cell lung cancer, triple-negative breast cancer, ovarian cancer, endometrial cancer and MGMT-unmethylated glioblastoma.

About Imbrium Therapeutics

Imbrium is a clinical-stage biopharmaceutical company dedicated to advancing medical science through the development of important new pharmacologic and biologic therapeutics. We are pursuing oncology chemotherapeutics, treatments for disorders of the central nervous system, and non-opioid approaches to the management of pain. As an operating subsidiary of Purdue Pharma L.P., Imbrium strives to develop and bring to market new medicines that serve the unmet needs of patients, physicians and health systems worldwide. We have built a robust and diversified pipeline of investigational drug candidates, and we actively collaborate with industry and academic partners to identify and advance future impactful medicines. For more information, please visit:

About Mundipharma EDO

Mundipharma EDO is part of the Mundipharma global network of privately-owned independent associated companies, which operate in over 120 countries worldwide. We develop treatments for patients around the world with rare or relapsed/refractory cancer, investigating smart approaches to new cancer treatments from concept through to clinical development and regulatory approval.

We operate a lean, agile research and development model, empowering the team to form conclusions and make quick decisions with the aim of getting new therapies to patients as rapidly as possible. For more information please visit:

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Media Contacts:



Europe and RoW

Tiffany Fretwell

Communications Lead, Mundipharma

Tel: +44 (0) 1223 393 361

Helen Rae

Makara Health

Tel: +44 (0) 23 81 247 327

1 U.S. Food & Drug Administration. Designating an Orphan Product: Drugs and Biological Products. Last updated Jul 2018. Accessed Mar 25, 2019. Retrieved from

2 U.S. Government Publishing Office. Electronic Code of Federal Regulations. 316.21: Verification of orphan-drug status. Accessed Mar 25, 2019. Retrieved from

3 Dearden C. How I treat prolymphocytic leukemia. Blood. 2012; 120(3):538–551. Accessed Mar 25, 2019. Retrieved from

4 National Institutes of Health. National Cancer Institute SEER Database: T-cell prolymphocytic leukemia. Accessed Mar 25, 2019. Retrieved from

5 Swerdlow SH, et al. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues (Revised 4th Edition). IARC: Lyon, 2017.

6 Leukemia and Lymphoma Society. T-cell Prolymphocytic Leukemia (T-PLL). Accessed Mar 25, 2019. Retrieved from

7 López-Iglesias AA, et al. The Alkylating Histone Deacetylase Inhibitor Fusion Molecule Edo-S101 Displays Full Bi-Functional Properties in Preclinical Models of Hematological Malignancies. Blood. 2014; 124:2100. 

8 López-Iglesias AA, et al. Preclinical Antimyleoma Activity of EDO-S101. Clinical Lymphoma, Myeloma & Leukemia. 2015; 15(Suppl 3):PO-238.

9 De Filippi R, et al. The First-in-Class Alkylating Histone-Deacetylase Inhibitor (HDACi) Fusion Molecule Edo-S101 Exerts Potent Preclinical Activity Against Tumor Cells of Hodgkin Lymphoma (HL) Including Bendamustine-Resistant Clones. Blood. 2015; 126:2481.

10 Yan S et. al. Synergistic inhibition of tumor growth and overcoming chemo-resistance by simultaneously targeting key components in DNA damage/repair, epigenetic, and putative cancer stem cell signaling pathways using novel dual-functional DNA-alkylating/HDAC inhibitor and tumor suppressor gene nanoparticles in lung cancer. Cancer Res 2012;72(8 Suppl):Abstract nr 2741. Accessed Mar 25, 2019. Retrieved from