Marlborough, Massachusetts — Sumitomo Pharma America said the U.S. Food and Drug Administration has granted orphan drug designation to enzomenib for the treatment of acute lymphoblastic leukemia.
Enzomenib, also known as DSP-5336, is an investigational oral small-molecule inhibitor designed to block the interaction between menin and lysine-specific methyltransferase 2A, or KMT2A. That interaction plays a role in the growth and proliferation of acute leukemia cells and other tumors.
The FDA previously granted enzomenib orphan drug designation for acute myeloid leukemia in June 2022.
The drug is being evaluated in an ongoing Phase 1/2 dose-escalation and dose-expansion study involving patients with relapsed or refractory acute leukemia. It is also being studied in the registrational Phase 2 Horizen-1 trial in patients with relapsed or refractory acute myeloid leukemia or acute lymphoblastic leukemia with KMT2A rearrangements or NPM1 mutations.
“The availability and selection of treatment choices is a major clinical and logistical challenge for patients with acute lymphoblastic leukemia, a challenge underscored by the complexity of sequencing therapies,” said Tsutomu Nakagawa, President and Chief Executive Officer of Sumitomo Pharma America.
“Receiving Orphan Drug Designation for enzomenib for the treatment of ALL is an exciting development that reinforces the molecule’s potential,” Nakagawa added. “We will work closely with the FDA to advance clinical research of enzomenib in the hopes of bringing an innovative new treatment option to people living with ALL.”
Acute lymphoblastic leukemia, also known as acute lymphocytic leukemia, is a rapidly progressing blood cancer in which the bone marrow produces excessive numbers of immature lymphocytes.
The disease can interfere with normal blood cell production, increasing the risk of infections, anemia and bleeding. Leukemia cells can also spread to other parts of the body, including the brain and spinal cord.
Menin is a nuclear scaffold protein involved in gene expression, cell growth, the cell cycle, genomic stability and blood cell formation.
In preclinical studies, enzomenib selectively inhibited the growth of human acute leukemia cell lines with KMT2A rearrangements or NPM1 mutations.
The drug also reduced expression of the leukemia-associated genes HOXA9 and MEIS1 while increasing expression of CD11b, a gene associated with cell differentiation, in leukemia cell models carrying those alterations.
The FDA granted Fast Track designation to enzomenib in June 2024 for relapsed or refractory acute myeloid leukemia with KMT2A rearrangements or NPM1 mutations.
Japan’s Ministry of Health, Labour and Welfare granted the drug orphan designation for the same AML patient population in September 2024.
