FDA Approves New Agent for Hairy Cell Leukemia

The Food and Drug Administration (FDA) approved the use of Lumoxiti (moxetumomab pasudotox-tdfk) for patients with relapsed or refractory hairy cell leukemia (HCL) who previously had at least two prior systemic therapies, including treatment with a purine nucleoside analog.

The drug is a CD22-directed cytotoxin, and the first of its kind to be approved in the HCL space.

“Lumoxiti fills an unmet need for patients with hairy cell leukemia whose disease has progressed after trying other FDA-approved therapies,” said Richard Pazdur, M.D., director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, in a statement.

The approval was based on a single-arm, open-label clinical trial that measured durable complete response (CR) — meaning that patients were in remission for at least 180 days after achieving CR – in 80 previously treated patients with HCL. Thirty percent of patients achieved durable CR, while the overall response rate (ORR) was 75 percent.

Before being approved, Lumoxiti recived an Orphan Drug designation from the FDA, which provides incentives for companies to develop drugs to treat rare diseases. HCL is a slow-growing cancer that occurs in the bone marrow, where the disease causes too many B cells to be produced, lowering the number of healthy white, red and platelet cells in a patient’s body.

Common side effects of Lumoxiti include infusion-related reactions, swelling caused by excess fluid in body tissue (edema), nausea, fatigue, headache, fever (pyrexia), constipation, anemia and diarrhea.

The drug also has a label warning regarding capillary leak syndrome, where fluid and proteins leak out of blood vessels and into the surrounding tissue. Patients and providers should be aware of the common symptoms: difficulty breathing, weight gain, hypotension, or swelling of arms, legs and/or face.

The Boxed Warning also includes hemolytic uremic syndrome, a condition caused by the abnormal destruction of red blood cells. It is vital that patients maintain enough fluid intake and that their health care team monitor their blood chemistry values frequently.

Other serious warnings include: decreased renal function, infusion-related reactions and electrolyte abnormalities. Women who are breastfeeding should not be given Lumoxiti.

“This therapy is the result of important research conducted by the National Cancer Institute that led to the development and clinical trials of this new type of treatment for patients with this rare blood cancer,” Pazdur said.