On September 13, 2018, the U.S. Food and Drug Administration (FDA) approved a new treatment option for adults with hairy cell leukemia (HCL) who have tried at least two prior systemic treatments: Lumoxiti™ (moxetumomab pasudotox-tdfk).1
How Lumoxiti works
Lumoxiti is a targeted treatment known as an immunotoxin. Immunotoxins can attach to specific compounds on cancer cells and deliver medication (a toxin) directly to the cancer cell.2 Lumoxiti targets CD22 on the surface of B cells. Once attached to the CD22 receptor, Lumoxiti is absorbed into the cell where it causes the cancer cell’s death.3
New option for hairy cell leukemia
HCL is a rare form of chronic lymphocytic leukemia (CLL) named for the appearance of the cancer cells under a microscope (which look “hairy”). HCL develops from B cells, a type of white blood cell that creates antibodies and is important in the immune system functioning. When the B cells become cancerous in HCL, they multiply and can crowd out healthy cells, causing a variety of symptoms including frequent infections, increased risk of bleeding, and anemia.4
Current treatment options for HCL include chemotherapy, biologic therapy, splenectomy, and targeted therapy. For those who have relapsed or refractory HCL after treatment, Lumoxiti offers a new option.
How effective is Lumoxiti?
Lumoxiti was studied in a clinical trial in which 80 patients with HCL who had previously received treatment with at least two systemic therapies (including a purine nucleoside analog) were given Lumoxiti. As a result of the treatment, 30% of the patients achieved durable complete response, which was measured as maintaining remission for more than 180 days. Another 45% of patients had a partial response.1,3
What are the possible side effects of Lumoxiti?
The most common side effects experienced with Lumoxiti include infusion-related reactions, swelling caused by excess fluid (edema), nausea, fatigue, headache, fever, constipation, diarrhea, and anemia. Lumoxiti may cause serious side effects, including capillary leak syndrome (in which fluid and proteins leak out of small blood vessels into the tissues), hemolytic uremic syndrome (in which red blood cells are abnormally destroyed), decreased kidney function, infusion-related reactions, and electrolyte abnormalities.1,3
Why this approval is significant
Immunotoxins are an exciting type of treatment because of their ability to target specific proteins. Treatments such as chemotherapy target rapidly growing cells. Cancer cells are rapidly growing, but there are other cells in the body that are also rapidly growing, such as those that line the digestive tract and hair cells. Because chemotherapy affects any cell that replicates quickly, it can cause many side effects. The goal of targeted therapy is to deliver the toxic chemical specifically to cancer cells, while sparing healthy cells in the body.2
Lumoxiti is the first treatment of its kind for HCL and offers patients a new, targeted approach to cancer treatment.1
FDA approves new kind of treatment for hairy cell leukemia. U.S. Food and Drug Administration. Available at https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm620448.htm. Accessed 9/17/18.
Aruna G. Immunotoxins: A Review of Their Use in Cancer Treatment. Journal of Stem Cells & Regenerative Medicine. 2006;1(1):31-36.
Lumoxiti prescribing information. Available at https://www.accessdata.fda.gov/drugsatfda_docs/label/2018/761104s000lbl.pdf. Accessed 9/17/18.
Hairy cell leukemia treatment (PDQ). National Cancer Institute. Available at https://www.cancer.gov/types/leukemia/patient/hairy-cell-treatment-pdq. Accessed 9/17/18.