According to a story from Medscape, the US Food and Drug Administration recently decided to approve Lumoxiti. This immunotoxin gained approval for the treatment of a rare form of cancer called hairy cell leukemia. More specifically, the drug is approved for adult patients who have experienced relapse after receiving two other treatments.
About Hairy Cell Leukemia
Hairy cell leukemia is a rare subtype of chronic lymphocytic leukemia. It is characterized by the abnormal proliferation of B cell lymphocytes, which are a type of white blood cell. This is one of the rarest blood cancers, with only about 2,000 diagnosed cases per year in both Western Europe and the US combined. The name is in reference to the “hairy” appearance of the cancerous B cells when observed under a microscope. The cause of this cancer is not well understood, but possible risk factors include exposure to herbicides or pesticides and mutations of the BRAF gene. Symptoms of hairy cell leukemia include enlarged spleen, bleeding and bruising easily, infections, anemia, and fatigue. Treatment options for this cancer can include single agent chemotherapy, monoclonal antibodies, interferon-alpha, and surgical removal of the spleen. Treatment is often successful and most patient’s lives are not shortened by the disease. To learn more about hairy cell leukemia, click here.
Lumoxiti represents an innovative treatment approach for hairy cell leukemia, as it is classified an immunotoxin or cytotoxin, delivered via an injection. While most patients with hairy cell leukemia respond well to currently available treatments and therefore will not necessarily have to use Lumoxiti, it provides a valuable fall back option for the small number of patients who disease returns even after extensive treatment.
The drug performed well in trials; thirty percent of participants had what was termed a durable complete response, which is defined in this study as a period of remission that lasts more than 180 days. The overall response rate in the trial was 75 percent.
While this treatment will be a valuable tool for doctors and their patients, Lumoxiti does carry the potential for some serious side effects, and carries a box warning for capillary leak syndrome. This can cause swelling, weight gain, low blood pressure, and breathing difficulties.