June 16, 2020
The U.S. FDA has approved an expanded indication for Pfizer’s Mylotarg™ (gemtuzumab ozogamicin) intravenous injection. Mylotarg is now indicated to treat newly diagnosed CD33-positive acute myeloid leukemia (AML) patients as young as one month of age. Previously, its use in treating newly diagnosed CD33-positive AML was restricted to adults only.
AML is a cancer that begins in the bone marrow, where the body creates new blood cells. It occurs when the bone marrow generates abnormal myeloblasts (a type of white blood cell), red blood cells, and/or platelets. Without treatment, AML progresses rapidly, first spreading from the bone marrow to the blood, and then sometimes beyond, into the lymph nodes, liver, spleen, and other organs. Some AML cells create a protein called CD33, which Mylotarg targets to deliver anti-cancer therapy directly to the cells, inhibiting their growth and causing the cancer cells to die.
In a clinical study, nearly half (48%) of patients treated with Mylotarg and chemotherapy had not died or had induction failure or a relapse at a five-year follow-up, compared to 40% of patients who received chemotherapy alone. However, Mylotarg did not deliver statistically meaningful improvement in overall patient survival.
Recommended dosing is based on individual factors including the patient’s weight, diagnosis, and whether Mylotarg is being used as a single agent or as part of a treatment regimen that includes chemotherapy. A black box warning cautions that there is a risk of hepatotoxicity, including severe or fatal hepatic veno-occlusive disease (VOD), associated with the drug’s use.
Originally FDA approved in 2000, Mylotarg is also indicated to treat relapsed or refractory CD33-positive AML in patients who are at least two years old.