New advanced multiple myeloma drug Darzalex from Johnson & Johnson received approval from the U.S. Food and Drug Administration on Nov. 16. Darzalex is the pioneer monoclonal antibody and first biologic drug for myeloma patients who have failed past treatments and with limited options. Approximately 26,850 people in the United States are affected by myeloma, as per the National Cancer Institute.
Darzalex is a genetically engineered drug treatment that only attacks ailing tissues, leaving healthy cells unharmed. Multiple myeloma is a cancer of the plasma cells, a type of white blood cells produced in the bone marrow. The immune system is made up of plasma cells. Healthy plasma cells produce infection-fighting antibodies called immunoglobulins. In patients with myeloma, the plasma cells fail to function normally and multiply at an uncontrollable rate. They produce just one type of antibody called paraprotein, which has no valuable function except to diagnose and monitor a myeloma patient.
Chemically known as daratumumab, Darzalex works by binding to a protein on the surface of malignant myeloma cells. Through multiple mechanisms, Darzalex coaxes the tumor cells to die, leaving healthy cells safe. Doctors suggest the new drug offers hope for patients who are left untreated with previous medication.
"Targeting proteins that are found on the surface of cancer cells has led to the development of important oncology treatments. Darzalex provides another treatment option for patients with multiple myeloma who have become resistant to other therapies," said Dr. Richard Pazdur, Office of Hematology and Oncology Products director at the FDA's Center for Drug Evaluation and Research.
In one study covering 106 myeloma patients receiving Darzalex, 29 percent experienced fractional or complete reduction of their malignant tumors. The result lasted 7.4 months on average. In the second study covering 42 myeloma patients, 36 percent experienced the same.
Common side effects may involve nausea, fatigue, back pain, cough, fever and allergic-like responses arising from the drug infusion. Patients taking the drug may incur serious side effects from reduced amounts of red blood cells (anemia), blood platelets (thrombocytopenia) and white blood cells (leukopenia, neutropenia and lymphopenia). Pregnant women are advised not to use Darzalex. Women planning to conceive are advised to use contraceptives during Darzalex treatment and three months more post-treatment.
