Darzalex (daratumumab) has received accelerated approval by the FDA to treat patients with multiple myeloma, a form of blood cancer that occurs in infection-fighting plasma cells (a type of white blood cell) found in the bone marrow normally responsible for producing antibodies.. Also known as plasma cell myeloma,myelomatosis, or Kahler’s disease, multiple myeloma may result in a weakened immune system and cause other bone or kidney problems. Most cases also feature the production of a paraprotein—an abnormal antibody which can cause kidney problems.Bone lesions and hypercalcemia (high blood calcium levels) are also often encountered.
Multiple myeloma is the 2nd most common hematological malignancy in the U.S. (after non-Hodgkin lymphoma), and makes up 1% of all cancers. According to the National Cancer Institute there will be an estimated 26,850 new cases of multiple myeloma and 11,240 related deaths in the United States by the end of this year. For unknown reasons, however, is more common in men and, twice as common in African Americans as it is in Caucasians. With conventional treatment, median survival is 3–4 years, which may be extended to 5–7 years or longer with advanced treatments. Darzalex injection, given as an infusion, is a monoclonal antibody that works by helping certain cells in the immune system attack cancer cells.
“Targeting proteins that are found on the surface of cancer cells has led to the development of important oncology treatments,” stated Dr.Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in FDA’s Center for Drug Evaluation and Research. “Darzalex provides another treatment option for patients with multiple myeloma who have become resistant to other therapies.” who have received at least 3 prior treatments.
The safety and efficacy of Darzalex were demonstrated in two open-label studies. In one study of 106 participants receiving Darzalex, 29% of patients experienced a complete or partial reduction in their tumor burden, which lasted for an average of 7.4 months. In the second study of 42 participants receiving Darzalex, 36% had a complete or partial reduction in their tumor burden. The most common side effects of the treatment were infusion-related reactions, fatigue, nausea, back pain, fever and cough. Darzalex may also result in low counts of infection-fighting white blood cells (lymphopenia, neutropenia, and leukopenia) or red blood cells (anemia) and low levels of blood platelets (thrombocytopenia).
In the meantime, the FDA warned blood banks that they need to be made aware of any patients who are receiving Darzalex because the drug may interfere with certain tests such as antibody screening for people who need a blood transfusion. In addition, women who are pregnant should not use Darzalex, while women hoping to become pregnant should use effective contraceptives during and for at least three months after treatment.