Multiple myeloma patients got some good news on November 16—the immunotherapy daratumumab (Darzalex®) was given approval by the FDA for the treatment of patients with multiple myeloma who have received at least three prior lines of therapy. It is the first monoclonal antibody ever approved for multiple myeloma.
The efficacy of daratumumab was demonstrated in two clinical trials. In one study of 106 participants receiving daratumumab, 29 percent of patients experienced a complete or partial reduction of multiple myeloma cells. In the second study, daratumumab demonstrated a 36 percent overall response rate in 42 patients with multiple myeloma, who had relapsed after or were resistant to at least two or more prior lines of therapy. Daratumumab also induced durable responses that improved over time, with 65 percent of responding patients in remission at 12 months. This is really big news for multiple myeloma patients who have become resistant to treatment, which—until now—had a survival of less than a year.
“Daratumumab is a breakthrough for multiple myeloma patients who no longer respond to existing therapies,” said Alexander M. Lesokhin, M.D., a medical oncologist specializing in multiple myeloma at Memorial Sloan Kettering Cancer Center and a CRI grantee. “This FDA approval is giving these patients hope in their battle with cancer.”
Multiple myeloma is a form of blood cancer that occurs in plasma cells, a type of white blood cell normally responsible for producing antibodies. In multiple myeloma, these cancerous cells multiply and push out other healthy blood cells from the bone marrow. Daratumumab is an anti-CD38 antibody. CD38 is expressed on the surface of many immune cells, including plasma cells and most, if not all, multiple myeloma cells. By going after CD38, daratumumab kills the myeloma cells.
Studies are ongoing testing daratumumab earlier in the course of multiple myeloma. The hope is that early use, in combination with other treatments, will be transformative in making multiple myeloma a chronic yet manageable disease, rather than a deadly one.
The National Cancer Institute estimates there will be 26,850 new cases of multiple myeloma and 11,240 related deaths in the United States this year. Multiple myeloma is the second most common blood cancer in the U.S. (after non-Hodgkin lymphoma), and constitutes 1 percent of all cancers. The five year survival rate is 46.6 percent.
More and more patients are alive thanks to daratumumab, which would not exist without decades of funding support from the Cancer Research Institute for the dedicated scientists who have been studying the immune system and cancer.