The targeted agent Darzalex (daratumumab) produces long-lasting anti-cancer responses among patients with multiple myeloma that has stopped responding to several prior therapies. These results were recently published in the jol Blood.
Multiple myeloma is a type of blood cancer that affects certain immune cells called plasma cells. Healthy plasma cells produce proteins called antibodies that are an important part of the immune system’s defense for fighting bacteria and viruses.
Cancerous plasma cells tend to replicate at a fast pace, crowding out other healthy immune cells, as well as producing malfunctioning antibodies. These antibodies tend to cause damage to the kidneys, in addition to reducing the immune system’s ability to efficiently fight infection.
Researchers continue to evaluate novel treatment options for multiple myeloma, particularly among patients whose disease has progressed or returned despite prior therapies (referred to as recurrent or refractory disease). Novel therapeutic agents that do not tend to create the severity of side effects associated with chemotherapy continue to be developed for the treatment of various types of cancers, including multiple myeloma. Studies are ongoing to explore optimal combinations and sequences of regimens containing these novel compounds.
Daratumumab is an agent referred to as a monoclonal antibody. It was developed through laboratory processes to specifically target a protein found on the surface of multiple myeloma cells, called CD38. Daratumumab binds to the CD38 protein on the cancerous cells, and causes cellular death through several different mechanisms. It is currently approved by the United States Food and Drug Administration (FDA) for the treatment of multiple myeloma that continues to progress following at least 3 prior therapies, including a proteasome inhibitor (PI) and/or an immunomodulatory drug (IMiD); it is also approved in Europe. Daratumumab continues to be evaluated in clinical trials for different treatment settings in multiple myeloma and different cancers affecting immune cells.
Researchers recently updated data from an analysis including two clinical studies evaluating daratumumab among patients with multiple myeloma who had stopped responding to prior therapies. The trials included 148 patients who had received a median of 5 prior therapies, and 86.5% of patients had multiple myeloma that had stopped responding to treatment including both a PI and an IMiD.
- 1% of patients achieved anti-cancer responses when treated with daratumumab.
- The median duration of anti-cancer responses was 7.6 months.
- The median time of survival without progression of disease was 4 months.
- Median overall survival time was 20.1 months.
- Survival benefit was achieved even among those patients whose cancer didn’t regress, but had stopped progressing and stabilized while receiving treatment with daratumumab.
- No new safety issues regarding side effects of were noted.
The researchers concluded that “In this pooled dataset, daratumumab 16 mg/kg monotherapy demonstrated rapid, deep, and durable responses, with a clinical benefit that extended to patients with stable disease or better.” Daratumumab is an effective treatment option for patients with multiple myeloma that have stopped responding to several prior therapies.
Patients with multiple myeloma may wish to speak with their healthcare provider regarding their individual risks and benefits of treatment with daratumumab.
Reference: Usmani S, Weiss B, Plesner T, et al. Clinical efficacy of daratumumab monotherapy in patients with heavily pretreated relapsed or refractory multiple myeloma. Blood. 2016; doi:10.1182/blood-2016-03-705210. Available at: http://www.bloodjournal.org/content/early/2016/05/23/blood-2016-03-705210?sso-checked=true. Accessed June 29, 2016.