Is daratumumab added to lenalidomide plus dexamethasone better in multiple myeloma?

This article investigated the safety and effectiveness of adding daratumumab (Darzalex) to lenalidomide (Revlimid) and dexamethasone (Decadron) for the treatment of relapsed or refractory (does not respond to treatment) multiple myeloma (RRMM). The authors concluded that the addition of daratumumab is safe and reduced the risk of progression and death.

Multiple myeloma (MM) is a cancer of plasma cells. These are a type of white blood cell normally responsible for producing antibodies. Lenalidomide and dexamethasone are a standard treatment for these patients. However, as MM progresses, there is a reduction in the response to treatments due to decreased sensitivity. 

An alternative treatment method is immunotherapy. This treatment uses monoclonal antibodies (laboratory-produced molecules engineered to stimulate the immune system to destroy cancer cells). Daratumumab is a type of immunotherapy. Added to lenalidomide and dexamethasone, daratumumab has been shown to induce rapid and long-standing responses in relapsed patients. However, the effect on overall survival and safety of daratumumab are still under investigation.

This study involved 569 patients with RRMM who had been previously treated. They were randomly assigned to two groups. Group 1 received treatment with daratumumab added to lenalidomide and dexamethasone (286 patients). Group 2 received treatment with lenalidomide and dexamethasone alone (283 patients). The outcomes measured were; progression-free survival (PFS; the time it took for cancer to start growing again), overall response rate (ORR), complete response (CR; no signs of cancer in the blood) and side effects. 

After an average of 25.4 months, the group that received daratumumab were 59% less likely to have cancer progression compared with the group that did not. Group 1 had an ORR of 92.9% compared with 76.4% in group 2. 26% of patients in group 1 achieved a CR compared with 8.7% of group 2.

The most common side effects reported included low white cell count (cells involved in fighting infection), low platelet count (cells involved in blood clotting), diarrhea, fatigue, cough, constipation, muscle spasms, anemia, pneumonia, and nausea. These did not affect the quality of life of patients treated with daratumumab.

The percentage of patients with side effects leading to stopping the treatment was similar between groups (12.0% for group 1, 12.8% for group 2). 

The authors concluded that the addition of daratumumab to lenalidomide and dexamethasone treatment is safe and reduced the risk of progression and death in patients with relapsed and refractory MM.

This study was supported by Janssen Research & Development, LLC, the developer of daratumumab.