Evaluating the effectiveness of daratumumab-containing regimens in patients with multiple myeloma who are unresponsive to lenalidomide maintenance therapy.

This study evaluated the effectiveness of daratumumab (Darzalex)-containing regimens in patients with multiple myeloma (MM) unresponsive to lenalidomide (Revlimid) maintenance therapy. The data showed that daratumumab-containing therapies are effective regimens in these patients.

Multiple myeloma (MM) is a type of cancer that comes from blood cells called plasma cells. A high number of patients with MM experience relapse (the tumor grows after treatment) or are refractory (not responsive to the treatment) to standard treatment. Currently, the treatment strategies for relapsed/refractory (r/r) MM are based on the different combinations of conventional drugs and novel drugs. The standard treatment combinations for r/r MM are pomalidomide (Pomalyst) in combination with dexamethasone (Decadron) (Pd) and bortezomib (Velcade) in combination with dexamethasone (Pd).

Another standard treatment combination in patients with newly diagnosed MM is lenalidomide in combination with dexamethasone (Rd). Lenalidomide is an immunotherapy drug that boosts the body’s immune system to help it attack cancer cells. Daratumumab is an immunotherapy drug that directly targets the cancer cells to kill them. Daratumumab combined with the Rd regimen (D-Rd), Pd regimen (D-Pd) or the Vd regimen (D-Vd) has been previously shown to improve the survival outcomes in patients with previously treated unresponsive MM. However, the effectiveness of daratumumab­-based therapies in patients with MM who are unresponsive to lenalidomide is not known.

The study involved 73 patients with MM. All patients had previously received lenalidomide maintenance therapy and did not respond or relapsed on this treatment. Patients were divided into 3 groups based on the treatment combinations they received after lenalidomide maintenance. Group 1 included 18 patients who received the D-Pd regimen. Group 2 included 32 patients who received the D-Rd regimen. Group 3 included 23 patients who received the D-Vd regimen. The average follow-up time was 41.8 months for group 1, 21.6 months for group 2, and 13.8 months for group 3.

The average survival without cancer worsening was 15.8 months for all patients. The average survival without cancer worsening was 18.9 months for group 1, 21.7 months for group 2, and 12.9 months for group 3.

The average overall survival was 49.1 months for all patients. The average overall survival was 49.1 months for group 1 and was not reached (exceeded the average follow-up period) for group 2 and group 3.

76.5% of the patients in group 1 achieved a complete response/very good partial response (complete or partial disappearance of cancer cells) compared with 58.1% of the patients in group 2 and 28.6% of the patients in group 3.

This study concluded that daratumumab-containing therapies are effective regimens in patients with MM who are unresponsive to lenalidomide maintenance therapy.

This study looked back in time at medical records. The sample size was very small. This study did not contain information on other emerging daratumumab-containing regimens, such as in combination with carfilzomib (DKd regimen). Additional studies are required to decide the optimal regimen for post-lenalidomide maintenance.