Evaluating the long-term effectiveness and safety of adding isatuximab to carfilzomib and dexamethasone therapy for the treatment of patients with relapsed multiple myeloma.

This study reported the long-term effectiveness and safety of adding isatuximab (Sarclisa) to carfilzomib (Kyprolis) and dexamethasone (Decadron) combination (Kd) for patients with previously treated relapsed multiple myeloma (MM). The data showed that over the long term adding isatuximab to the Kd regimen was effective with manageable side effects for 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 r/r MM are based on the different combinations of conventional drugs and novel drugs.

One standard treatment combination for r/r MM is pomalidomide (Pomalyst) in combination with dexamethasone (Pd). Isatuximab is an immunotherapy drug that has been approved for the treatment of r/r MM. It has been shown to improve the outcomes of these patients when combined with Pd therapy. Carfilzomib is a proteasome inhibitor. Proteasomes are large molecules present in all body cells. It blocks the action of proteasomes, therefore preventing cancer cells from growing and multiplying. Carfilzomib and dexamethasone (Kd) are commonly used together to treat r/r MM. However, the long-term effectiveness and safety of adding isatuximab to Kd therapy for patients with previously treated relapsed MM remain under investigation.

The study involved 302 patients with previously treated relapsed MM. Patients were randomly assigned into 2 groups. Group 1 included 179 patients who received isatuximab + Kd treatment. Group 2 included 123 patients who received Kd treatment alone. The average follow-up time was 44 months.

The average survival without progression or cancer worsening was 35.7 months in group 1 compared to 19.2 months in group 2. Patients in group 1 were 42% more likely to survive without progression or cancer worsening than patients in group 2.

Overall, 86.6% of the patients in group 1 responded to the treatment compared to 83.7% of the patients in group 2. The complete response (CR) rate (complete removal of cancer cells) was 44.1% for group 1 compared to 28.5% for group 2.

The negative minimal residual disease (MRD; no cancer cells that remain after treatment) response rate was 33.5% in group 1 compared to 15.4% of the patients in group 2. The CR with negative MRD was 26.3% in group 1 compared to 12.2% of the patients in group 2.

70.1% of the patients in group 1 experienced severe treatment-related side effects compared to 59.8% of patients in group 2. The most common side effects were high blood pressure, diarrhea, and respiratory infections. 

This study concluded that over the long-term adding isatuximab to carfilzomib and dexamethasone regimen was effective with manageable side effects for the treatment of patients with previously treated relapsed MM. This treatment regimen is the new standard of care for these patients.

This study was sponsored by Sanofi, the manufacturer of isatuximab.