Are injections under the skin of daratumumab as effective as intravenous infusions for patients with relapsed or refractory multiple myeloma?

This study examined if subcutaneous (sc) injections of daratumumab (Darzalex) were as effective and safe as intravenous (iv) infusions for patients with relapsed or refractory multiple myeloma (MM). The authors found that sc injections were as effective as iv infusions and caused fewer side effects.

Daratumumab is a biological therapy that targets MM cells and helps to destroy them. It is given by iv infusion in hospitals or medical centers. The first infusion takes up to 7 hours and the following infusions take 3 to 4 hours. This practice is time-consuming, can affect patients’ quality of life, and increases the risks of developing side effects. Daratumumab sc injections may be a more feasible alternative. It is unknown if daratumumab is as effective when injected sc as it is as an iv infusion.

522 patients with relapsed or refractory MM were divided into two groups. 263 patients were given daratumumab by sc injection (sc group) and 259 by iv infusion (iv group). Patients’ results were compared for an average of 7.5 months.

41% of patients in the sc group responded to treatment (had a reduction in MM). This was compared to 37% of patients in the iv group. Patients survived for an average of 5.6 months without cancer worsening in the sc group and 6.1 months in the iv group. After 6 months, 88% of the sc group and 83% of the iv group survived.

Patients were 72% less likely to develop a side effect from the administration mode with a sc injection of daratumumab. 13% of patients in the sc group developed a side effect from the injection itself, compared with 34% of patients in the iv group. The most common injection/infusion side effects were chills and breathing difficulties.

88% of the injection group and 89% of the infusion group experienced side effects caused by daratumumab treatment. The most common side effects were low red blood cells, low white blood cells, and low platelets.

The authors concluded that daratumumab sc injections are as effective and safer than iv infusions for patients with relapsed or refractory MM.

The manufacturer of daratumumab, Janssen, funded this study. This study would benefit from extending the study out for a longer period of time. There was no placebo in this study which may have caused bias in the results.