Adding ixazomib to treatment improves outcomes for relapsed/refractory multiple myeloma

This study examined the safety and effectiveness of ixazomib (Ninlaro) when added to the treatment of relapsed multiple myeloma. Researchers concluded that ixazomib was safe and effective at improving treatment outcomes for relapsed multiple myeloma.

The addition of biologic drugs to standard treatment regimens for multiple myeloma have substantially improved outcomes. They are particularly suited for cases of relapsed disease or when patients no longer respond to first-line therapy (refractory disease). Biologic drugs with slightly different mechanisms of action are often administered together to enhance effectiveness.

Ixazomib is a recently developed type of biologic therapy. It is a proteasome inhibitor that blocks the protein proteasomes in cancer cells and may prevent the growth of tumors. Early results have been promising when ixazomib was combined with the biologic drug lenalidomide (Revlimid) and the steroid drug dexamethasone (Dexasone).

The aim of this study was to examine the benefit of adding ixazomib to the treatment of relapsed multiple myeloma.

722 patients with relapsed or refractory multiple myeloma were included. Patients were randomly assigned to one of two treatment groups. They received either ixazomib plus lenalidomide and dexamethasone or lenalidomide and dexamethasone alone (control group). Patients were followed for an average of 14.7 months.

In the ixazomib group, 129 progressions or deaths were observed over the study period. In the control group, 157 progressions or deaths were observed.

Average time to progression in the ixazomib group was 20.6 months. This was significantly longer compared to the control group (14.7 months). Overall, patients in the ixazomib group were 26% less likely to show disease progression during the study period. These results were unaffected by poor prognosis, age, or number of previous therapies.

The rates of treatment response were 78.3% in the ixazomib group and 71.5% in the control group. 48% of patients in the ixazomib group were complete responders (no sign of active disease) or showed a very good partial response (highly decreased signs of disease). This was 39% in the control group.

Serious side effects were reported in 47% of patients in the ixazomib group and in 49% of patients in the control group. These included low neutrophil levels (type of white blood cells), low platelet levels (blood cells involved in blood clotting), and anemia (low red blood cell levels). Less serious side effects included rash, diarrhea, constipation, nausea, fatigue, and neuropathy (temporary nerve damage). Patient-reported quality of life was similar in the two groups.

Researchers concluded that adding ixazomib to treatment delayed disease progression in patients with relapsed or refractory multiple myeloma.