Ixa-dex, pom-dex both effective in heavily pretreated relapsed, refractory multiple myeloma

Ixazomib-dexamethasone (ixa-dex) and pomalidomide-dexamethasone (pom-dex) achieve comparable levels of efficacy and safety in relapsed and refractory multiple myeloma (RRMM) patients who had already been exposed to prior lenalidomide-based regimens, a recent study has found.

Researchers randomly assigned eligible patients to receive either ixa-dex (n=73, median age 72 years, 52 percent women) or pom-dex (n=49, median age 68 years, 47 percent women) and followed them until disease progression or toxicity.

Median progression-free survival (PFS) was 7.1 months in the ixa-dex arm, only marginally longer than the 4.8-month PFS in pom-dex comparators (hazard ratio [HR], 0.847, 95 percent confidence interval [CI], 0.535–1.341; p=0.477). The same was true when the analysis was restricted to those with 2 (HR, 1.083, 95 percent CI, 0.547–2.144) or ≥3 (HR, 0.686, 95 percent CI, 0.368–1.279) prior lines of therapy.

Treatment response was likewise comparable between groups. The overall response rate was 38 percent in the ixa-dex arm and 41 percent in the pom-dex group (odds ratio, 0.90, 95 percent CI, 0.43–1.90). Similarly, time to progression did not differ between treatments (HR, 0.830, 95 percent CI, 0.506–1.361).

In terms of safety, grade ≥3 treatment-emergent adverse events (TEAE) were reported in 69 percent and 81 percent of the ixa-dex and pom-dex groups, while 51 percent and 53 percent developed serious TEAEs, respectively. Rates of discontinuation and death were also similar between groups.

“RRMM is a heterogeneous disease, and no single treatment benefits all patients. Ixa-dex is an appropriate option for patients who cannot tolerate triplet combinations, or who are not able or prefer not to receive parenteral treatment administration, or who require a non-immunomodulatory drug-based treatment approach,” the researchers said.