The combination of ixazomib and dexamethasone is clinically active and well tolerated in patients with relapsed multiple myeloma not refractory to bortezomib, a study published in the journal Blood has shown.1
Ixazomib is an oral proteasome inhibitor approved in combination with lenalidomide and dexamethasone for the treatment of patients with multiple myeloma who have received at least 1 prior therapy. It is being studied in a variety of combination, but in this particular phase 2 trial (Ixazomib in Treating Patients With Relapsed Multiple Myeloma That Is Not Refractory to Bortezomib; ClinicalTrials.gov Identifier: NCT01415882), researchers sought to evaluate the efficacy and tolerability of 2 different doses of ixazomib with dexamethasone in patients with relapsed multiple myeloma.
For the study, investigators enrolled 70 patients and randomly assigned them 1:1 to receive ixazomib 4 mg or 5.5 mg weekly for 3 or 4 weeks plus dexamethasone 40 mg weekly.
Results showed that 43% (95% CI, 31-55) of patients achieved a confirmed partial response or better overall, with 31% in the 4 mg group and 54% in the 5.5 mg group achieving a response.
Overall median event-free survival was 8.4 months and the 1-year overall survival rate was 96%
Among patients who previously received bortezomib, median event-free survival was 5.7 months vs 11.0 months in bortezomib-naïve patients.
Though well tolerated, ixazomib 5 mg was associated with higher rates of treatment-related adverse events and more frequent dose reductions.
1. Kumar SK, LaPlant BR, Reeder CB, et al. Randomized phase 2 trial of ixazomib and dexamethasone in relapsed multiple myeloma not refractory to bortezomib. Blood. 2016 Oct 4. doi: 10.1182/blood-2016-05-717769 [Epub ahead of print]