The addition of elotuzumab to bortezomib and dexamethasone prolongs progression-free survival without worsening clinical toxicity in patients with relapsed/refractory multiple myeloma, a study published in the journal Blood has shown.1
Elotuzumab is a SLAMF7-directed immunostimulatory antibody indicated in combination with lenalidomide and dexamethasone for the treatment of patients with multiple myeloma who have received 1 to 3 prior therapies. Researchers sought to evaluate the efficacy and safety of bortezomib plus dexamethasone with or without elotuzumab in patients with relapsed/refractory disease.
For the open-label, phase 2 trial, researchers enrolled 152 patients and randomly assigned them 1:1 to receive elotuzumab plus bortezomib and dexamethasone or bortezomib plus dexamethasone.
Results showed that median progression-free survival was 9.7 months with elotuzumab compared with 6.9 months without the immunotherapy (HR, 0.72; 95% CI, 0.59-0.88; P = .09).
Researchers found that among patients homozygous for the high-affinity FcγRIIIa allele, median progression-free survival was 22.3 months with elotuzumab, bortezomib, and dexamethasone vs 9.8 months for elotuzumab-treated patients homozygous for the low-affinity allele.
Overall response rate was 66% with elotuzumab vs 63% with bortezomib and dexamethasone alone. A total of 36% of elotuzumab-treated patients achieved a very good partial response or better compared with 36% of those in the bortezomib-dexamethasone arm.
The study further demonstrated that elotuzumab may reduce the risk of death by 39% vs bortezomib plus dexamethasone alone (HR, 0.61; 70% CI, 0.43-0.85), but this finding is based on early results.
In terms of safety, grade 1 or 2 infusion reactions only occurred in 5% of patients in the elotuzumab group. No other clinically significant adverse events occurred in the elotuzumab arm that did not occur in the bortezomib-dexamethasone arm.
1. Jakubowiak A, Offidani M, Pégourie B, et al. Randomized phase 2 study of elotuzumab plus bortezomib/dexamethasone (Bd) versus Bd for relapsed/refractory multiple myeloma [published online ahead of print April 18, 2016]. Blood. doi:10.1182/blood-2016-01-694604.