Elotuzumab Does Not Improve PFS in Newly Diagnosed Multiple Myeloma

Adding elotuzumab to treatment with lenalidomide and dexamethasone does not improve outcomes in patients with newly diagnosed multiple myeloma who are ineligible for transplant, according to results of the phase 3 ELOQUENT-1 trial.

Elotuzumab did not improve progression-free survival (PFS), overall survival (OS), or any other efficacy endpoint in this trial. These results were published in The Lancet Haematology.

ELOQUENT-1 (ClinicalTrials.gov Identifier: NCT01335399) included 742 patients with newly diagnosed multiple myeloma who were ineligible for hematopoietic stem cell transplant. The patients’ median age was 73.0 years, 95% of patients were White, and 55% were men. 

The patients were randomly assigned to receive treatment with elotuzumab plus lenalidomide and dexamethasone (n=371) or lenalidomide-dexamethasone only (n=371). Baseline characteristics were generally well balanced between the treatment arms. 

Most patients in the elotuzumab arm (90%) and the control arm (91%) discontinued treatment due to disease progression or adverse events (AEs), both related and unrelated to study treatment. 

At a minimum follow-up of 65.3 months, 38 patients in the elotuzumab arm and 32 in the control arm remained on therapy.

The median follow-up was 70.6 months. The median number of treatment cycles was 26 (range, 9-53) in the elotuzumab arm and 21 (range, 8-46) in the control arm.  

The study’s primary endpoint was not met, as there was no significant difference in PFS between the treatment arms. The median PFS was 31.4 months in the elotuzumab arm and 29.5 months in the control arm (hazard ratio [HR], 0.93; 95.71% CI, 0.77-1.12; P =.44). The 5-year PFS rates were 26% and 25%, respectively.  

There were no significant differences in any other efficacy endpoints. The overall response rate was 83% in the elotuzumab arm and 79% in the control arm (odds ratio, 1.26, 95% CI, 0.87-1.82; P =.22).

The median time to disease progression was 42.0 months in the elotuzumab arm and 36.0 months in the control arm (HR, 0.85, 95% CI, 0.69-1.05; P =.14). The median time to next treatment was 34.3 months and 29.2 months, respectively (HR, 0.85; 95% CI, 0.72-1001; P =.06). 

The median PFS2 was 51.7 months in the elotuzumab arm and 43.5 months in the control arm (HR. 0.88; 95% CI, 0.73-1.05; P =.15). The median OS was 60.4 months and 57.6 months, respectively (HR, 0.99; 95% CI, 0.82-1.19; P =.89). 

The most common grade 3-4 treatment-related AE was neutropenia, which occurred in 17% of patients in the elotuzumab arm and 21% of those in the control arm. There were 5 fatal AEs in the elotuzumab arm and 4 in the control arm. 

The researchers noted that the reasons for the lack of PFS benefit with elotuzumab remain unclear and may be multifactorial.

“[F]urther research is required to investigate the difference in treatment responses between patients with newly diagnosed and those with relapsed or refractory multiple myeloma,” the researchers concluded. 

Disclosures: This research was supported by Bristol Myers Squibb. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Dimopoulos MA, Richardson PG, Bahlis NJ, et al. Addition of elotuzumab to lenalidomide and dexamethasone for patients with newly diagnosed, transplantation ineligible multiple myeloma (ELOQUENT-1): An open-label, multicentre, randomised, phase 3 trial. Lancet Haematol. Published online May 9, 2022. doi:10.1016/S2352-3026(22)00103-X

This article originally appeared on Cancer Therapy Advisor