Photo Credit: jkil
Advances in the treatment of multiple myeloma (MM) have significantly improved patient outcomes. However, the prognosis remains heterogeneous, influenced by various risk factors and treatment responses. The German-speaking Myeloma Multicenter Group (GMMG) Myeloma Registry provides a valuable resource for examining long-term data, including the outcomes of the GMMG-HD6 trial, according to researchers at the ASH Annual Meeting. This phase 3 study assessed the efficacy of adding the anti-SLAMF7 monoclonal antibody elotuzumab to standard induction and consolidation therapy with lenalidomide, bortezomib, and dexamethasone (RVd) in transplant-eligible MM patients.
The GMMG-HD6 trial enrolled 564 patients between June 2015 and September 2017, with 436 patients ultimately included in the registry for long-term follow-up analysis. The study compared four treatment arms—RVd/R, RVd/E-R, E-RVd/R, and E-RVd/E-R—focusing on progression-free survival (PFS), overall survival (OS), and causes of death. Data on treatment-free intervals, relapse management, and outcomes were also analyzed. The median follow-up time was 85 months.
The study found no statistically significant differences in PFS or OS among the four treatment groups. Five-year estimated PFS rates ranged from 48.0% to 56.3%, with no significant variation in time to progression. The median OS was not reached in any treatment arm, and 135 of 559 patients had died by the cut-off date. Causes of death were categorized into MM-dependent (67%), MM-independent (9.5%), unclassifiable (9.5%), and unknown (14%). Among MM-dependent deaths, 66.7% were due to disease progression, and 23.3% were related to therapy, primarily infections.
Post-relapse treatment strategies were diverse, the authors stated. Of the 183 patients experiencing at least one relapse, 62.7% were treated with the anti-CD38 monoclonal antibody daratumumab, either alone or in combination with proteasome inhibitors and immunomodulators. Notably, 22.4% of relapsed patients did not require immediate therapy and were managed with observation alone.
Based on the trial findings, the addition of elotuzumab to standard therapy in transplant-eligible patients with MM did not improve PFS or OS in the long-term follow-up of the GMMG-HD6 trial. MM progression and therapy-related infections were the leading causes of death, emphasizing the need for vigilant monitoring and infection management.
