EHA25 Virtual: Long-Term Follow-up of Early Treatment of Smoldering Multiple Myeloma
Posted: Tuesday, June 30, 2020
Early treatment of patients with high-risk smoldering multiple myeloma with lenalidomide plus dexamethasone produced a significant improvement in both overall survival and time to progression to myeloma. Of note, this early treatment did not seem to induce more resistant disease relapses. Maria-Victoria Mateos, MD, PhD, of the University Hospital of Salamanca, Spain, and colleagues presented the 10-year follow-up results of their phase III trial during the virtual edition of the 25th European Hematology Association Annual Congress (EHA25 Virtual; Abstract EP950).
The trial was initiated in 2007, with 119 patients with high-risk smoldering multiple myeloma recruited. Patients were randomly assigned to the observation group or the treatment group. Those receiving treatment were administered nine 4-week induction cycles of lenalidomide plus dexamethasone followed by maintenance therapy for up to 2 years.
After a median of 10.8 years of follow-up, there was a 46% reduction in the risk of death for those receiving treatment compared with the control group. Overall survival was not yet reached in the treatment group and was 7.8 years in the control arm. The median time to progression to myeloma was 9 years in the group receiving treatment, compared with just 2 years in the observation group.
Progression to multiple myeloma occurred in 90% of patients in the control arm and 49% of patients receiving lenalidomide and dexamethasone. All patients who developed multiple myeloma were treated with standard-of-care therapy. There was no difference observed in overall survival from the start of multiple myeloma treatment between the two original groups. The overall survival in patients who were originally assigned to receive lenalidomide plus dexamethasone (6.4 years) was trending to be superior compared with the observation group (4.7 years), but it did not reach statistical significance (P = .50).
Disclosure: The study authors report no conflicts of interest.