Lenalidomide can reduce the risk of progression from smoldering multiple myeloma (SMM) to multiple myeloma (MM), according to a phase 2/3 trial.
At 3 years, the rate of progression-free survival (PFS) was 91% in SMM patients randomized to lenalidomide and 66% in those randomized to observation.
However, more than half of patients randomized to lenalidomide discontinued treatment because of toxicity.
These results are scheduled to be presented at the annual meeting of the American Society of Clinical Oncology.
Sagar Lonial, MD, of Winship Cancer Institute, Emory University, Atlanta, discussed the results in a press briefing in advance of the meeting.
A prior trial suggested that lenalidomide plus dexamethasone can improve time to MM development and overall survival in patients with high-risk SMM (Mateos MV et al. NEJM 2013). However, inferior imaging was used in this trial, and the addition of dexamethasone hindered researchers’ ability to isolate the effects of lenalidomide, Dr. Lonial said.
With their trial (NCT01169337), Dr. Lonial and colleagues tested lenalidomide alone and screened patients using magnetic resonance imaging.
The trial enrolled patients with intermediate or high-risk SMM in two phases. In phase 2, all 44 patients received lenalidomide at 25 mg daily on days 1-21 of a 28-day cycle. They also received aspirin at 325 mg on days 1-28.
In the phase 3 portion of the trial, 182 patients were randomized to observation or lenalidomide and aspirin at the aforementioned dose and schedule. Patients were stratified according to time since SMM diagnosis – 1 year or less vs. more than 1 year.