ASCO 2019: Lenalidomide vs. Observation in Smoldering Multiple Myeloma
Posted: Thursday, May 16, 2019
For patients with asymptomatic high-risk smoldering multiple myeloma, lenalidomide may delay progression to myeloma and improve progression-free survival compared with observation alone, according to findings to be presented at the 2019 American Society of Clinical Oncology (ASCO) in Chicago (Abstract 8001). The E3A06 trial, conducted by Sagar Lonial, MD, of the Winship Cancer Institute at Emory University, Atlanta, and colleagues, is reportedly the largest randomized trial in smoldering multiple myeloma to date, and the results support previous findings from a randomized Spanish trial also comparing lenalidomide and observation alone.
“When you put our trial together in aggregate with the Spanish trial, it’s pretty clear that early intervention is a prevention strategy—not a treatment strategy—which can reduce the risk of conversion to symptomatic myeloma,” stated Dr. Lonial in an ASCO press release.
This phase III intergroup trial enrolled 182 patients with intermediate- or high-risk smoldering multiple myeloma. Patients were randomly assigned to receive lenalidomide (90 patients) or observation alone (92 patients). In an initial phase II trial, 44 patients received lenalidomide to demonstrate its safety. Patients were required to have at least 10% plasma cells and abnormal serum free light chain ratio (< 0.26 or > 1.65).
Among the lenalidomide-treated patients, grade 3 or 4 nonhematologic adverse events occurred in 28% of phase III patients, with fatigue as the most common event (5 patients). Researchers found that the 3-year rate of cumulative incidence of invasive second primary malignancies was 5.2% with lenalidomide and 3.5% with observation alone. No difference in quality-of-life scores was noted between treatment arms.
Among patients in the phase II trial, the overall response rate for those receiving lenalidomide was 47.7%, with a 3-year progression-free survival of 87%. In patients in the phase III trial, lenalidomide yielded an overall response rate of 48.9%, compared with 0% with observation. In patients receiving lenalidomide, the 1-, 2-, and 3-year progression-free survival rates were 98%, 93%, and 91%, respectively; with observation, the corresponding rates were 89%, 76%, and 66%, respectively.
Disclosure: The study authors’ disclosure information may be found at coi.asco.org.
