A comparison of melphalan, prednisone plus either thalidomide or lenalidomide found that patients assigned to lenalidomide had fewer grade 3 or higher toxicities and a better quality of life at the end of induction therapy.
A comparison of melphalan, prednisone plus either thalidomide or lenalidomide did not find any significant differences in response rate, depth of response, time on therapy, progression-free, or overall survival in patients with newly diagnosed multiple myeloma. However, patients assigned lenalidomide did have fewer grade 3 or higher toxicities and a better quality of life at the end of induction therapy.
These results were taken from of the ECOG E1A06 study, presented at the 2014 American Society of Clinical Oncology (ASCO) Annual Meeting by A. Keith Stewart, MBChB, of the Mayo Clinic in Scottsdale, Ariz.
“This study was statistically inconclusive and, thus, did not provide inferiority or non-inferiority of the two regimens,” Stewart said.
Current standard treatment for patients with newly diagnosed multiple myeloma who are ineligible for transplant is combination therapy with melphalan, prednisone, and thalidomide (MPT). Early phase clinical trials though had suggested that patients might get better efficacy and less toxicity if lenalidomide (MPR) were substituted for thalidomide.
At the initiation of the study, the researchers had an expectation for a progression-free survival of about 20 months for MPT and about 24.7 months for MPR; however, long-term followed-up of the MPR regimen was lacking.
The study enrolled 306 patients randomly assigned to treatment with MPT with maintenance thalidomide or MPR with maintenance lenalidomide. The median age of patients was 75.7 years, and patients were followed for a median of 40.7 months.
No significant difference in the per protocol response rate was found between patients assigned MPT and MPR (partial response 64% vs 60%; P = .557). However, Stewart pointed out that about 17% of patients were not included in this per protocol analysis because of a missing lab from some portion of the study. Therefore, he also presented data on investigator adjudicated response rate. In this analysis, the MPT response rate was 75% compared with 70% with MPR. Specifically, the very good partial response/complete response rate was 25% for MPT and 32% for MPR.
The researchers also did not find a significant difference in progression-free survival (HR = 0.84; 95% CI, 0.64-1.09). The median progression-free survival was 21 months for MPT compared with 18.7 months for MPR. Subgroup analyses by sex, disease stage, performance status, age, or race also revealed no differences in progression-free survival.
Results for the secondary overall survival analysis also revealed no difference between the treatment arms (HR = 0.88; 95% CI, 0.63-1.24).
Several differences with respect to toxicity were found. Patients in the MPT arm had significantly more grade 3 or higher overall toxicity (73% vs 58%; P = .007) and grade 3 or higher non-hematologic toxicity (59% vs 40%; P = .001) compared with patients in the MPR arm.
Finally, Stewart and colleagues conducted a quality-of-life analysis that favored the lenalidomide arm by the end of induction with a mean change of -2.8 for thalidomide and +3.3 for lenalidomide (P = .007).
Another trial presented at the 2014 ASCO Annual Meeting found that treatment with lenalidomide and low-dose dexamethasone significantly improved some quality-of-life measures over melphalan, prednisone, and thalidomide in multiple myeloma patients.