Lenalidomide with low-dose dexamethasone showed a significant overall survival benefit, compared with melphalan with prednisone and thalidomide, for patients with transplant-ineligible newly diagnosed multiple myeloma, according to the final analysis of the phase 3 FIRST trial.
The prespecified final analysis evaluated overall survival (OS) at a follow-up of 60 months or longer, according to the study, which was published in Blood. The FIRST study included 1,623 patients randomized to receive lenalidomide with low-dose dexamethasone continuously until disease progression (Rd continuous), lenalidomide plus low-dose dexamethasone for 18 cycles instead of continuously (Rd18), or melphalan plus prednisone and thalidomide (MPT). Patients with high-risk cytogenetics were distributed evenly across the three treatment arms.
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The Rd continuous cohort also experienced significantly longer PFS, compared with the MPT arm (HR, 0.69, 95% CI, 0.59-0.79, P less than .00001).
“Taken together, these findings suggest that Rd affords a clinical advantage in subsequent lines of therapy and highlight the importance of using Rd continuous and not MPT as first-line treatment of transplant-ineligible patients with [newly-diagnosed multiple myeloma],” the researchers wrote.
The OS benefit was similar for patients who received Rd continuous (59.1 months) and Rd18 (62.3 months). The researchers suggested that the similar survival could be due to a combination of factors, including the impact of subsequent lines of treatment and the older age of the patient population.
However, the benefit for Rd18 was not seen in the PFS analysis. Patients in the Rd18 group had a median PFS similar to that of patients in the MPT group (21 months vs. 21.9 months), both of which were shorter than the Rd continuous group (26 months).
The 4-year PFS more than doubled among patients in the Rd continuous arm (32.6%), compared with patients in both the Rd18 group (14.3%) and the MPT group (13.6%).
Patients in the Rd continuous group also experienced a decreased risk for progression or death, compared with patients in the Rd18 group (HR, 0.70, 95% CI, 0.60-0.81).
The researchers noted that no new safety concerns were observed in the final analysis. Second primary malignancies, including hematologic and solid tumors, were found in 36% of patients in the Rd continuous group, 38% of patients in the Rd18 group, and 46% of patients in the MPT group.
Celgene Corporation sponsored the study. Dr. Facon and his coauthors reported financial ties to various pharmaceutical companies, including Celgene.
SOURCE: Facon T et al. Blood. 2018 Jan 18;131(3):301-10.