The US Food and Drug Administration (FDA) has expanded the approval of lenalidomide (Revlimid) to include its use as maintenance therapy for patients with multiple myeloma following autologous stem cell transplant (ASCT).
“ASCT after induction therapy is part of the continuum of care for transplant-eligible multiple myeloma patients. However, most patients will still see their disease recur or progress after this treatment,” said Philip McCarthy, MD, director of the Blood and Marrow Transplant Center at Roswell Park Cancer Institute in Buffalo, in a press release. “Lenalidomide maintenance therapy, which has been shown to increase progression-free survival (PFS) following ASCT in clinical trials can be considered a standard of care for these patients.”
The expanded approval was based on a pair of studies (CALGB 100104 and IFM 2005-02) that together included over 1,000 patients. Following ASCT, the studies compared maintenance therapy with lenalidomide vs placebo, with PFS as the primary endpoint.
In CALGB 100104, the median PFS in patients who received maintenance therapy was 5.7 years vs 1.9 years with placebo, for a hazard ratio (HR) of 0.38 (95% CI, 0.28–0.50).
In IFM 2005-02, a European-based study, lenalidomide maintenance yielded a median PFS of 3.9 years vs 2 years with placebo, for an HR of 0.53 (95% CI, 0.44–0.64). The studies were not powered to measure overall survival.
The most frequently reported adverse events (20% or higher in either trial) among patients receiving lenalidomide were thrombocytopenia, leukopenia, neutropenia, anemia, diarrhea, gastroenteritis, bronchitis, nasopharyngitis, upper respiratory tract infection, cough, rash, asthenia, muscle spasm, pyrexia, and fatigue. Onset of adverse events was generally highest in the first 6 months of treatment.
The most frequently reported grade 3/4 events (greater than 20%) were thrombocytopenia, leukopenia, and neutropenia.
Second primary malignancies were also more frequent in patients receiving lenalidomide maintenance (7.5% had second hematologic cancers vs 3.3% with placebo). When including solid tumors, the incidence rate of second primary cancers was 14.9% among patients receiving lenalidomide vs 8.8% among those receiving placebo. Non-melanoma skin cancers were also higher (3.9% vs 2.6%).