Data from a second interim analysis (median follow-up of 21 months) of a phase III, randomized, double-blind study of continuous lenalidomide (Revlimid?) for the treatment of elderly patients with newly diagnosed multiple myeloma (also known as myeloma or plasma cell myeloma) show improvement in progression-free survival (PFS), the primary endpoint of the study. The data were presented during the EHA | European Haematology Association?s annual congress being held from June 10-13 in Barcelona, Spain.
Multiple myeloma is a cancer of the blood in which malignant plasma cells are overproduced in the bone marrow. Plasma cells are white blood cells that help produce antibodies called immunoglobulins that fight infection and disease. However, most patients with multiple myeloma have cells that produce a form of immunoglobulin called paraprotein (or M protein) that does not benefit the body. In addition, the malignant plasma cells replace normal plasma cells and other white blood cells important to the immune system. Multiple myeloma cells can also attach to other tissues of the body, such as bone, and produce tumors. The cause of the disease remains unknown.
The study of 459 patients 65 years or older evaluated patients receiving lenalidomide in combination with melphalan and prednisone, followed by lenalidomide alone (MPR-R) (n=152); patients receiving lenalidomide in combination with melphalan and prednisone, followed by placebo (MPR) (n=153); and patients receiving placebo, melphalan and prednisone, followed by placebo (MP) (n=154).
Median PFS of the MPR-R arm has yet to be reached, while the MP arm had a median PFS of 13 months (p0.001). Patients treated with MPR-R had a 58% reduction in the risk of disease progression compared to MP, an improvement over the reduction in risk of disease progression reported at the first interim analysis in December 2009. At the time of the second analysis, it was estimated that 55% of all patients receiving MPR-R would remain progression free after two years compared to only 16% of patients receiving MP.
In the safety population (the patients who received at least one dose of therapy on study), the most common grade 3 or 4 hematological adverse events included neutropenia (71%, MPR-R vs. 30%, MP), thrombocytopenia (39%, MPR-R vs. 14%, MP) and febrile neutropenia (7%, vs. 0%, MP). Grade 3 or 4 non-hematological adverse events included fatigue (6%, MPR-R vs. 3%, MP), deep-vein thrombosis/pulmonary embolism (4%, MPR-R vs. 1%, MP), and rash (5%, MPR-R vs. 1%, MP). No grade 3 or 4 peripheral neuropathy was experienced by patients in this study.
These data are from an investigational study. Lenalidomide is not approved as an initial treatment for patients with multiple myeloma. Lenalidomide in combination with dexamethasone is indicated for the treatment of multiple myeloma patients who have received at least one prior therapy. The drug is indicated for patients with transfusion-dependent anemia due to low- or intermediate-1?risk myelodysplastic syndromes (MDS) associated with a deletion 5q cytogenetic abnormality with or without additional cytogenetic abnormalities.