Pomalidomide in the Treatment of Relapsed and Refractory Multiple Myeloma

Despite improvements in multiple myeloma therapy, the vast majority of patients continue to suffer relapses. Unfortunately, many patients event. develop disease that is refractory to lenalidomide and bortezomib and have few treatment options. Pomalidomide is a potent second-generation immunomodulatory agent with direct antiproliferative, pro-apoptotic, and antiangiogenic effects, as well as modulatory effects on bone resorption and on the immune system. Pomalidomide exhibited more potent anti-myeloma activity compared with thalidomide and lenalidomide. The optimal starting dose of pomalidomide is 4 mg given orally on days 1-21 of each 28-day cycle and combination with dexamethasone produces synergistic effects. In clinical trials, pomalidomide plus low-dose dexamethasone has shown better responses, progression-free and overall survival than high-dose dexamethasone or pomalidomide alone. Pomalidomide has limited cross-resistance with lenalidomide, and the overall response rates of pomalidomide in lenalidomide/bortezomib dual-refractory patients ranged from 26 to 31%. The most common grade 3 or 4 adverse events are hematologic, consisting of neutropenia, thrombocytopenia and anemia. Pomalidomide was approved by the FDA and the EMA in patients with multiple myeloma who have received at least two prior therapies including lenalidomide and bortezomib and have demonstrated disease progression on their last therapy. We review pomalidomide mechanism of action, clinical trials in relapsed and refractory patients, and novel pomalidomide-based combinations.