Kyprolis (carfilzomib) received the Food and Drug Administration's (FDA) approval today for treating multiple myeloma patients who have had at least two prior therapies, including Velcade (bortezomib) and an immunomodulating drug, such as Thalomid (thalidomide) or Revlimid (lenalidomide).The FDA's Oncology Drug and Advisory Committee met just last month and recommended the drug for approval. The recommendation came after an FDA staff report expressed concerns about the adverse effects of Kyprolis outweighing the benefits. Kyprolis, which is administered intravenously, works similarly to the targeted drug Velcade by preventing the normal breakdown of proteins in a cell, which might lead to cell death and inhibit tumor growth. It has shown activity in Velcade-resistant disease in earlier studies. Kyprolis's approval is based on a phase 2, single-arm study in 266 patients with relapsed disease. About 23 percent of patients experienced complete or partial tumor shrinkage and maintained the response for a median of 7.8 months. There currently is no data on improvement in survival for Kyprolis. While Kyprolis does not seem to result in peripheral neuropathy that is associated with Velcade use, more than a third of patients experienced side effects that included low blood cell and platelet levels, fatigue and diarrhea. Serious side effects include heart failure, pneumonia and renal failure, so patients should be closely monitored for symptoms of these impairments. The drug should be available to doctors by Aug. 1 and will cost about $1,658 per vial. Comparatively, Velcade costs about $1,471 per vial. For more information, visit kyprolis.com.