Maintenance Therapy With Ixazomib Without Stem Cell Transplant in Patients With Myeloma
Long-term follow-up data from a phase I/II study demonstrated durable responses with weekly ixazomib, lenalidomide, and dexamethasone, followed by maintenance ixazomib, for newly diagnosed patients with multiple myeloma. Shaji K. Kumar, MD, of the Mayo Clinic, Rochester, Minnesota, presented these results at the 2017 European Hematology Association (EHA) Annual Congress (Abstract S408).
Among 65 patients, 42 did not withdraw from the study early to receive stem cell transplant. At a median follow-up of 56 months, investigators reported an overall response rate of 80% in these patients, including a complete response rate of 32%.
Grade 3 or higher adverse events during induction therapy occurred in 74% of patients. They included thrombocytopenia, neutropenia, and fatigue. One patient died of treatment-related cardiac arrest.
Following induction therapy, 25 patients went on to receive maintenance therapy with single-agent ixazomib. In these patients, the investigators reported an overall response rate of 100% at data cutoff, including a complete response in 44% and a very good partial response in 32%. The median progression-free survival was 24 months.
Grade 3 or higher adverse events during maintenance occurred in 24% (6 patients). These events included thrombocytopenia (4%) and hypokalemia (4%).
Dr. Kumar concluded: “Data showed that patients had deep responses on single-agent therapy and median progression-free survival of more than 2 years. We remain committed to gathering additional data on ixazomib in this investigational, maintenance setting.”