Phase II study of melphalan, thalidomide and prednisone combined with oral panobinostat in patients with...

The combination of melphalan, prednisone and thalidomide (MPT) has demonstrated efficacy and acceptable toxicity in newly diagnosed and relapsed/refractory patients with multiple myeloma (MM). Panobinostat is a potent oral pan-deacetylase inhibitor (pan-DACi). In preclinical and clinical studies, panobinostat showed good anti-myeloma activity in combination with several agents. This phase II study evaluated the combination of a fixed dose of MPT with escalating doses of panobinostat (three times weekly for 3 weeks, followed by a 9-day rest period) in relapsed/refractory MM. We used a two-stage design to determine whether the combination was safe and effective. At least a partial response was observed in 38.5% of patients. The maximum tolerated dose of panobinostat in combination with MPT could not be determined due to the high rate of dose-limiting toxicities experienced with panobinostat at doses of 10 and 15 mg. The most common grade 3/4 adverse events were neutropenia (71%) and thrombocytopenia (35.5%). In conclusion, MPT in combination with panobinostat three times weekly for 3 weeks followed by a 9-day rest period is not well tolerated in patients with relapsed/refractory MM. Future studies should evaluate alternative dose schedules of panobinostat.