Purpose

This will be a multi-center, open label, expanded treatment protocol of panobinostat, bortezomib and dexamethasone in patients with relapsed and/or refractory multiple myeloma. Panobinostat will be administered at a starting dose of 20mg orally three times a week (every other day) for two weeks on and one week off, with dose adjustments permitted based on observed toxicity. Bortezomib will be administered either intravenously or sub-cutaneously, twice a week on days 1 and 4, two weeks on 1 week off. After 8 cycles of treatment, patients who have achieved stable disease or better by modified EBMT 1998 criteria may continue combination therapy with bortezomib dosing changed to days 1 and 8 of a 21 day cycle for up to 48 weeks of therapy. At the end of the treatment period, (48 weeks) patients with stable disease or better may continue on therapy at the discretion of their investigator until September 2015 or until drug is commercially available, whichever comes first. Patients who have not achieved at least stable disease by 8 cycles must discontinue from study treatment. Dexamethasone will be administered on the day of and the day immediately following bortezomib treatment. Patients will not receive any study treatment during the third week of each cycle. Cycles will be defined as 21 days of treatment. Investigators may not add any other anti-myeloma agents (with the exception of bisphosphonates) while patients remain on study treatment. Patients will remain on study until disease progression, unacceptable toxicity, or end of the study