Inclusion Criteria:

• Patient is a male or female at lease 18 years old
• Patient has relapsed or refractory MM and has had at least one prior therapy
• Female patients of childbearing potential must have 2 negative serum pregnancy tests prior to receiving the first dose of study drugs
• Female patients who can become pregnant must agree to use 2 separate forms of effective birth control at the same time, 4 weeks before, while taking, and for 4 weeks after stopping lenalidomide. Post menopausal patients should be free from menses for > 2 years, or are surgically sterilized
• Male patient agrees to use an adequate method of contraception for the duration of the study, even if the patient has undergone a successful vasectomy
• Male patients must agree to use a latex condom during sexual contact with a pregnant female or a female who can become pregnant. This is required for the duration of the study, and for 4 weeks after stopping therapy
• Patient has at least 3 weeks washout prior to treatment
• Patient is able to swallow capsules and is able to take or tolerate oral medications on a continuous basis

Exclusion Criteria:

• Patient has prior treatment with an HDAC inhibitor
• Patient has prior allogenetic bone marrow transplant
• Patient has received intravenous antibiotics, antiviral, or antifungal agents within 2 weeks prior to the start of the study drug
• Patient uses illicit drugs, substance abuse or had a recent history (within the last year) of drug or alcohol abuse
• Patient is pregnant or breast feeding or expecting to have baby during the course of the study
• Patient has HIV infection
• Patient has Hepatitis B/C infection
• Patient is currently receiving treatment for another type of cancer other than skin or cervix cancer that has not been in remission for 5 years or longer