Vorinostat and Lenalidomide After Autologous Stem Cell Transplant in Treating Patients With Multiple Myeloma

DISEASE CHARACTERISTICS: * Diagnosis of multiple myeloma * Has undergone melphalan-conditioned autologous peripheral blood stem cell transplant myeloma. PATIENT CHARACTERISTICS: * ECOG/WHO performance status 0-2 * ANC ≥ 1,000/mm³ * Platelet count ≥ 75,000/mm³ * Total bilirubin ≤ 2 times upper limit of normal (ULN) * AST and ALT ≤ 2 times ULN * Serum creatinine ≤ 1.5 times ULN OR creatinine clearance ≥ 50 mL/min * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 90 days after completion of study treatment * No blood, sperm, or ova donation during and for ≥ 4 weeks after completion of study treatment * Able to obtain commercially available lenalidomide via Celegene's RevAssist® program * Registered in the RevAssist® program * Willing and able to comply with the requirements of RevAssist® * Able to swallow capsules * No severe or uncontrolled systemic illness * No "currently active" second malignancy, other than nonmelanoma skin cancer or carcinoma in situ of the cervix * Patients are not considered to have a "currently active" malignancy if they completed therapy for the malignancy, are disease free from the malignancy for \> 5 years, and are considered by their physician to be at \< 30% risk of relapse * No congenital long QT syndrome * No drug or alcohol abuse within the past 12 months * No history of allergic reactions (including erythema nodosum) attributed to compounds of similar chemical or biologic composition to lenalidomide, thalidomide, or vorinostat * No other medical condition, including mental illness or substance abuse, deemed by the investigator(s) to likely interfere with a patient's ability to sign informed consent, cooperate and participate in the study, or interfere with the interpretation of the study results PRIOR CONCURRENT THERAPY: * See Disease Characteristics * More than 4 weeks since prior class Ia, Ib, or Ic antiarrhythmic medication * No prior HDAC inhibitor-like compounds (e.g., valproic acid) as anticancer therapy * More than 30 days since prior HDAC inhibitor-like compounds for other indications (e.g., valproic acid for epilepsy) * No prior gastrointestinal surgery or other procedure that may, in the opinion of the investigator, interfere with the absorption or swallowing of the study drugs * No concurrent corticosteroids other than for physiologic maintenance treatment * No concurrent radiotherapy, unless for local control of bone pain * Irradiated area should be as small as possible * Lesions within the irradiated field cannot be used for response assessment * No concurrent use of complementary or alternative medicines that would confound the interpretation of toxicities and anticancer activity of the study drugs * No other concurrent anticancer therapy, including chemotherapy or biologic therapy * No other concurrent HDAC inhibitors (e.g., valproic acid)