DISEASE CHARACTERISTICS:

• Symptomatic multiple myeloma, meeting the following criteria at original diagnosis:

  • Bone marrow plasmacytosis with ≥ 10% plasma cells or sheets of plasma cells or biopsy proven plasmacytoma
  • Symptomatic disease (e.g., anemia, hypercalcemia, bone disease, or renal dysfunction) that requires the initiation of therapy

• Measurable disease as assessed by one of the following:

  • Monoclonal plasma cells detectable in the bone marrow
  • Monoclonal serum spike detectable by serum protein electrophoresis or immunofixation
  • Monoclonal protein detectable in the urine by electrophoresis or immunofixation
  • Abnormal levels of the serum free light chains with an abnormal ratio between kappa and lambda NOTE: If both serum and urine m-components are present, both must be followed in order to evaluate response
• Progressive disease after ≥ 1 prior therapy for myeloma

• Previously treated with ≤ 10 courses (30 weeks) of bortezomib and had no disease progression during therapy OR completed bortezomib therapy within the past 6 weeks

  • No prior discontinuation of bortezomib therapy due to drug intolerance
• No known brain metastases

• No intracranial edema, intracranial metastasis, or active epidural disease

  • Patients with lytic lesions of the cranium secondary to myeloma are eligible

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Life expectancy > 6 months
• ANC ≥ 1,000/mm³
• Platelet count ≥ 50,000/mm³
• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal (ULN)
• Creatinine ≤ 2 times ULN
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No peripheral neuropathy > NCI toxicity grade 2
• No history of allergic reactions attributed to compounds of similar chemical or biologic composition to obatoclax mesylate or bortezomib

• No concurrent uncontrolled illness including, but not limited to the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia, including QTc > 450 msec
  • Psychiatric illness/social situations that would limit compliance with study requirements
• No history of seizure disorder
• No other neurological disorder or dysfunction that, in the opinion of the investigator, would confound the evaluation of neurologic and other adverse events associated with obatoclax mesylate

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• At least 14 days since prior chemotherapy and recovered
• More than 28 days since prior experimental drugs and/or investigational agents
• No concurrent CYP interactive medications
• No concurrent combination antiretroviral therapy for HIV-positive patients

• No other concurrent anticancer therapy

  • Growth factors and bisphosphonates are allowed as medically indicated
  • Prednisone (≤ 10 mg per day) allowed provided there has been no dose increase within the past 2 weeks
• No other concurrent investigational agents