Patients receive R-(-)-gossypol acetic acid orally (PO) once a day (QD) on days 1-21. Beginning in course 2, patients also receive lenalidomide PO QD on days 1-21 and dexamethasone PO QD on days 1, 8, and 15. Treatment repeats every 28 days for 12 courses in the absence of disease progression or unacceptable toxicity.