I. To determine the maximum tolerated dose of R-(-)-gossypol acetic acid (AT-101) that can be combined with lenalidomide and dexamethasone in patients with relapsed symptomatic multiple myeloma (MM). (Phase I) II. To determine the overall response rate (partial response or better) of AT-101 when used in combination with lenalidomide and dexamethasone in patients with relapsed symptomatic MM. (Phase II)