- Any prior therapy must have been completed >= 4 weeks or, if known, >= 5 half-lives of the prior agent (whichever is shorter) prior to enrollment on protocol (minimum of 1 week between prior therapy and study enrollment), and the participant must have recovered to eligibility levels from prior toxicity; patients should be at least 6 weeks out from nitrosoureas and mitomycin C; prior definitive radiation should have been completed >= 4 weeks or palliative radiation should have been completed >= 2 weeks prior to study enrollment and all associated toxicities resolved to eligibility levels; patients who have had prior monoclonal antibody therapy must have completed that therapy >= 6 weeks (or 3 half-lives of the antibody, whichever is shorter) prior to enrollment on protocol (minimum of 1 week between prior therapy and study enrollment); patients who have received more than a cumulative dose of 350 mg/m^2 of doxorubicin may be enrolled at the discretion of the coordinating center principal investigator (PI), with a screening echocardiogram