Treating Patients With Metastatic Prostate Cancer Not Responding to Hormone and Chemotherapy

Inclusion Criteria: Histologically confirmed adenocarcinoma of the prostate Progressive metastatic disease (i.e., positive bone scan or measurable disease) despite castrate levels of testosterone (either from orchiectomy or luteinizing hormone-releasing hormone [LHRH] agonist therapy) Progressive disease after discontinuing hormonal therapy Progressive disease is based on any of the following*: Transaxial imaging Rise in prostate-specific antigen (PSA) Radionuclide bone scan (must show new metastatic lesions) Nonmeasurable or measurable disease For measurable disease, progression is defined by RECIST criteria Positive bone scan and elevated PSA required for nonmeasurable disease PSA evidence of progressive prostate cancer during or after first-line chemotherapy consists of a PSA level ≥ 2 ng/mL that has risen on ≥ 2 successive occasions ≥ 1 week apart Received ≥ 3 prior courses of paclitaxel- or docetaxel-based therapy, with disease progression documented during therapy or after cessation of therapy No more than 1 prior chemotherapy regimen Re-treatment with the same taxane-based regimen allowed Changes in prior chemotherapy regimen (addition of other agents) for disease progression are considered 2 chemotherapy regimens, and are not allowed PSA ≥ 2 ng/mL Testosterone < 50 ng/dL Patients must continue primary androgen deprivation with LHRH analogue if they have not undergone orchiectomy No known active brain metastases ECOG performance status 0-2 Life expectancy ≥ 12 weeks Creatinine ≤ 1.5 times upper limit of normal (ULN) OR creatinine clearance > 40 mL/min ALT and AST < 2.5 times ULN Granulocyte count ≥ 2,000/mm³ Platelet count ≥ 100,000/mm³ Bilirubin < 1.5 times ULN Ejection fraction normal by MUGA scan or echocardiogram No significant cardiovascular disease, including any of the following: Congestive heart failure (New York Heart Association class III-IV heart disease) Active angina pectoris Myocardial infarction within the past 6 months No serious infections or nonmalignant medical illnesses that are uncontrolled or whose control may be jeopardized by study therapy No psychiatric illness or social situation that would preclude study compliance No pre-existing motor or sensory peripheral neuropathy > grade 1 No known prior severe hypersensitivity reactions to agents containing Cremophor® EL No "currently active" second malignancy other than nonmelanoma skin cancer Patients are not considered to have a "currently active" malignancy if they have completed therapy and are considered to be at < 30% risk of relapse Fertile patients must use effective contraception prior to, during, and for 3 months after completion of study treatment See Disease Characteristics No prior mitoxantrone hydrochloride, ixabepilone, or other epothilones At least 4 weeks since prior hormonal therapy (i.e., any dose of megestrol, finasteride, or any herbal product known to decrease PSA levels [e.g., saw palmetto or PC-SPES]) other than LHRH agonist or a stable dose of corticosteroids from a prior chemotherapy regimen More than 4 weeks since other prior systemic therapies for prostate cancer At least 4 weeks since prior radiation therapy More than 8 weeks since prior radiopharmaceuticals (e.g., strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium) No concurrent moderate to strong CYP3A4 inhibitors No concurrent prophylactic colony-stimulating factors No concurrent radiotherapy