Ixabepilone Compared With Mitoxantrone and Prednisone in Treating Patients With Refractory Metastatic Prostate Cancer

Inclusion Criteria:

* Histologically confirmed adenocarcinoma of the prostate
* Metastatic disease (positive bone scan or measurable disease)
* Progressive hormone-refractory disease

  * Based on 1 of the following:

    * Transaxial imaging
    * Rise in prostate-specific antigen (PSA)
    * Radionuclide bone scan
  * Must have undergone primary hormonal treatment (e.g., orchiectomy or gonadotropin-releasing hormone analog with or without an antiandrogen) and demonstrated disease progression after antiandrogen discontinuation as defined below:

    * Two consecutive rising PSA values, obtained at least 2 weeks apart, or documented osseous or soft tissue progression
    * For patients receiving flutamide, at least 1 PSA value must be obtained at least 4 weeks after flutamide discontinuation
    * For patients receiving bicalutamide or nilutamide, at least 1 PSA value must be obtained at least 6 weeks after antiandrogen discontinuation
  * Ineligible if sole manifestation of progression is an increase in disease-related symptoms
* Meets 1 of the following criteria:

  * Measurable disease and an elevated PSA
  * Nonmeasurable disease and an elevated PSA, as follows:

    * Positive bone scan
    * PSA level at least 5 ng/mL, with increases on at least 2 successive occasions at least 2 weeks apart
  * New metastatic lesions by radionuclide bone scan
* Must have received at least 2 courses of paclitaxel- or docetaxel-based therapy, with disease progression documented during therapy or no more than 60 days after cessation of therapy\*
* Testosterone \< 50 ng/dL
* No known active brain metastases
* Performance status - ECOG 0-2
* At least 12 weeks
* Granulocyte count ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Bilirubin \< 1.5 times upper limit of normal (ULN)
* AST and ALT \< 3 times ULN
* Creatinine ≤ 1.5 times ULN
* Creatinine clearance \> 40 mL/min
* Ejection fraction ≥ lower limit of normal by MUGA or echocardiogram
* No myocardial infarction within the past 6 months
* No significant cardiovascular disease
* No New York Heart Association class III or IV congestive heart failure
* No active angina pectoris
* Fertile patients must use effective contraception before, during, and for 3 months after study therapy
* No prior hypersensitivity reaction to agents containing Cremophor®EL
* No serious infection
* No nonmalignant medical illnesses that are uncontrolled or whose control would be jeopardized by complications of study therapy
* No psychiatric illness or social situation that would preclude study compliance
* No motor or sensory neuropathy grade 2 or greater
* No "currently active" second malignancy except nonmelanoma skin cancer

  * Patients are not considered to have a "currently active" malignancy provided they have completed therapy and are considered to have less than a 30% risk of relapse
* No concurrent prophylactic colony-stimulating factors for myelosuppression
* See Disease Characteristics
* No more than 1 prior chemotherapy regimen
* No prior mitoxantrone or epothilone
* No other concurrent chemotherapy
* See Disease Characteristics
* At least 4 weeks since prior antiandrogens (e.g., flutamide) (6 weeks for bicalutamide or nilutamide)

  * Patients must continue primary androgen deprivation therapy with luteinizing hormone-releasing hormone agonist during study if prior orchiectomy was not performed
* At least 4 weeks since prior systemic (including oral) corticosteroids except corticosteroids as part of first-line chemotherapy tapered off over 10-14 days prior to study entry
* At least 4 weeks since any prior hormonal therapy, including megestrol or finasteride
* No other concurrent systemic steroids
* At least 4 weeks since prior radiotherapy
* More than 8 weeks since prior radiopharmaceuticals (e.g., strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium)
* No concurrent radiotherapy
* See Disease Characteristics
* At least 4 weeks since prior herbal products known to decrease PSA levels (e.g., Saw Palmetto or PC-SPES)
* More than 4 weeks since other prior antiprostate cancer therapy
* More than 4 weeks since prior systemic therapies for prostate cancer
* No other concurrent investigational agents