Pazopanib Hydrochloride After Leuprolide Acetate or Goserelin Acetate in Treating Patients With Relapsed Prostate Cancer

Inclusion Criteria:

* Histologically or cytologically confirmed prostate cancer

  * Stage D0
* Must have undergone some definitive local therapy for prostate cancer
* Must be free of macrometastatic disease, as evidenced by computed tomography (CT) scan and bone scan, if serum PSA ≥ 10 ng/mL prior to GnRH agonist therapy
* Progressive disease meeting the following criteria: NOTE: Patients who have undergone a prostatectomy and have two detectable, rising serum PSA levels are eligible

  * Two consecutive rises in PSA above nadir recorded after definite local therapy
  * Serum PSA concentrations must have absolute value of \> 0.5 ng/mL (separated by ≥ 2 weeks) prior to beginning GnRH agonist therapy
* PSA \< 0.5 ng/mL
* Testosterone \< 30 ng/mL
* No measurable disease
* No brain metastases requiring steroid or anticonvulsant therapy
* Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-2 OR Karnofsky PS 60- 100%
* Prothrombin time (PT)/international normalization ratio (INR)/partial thromboplastin time (PTT) ≤ 1.2 times upper limit of normal (ULN)
* Bilirubin normal
* Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 times ULN
* Creatinine ≤ 1.5 times ULN OR creatinine clearance \> 50 mL/min
* Proteinuria ≤ 1+ on 2 consecutive dipsticks \> 1 week apart
* Urine protein: creatinine ratio \< 1 OR urine protein \< 1.0 g/24 hours
* Fertile patients must use effective double-barrier contraception during study therapy OR completely abstain from sexual intercourse 14 days prior to, during, and for ≥ 21 days after completion of study therapy
* No history of allergic reactions attributed to compounds of similar chemical or biological composition to pazopanib hydrochloride or to other agents used in the study
* No concurrent uncontrolled illness including, but not limited to, any of the following:

  * Ongoing or active infection
  * Psychiatric illness or social situations that would preclude compliance with study requirements
* No human immunodeficiency virus (HIV) positivity
* No condition that impairs the ability to swallow and retain pazopanib hydrochloride tablets, including any of the following:

  * Gastrointestinal tract disease resulting in an inability to take oral medication
  * Requirement for intravenous (IV) alimentation
  * Prior surgical procedures affecting absorption
  * Active peptic ulcer disease
* No other conditions, including any of the following:

  * Serious or nonhealing wound, ulcer, or bone fracture
  * Abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within the past 28 days
  * Cerebrovascular accident within the past 6 months
  * Myocardial infarction, admission for unstable angina, cardiac angioplasty, or stenting within the past 6 months
  * Venous thrombosis within the past 12 weeks
  * New York Heart Association (NYHA) class III or IV heart failure

    * History of currently treated asymptomatic NYHA class II heart failure allowed
* Systolic blood pressure (BP) ≤ 140 mm Hg and diastolic BP ≤ 90 mm Hg

  * Prior initiation or adjustment of BP medication allowed provided that the average of 3 BP readings at a visit prior to enrollment is \< 140/90 mm Hg
* More than 3 months since prior antiandrogen
* More than 4 months since prior orchiectomy or implantable luteinizing LHRH agonist
* No prior GnRH agonists except for neoadjuvant or adjuvant therapy associated with local therapy

  * Patients who have started a GnRH agonist for micrometastatic disease after local therapy allowed provided the following criteria are met:

    * Progressive disease
    * Willing to discontinue therapy before 6 months have elapsed
    * Have signed consent prior to completing 6 months of the initial hormone therapy
    * Are within 4 months of initiating GnRH agonist therapy
* No prior or concurrent GnRH antagonist therapy
* No concurrent ketoconazole
* No concurrent cytochrome P450 2C9 (CYP2C9) substrates, including any of the following:

  * Anticoagulants (e.g., warfarin \[therapeutic doses only\])

    * Low molecular weight heparin or prophylactic low-dose warfarin allowed
  * Oral hypoglycemics (e.g., glipizide, glyburide, tolbutamide, glimepiride, or nateglinide)
  * Ergot derivatives (e.g., dihydroergotamine, ergonovine, ergotamine, or methylergonovine)
  * Neuroleptics (e.g., pimozide)
  * Erectile dysfunction agents (e.g., sildenafil, tadalafil, or vardenafil)
  * Antiarrhythmics (e.g., bepridil, flecainide, lidocaine, mexiletin, amiodarone, quinidine, or propafenone)
  * Immune modulators (e.g., cyclosporine, tacrolimus, or sirolimus)
  * Miscellaneous medications (e.g., theophylline, quetiapine, risperidone, tacrine, clozapine, or atomoxetine)
* No concurrent medications associated with the risk of QTc prolongation and/or Torsades de Pointes

  * Replacement of drugs that do not carry these risks allowed
* No other concurrent non-Food and Drug Administration (FDA)-approved agents