Inclusion Criteria:

- Histologically or cytologically confirmed prostate cancer

- Measurable or non-measurable disease

- Measurable defined as ≥ 1 lesion that can be accurately measured in ≥ 1
dimension (longest diameter to be recorded) as ≥ 20 mm by conventional
techniques or as ≥ 10 mm by spiral CT scan

- Lymph nodes considered measurable if ≥ 20 mm

- Non-measurable are all other lesions, including small lesions (longest diameter
< 20 mm by conventional techniques or < 10 mm by spiral CT scan) and the
following:

- Bone lesions

- Leptomeningeal disease

- Ascites

- Lymphangitis cutis/pulmonis

- Inflammatory breast disease

- Abdominal masses not followed by CT or MRI

- Cystic lesions

- Patients with elevation of PSA alone without measurable or nonmeasurable disease
are not eligible

- Must have received prior hormonal therapy with medical (LHRH agonist) or surgical
(orchiectomy) castration

- Castrate level of testosterone (< 50 ng/dL) required (baseline measurement of
test not required for patients who have had surgical castration)

- Clinical and/or radiographic evidence of progression on or after docetaxel therapy

- No active pleural or pericardial effusion of any grade

- No meningeal metastases or untreated known brain metastases

- Patients with treated brain metastasis with radiologic and clinical evidence of
stability, with no evidence of cavitation or hemorrhage in the brain lesions
allowed provided that they are asymptomatic and do not require corticosteroids

- Life expectancy > 3 months

- ECOG performance status (PS) 0-2 (Karnofsky PS 60-100%)

- ANC ≥ 1,500/mm³

- Platelet count ≥ 100,000/mm³

- Hemoglobin ≥ 9 g/dL

- INR ≤ 1.3

- Total bilirubin ≤ 1.25 times upper limit of normal (ULN)

- AST and ALT ≤ 2.0 times ULN (5 times ULN if clearly attributable to liver metastasis)

- Creatinine normal OR creatinine clearance ≥ 60 mL/min

- LVEF > 50% by ECHO/MUGA

- Urine dipstick for protein < 1+ OR < 1 g on 24-hour urine collection

- More than 5 years since any malignancy except in situ cancer, non-metastatic basal or
squamous cell skin cancer, or other cancer for which the patient has been curatively
treated by definitive primary therapy alone and has been continuously disease-free

- Fertile patients must use effective contraception

- No condition that potentially impairs ability to swallow or absorb, including any of
the following:

- Gastrointestinal tract disease resulting in an inability to take oral medication
or a requirement for IV alimentation

- Active peptic ulcer disease

- Short gut syndrome

- Malabsorption syndrome of any type

- Total or partial bowel obstruction

- Inability to tolerate oral medications

- No history of allergic reactions attributed to compounds of similar chemical or
biologic composition to cediranib or dasatinib

- No systolic BP > 150 mmHg and/or diastolic BP > 100 mmHg (with or without stable dose
anti-hypertensive medication), poorly controlled hypertension, history of labile
hypertension, or poor compliance with anti-hypertensive medication

- No QTc prolongation ≥ 450 msec, or other significant ECG abnormalities (i.e.,
clinically significant arrhythmias requiring medication, conduction delays such as
2nd or 3rd degree atrioventricular blocks, etc)

- None of the following conditions:

- Serious or non-healing wound, ulcer, or bone fracture

- History of abdominal fistula, gastrointestinal perforation, or intra-abdominal
abscess within the past 28 days

- Any history of cerebrovascular accident (CVA) within the past 6 months

- History of symptomatic cardiac dysfunction within the past 12 months including,
but not limited to, any of the following:

- Unstable angina

- NYHA class III or IV heart failure

- Myocardial infarction

- Cardiac angioplasty, stenting, or bypass

- No active or uncontrolled infections, serious illness, or medical conditions that
would not permit the patient to be managed according to the protocol

- No known immunodeficiency syndrome

- No clinical or radiological evidence of severe or uncontrolled interstitial lung
disease (e.g., bilateral, diffuse, or parenchymal lung disease), or current unstable
or uncompensated respiratory conditions

- No history or concurrent idiopathic pulmonary fibrosis

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No unresolved toxicity ≥ CTC grade 2 (except alopecia) from prior anticancer therapy

- At least 4 weeks since prior anti-androgens

- At least 4 weeks since prior chemotherapy following docetaxel for metastatic disease

- Any number of regimens allowed

- At least 4 weeks since prior hormonal therapy or abiraterone

- If patient was receiving prior LHRH agonists, then therapy must be continued or
restarted

- At least 3 weeks since prior radioisotopes or radiotherapy and recovered

- Concurrent low-dose, nonmyelosuppressive radiotherapy may be allowed

- No prior therapy with angiogenesis or Src or FAK inhibitors

- Prior COX-2 inhibitor in standard dose is not considered antiangiogenic therapy

- At least 4 weeks since prior non-angiogenic therapy

- At least 3 weeks since prior major surgery and recovered

- At least 1 week since prior corticosteroids

- Concurrent low-dose corticosteroid (≤ 20 mg of prednisone daily) and appropriate
analgesics and/or narcotics allowed

- Concurrent zoledronic acid allowed provided patient has been receiving it prior to
start of study treatment

- Concurrent medications or substances known to affect or with the potential to affect
the activity or pharmacokinetics of cediranib and dasatinib will be determined
following review of their case by the principal investigator or co-investigator

- At least 14 days before and after study and no concurrent CYP3A4-active agents or
substances (including strong inhibitors or inducers)

- Concurrent prophylactic low-dose warfarin (INR must be close monitored) or
low-molecular weight heparin allowed

- No other concurrent investigational agents