This is a Prospective, Randomized, Double-Blind Study Comparing Intravesical Injection of Botox® to Placebo.

Overactive bladder is a common problem that follows chronic prostatic bladder outlet
obstruction and is part of the benign prostatic hyperplasia syndrome (BPH) in men.
Unfortunately, it does not often resolve after treatment (TURP, etc) of the obstruction from
enlarged prostate gland. Patients with obstructive BPH typically commence treatment with
alpha-blockers or anticholinergic agents; the former being used to treat enlarged prostate
medically, and the latter to treat overactive bladder symptoms. However, as mentioned,
anticholinergics cause many intolerable side effects leading to discontinuation in many
patients. Furthermore this class of drug is still considered a relative contraindication in
this population by some clinicians. Therefore other modalities need to be studied in these
men.

Based on numerous studies in overactive bladder (OAB), we hypothesize that these patients
will experience significant improvement (particularly if their symptoms of urgency and
frequency) without significant side effects from intradetrusor injections of BOTOX® even
though they have were refractory to systemic anticholinergics.

Inclusion Criteria:

1. Male between 40 and 90 years of age.

2. Clinical signs and symptoms of frequency and urgency

3. Urodynamic history consistent with OAB that developed in conjunction with Benign
Prostate Obstruction and that persists for at least 3 months post TURP or PVP, or
other obstruction relieving procedure.

4. OAB inadequately controlled with anticholinergic medications

5. Qmax >12mL/s with a voided volume of >125mL.

6. IPSS >12, with IPSS QoL >3 at study Visit 1.

7. Willing to use clean intermittent catheterization (CIC) to empty the bladder or is
willing to have an indwelling catheter, if necessary following study treatment.

Exclusion Criteria:

1. Known history of interstitial cystitis, uninvestigated hematuria, bladder outlet
obstruction due to vesical neck contracture, mullerian duct cysts, urethral
obstruction due to stricture/valves/sclerosis of urethral tumor, radiation cystitis,
genitourinary tuberculosis, bladder calculi, or detrusor-sphincter dyssynergia.

2. Current indwelling catheter, or removal of chronic catheter <1 month prior to study
entry.

3. Non-compliance with wash-out periods for prohibited medications/therapies

4. Evidence of Urinary Tract Infection according to local standard of care.

5. History of prostate cancer.

6. Serum PSA of >10ng/mL. [NOTE: Subjects with serum PSA concentrations >4 and <10 must
have prostate cancer excluded according to the local standard of care.]

7. 24 hour total volume voided >3000 mL of urine

8. Medical condition that may increase their risk of exposure to botulinum toxin
including diagnosed Myasthenia Gravis, Eaton-Lambert Syndrome, Amyotrophic Lateral
Sclerosis or any other disease that might interfere with neuromuscular function.

9. Allergy or sensitivity to any component of BOTOX®