Assessing Induction of Double Strand Breaks With Androgen Receptor Partial Agonist in Patients on Androgen Suppression

This is a prospective, single-center, two-phase study to assess the efficacy of single
pulsed-dose flutamide in creating DSBs (double strand breaks) in prostate cancer within
patients receiving central androgen suppression and brachytherapy. The initial phase is a
6-patient single-arm run-in phase to test feasibility and rule out futility of the
intervention. All patients within the run-in phase will receive 50mg flutamide prior to
brachytherapy and prostatic biopsy. If futility is ruled out (>1 patients with DSBs on
biopsy), then accrual will continue in the randomized, double-blind phase. Subjects will be
randomized in a 2:1 ratio (12:6 patients), for an all-trial total of 18 patients receiving
flutamide vs 6 patients receiving placebo.

Inclusion Criteria:

- Histologically confirmed prostate cancer

- At least one biopsy core with Gleason 7 or higher disease

- The patient has decided to undergo brachytherapy plus androgen suppression as
treatment modality for his prostate cancer (with or without supplemental external beam
radiation)

- Suitable volume of disease for biopsy:

- clinically palpable disease corresponding to (ipsilateral to) any involved core on
biopsy

- Signed study-specific consent form prior to registration

Exclusion Criteria:

- Known hypersensitivity or allergic response to flutamide

- Severe hepatic impairment

- Major medical or psychiatric illness which, in the investigator's opinion, would
prevent completion of treatment and would interfere with follow up.