Effect of dutasteride in men receiving intermittent androgen ablation therapy: The AVIAS trial - Abstract

INTRODUCTON: We studied the effect of dutasteride on the length of the off-treatment period in prostate cancer patients on intermittent androgen deprivation (IAD) therapy.

METHODS: We conducted a randomized, placebo-controlled Phase II trial in men with localized prostate cancer and a rising prostate-specific antigen (PSA) level post-primary treatment. Patients were randomized to dutasteride (0.5 mg/day) or placebo. All patients received androgen deprivation therapy (ADT), which was stopped at month 9 if the PSA level was < 1.0 ng/mL. ADT was resumed when PSA increased to ≥5.0 ng/mL. End points included time off treatment, PSA nadir after 9 months of ADT, serum testosterone and dihydrotestosterone levels, and time to castrate-resistant prostate cancer (rising PSA while testosterone levels remain < 50 ng/mL).

RESULTS: There were 87 evaluable patients: 49 dutasteride, 38 placebo. In total, 80 patients completed one treatment cycle: 45 dutasteride, 35 placebo. The median time off treatment for patients reaching ≥5 ng/mL was 18.6 and 16.7 months for dutasteride and placebo, respectively (p = 0.7600). The median PSA nadir at 9 months was 0.1 and 0.075 ng/mL, respectively (p = 0.4486). There were no cases of androgen-independent prostate cancer. Our study limitations include its short duration with only one treatment cycle evaluated.

CONCLUSIONS: This small-scale Phase II randomized controlled trial showed no benefit to the addition of dutasteride to an IAD regimen.

Written by:
Klotz L, Nabid A, Higano C, Ryanm C, Kebabdjian M, Chin J.   Are you the author?
Division of Urology, Sunnybrook Health Sciences Centre, Toronto, ON; Department of Radiation Oncology, Centre Hospitalier de Universitaire de Sherbrooke, Sherbrooke, QC; Departments of Medicine and Urology, University of Washington Seattle Cancer Care Alliance, Seattle, WA; Department of Medicine, Oregon Health Sciences University, Portland, OR; Division of Urology, London Health Sciences Centre, London, ON.

Reference: Can Urol Assoc J. 2014 Nov;8(11-12):E789-94.
doi: 10.5489/cuaj.2332

PubMed Abstract
PMID: 25485005

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