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


  • Laurence Klotz Sunnybrook Health Sciences Centre, University of Toronto
  • Abdenour Nabid Dept Radiation Oncology, Centre Hospitalier de Universitaire de Sherbrooke
  • Celestia Higano University of Washington Seattle Cancer Care Alliance, Seattle, WA, USA;
  • Chris Ryan Department of Medicine, Oregon Health Sciences University, Portland, OR, USA;
  • marlene Kebabdjian Division of Urology, Sunnybrook Health Sciences Centre
  • Joseph Chin Division of Urology, London Health Sciences Centre, London, Ontario, Canada




prostate cancer, intermittent androgen deprivation, 5 ARI,


Introduction: 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.


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Author Biography

Laurence Klotz, Sunnybrook Health Sciences Centre, University of Toronto

Professor, Dept of Surgery




How to Cite

Klotz, L., Nabid, A., Higano, C., Ryan, C., Kebabdjian, marlene, & Chin, J. (2014). Effect of dutasteride in men receiving intermittent androgen ablation therapy: The AVIAS trial. Canadian Urological Association Journal, 8(11-12), e789–94. https://doi.org/10.5489/cuaj.2332



Original Research