In this three-arm study, 120 patients following radical prostatectomy ± salvage radiotherapy were randomized to either abiraterone acetate and prednisone (AAP), AAP plus degarelix (AAP+D), or degarelix (D) alone. Inclusion criteria included rising PSA ≥1.0 ng/ml, doubling time ≤9 months, no evidence of metastatic disease on CT/bone scan, and a testosterone level greater than 150 mg/dL.
Patients were treated for 8 months with their assigned therapy and then therapy was stopped. The primary endpoint was total number of patients with undetectable PSA with a testosterone above 150 at 18 months. The second endpoint was those with an undetectable PSA at 8 months.
With regards to the primary endpoint, there was no significant difference between the three arms (AAP – 5%, AAP+D – 16%, D – 13%) – the authors note that “these results set a benchmark for future trials that 10-15% of pts can achieve this outcome”. There was also no significant difference in the secondary outcome (See table 1).
For future studies, it may be interesting to investigate whether or not quality of life was significantly different between these three cohorts, as the primary and secondary outcomes did not significantly differ. Also, it would be interesting to see if there is any difference for metastasis free survival – a potential surrogate for overall survival which is being described in several abstracts during this ASCO meeting. Additionally, it would be interesting to examine the difference in cost of treatment for each arm over the 8 months of therapy.
Presented By: Karen A. Autio, MD. Memorial Sloan Kettering Cancer Center
Written By: Jason Zhu, MD. Fellow, Division of Hematology and Oncology, Duke University @TheRealJasonZhu
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2. Buyyounouski MK, Pickles T, Kestin LL, Allison R, Williams SG. Validating the Interval to Biochemical Failure for the Identification of Potentially Lethal Prostate Cancer. Journal of Clinical Oncology 2012;30:1857-63.
3. D’Amico AV, Moul JW, Carroll PR, Sun L, Lubeck D, Chen M-H. Surrogate End Point for Prostate Cancer–Specific Mortality After Radical Prostatectomy or Radiation Therapy. JNCI: Journal of the National Cancer Institute 2003;95:1376-83.
4. Caire AA, Sun L, Ode O, et al. Delayed Prostate-specific Antigen Recurrence After Radical Prostatectomy: How to Identify and What Are Their Clinical Outcomes? Urology 2009;74:643-7.
J Clin Oncol 36, 2018 (suppl; abstr 5016)