(UroToday.com) The 2026 American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL between Fri, May 29 – Tues, Jun 2, 2026., was host to Prostate, Testicular, and Penile Cancer – Posters Session. Dr. Stephen J. Freedland presented Abstract 5088: EMBARK: Testosterone recovery to >250 ng/dL following treatment suspension.
Dr. Freedland highlighted that the phase 3 EMBARK trial previously demonstrated significantly improved metastasis-free survival and overall survival with enzalutamide plus leuprolide compared with leuprolide alone in patients with high-risk biochemical recurrence (hrBCR) prostate cancer. (1) In EMBARK, patients who achieved a PSA <0.2 ng/mL at week 36 underwent treatment suspension beginning at week 37, creating an opportunity to evaluate testosterone recovery off therapy.1
Given the known association between prolonged testosterone suppression and adverse health outcomes, this post hoc analysis evaluated testosterone recovery to >250 ng/dL during treatment suspension among patients treated with enzalutamide plus leuprolide.
Patients enrolled in EMBARK had hrBCR with a PSA doubling time ≤9 months and were randomized to enzalutamide plus leuprolide, leuprolide alone, or enzalutamide monotherapy. Testosterone levels were assessed every 12 weeks, and treatment was reinitiated upon PSA rise to protocol-defined thresholds. The study design is shown below:
In EMBARK, patients who suspended treatment at week 37 were allowed to restart therapy if PSA levels increased to protocol-defined thresholds. Testosterone levels were centrally assessed every 12 weeks, and recovery to thresholds of >50 ng/dL, >175 ng/dL, and >250 ng/dL was recorded among patients undergoing treatment suspension. He also emphasized that testosterone recovery analyses were limited to the subgroup of patients with treatment suspension, and therefore only enzalutamide combination data were presented to avoid non-randomized comparisons.
Dr. Freedland noted that among 355 patients in the enzalutamide combination arm, 320 patients (90%) suspended treatment, 108 patients (33.8%) achieved testosterone recovery to >250 ng/dL during the treatment suspension period. Among those who recovered testosterone levels, the median time to recovery was 5.6 months (range 0.0–22.1 months), while the mean time to recovery was 6.8 months.
The cumulative probability of testosterone recovery to thresholds of >50 ng/dL, >175 ng/dL, and >250 ng/dL among patients undergoing treatment suspension, as illustrated in Figure 2. Median time to testosterone recovery was 8.6 months.
Dr. Freedland concluded his presentation with the following key takeaways:
- In EMBARK, approximately one-third of patients treated with enzalutamide plus leuprolide achieved testosterone recovery to >250 ng/dL during treatment suspension
- Among patients who recovered testosterone, the median time to recovery was 5.6 months
- Testosterone recovery occurred relatively quickly for many patients, although delayed recovery was observed in some individuals (22,1 months)
- These findings provide additional insight into hormonal recovery patterns during intermittent treatment strategies in patients with hrBCR prostate cancer
Presented by: Stephen J. Freedland, MD, Urologist, Director of the Center for Integrated Research in Cancer and Lifestyle, Associate Director for Training and Education at the Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai, Los Angeles, CA
Written by: Julian Chavarriaga, MD, Clinical Assistant Professor, Urologic Oncologist, Department of Urology at Penn State Health @chavarriagaj on X during the American Society of Clinical Oncology Genitourinary (ASCO) Annual Meeting held in Chicago, IL between May 29th and June 1st, 2026
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