Breakthrough Prostate Cancer Treatment Shows Remarkable Survival Rates

In a groundbreaking study, researchers have unveiled promising results in the treatment of prostate cancer, offering hope to patients facing high-risk biochemical recurrence. The phase 3 clinical trial found that in patients with prostate cancer and high-risk biochemical recurrence, both enzalutamide plus leuprolide and enzalutamide monotherapy were found to be superior to leuprolide alone in terms of metastasis-free survival. The safety profile of enzalutamide was consistent with previous studies, and it did not negatively impact the patient's quality of life. 

The trial results were published in the journal The New England Journal of Medicine. 

The American Cancer Society projected many new prostate cancer cases and deaths. Biochemical recurrence, indicated by rising PSA levels, occurs in 20-50% of patients after initial treatment, often signifying disease progression. Limited clinical evidence necessitates risk-based treatments, especially for high-risk cases with PSA doubling time under 9 months, which significantly impacts survival rates.

Previous studies showed that treatment intensification with next-generation hormonal therapies, such as enzalutamide, prolongs imaging-based progression-free survival and overall survival, delays the development of castration-resistant prostate cancer, and maintains quality of life in patients with metastatic hormone-sensitive prostate cancer. Hence researchers conducted an international, randomized, phase 3 trial to evaluate the efficacy and safety of enzalutamide plus leuprolide and enzalutamide monotherapy, as compared with leuprolide alone, in patients with prostate cancer who have had high-risk biochemical recurrence. 

The EMBARK trial is a phase 3 clinical trial, in which patients with high-risk biochemical recurrence of prostate cancer (PSA doubling time ≤ 9 months) were randomly assigned to three groups: enzalutamide plus leuprolide, placebo plus leuprolide, or enzalutamide alone. The study aimed to compare metastasis-free survival between the combination and leuprolide-alone groups and between the monotherapy and leuprolide-alone groups. Secondary endpoints included patient-reported outcomes and safety assessments, with evaluations conducted by blinded independent central review. 

Findings: 

• Out of the 1068 patients randomized, 355 were in the combination group, 358 in the leuprolide-alone group, and 355 in the monotherapy group.
• Over a median period of 60.7 months, results at the 5-year mark revealed metastasis-free survival rates of 87.3% (95% CI, 83.0 to 90.6) for the combination group, 71.4% (95% CI, 65.7 to 76.3) for the leuprolide-alone group, and 80.0% (95% CI, 75.0 to 84.1) for the monotherapy group.
• Enzalutamide plus leuprolide demonstrated superiority over leuprolide alone, and enzalutamide monotherapy also outperformed leuprolide alone in terms of metastasis-free survival. 
• Additionally, no new safety concerns were identified, and there were no significant differences in quality-of-life measures among the groups. 

Dr.Stephen Freedland, MD, associate director for Training and Education and the Warschaw, Robertson, Law Families Chair in Prostate Cancer at Cedars-Sinai, and lead author of the study, expressed enthusiasm about the results. "If these treatments are approved by the Food and Drug Administration, our results will be practice-changing. In the study, both of these new options improved metastasis-free survival while preserving quality of life,” commented Dr. Stephen Freedland. 

Thus, with these remarkable findings, the medical community is looking ahead with anticipation. As further research builds on this foundation, it is hoped that similar successes will be achieved in the treatment of other cancers. For now, this study stands as a beacon of hope, illuminating the path toward more effective and compassionate cancer care. 

Further reading: Improved Outcomes with Enzalutamide in Biochemically Recurrent Prostate Cancer. Doi: 10.1056/NEJMoa2303974