New Research: Daily Oral Apalutamide Delays Prostate Cancer Progression Past 6 Years

The PROTEUS Study Offers Hope With Apalutamide For High-Risk Prostate Cancer

Approximately 330,000 men are diagnosed with prostate cancer each year in the U.S. Up to 40% of those patients are classified as high risk. These prostate cancer tumors are more aggressive and have a higher chance of spreading outside of the prostate or recurring after treatment. This level of disease requires active and immediate treatment. 

On May 31, 2026, Johnson and Johnson released the results from the final Phase 3 PROTEUS study that offered positive information for those patients with high-risk disease. It showed that the use of apalutamide (ERLEADA®) plus hormone therapy (androgen deprivation therapy, ADT), given 6 months before and after prostate cancer surgery, significantly improved short-term and long-term outcomes. 

Patients who received apalutamide in addition to hormone therapy were 9 times more likely to have no cancer remaining at the time of surgery. This drug combination also reduced the risk of cancer spreading (metastasis) or death by 20% and increased the time that patients would require additional therapy to more than 6 years (previously this statistic was 5 years).

These findings were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. And simultaneously published in The New England Journal of Medicine. 

What Is Apalutamide (ERLEADA®)?

This is an oral hormone therapy medication used to treat prostate cancer. It works by blocking the effects of the male hormones (like testosterone) that promote cancer growth. This medication is used when cancer does not respond to other medical treatments.

Apalutamide is typically taken once a day by pill and should be taken at the same time every day. Side effects include: fatigue, joint pain, rash, decreased appetite, hot flashes, and high blood pressure.

Read more at the official Erleada website.

Surgery Plus Apalutamide For Prostate Cancer

Surgery to remove the prostate is a standard treatment (radical prostatectomy) for high-risk prostate cancer. Unfortunately, nearly half of patients will have their cancer return, which requires further treatment and may reach beyond the point of a cure. 

Apalutamide blocks androgen hormones and their signaling pathway, which starves the cancer cells of the hormones needed to grow and spread. It is currently approved for use in advanced prostate cancer, even in cases where the disease has spread or is no longer responding to treatment.

Having an initial, frontline treatment available for high-risk patients has been an unmet need in the prostate cancer arena. The PROTEUS study shows that these patients now have an effective option to use. Apalutamide before and after surgery is increasing cure rates.

The PROTEUS Study

This trial enrolled 2,109 patients who received treatment 6 months prior to and 6 months post-surgery. Patients had high-risk cancer that had not been treated. (Read the trial details)

Key findings and breakthroughs:

• After 5 years of tracking these patients, this global trial found that the apalutamide and androgen deprivation therapy worked.

• At the time of surgery, the apalutamide patients were 10 times more likely to have little to no tumor left. When a tumor shrinks that significantly, it is less likely to come back.

• After more than 5 years, 8 out of 10 patients were alive and free of metastasis. 

• Those patients who received this medication combination 1 year prior to and 1 year after surgery went more than 6 years before needing additional therapy.

• Most patients also regained sufficient testosterone levels within 8.1 months.

• 29% reduction in disease relapse.

Conclusion

The results of the PROTEUS study represent a significant advancement for high-risk prostate cancer. By combining apalutamide with androgen deprivation therapy before and after surgery, researchers demonstrated important improvements in tumor response, metastasis-free survival, and the length of time patients can remain free from additional treatment. As prostate cancer treatment continues to evolve, the PROTEUS trial may help establish a new standard of care for men diagnosed with high-risk localized disease.