A large international trial has reported that giving men with aggressive, early prostate cancer an extra hormone-blocking pill before and after surgery lowered their risk of the cancer spreading or of death. The pill is apalutamide, sold by Johnson & Johnson as Erleada. The trial, called PROTEUS, enrolled 2,109 men with newly diagnosed high-risk prostate cancer that was still in or near the prostate1. The main results were presented as the opening session of the 2026 meeting of the American Society of Clinical Oncology (ASCO) and published at the same time in the New England Journal of Medicine2. On October 24, the company added results from a smaller part of the study that compared the treatment with surgery alone3.
What happened
Surgery to remove the prostate is a standard treatment meant to cure the cancer, yet nearly half of men who have it will see their cancer come back2. In men with high-risk disease, relapse rates after surgery can reach 50% to 70% depending on the cancer’s features1.
PROTEUS tested whether stronger hormone blocking around the operation could change that. Every man got androgen deprivation therapy (ADT), a standard hormone treatment for prostate cancer, for six months before surgery and six months after1. Half also took apalutamide, a drug that stops male hormones from binding to their receptor, which can slow prostate cancer3. The other half took a placebo (a dummy pill)1. Neither the men nor their doctors knew who got which, a design called double-blind1.
The men were randomly assigned between July 2019 and June 20224. Their median age was 66, and nearly 96% had tumors with a Gleason score of 8 or higher, a grading that marks particularly aggressive disease1. About 20% had cancer in nearby lymph nodes when they joined1.
The evidence so far
The trial had two main goals, and it met both after a median follow-up of 61.7 months, a little over five years1.
- Little or no cancer left at surgery. When the removed prostates were examined, 8.9% of men on apalutamide had no cancer or only a tiny amount left, compared with 1.0% on the dummy pill: 94 of 1,057 men versus 10 of 1,0524. Reports describe this as making men about nine times2 or about 10 times1 more likely to reach that state; the statistical measure behind both descriptions is an odds ratio of 10.171.
- Cancer spread or death. The risk of the cancer spreading to distant parts of the body, or of death, was 20% lower with apalutamide1. At five years, 78.2% of men on apalutamide were alive and free of spread, compared with 73.5% on the dummy pill1.
Other measures pointed the same way. The median time until any sign the cancer had returned or progressed was 57.1 months with apalutamide and 38.4 months without it5. Men on apalutamide went a median of 74.2 months before needing another cancer treatment, against 41.5 months5. At four years, 21.9% of men on apalutamide showed no evidence of disease, compared with 18.3%5.
The lead author, Mary-Ellen Taplin of the Dana-Farber Cancer Institute, said at the meeting:
These results support the perioperative use of apalutamide plus ADT as a new standard of care for patients with localized high risk prostate cancer.
Her remarks were reported by Targeted Oncology4. William K. Oh of the Yale School of Medicine, who commented on the results for ASCO, said, “I think the [PROTEUS] study will change the standard of care for many patients who are candidates for surgery and have high-risk localized prostate cancer”4.
Side effects
The added pill brought more side effects. Serious side effects (grade 3 or 4, meaning severe or potentially dangerous) occurred in 39.6% of men on apalutamide and 31.0% of men on the dummy pill6. Stopping treatment because of side effects happened in 7.4% versus 2.7%6.
Skin rash was the most notable extra problem1. The company’s summary lists rash in 21.2% of men on apalutamide versus 10.0% on the dummy pill5, while a broader grouping of skin rash events reported by Targeted Oncology came to 33.0% versus 15.3%4. Taplin said the rash was mostly mild and that 98% of men were able to restart apalutamide after it was treated1.
Many common problems were similar in both groups, including urine leakage (50.2% vs 50.9%) and erection problems (41.6% vs 41.4%), while hot flushes were somewhat more common with apalutamide (63.4% vs 56.5%)5. Treatment-related side effects led to death in 7 men (0.7%) on apalutamide and 1 man (0.1%) on the dummy pill4.
The new comparison with surgery alone
The main trial compared apalutamide plus hormone therapy with hormone therapy alone. It did not answer how the full treatment compares with simply having surgery, which has long been a standard approach. A separate part of the study, called a substudy, looked at that in 408 men3.
Johnson & Johnson reported that, after a median of 37.8 months, apalutamide plus hormone therapy around surgery lowered the risk of the cancer returning or death by 62% compared with surgery alone3. At three years, 63% of men on the combined treatment had no such event, compared with 41.4% of men who had surgery alone3. The company described a 51% lower risk of spread or death as a “numerical improvement,” wording that suggests this second result was not a formal, statistically confirmed finding3. These results were presented at the European Society for Medical Oncology (ESMO) Congress 2026, and the company said the paper has been accepted by the journal European Urology3. Biohack has seen only the company’s release, not the paper.
What it does not show yet
The trial does not yet show that men live longer. Overall survival data are still immature, meaning too few deaths have occurred to compare the groups6. Oh noted that the measure the trial used, time free of cancer spread, has been shown to be a validated stand-in for overall survival4, but a stand-in is not the same as a direct survival result.
The absolute gap is also worth seeing plainly: at five years, about 5 more men in every 100 were alive and free of spread with apalutamide than without it1. And the treatment is not approved for this use. Apalutamide is currently approved for more advanced prostate cancer, and the company calls its use around surgery investigational3.
Sources differ slightly on the trial’s size. Oncology Times reported 118 centers1, while the company and Targeted Oncology list 184 sites in 18 countries and regions54. The public trial registry lists 2,517 people enrolled in total and an expected primary completion date of December 1, 20267.
Who is behind it
The trial is sponsored by Janssen Research & Development, part of Johnson & Johnson, which makes and sells Erleada7. The detailed figures in this article come from independent medical news reports and from the company’s own materials, which were prepared from the published paper and meeting presentation5.
What to watch next
The open question for regulators is whether Johnson & Johnson will ask the FDA to approve the drug for use around surgery, and how reviewers will weigh the share of men with little or no cancer left at surgery as evidence, according to an analysis in The Clinical Trial Vanguard2. Longer follow-up should show whether the lower risk of spread turns into longer lives. The full surgery-alone results in European Urology will allow a closer look at that comparison3.
