The EMBARK study, we started this over ten years ago. We looked at patients with high risk biochemical recurrence, prostate cancer patients who previously had had prostatectomy, radiation therapy or another 25% who had both prostatectomy followed by radiation therapy. So about 75% of the patients ended up having radiation treatment.

The bottom line was we looked a three different cohorts, 355 patients in each cohort. The doubling time had to be less than 9 months; earlier data had showed that these are patients who have a more biological aggressive predisposition towards developing metastatic disease based upon a lot of Johns Hopkins data. The first cohort had a combination of LHRH q3 month and enzalutamide; the second cohort was the q3 months LHRH and a placebo, so blinded; the third cohort was an open label approved dose of enzalutamide, 160mg daily. So enzalutamide monotherapy, LHRH monotherapy versus combination of enza/LHRH.

The data was presented and published previously in both New England Journal twice now, first the MFS data showing a hazard ratio of 0.37 favouring combination over monotherapy ADT, a similar benefit to monotherapy enza over monotherapy LHRH from MFS, a hazard ratio of about 0.63. Then we presented our overall survival data at ESMO this past year, 2025, demonstrating a hazard ratio of just slightly below 0.6 favouring combination enza/LHRH over monotherapy ADT. There’s a trend towards an improvement in survival of enza monotherapy versus monotherapy LHRH but it was not statistically significant.

How can these findings inform shared decision-making in clinical practice?

In our poster that we presented here at ASCO GU, and particularly we looked at patients who at the end of nine months there was a stopping threshold if you got less than 0.2. So what we looked at, all the patients in the three different cohorts that I just described – the combo, the mono LHRH, the mono enza – and we looked at one year, two years, three years how long did they make it, especially to three years. The combination group of enza and ADT, a little less than 5% lasted out to three years. These were the excellent or super-responders and we looked at the patients who had returned to testosterone levels of 175 versus 250 or their baseline, those were the composite. So it was nearly 5%, or almost one in 25, in the combo group, about 1.6% in the mono LHRH and about 1.4%, roughly speaking, in the enza mono.

So that’s pretty remarkable even though there’s relatively small numbers there are super-responders. If you’re fortunate to be in the one year, the two years, especially that three year group, and you get back to normal testosterone level, you can imagine that the tolerability and less toxicity from no longer having T suppression is quite remarkable, and not being on therapy.

So we were really happy to present that information here at ASCO GU.