-Alessa Therapeutics (“Alessa”), a clinical-stage biopharmaceutical company advancing novel localized drug delivery technology for the treatment of early-stage prostate cancers, announced the presentation of positive preliminary data from its ongoing Phase 1 clinical trial of Enolen^®, the Company’s lead product candidate for the treatment of low to intermediate risk, localized prostate cancer. These results were shared as part of an oral presentation at the 2026 European Association of Urology Congress (“EAU2026”), taking place March 13-16, 2026, in London.

Enolen utilizes novel anti-androgen eluting implants containing the FDA-approved prostate cancer compound enzalutamide. It is currently being studied in a Phase 1 trial evaluating its safety, tolerability and preliminary efficacy for localized sustained delivery of enzalutamide into the prostate in men with localized prostate cancer undergoing prostatectomy. The study is being conducted at the National Cancer Institute (NCI), part of the National Institutes of Health.

Findings presented yesterday at EAU2026 by researchers at the NCI demonstrated that all 20 patients enrolled in the initial cohort were successfully implanted. These implantations achieved very high intraprostatic enzalutamide levels with minimal systemic drug exposure and resulted in no delay to surgery. Furthermore, pre-radical prostatectomy MRI’s conducted for 18/20 patients (2 pending) showed a reduction in tumor volume in 84% of the lesions over an average duration of 35 days. There were no reported effects on testosterone levels or negative effects on sexual function. Reported side effects were consistent with a biopsy-like procedure, and without impact on future surgery or imaging.

“The preliminary safety and efficacy data from this study are compelling and demonstrate the potential of Enolen to serve as a new treatment option for men with localized prostate cancer that avoids the negative side effects of current treatments,” said Peter Pinto, M.D., Chief, Prostate Cancer Division at the National Cancer Institute and Principal Investigator on the study. “These initial findings, particularly MRI-documented tumor shrinkage and therapeutic enzalutamide levels in the prostate with minimal systemic exposure, strongly support further development of Enolen.”

“Being the first study to demonstrate that enzalutamide can be safely and locally administered to the prostate via sustained drug eluting implants is a significant clinical milestone both for Alessa and for the broader treatment landscape for prostate cancer,” said Pamela Munster, M.D., Chief Scientific Advisor and founder of Alessa. “We look forward to continuing our clinical advancement of Enolen, which includes further investigation of dose optimization and duration of drug exposure through two additional cohorts underway in this Phase 1 trial.”