Dr Garzotto on Aglatimagene Besadenovec Plus Valacyclovir and EBRT in Localized Prostate Cancer

“The most notable [outcome from this study] was that that there was an [approximately] 40% lower chance of having cancer at follow-up if a patient was treated with aglatimagene besadenovec compared with placebo. That number translates into real-world benefits for these patients.”

Mark Garzotto, MD, a professor of urology in the School of Medicine at Oregon Health & Science University, discussed findings from the phase 3 PrTK03 trial (NCT01436968) evaluating aglatimagene besadenovec (CAN-2409) plus valacyclovir and external beam radiation therapy (EBRT) for the treatment of patients with localized prostate cancer.

The study randomly assigned patients (n = 745) 2:1 to receive aglatimagene besadenovec or placebo, both in combination with the prodrug valacyclovir and EBRT, with or without short-course androgen deprivation therapy. The primary end point was disease-free survival (DFS). Secondary end points included prostate cancer–specific outcomes, overall survival (OS), and prostate specific antigen freedom from biochemical recurrence.

Findings from the study, which were presented during the 2026 American Urological Association (AUA) Annual Meeting, demonstrated that patients in the investigational arm experienced a significant improvement in prostate cancer–specific DFS compared with the control arm (HR, 0.61; 95% CI, 0.44-0.85; P = .0031). Benefits in terms of time to new anticancer therapy (HR, 0.72; 95% CI, 0.39-1.31) and time to biochemical failure (HR, 0.72; 95% CI, 0.40-1.31) in favor of the investigational arm were also reported.

Garzotto noted that time to metastasis findings also favored the investigational arm vs the placebo arm (HR, 0.58; 95% CI, 0.21-1.59); this was the most notable aspect of the data he added. Treatment with aglatimagene besadenovec also conferred a significant advantage in terms of prostate cancer DFS in patients with intermediate-risk disease (HR, 0.59; 95% CI, 0.41-0.84; P = .0034). OS data were immature at the time of presentation and will be analyzed at a later date, he concluded.