Aglatimagene Besadenovec + Valacyclovir Ups DFS in Localized Prostate Cancer

FRIDAY, June 12, 2026 (HealthDay News) — For patients with localized prostate cancer, aglatimagene besadenovec, an adenoviral-based immunotherapy, plus valacyclovir is associated with longer disease-free survival (DFS) than placebo plus valacyclovir when added to standard radiotherapy, according to a study published in the June issue of The Lancet Oncology.

Theodore L. DeWeese, M.D., from Johns Hopkins School of Medicine in Baltimore, Maryland, and colleagues conducted a phase 3, randomized, placebo-controlled trial at 51 medical centers involving patients with intermediate or high-risk prostate cancer who were planning to undergo external beam radiation therapy (EBRT). Participants were randomly assigned to receive three courses of intraprostatic aglatimagene plus valacyclovir (496 participants) or placebo plus valacyclovir (249 participants). Patients received standard-of-care EBRT or hypofractionated EBRT with optional androgen deprivation therapy.

The researchers found that median DFS was not reached in the aglatimagene plus valacyclovir group versus 86.1 months in the placebo plus valacyclovir group after a median follow-up of 50.3 months (hazard ratio, 0.70). Treatment-emergent adverse events (TEAE) of grade 3 or worse occurred in 8 percent of participants in the aglatimagene group and 7 percent of participants in the placebo group; acute kidney injury was the most common TEAE of grade 3 or worse in both groups (2 percent in each group).

“This pivotal phase 3 trial, showing a clinically meaningful reduction in disease recurrence in patients treated with aglatimagene in combination with radiotherapy,  provides important peer-reviewed validation of the significance of these findings for patients with localized prostate cancer who elect to undergo radical treatment with curative intent,” coauthor Paul Peter Tak, M.D., Ph.D., from Candel Therapeutics, said in a statement.

Several authors disclosed ties to biopharmaceutical companies, including Candel Therapeutics, which is developing aglatimagene and funded the study with the National Institutes of Health.

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