Candel Therapeutics, Inc. (Nasdaq: CADL) presented new biomarker data from its completed phase 3 clinical trial of aglatimagene besadenovec in patients with localized intermediate- to high-risk prostate cancer at the American Society for Radiation Oncology Annual Meeting 2026.

The data, drawn from digitized biopsy samples from 647 patients who completed a three-injection course in a randomized, placebo-controlled phase 3 study, used AI-enabled digital pathology analysis on 622 pre-treatment and 427 post-treatment biopsies collected more than two years after completion of radiation therapy.

According to the company's findings, aglatimagene combined with external beam radiation therapy significantly increased intratumoral lymphocyte infiltration and remodeled the tumor microenvironment compared with placebo plus radiation. Among patients with residual tumor, aglatimagene increased lymphocyte infiltration within tumor regions and enhanced lymphocyte-tumor engagement.

Key data points from the presentation include: 80% of evaluable aglatimagene patients (n=167) had negative prostate biopsies at two years versus 63% of control patients (n=62) (p=0.0018). Aglatimagene significantly increased overall lymphocytic fraction compared to control (p=0.048). In paired biopsies from patients with residual tumor (n=108), aglatimagene significantly increased intratumoral lymphocyte fraction (p=0.006), lymphocyte-tumor enrichment (p=0.003), and lymphocyte-tumor mixing (p<0.001).

"While radiation therapy alone drives immune infiltration into prostate tumors, these data support that aglatimagene produced a qualitatively distinct immune response," said Francesca Barone, M.D., Ph.D., Chief Scientific Officer of Candel Therapeutics.

Paul Peter Tak, M.D., Ph.D., President and Chief Executive Officer of Candel, referenced the company's planned Biologics License Application submission in connection with the findings.

The data was presented during the Genitourinary Cancer session at ASTRO 2026 on September 29, 2026. Aglatimagene is not currently approved by the U.S. Food and Drug Administration or any other regulatory authority.