Candel Therapeutics (NASDAQ:CADL) said extended follow-up data from its phase 3 trial of aglatimagene besadenovec in localized prostate cancer showed continued evidence of clinical benefit when added to standard-of-care radiation therapy.
The company discussed the results after an oral plenary presentation at the 2026 American Urological Association annual meeting in Washington, D.C. The trial evaluated aglatimagene plus the oral prodrug valacyclovir in patients with intermediate- to high-risk localized prostate cancer receiving radiotherapy, with or without short-course androgen deprivation therapy, or ADT.
Tak said Candel previously reported in December 2024 that the phase 3 trial met its primary endpoint of disease-free survival, with a statistically significant improvement for patients receiving aglatimagene plus prodrug and standard-of-care radiation therapy compared with placebo plus standard-of-care radiation therapy. He also said the treatment improved the rate of pathological complete response in two-year biopsies.
Extended Follow-Up Shows Benefit Across Key Measures
Chief Medical Officer Dr. W. Garrett Nichols said the updated analysis, with a March 15, 2026 data cutoff and median follow-up of 58 months, showed aglatimagene significantly improved prostate cancer-specific disease-free survival by 39% in the intent-to-treat population.
The trial enrolled 745 patients with localized intermediate- to high-risk prostate cancer with one high-risk feature. Patients were randomized 2-to-1 to receive three injections of aglatimagene plus prodrug or placebo plus prodrug, both with standard-of-care radiotherapy. Randomization was stratified by NCCN guideline risk group and planned ADT use.
Nichols said the updated results showed longer time to salvage anti-cancer therapy and time to biochemical failure in the aglatimagene arm, with hazard ratios of 0.72 for both measures. He also said there was a lower incidence and increased time to metastasis in the aglatimagene arm.
Among the intermediate-risk patients, who represented about 85% of the study population, Nichols said aglatimagene improved prostate cancer-specific disease-free survival by 41%. In that subgroup, the therapy reduced time to salvage anti-cancer therapy by 49% and time to biochemical failure by 52%. Metastatic disease occurred in 0.24% of patients in the aglatimagene arm versus 2.35% in the placebo arm, with a hazard ratio of 0.1 for time to metastasis.
Nichols said aglatimagene was generally well tolerated in combination with external beam radiotherapy, with or without ADT. Serious adverse events and treatment discontinuations were numerically lower in the aglatimagene arm than in the placebo arm. The most common treatment-related adverse events were chills, fever and flu-like symptoms, occurring in about one-third of patients, and were described as low-grade and self-limited.
Company Outlines Regulatory Plans
Tak said the phase 3 study was conducted under a special protocol assessment agreed with the U.S. Food and Drug Administration. He also said Candel has received Fast Track designation and Regenerative Medicine Advanced Therapy designation for aglatimagene.
The company said it plans to file a biologics license application in the fourth quarter of 2026. During the question-and-answer session, Nichols said Candel intends to seek an indication covering the population treated in the phase 3 trial, including favorable intermediate-risk, unfavorable intermediate-risk and high-risk patients with one high-risk feature.
Candel also said a pivotal trial manuscript is expected to be published in The Lancet Oncology. Chief Technical and Development Officer Seshu Thyagarajan said the company has been using a commercial-scale manufacturing process and is conducting process validation, with plans remaining on track for the BLA filing.
Physicians Discuss Potential Clinical Role
Several prostate cancer specialists participating in the call said the data could be meaningful for patients deciding between radiation therapy and surgery, particularly because many patients want to avoid ADT.
Dr. Steven Finkelstein, National Director of Radiation Oncology at U.S. Urology Partners and Director of Radiation Oncology Research at Associated Medical Professionals, called the data “transformative” for radiation oncology. He said the therapy could fit into existing radiation workflows because clinicians already perform procedures such as fiducial marker placement and spacer placement.
Dr. Daniel George, Professor of Medicine, Surgery and Urology at Duke University School of Medicine and Director of Genitourinary Oncology at Duke Cancer Institute, said many patients seek to avoid hormonal therapy because of its quality-of-life effects. He said a 40% reduction in relapse rate would be “really important” to patients and described the treatment as a “low lift” because it is incorporated into the radiation workflow.
Dr. Neal Shore, Medical Director at Carolina Urologic Research Center, said the injection procedure is similar to routine transrectal or transperineal ultrasound-guided urology procedures. He said the needle gauge is small and that the treatment would not require new capital equipment for the injection procedure.
In response to analyst questions, the physicians cautioned against direct comparisons with surgery because the trial was not designed to compare aglatimagene plus radiation with prostatectomy. However, George said the relapse-free survival rates appeared comparable to what might be expected with surgery, while emphasizing that randomized comparisons would be needed for definitive conclusions.
Tak closed the call by saying the company’s objective is to offer patients better disease control and reduce recurrence, local and metastatic progression, and the need for salvage anti-cancer therapies.
About Candel Therapeutics (NASDAQ:CADL)
Candel Therapeutics (NASDAQ:CADL) is a clinical-stage immuno-oncology company focused on the development of next-generation oncolytic viral therapies designed to treat solid tumors. The company’s lead candidate, CAN-2409, is a locally administered, gene-delivered viral therapy engineered to selectively replicate in cancer cells and induce immunogenic cell death. Candel leverages proprietary virus engineering platforms to enhance tumor-specific replication and stimulate anti-tumor immune responses, aiming to improve outcomes for patients with high unmet medical needs.
In addition to its lead program, Candel’s pipeline includes CAN-3110, an oncolytic herpes simplex virus targeting recurrent high-grade glioma, and other novel viral constructs being explored for a variety of solid tumor indications.
