In December, the share price of Candel Therapeutics surged by more than 200% when the company revealed the success of a phase 3 trial of its multimodal biological immunotherapy CAN-2409 (aglatimagene besadenovec) in localized prostate cancer.
Five months later, Candel has unveiled more information from the study, bolstering the value of the first-in-class treatment. The company will discus the results next weekend at the American Society of Clinical Oncology (ASCO) conference in Chicago.
In the study of patients with immediate- to high-risk, newly diagnosed localized prostate cancer, those in the treatment arm were given an injection of CAN-2409 into the prostate, plus oral prodrug valacyclovir, in addition to standard-of-care external beam radiation treatment. Meanwhile, participants in the control arm received placebo and radiation.
In showing a 30% reduction versus placebo in the risk of prostate cancer recurrence or death, the study accomplished its primary endpoint of disease-free survival (DFS).
As an example of the new data Candel is presenting, analysis of patient biopsy samples two years after treatment show that CAN-2409 induced pathological complete responses in 80% of the 496 patients in the treatment arm versus a 64% rate for the 249 participants in the control arm.
To one of the principal investigators in the study, Glen Gejerman, M.D., of Hackensack Meridian Health, this tissue analysis indicates that the “cancer may have been eliminated at the microscopic level,” he said in a release.
“Effective local control of prostate cancer is essential in patients who seek treatment with curative intent, as patients with positive prostate biopsies, two or more years after radical treatment, face a well-established higher risk of disease spreading within the pelvic region, developing distant metastases, and ultimately dying from prostate cancer during long-term follow-up,” he added.
Candel CEO Paul Peter Tak, M.D., Ph.D., added that the company is “advancing its preparations” on its way to applying for approval of CAN-2409 by the end of 2026.
At the ASCO conference, which starts next week, Candel also will discuss that DFS improvement was evident in patients who received androgen deprivation therapy and those who did not. There also was a higher level of patients reaching a prostate-specific antigen nadir in the treatment arm at 67% versus 59% in the placebo group.
Another topic will be the low incidence of serious adverse events—1.7% in the CAN-2409 arm versus 2.2% in the control arm. The most prevalent side effects were flu, fever and chills.
According to Candel, the study is the first multicenter, randomized phase 3 trial in localized prostate cancer in more than two decades to achieve each of its primary and secondary endpoints.
When Candel revealed the success of the trial in December, it also said that CAN-2409 came up short in a phase 2b study of 190 patients with low- to intermediate-risk localized prostate cancer as the treatment had no statistically significant effect on the time to radical treatment and the percentage of patients with prostate cancer-free biopsies after one year.
The 26-year-old Massachusetts-based company also is investigating CAN-2409 in non-small cell lung cancer and borderline resectable pancreatic adenocarcinoma.
In November 2023, the cash-strapped company announced that it would lay off 50% of its staff in a restructuring move to stay afloat. Along with the cash savings, the company said it was looking for a partner to buy into CAN-2409.