Advantagene Reaches Enrollment Goal in Phase 2 Trial Testing Prostate Cancer Vaccine

Advantagene, also known as Candel Therapeutics, has reached its patient enrollment goal in an ongoing Phase 2 trial testing the effectiveness of ProstAtak, the company’s prostate cancer vaccine, among men with localized prostate cancer who chose to remain on active surveillance.

ProstAtack is a gene-mediated cytotoxic immunotherapy (GMCI). That’s a type of low-toxicity immunotherapy that stimulates patients’ immune systems to build up a strong immune response against cancer, much like a vaccine.

It is based on the combination of aglatimagene besadenovec — a viral vector that infects cancer cells with the herpes simplex virus — and oral valacyclovir, an antiviral drug. The combo kills cancer cells and, at the same time, triggers an immune response against them.

The effectiveness of ProstAtak among patients with localized prostate cancer who chose active surveillance — close monitoring of cancer progression — as their primary form of treatment is currently being assessed in the randomized, double-blind, placebo-controlled, ULYSSES Phase 2 trial (NCT02768363).

The trial has reached its patient enrollment goal, with 190 participants recruited from 22 different clinical centers in the U.S. and Mexico. The study has been expanded from its original target enrollment of 150 patients to almost 200 participants, following patients’ and researchers’ requests.

Participants in the trial will be randomly assigned to receive either ProstAtak, or a placebo, while remaining on active surveillance.

The study’s primary goal is to assess changes in tumor risk markers, such as tumor grade and disease extent, from baseline, or the start of the study period, to its end. Secondary endpoints include treatment safety, impact on patients’ quality of life, biochemical response, as assessed by changes in the  prostate-specific antigen (PSA) test, and time to radical treatment.

Advantagene is expecting to announce topline findings from ULYSSES by the end of 2020.

“Men with low-risk prostate cancer benefit from active surveillance but a significant proportion have cancer progression and ultimately require surgery or radiation therapy,” Scott Eggener, professor of surgery and radiology, director of the prostate cancer program at University of Chicago, and a lead investigator in the ULYSSES trial, said in a press release.

“It would be very exciting if there was an easily delivered and safe intervention that significantly lowers the likelihood of these men ever requiring surgery or radiation,” he said.

“We are thrilled with the progress of the ULYSSES study,” said Estuardo Aguilar-Cordova, Advantagene’s CEO. “[W]e are grateful to the patients and doctors that are participating and are very hopeful that their efforts will result in better outcomes for future cancer patients. With side effects similar to those of a flu shot, ProstAtak could one day become a first-line ‘Pro-Active Surveillance’ option for the thousands of men diagnosed with low-risk prostate cancer every year.”

The company is conducting another trial testing the effectiveness of ProtAtack. That randomized, placebo-controlled, Phase 3 trial (NCT01436968), is assessing the efficacy of ProstAtak among patients with intermediate- or high-risk localized prostate cancer who chose radiation therapy as their main form of treatment. That trial is currently recruiting patients at 53 study locations across the U.S. and in Puerto Rico.

If proven effective, ProstAtak may become the first and only therapeutic option for men newly diagnosed with prostate cancer.

Additional clinical trials assessing the effectiveness of cytotoxic immunotherapy are currently underway among patients with pancreatic, lung and brain cancer. According to the company, topline data from these studies looks promising.