A Vaccine to Prevent Cancer Recurrence

A team of Mexican researchers is preparing for clinical trials of a treatment to prevent the recurrence of different types of cancers by prompting the immune system into action.

The new therapy "trains the immune system to recognize and eliminate remaining cancerous cells" after conventional treatment, team leader Dr. Juan Pablo Márquez Manriquez, of the International Cancer Center in Sonora, told EFE.

Although the treatment is referred to as a vaccine, Márquez said it was comprised of "a number of vaccines mixed together, like in a cocktail, which are specifically designed to fight against several neoplasms simultaneously."

Since early in the past decade, the team has synthesized four peptides able to induce an immune response to tumor cells.

First, the researchers tested the compound on mice that were genetically modified to develop cancer at a set time.

"The animals that received the vaccine, both individual vaccines and the cocktail, never developed colon, pancreatic or ovarian cancer," Márquez said.

"In 2006, we conducted a pilot study in Sonora on 25 patients with ovarian [cancer], 25 with colon cancer, 25 with multiple myeloma and 25 with breast cancer. We included four patients with pancreatic cancer because there weren't many at the time," the researcher said.

So far, only one of the participants has died and that was due to an unrelated cardiac problem in 2014.

The studies have shown, in addition, that the vaccine does not cause an auto-immune reaction or toxicity, Márquez said.

The next step is clinical trials, which will be conducted after federal regulators approve the protocol in January or February.

Trials are usually conducted in three phases to determine the safety and efficacy of a treatment, with the number of participants ranging from a few score in the initial phase to thousands in the final phase.

"In our case, phases one and two will be conducted together, since there has already been a pilot protocol with positive results, which lets us combine both phases and move faster," the researcher said.

Tests will be conducted in Mexico City, Ciudad Obregón, Sonora and probably Tijuana in coordination with the National Oncology Institute, "which is the top cancer institution in Mexico and Latin America," Márquez said.

"We think that if everything goes right, the vaccine will be approved in Mexico and the United States by 2017 or 2018 or by 2019 at the latest," the researcher said, adding that the treatment "has given hope to many patients with these types of cancers."

If the treatment becomes available for the public, Márquez said, "we will have fewer recurrences, fewer hospitals full of patients with recurrent cancer and less palliative care, patients will suffer less pain or will have a life or a death with less suffering."

"That is what matters, that there will be less pain," the scientist said.