New cancer vaccine beats a tumor’s defenses better than ever

Modern science has a few tricks up its sleeve when it comes to fighting cancer. Almost a century ago, we discovered that our immune systems could recognize and wipe out these abnormal invaders. We have used this knowledge to develop drugs that prevent tumors from growing and therapies that help the immune system fight cancer better.

We have also developed vaccines that prevent certain types of cancer by targeting viruses that mutate healthy cells. However, we have been less successful in developing vaccines that target cancer direct.

That could change drastically. In a study published in the journal on Wednesday NatureResearchers led by the Dana-Farber Cancer Institute in Boston have developed a cancer vaccine that prevents a tumor from evading immune cells. The vaccine recruits the immune system’s T cells and natural killer (NK) cells, essentially to trap cancer cells and attack them, while simultaneously setting off the immune system’s alarm. Early results suggest the vaccine could be the first step in creating a universal cancer vaccine that could potentially work alongside traditional cancer therapies and protect patients from recurrence.

“This is an impressive vaccine approach that targets a protein expected to be expressed on cancer cells and turns this into a full-scale, multi-pronged immune attack against the tumor,” Dr. Andy Minn, a radiation oncologist at the Abramson Cancer Center at the University of Pennsylvania, who was not involved in the study, told The Daily Beast in an email.

dr Kai Wucherpfennig, a cancer biologist at the Dana-Farber Cancer Institute and lead researcher on the new study, told The Daily Beast that the vaccine relies on two proteins that cancer cells produce when they’re stressed and suffer DNA damage: MICA and MICB. These two proteins serve as chemical beacons for the immune system that lead to the death of a cancer cell by T cells and NK cells.

Wucherpfennig said cancer cells get around this by secreting MICA and MICB from their surfaces so they don’t trigger an immune system response. This led his team to wonder if it would be possible to completely prevent this hair loss.

The researchers tested their new vaccine on mice infected with an aggressive form of melanoma, a dangerous type of skin cancer. Not only did the vaccination stimulate the production of anti-MICA/MICB antibodies and stop their shedding, but other parts of the immune system also joined forces to fight the tumor. Some of these cells were expected, like T cells and NK cells; while some were unexpected, like helper T cells that help round up antibody-producing immune cells.

This two-in-one approach is critical for many reasons, Minn said. Most current cancer vaccines are unsuccessful because they are so tailored to a specific weakness or to boost a single arm of an immune response. But tumors are clever and able to evade an immune attack by switching their proteins, allowing them to fester incognito. Having a vaccine that targets a range of proteins that cancer cells share means our bodies can mount a diverse and orchestrated immune attack on multiple fronts.

However, Wucherpfennig said there’s a small possibility that cancers could learn to evade an anti-MICA/MICB vaccine by turning off the genes that make the proteins. That’s why he doesn’t envision the jab being given by itself.

“In my view, combination therapies are about cutting off the exit routes for a tumor,” he said. “This vaccine could be given alongside other immunotherapies or in combination with other cancer vaccines to reduce the risk of absconding.”

For example, if someone has prostate cancer and has undergone radiation therapy, they could potentially be vaccinated afterwards to prevent metastases — or growths that occur when cancer cells break away from the main tumor and can cause a patient to have a recurrence in the future .

We are still a long way from getting this vaccine into the clinic. Monkeys given the vaccine had no side effects and seemed to tolerate it well, meaning it might work well in us humans, Minn said. But future clinical trials, expected to start next year, are needed to ensure the vaccine is safe and effective in humans. If successful, it promises to help countless patients overcome their battle with cancer.