Cancer Research Goes From Generic To Precise
The Marvel comic book character Deadpool is not the type of superhero you want your daughter to bring home for dinner. He’s crude, irreverent and sarcastic. But he has a truly remarkable gift: he has an immune system that can put him back together in 30 seconds or less, no matter how severe his injuries.
What if we could all do that? Well, believe it or not, we’re heading in that direction. Researchers are now targeting cancer cells and the cellular mechanisms from the inside, such as their genetic makeup. The practice is precision medicine and the targets are some of the most intractable illnesses known to humankind, including genetic mutational disorders and the “Big C,” cancer.
According to Arturo Loaiza-Bonilla, MD, MSEd, FACP, Vice Chair, Cancer Treatment Centers of America® (CTCA) Department of Medical Oncology, cancer treatment is going in the direction of developing drugs that react to specific biomarkers, including genes and proteins inside a cancer cell, then choosing a response based on that individual’s cancer source.
In the “old” days, the focus of stomach cancer treatment, for example, was in the tissue of the stomach. Treatment models are now shifting gears. Two people with stomach cancer could have very different precision treatments customized for their own illness because, just like two people with different DNA sequencing, they may have different manifestations of the disease. Not only is the cancer the focus, but the mechanisms of the cancer cells are the new target. Furthermore, specific cases will get individual treatment based on their own cancer cells’ DNA profiles.
One example of this new tailored approach to cancer is immunotherapy. Not unlike a superhero with an immune system you can’t beat, non-specific immunotherapies simply boost a patient’s immune system, allowing the body to respond effectively to fast-growing cancers. One approach, adoptive cell therapy, uses genetically modified immune cells to kill cancer cells by “training them to target the cancer cells,” according to Dr. Bonilla.
How do you conduct gene splicing or cell manipulation with a walking, talking patient whose 37.2 trillion cells are doing their own thing? One technique is to place the genes next to multiplying cells. Another is to supply drugs made with molecules so small they can penetrate a cell membrane. If that doesn’t work, try coercing a virus. Onolytic virus therapy, as it’s called, uses genetically engineered viruses to kill cancer cells by prompting the immune system to go after the cancer.
While traditional chemotherapy, radiation and surgery are still very viable options in oncology, “the shift we are experiencing is that in some cases, we can add precision oncology approaches, particularly when the cancer has certain biomarkers that predict responses to these targeted agents,” says Dr. Bonilla. In effect, oncology is shifting from approaching cancer as a generic illness to sabotaging cancer from the inside out.
The green light for gene editing to possibly impact precision cancer treatment, in fact, came from a different field. In December 2017, the U.S. Food and Drug Administration (FDA) approved the use of LuxturnaTM for a rare genetic disorder that results in tunnel vision and, eventually, blindness.
The treatment was the first-ever gene therapy approved in the U.S. to combat a gene mutation. It works by delivering a healthy gene directly to the cells of the retina. This allows the cells to begin producing the correct protein that converts light into electrical signals. The electrical signals zip along the nervous system to the brain and restore vision. In effect, it “turns the lights back on.”
With FDA approval for Luxturna, precision cancer treatment options were now reaching the patient. “This is a pivotal time for cancer patients as we are driving real momentum in cancer research and treatment, changing the paradigm of how we approach the disease,” says Dr. Bonilla.
And he looks forward with unmitigated excitement to the future. “I encourage everyone to learn more about precision oncology and to promote enrollment and access to clinical trials so that we can continue to find better options and, hopefully, cures,” says Dr. Bonilla. “We are changing the face of cancer care. What was unimaginable not that long ago is quickly coming to fruition.”