Cancer is one of humanity’s greatest health challenges, killing millions of people every year. For decades, treatment for the disease has focused primarily on surgery (removing it) and chemotherapy and radiation therapy (attacking it). While these procedures continue to be essential in a patient’s overall treatment, new developments with a more personalized approach have gained momentum recently, with some treatments even going so far as to attempt to “re-educate” the body’s immune system.
Even just a couple of years ago, some of these therapies would have seemed like science fiction, but the field of oncology is progressing with breathtaking speed—with some of the advances happening right here in Houston. From targeted immunotherapies like oncolytic virotherapy (OV) and CAR-T cell therapy to the latest in genetic testing, here are the top innovations that have the potential to dramatically shift the paradigm of cancer care in the coming years.
Over the past decade, immunotherapy has rapidly become what researchers call the “fifth pillar” of cancer treatment (the first four being surgery, radiation, chemotherapy, and targeted therapies), thanks in part to groundbreaking immunology research led by MD Anderson’s very own Chair of Immunology, Jim Allison, PhD.
Allison was also a winner of the 2018 Nobel Prize in Physiology or Medicine for his fundamental discoveries in T-cell biology and his invention of ipilimumab, the first FDA-approved immune checkpoint inhibitor to treat cancer checkpoint inhibitor to treat cancer. According to the University of Texas MD Anderson Cancer Center, rather than attacking the cancer cells directly (with chemo and radiation), immunotherapy “trains” our immune system to attack cancer.
Here’s how it works: Immune system cells (otherwise known as white blood cells), such as T cells and antigen-presenting cells (APCs), defend and protect the body. APCs act as a patrol, looking for cancer and other diseases, and T cells act as soldiers for the immune system. When an APC finds something suspicious, it sends a signal to the T cell, which multiplies and attacks the suspicious cells. But if T cells don’t stop, they can damage healthy cells. A safety switch, called a checkpoint, prevents this. Because cancer is so complex, however, T cells are often turned off before their work is done.
With checkpoint inhibitor drugs (also known as immune system–boosting drugs), the most common type of immunotherapy, those T cells can be prevented from switching off, allowing them to finish their job. And immunotherapy benefits don’t stop when the treatment ends; instead, they help the immune system remember cancer, so that T cells can quickly target cancer if it returns.
Immunotherapy is able to effectively treat bladder cancer, head and neck cancers, Hodgkin’s lymphoma, kidney cancer, non–small cell lung cancer, and melanoma. In March of this year, the James P. Allison Institute was launched, a visionary research and innovation hub within MD Anderson designed to foster groundbreaking science, to develop new treatments, and to bring the benefits of immunotherapy to all patients.
“Immunotherapy has transformed cancer care over the past decade, but, unfortunately, not all patients benefit equally,” says Allison, chair of immunology and director of the Allison Institute. “Our goal is to change that.”
Oncolytic virotherapy (OV)
Viruses are known to be harmful invaders of the body. Normally, we try to avoid viral infections, since viruses can kill healthy cells and cause disease. But some viruses can actually be used to target and infect cancer cells specifically, while leaving nearby healthy cells and tissues intact. These viruses, called oncolytic viruses (OV), can be used as a form of—and catalyst for—immunotherapy.
There are two main ways that OVs help fight cancer. First, the oncolytic viruses kill cancer cells directly when they infect these cells and cause them to burst. Second, when the cancer cells die, they release telltale markers called antigens into the body. These cancer antigens are taken up by cells of the immune system, which then alert our bodies’ attack cells, the T cells, to look for and kill cancer elsewhere in the body.
Several OVs are in clinical testing. According to Shaun Zhang, director of the Center for Nuclear Receptors and Cell Signaling at the University of Houston and MD Anderson, various forms of immunotherapy, such as immune checkpoint blockers, have produced significant benefits, but they only work on roughly 15 percent of cancer patients.
“In recent years, a few new cancer therapeutic technologies have really revolutionized cancer treatment. The one I’m working on, called cancer viral therapy, has generated a lot of excitement for cancer treatment,” Zhang says. “Basically, you are combining two frontier cancer treatments [OV and immunotherapy] together to not only increase the benefit for a majority of cancer patients, but enhance the benefit of immunotherapy for cancer patients.”
Another huge advantage of OV, Zhang says, is that it is much less toxic than chemotherapy. Those improvements are now being made in Zhang’s lab, which received a $1.8 million grant this year from the National Institutes of Health to support his work.
“Oncolytic viruses induce a powerful immune response against viral components and tumor antigens,” Zhang says, “and are a promising strategy for targeting T-cell-poor tumors that are not amenable for immunotherapy.”
CAR-T cell therapy
Another form of immunotherapy treatment, called CAR-T cell therapy, has also generated excitement among researchers and oncologists. This treatment, which induces immune cells to hunt down and kill cancer cells, was declared a success for leukemia patients this year after a 10-year follow-up from two of the first patients treated with CAR-T cells.
The treatment involves removing and genetically altering T cells from cancer patients. The altered cells then produce proteins called chimeric antigen receptors (CARs). Six CAR-T cell therapies have been approved by the Food and Drug Administration to treat blood cancers, and they hold enormous promise for the treatment of solid tumors.
Today, there are hundreds of thousands of people at high risk for cancer who don’t know it and who could possibly benefit from targeted therapies. A frustrating point to recognize about immunotherapies has been the inability to predict who will benefit from them and who will not.
While scientists have been able to successfully map humans’ genetic information to create more personalized therapies, it has now also become possible to analyze the DNA of a person’s tumor and use therapies designed to target the specific mutations found. By analyzing a person’s individual DNA, physicians are able to identify mutations that put them at high risk for certain kinds of cancer. Patients can then be placed on specific treatments, personalized to them, that are aimed at prevention.
As the largest “medical city” in the world, Houston is at the forefront of advancing life sciences and setting the standard for the medical field. From Memorial Hermann being one of the nation’s busiest Level I trauma centers to Houston Methodist establishing itself as a leader in heart and vascular treatments and organ transplants, our hospital systems provide access to some of the finest care anywhere. And now in terms of contemporary cancer care research, institutions like MD Anderson and its network of affiliates across the nation are helping make significant inroads in tackling our greatest health challenge.
For more information on emerging cancer treatments, consult with your medical professional or visit cancer.gov.