A long sought weapon against cancer is gaining ground as doctors develop new immunotherapy technologies that empower the immune system to better attack previously evasive tumors, advancing a rapidly emerging pillar of cancer therapy.
Last month at the annual meeting of the American Academy for the Advancement of Science, Dr. Stanley Riddell of the Fred Hutchinson Cancer Research Center in Seattle, WA announced the astounding results of a clinical trial of an adoptive T-cell transfer he launched in 2013.
Dr. Riddell with colleagues in his lab
Dr. Riddell’s groundbreaking technique involves reprogramming the patient’s own T-cells with synthetic molecules called chimeric antigen receptors (CARs) to make them target and destroy specific molecules associated with the cells of a tumor.
T-cells are white blood cells which mature in the thymus, an primary organ of the immune system located in the chest. They naturally attack foreign or abnormal cells, but Dr. Riddell’s process boosts their abilities by extracting T-cells that are most optimal for genetic modification and adoptive therapy from a patient, modifying them to attack cells associated with the specific offending cancer, and reintroducing them to the patient two weeks later. The idea is that this makes the immune system more potent and persistent in destroying the particular cancer a patient is afflicted with than what the body can do on its own.
“We are treating patients with advanced leukemia and lymphoma that have failed every conventional chemotherapy, radiation therapy, including transplants,” says Dr. Riddell. “What’s really remarkable is that it requires taking the cells from the patient, engineering them in the laboratory, growing them up to relatively small numbers, and giving them a single treatment – one infusion of these cells – that takes about 30 minutes to deliver.”
Excerpt from a poster demonstrating the efficacy of Dr. Riddell’s treatment
Even more remarkable is Dr. Riddell’s success rate: within weeks, an overwhelming majority of patients who previously had just months or even weeks left to live experience complete and sustained remission. An oncologist treating one patient with Non-Hodgkin lymphoma who joined the trial explained that within one week of receiving the single infusion, tumors in the patient’s neck that weighed multiple pounds were “just melting like ice cubes”.
Dr. Riddell’s team is now initiating trials in lung cancer, breast cancer, sarcoma, melanoma, and soon pancreatic cancer. In the future he expects to move into kidney cancer, colon cancer, and many other types of tumors.
Another approach to immunotherapy for patients with cancers deemed terminal is a vaccine of cancer proteins that started being tested in human trials in the United Kingdom earlier this month. While previous vaccine treatments have not proved fruitful, this approach differs by also including a topical cream on the injection area that stimulates immunity in an effort to fortify the suppressed immune system of cancer patients.
In 2016, 600,000 people will die from cancer in the United States alone, a fact that led President Obama to launch the National Cancer Moonshot in his 2016 State of the Union Address. The initiative, led by Vice President Joe Biden, is backed by $1 billion USD from the White House over the next two years.
