This level of success was “unprecedented” and “really a revolution,” experts say.
Researchers have unveiled a potential new weapon for the fight against cancer — cancer patients’ own immune cells. In an initial round of clinical trials, specialized white blood cells called T-cells were engineered to target specific types of blood cancers. Scientists say these experimental trials have had “extraordinary results.”.
In one trial, the symptoms of 94 percent of patients with acute lymphoblastic leukemia completely disappeared. The response rates were above 80 percent for patients with other types of blood cancer, and more than half of the patients experienced complete remission. The trial with the 94 percent success rate involved 35 patients, and the blood cancer study with 80 percent response rates involved 40 participants.
"This is unprecedented in medicine, to be honest, to get response rates in this range in these very advanced patients," Stanley Riddell, an immunotherapy researcher at Fred Hutchinson Cancer Research Centre in Seattle, explained at the American Association for the Advancement for Science conference, as The Guardian reports.
T-cells are white blood cells whose job is to detect abnormal or foreign cells, like cancerous ones, and then attach themselves to the foreign invaders to alert the rest of the immune system that they need to be attacked.
However, sometimes this natural immune response isn’t aggressive enough to battle the rapidly-growing cancer tumors. Just like us, the T-cells get tired after working hard, and sometimes the foreign invaders learn to trick them and dodge the immune system. This is where immunotherapy can help out.
First, scientists extract the T-cells from the blood and reprogram them with receptors that will aggressively target a specific cancer cell. Once the newly-equipped T-cells are sent back into the body, they regenerate to build up an army of immune cells ready to take on cancer.
Immunotherapy has been around for decades, but only recently have scientists started testing the T-cell therapy in humans. Since the treatment is still in the experimental stage, the scientists are only conducting the research on patients who are no longer responding to other cancer treatments and only have a few months to live.
"In the laboratory and in clinical trials, we are seeing dramatic responses in patients with tumours that are resistant to conventional high-dose chemotherapy," Riddell said in a statement. "The merging of gene therapy, synthetic biology and cell biology is providing new treatment options for patients with refractory malignancies and represents a novel class of therapeutics with the potential to transform cancer care."
The results are just now being peer-reviewed, so before getting too excited, there’s still an important step in the process that has yet to be completed. Additionally, despite the promising results, the treatment will likely only be used for the most extreme cases due to the severe potential side effects — 20 patients suffered symptoms of fever, hypotension, and neurotoxicity during the trials, and two patients died.
"Much like chemotherapy and radiotherapy, it’s not going to be a save-all," said Riddell. "These are in patients that have failed everything. Most of the patients in our trial would be projected to have two to five months to live ... [But] I think immunotherapy has finally made it to a pillar of cancer therapy."
An Italian cancer researcher, Chiara Bonini, also spoke at the conference and had promising things to say about the treatment: "This is really a revolution," she said, according to The Guardian. "T-cells are a living drug, and in particular they have the potential to persist in our body for our whole lives ... Imagine translating this to cancer immunotherapy, to have memory T-cells that remember the cancer and are ready for it when it comes back."
The next step is to figure out how to apply this T-cell treatment to other types of cancer instead of just blood cancers. It will also be important for the researchers to track how long patients stay in remission following the treatment in order to better understand it.
Since the peer-review still has yet to be completed, it will be exciting to see how it all pans out. Hopefully this new T-cell treatment will restore terminally-ill cancer patients with a glimmer of hope.