Researchers and doctors have found many effective ways to modify cancer patients’ own immune cells and use them to attack cancer cells. They have been so successful that one type of these so-called “immunotherapies” was even considered the “Advance of the Year” in 2018 by the American Society of Clinical Oncology. However, these therapies are not perfect. Some immunotherapies cause overactivation of the immune system, which can result in terrible side effects including damage to internal organs. Cumulatively, this overactivation and its side effects are known as cytokine release syndrome. Thankfully researchers are coming up with inventive ways to limit or stop cytokine release syndrome, which makes immunotherapies even more powerful.
Researchers don’t yet fully understand all the specific activities that cause the dangerous overactivation of the immune system during immunotherapy. You can think of this overactivation as something like a riot or stampede of cells. When doctors give cancer patients modified immune cells, they do a fantastic job of killing cancer cells, but they also sound the alarm and throw out a bunch of signals saying “SOMETHING NEEDS TO BE DONE!” These signals activate other immune cells, those immune cells send out more signals, and then even non-immune cells can begin acting irregularly.
This cellular rioting can lead to disruption of blood vessels, flu-like symptoms, and damage to organs; but, luckily, doctors know how to treat many of these things. Doctors can give patients drugs that will limit the negative side effects of the cellular riot and block some of the alarms. Nonetheless, these drugs aren’t equally effective in all patients, and there is no one-size-fits-all treatment that can be used in every case.
Recognizing this issue, researchers are working to make it so the modified cells used in immunotherapy don’t cause cellular riots. These researchers are further modifying the immune cells so that they send out fewer alarm signals in the first place and can be destroyed if a riot begins.
Importantly, even without these new modifications, immunotherapies are already very effective at treating cancers of the blood (read the Advance of the Year article for more). I’m hopeful that researchers will be able to make immunotherapies more effective against other types of cancers soon (think solid tumors), and the ability to control these cellular riots will be the icing on the immunotherapy cake. It’s an exciting and hopeful time for cancer researchers and patients!
References:
- Chakravarti, Deboki, and Wilson W. Wong. “Synthetic biology in cell-based cancer immunotherapy.” Trends in biotechnology33.8 (2015): 449-461. PubMed PMID: 26088008. PubMed Central PMCID: PMC4509852.
- Shimabukuro-Vornhagen, Alexander, et al. “Cytokine release syndrome.” Journal for immunotherapy of cancer 6.1 (2018): 56. PubMed PMID: 29907163. PubMed Central PMCID: PMC6003181.