Study Highlights Patients at Risk For Severe Cancer Immunotherapy Side Effects

Study Highlights Patients at Risk For Severe Cancer Immunotherapy Side Effects

A study led by researchers at Massachusetts General Hospital reveals that factors such as age, combination of therapy and specific cancer type can influence the risk of severe adverse events in cancer patients prescribed immune checkpoint inhibitor immunotherapy.

“Understanding the risk factors for predicting high-grade toxicities will help in appropriately selecting patients most likely to tolerate immune checkpoint inhibitor therapy,” says¬† Yevgeniy Semenov, M.D., a clinician and researcher based at Massachusetts General Hospital who co-led the research.

“It will also help to identify higher risk patients who should be carefully monitored if they initiate this therapy.”

While new immunotherapy options such as immune checkpoint inhibitors have revolutionized cancer therapy in recent years, they are not problem free. Some patients respond well to them, but others do not and a small, but significant minority experience side effects bad enough to require hospitalization.

This means that prescribing this kind of treatment, which almost 40% of cancer patients are now eligible for, can pose a dilemma for oncologists. To try and predict who is at highest risk for severe adverse events, Semenov and team analyzed patient claims data from 14,378 individuals in the U.S. with cancer who had at least one dose of immune checkpoint therapy between 2011 and 2019.

Writing in the Journal for ImmunoTherapy of Cancer, the researchers report that during 19,117 patient years of follow up, 504 (3.5%) of the 14,378 patients included in the study had side effects bad enough to require hospitalization and immune suppression (to treat the adverse effects) during their treatment.

Several factors contributed to this increased risk. For example, being given a combination of different immune checkpoint inhibitors as opposed to a single therapy increased the risk of severe side effects 2.4-fold. Patients with lung cancer also seemed to be at 30-50% higher risk than those with melanoma, renal cell carcinoma or other cancers being treated with the same drugs.

Notably, increasing age seemed to decrease the risk of bad side effects by approximately 2% per additional year of age.

“This study provides the foundation for studying severe immunotherapy toxicities using a big data analytic framework, which will be necessary when understanding the impact of these life-saving medications across diverse populations,” says Semenov. “Also, it is the first step in developing robust clinical risk prediction models to identify patients at highest risk for the development of life-threatening treatment complications.”

Semenov and colleagues also published another analysis this month looking at adverse skin related effects associated with immune checkpoint inhibitors in the Journal of the American Academy of Dermatology. In this study, which included 8,637 patients being treated with immune checkpoint inhibitors and 8,637 matched controls, the overall rate of skin related complications was similar in both groups at around 25% overall.

Although the overall number of skin-related adverse effects did not appear to be significantly higher in the immune checkpoint inhibitor group versus controls, within this group those with melanoma or renal cell carcinoma were more likely to have skin-related adverse effects than those with lung cancer.