People undergoing immunotherapy for advanced lung cancer may be able to reasonably stop treatment after two years if their cancer has not progressed, according to a new retroactive study by researchers at Penn Medicine. The study could guide treatment duration recommendations which have been so far unknown.

Sun L, Bleiberg B, Hwang W-T, et al. Association between duration of immunotherapy and overall survival in advanced non–small cell lung cancer. JAMA Oncology. Published online 2023.

Lova Sun, MD, MSCE, lead study author and an assistant professor of Hematology-Oncology at the Perelman School of Medicine at the University of Pennsylvania, says the study provides the best evidence to date on how a fixed two-year immunotherapy strategy compares to an indefinite treatment strategy.

“For patients and providers considering stopping immunotherapy at two years, this data provides some reassurance that stopping treatment at two years does not appear to compromise survival,” adds Sun.

This was the most striking finding of the study, “indicating that the majority of patients nationwide are being continued on checkpoint inhibitor therapy beyond two years,” says Sun.

How setting a time limit on immunotherapy could help patients

While being at times a life-saving intervention, immunotherapy is taxing—both on the body and a person’s medical bills.

“Continuing treatment beyond two years in the absence of known benefit carries risks including occurrence of long-term immune-related adverse events, as well as the obvious financial cost associated with indefinite treatment with checkpoint inhibitor therapy,” says Sun.

Immunotherapy can cost about $100,000 a year or more, depending on the specific drugs a person needs and if they require multiple medications. Costs and side effects can build up over time.

The value and cost of immunotherapy cancer treatments. Healthline.

Changing trends in care?

“This is a retrospective study and not a randomized controlled trial, which is our gold standard for changing clinical practice,” adds Sun. “There may be residual unmeasured differences between the fixed and indefinite duration groups that we were not able to account for in our adjusted analyses.”

Still, the study findings aligned with the researchers' hypothesis that continuing immunotherapy indefinitely would not significantly benefit lung cancer patients.

It is yet to be seen how the study will influence the medical world and how it will be followed up on. However, it could influence treatment pathways for lung cancer patients who are eligible for discontinuing immunotherapy by giving patients and practitioners more peace of mind if deciding to do so.