IMMUNE CHECKPOINT INHIBITORS (ICIs), which use a person’s own immune system to fight cancer, have become a standard treatment for many people with non-small cell lung cancer (NSCLC). However, those with advanced NSCLC who have a sustained response to ICIs may wonder whether it’s safe to stop treatment.

To better assess the impact of stopping treatment on patient outcomes, a study published August 2023 in JAMA Oncology examined medical records from a national database of patients with advanced NSCLC, including 113 patients who took immunotherapy for a fixed duration of two years and 593 patients who continued therapy indefinitely beyond two years. Patients who stopped immunotherapy after two years had survival rates similar to patients who continued treatment, says Lova Sun, a medical oncologist at the Hospital of the University of Pennsylvania in Philadelphia who led the study. Two-year overall survival was 79% in the fixed‑duration group and 81% in the group that continued immunotherapy indefinitely, calculated four years after starting ICIs in both groups.

Current studies that show the benefits of ICIs for metastatic NSCLC generally follow patients for two years. Some organizations, including the National Comprehensive Cancer Network, recommend that patients with NSCLC receive immunotherapy for two years. “We know that based on the mechanism of immunotherapy, unlike chemotherapy, the effects on the immune system—including improved anti-tumor activity—may persist after discontinuing the treatment itself,” Sun says.

Jack West, a thoracic oncology specialist at Summit Therapeutics in Menlo Park, California, says the study adds insight to limited findings about the optimal duration of immunotherapy. “More treatment does not appear to translate to a better outcome, defined by overall survival, which is our gold standard for what we strive for when managing patients in this setting,” says West, who was not involved in the study.

Irisaida Méndez, who was diagnosed with stage IV lung cancer in 2017, discontinued immunotherapy after two years. Currently, Méndez has no evidence of disease. She is thankful for the extra time she now has to spend with family, noting the expense of treatments and the time needed to receive infusions.

Immunotherapy is administered every two to six weeks, and out-of-pocket costs can be anywhere from hundreds to thousands of dollars for each infusion. “Insurance reimbursements differ, but financial toxicity—either to the patient or the health care system at large—is certainly one of the drawbacks to continuing immunotherapy indefinitely,” Sun says.

Stopping immunotherapy after two years can also eliminate side effects associated with long-term use. For example, Méndez experienced peripheral neuropathy, which is a rare side effect of immunotherapy that causes numbness and tingling in the hands and feet. “The sense of freedom came months later when my body wasn’t as weak, when I wasn’t tripping or falling, and the tingling in my fingers significantly reduced,” Méndez says. Though she is still anxious about the possibility of relapse, she has been able to enjoy life with her family. “Gaining control over my body and getting rid of side effects gave me a sense of freedom,” she says.

In addition, patients still have options if their cancer grows after ending immunotherapy treatment, West stresses. “It is also important to remember that patients who experience disease progression after stopping immunotherapy may resume it, and we can expect their cancer to show significant shrinkage again in nearly half of these cases,” West says.