Cancer immunotherapy can extend survival even if stopped due to side effects

Study author Federica Pecci, MD of Dana Farber Cancer Institute – photo credit Dana Farber

CANCER DIGEST – April 20, 2025 – Cancer patients with non-small cell lung cancer who have to discontinue their immunotherapy treatments due to complications can still obtain durable cancer control, a new analysis shows.

Researchers at Memorial Sloan Kettering and Dana Farber published the data analysis study in the April 15, 2025 issue of the journal Clinical Cancer Research. 

Led by Federica Pecci, MD of Dana Farber and Mark Awad, MD, PhD of Memorial Sloan Kettering the researchers analyzed the outcomes of 2,794 non-small cell lung cancer patients who were treated with a type of immunotherapy called immune checkpoint inhibitors (ICIs) such as Opdivo® and Yervoy® either alone or in combination with other treatments. 

They found that approximately 10 percent of these patients discontinued the treatment due to immune system related adverse events, meaning the therapy triggered a complication such as lung inflammation (pneumonitis), inflammation of the colon (colitis) or liver inflammation (hepatitis). They stratified these patients into three groups by length of time they were able to undergo immunotherapy before discontinuing it: those who received the immunotherapy for 3 months or less, those who discontinued therapy between 3 and 6 months, and those who underwent the treatment for more than 6 months before discontinuation.

What the data showed was that overall progression free survival (PFS) of all patients who discontinued the immunotherapy was 12.7 months, and that the longer the patients were able to undergo the immunotherapy the longer their progression-free survival. Progression-free survival is the amount of time the cancer has stopped growing. Patients in the 3 months or less group had PFS was 6.2 months, among those in the 3-6 months of therapy group, PFS was 13.9 months, and those who had 6 months or more of the immunotherapy before discontinuing it, PFS was 25.8 months.

When they looked at overall survival the results were similar. The patients who underwent treatment for 3 months or less survived 21.7 months after discontinuation, patients in the 3-6 month therapy group survived 42.7 months after discontinuation, and those in the 6 months or more of therapy group survived an average of 86.9 (7 years and 3 months).

“These outcomes suggest that patients can experience prolonged disease control and survival after stopping treatment due to toxicity or if side effects are impacting their quality of life,” Pecci said in a press release.

The researchers also found that the use of steroids or other immunosuppressants to treat the side effects did not seem to affect the anti-cancer response.

The researchers concluded that although discontinuation of checkpoint inhibitor immunotherapy is clearly warranted in cases of severe side effects, this study may help guide clinical decision-making in determining when to discontinue the therapy.

Sources: Dana Farber press release  Eurekalert.org press release