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There is debate over whether immunotherapy treatments for some lung cancers needs to be continued after two years. Westend61/Getty Images
  • For people with late-stage non-small cell lung cancer (NSCLC) undergoing initial immunotherapy treatment, a key question has been how long they should continue the therapy for the best chance at survival.
  • A recent retrospective study examined medical records to compare the outcomes of people who stopped immunotherapy around the two-year mark with those who continued beyond that point.
  • The findings suggest that stopping treatment after two years doesn’t seem to negatively affect survival rates, potentially offering reassurance to patients and healthcare providers contemplating whether to discontinue the treatment at that stage.

New research offers perspective on how long treatment with immune checkpoint inhibitor drugs should be given to people with late-stage non-small cell lung cancer (NSCLC).

In particular, researchers investigated whether stopping the immunology treatments after two years affects how long a patient will live.

In their study, recently published in JAMA Oncology, the researchers looked at medical records of adults diagnosed with late-stage NSCLC between 2016 and 2020 and started their treatment with immunotherapy.

The study focused on two different treatment paths: one where treatment was stopped at around two years (specifically between 700 and 760 days), and another where treatment continued for more than two years (more than 760 days).

The main objective was to see how long people lived after the 760-day mark using specific statistical models.

Out of 1,091 people who were still receiving immunotherapy for the initial two years, there were two main groups: one that stopped treatment around the two-year mark (113 people), and one that kept going with the treatment (593 people).

People in the group that stopped treatment were generally around 69 years old. Most of them were women and white. This group also had more smokers and were more likely to be treated at a university hospital.

When looking at how long people lived after the two-year point, researchers reported that about 79% of the group that stopped treatment were still alive, compared to 81% in the group that continued treatment.

From a statistical perspective, the researchers said there was no meaningful difference in survival rates between the two groups.

Also, roughly one out of every five patients stopped immunotherapy at the two-year point even if their cancer hadn’t gotten worse.

Dr. Lova Sun, a lead author of the study who works in the Division of Hematology and Oncology in the Department of Medicine at the Perelman School of Medicine at the University of Pennsylvania, told Medical News Today that “a common clinical question for patients with metastatic non-small cell lung cancer with long-term response to immunotherapy-based treatment is how long to continue treatment.”

“The major clinical trials stopped immunotherapy at a maximum of two years, but in clinical practice many patients and clinicians continue treatment beyond this time point,” Dr. Sun explained.

“We conducted a retrospective study of lung cancer patients across the U.S. with long-term response to immunotherapy to compare survival between those who stopped treatment at two years vs those who continued beyond two years. We found that there was no statistically significant difference in survival between the two groups.”

— Dr. Lova Sun, lead study author

Dr. Haiying Cheng, an associate professor of oncology and medicine at the Albert Einstein College of Medicine as well as an oncologist at Montefiore Health System said that “immunotherapy has emerged as a significant breakthrough in the treatment of advanced NSCLC.”

“Yet, one question remains elusive: what is the ideal duration for immunotherapy? A two-year duration of immunotherapy has been commonly considered; however, a substantial number of patients opt to extend their treatment beyond this timeframe,” Dr. Cheng, who was not involved the study, told MNT.

“Striking the right balance between effectiveness, safety, and cost has proven to be a persistent challenge. We need to avoid unnecessary treatment, minimize side effects, and control expenses without compromising their protection against potential disease recurrence.”

— Dr. Haiying Cheng, oncologist

“This recent real-world retrospective study, involving 1,091 patients with advanced NSCLC, has shed light on this matter,” Dr. Cheng noted. “The study revealed no statistically significant difference in overall survival between patients who discontinued immunotherapy at the two-year mark and those who persisted beyond it.”

Dr. Wael Harb, a hematologist and medical oncologist at Memorial Care Cancer Institute at Orange Coast Medical Center in California and vice president of medical affairs at Syneos Health, said, “the paper by Sun et al. is both timely and impactful.”

“It addresses a critical question in the management of advanced non-small cell lung cancer (NSCLC): the optimal duration of immunotherapy,” Dr. Harb, who was not involved in the study, told MNT.

The study provides valuable real-world evidence, suggesting that a fixed duration of two years of immunotherapy may be sufficient for most patients who are progression-free at that point. This could potentially revolutionize how we approach treatment duration, moving away from indefinite treatment courses that come with their own set of challenges, such as increased toxicity and financial burden.

— Dr. Wael Harb, hematologist and medical oncologist

Dr. Sun highlighted the fact that “these findings provide reassurance that for patients and providers who are considering stopping immunotherapy for mNSCLC at two years, this strategy does not appear to compromise survival outcomes.”

Dr. Cheng, agreed but also pointed out the need for further research, saying “these findings, while promising, call for validation through randomized prospective clinical trials.”

“Nevertheless, in the absence of prospective data, this real-world study offers valuable insights into the critical question of treatment duration. It suggests that discontinuing immunotherapy after two years is a reasonable approach, provided that the cancer remains under control. “

— Dr. Haiying Cheng, oncologist

Dr. Harb noted that “the implications of this research are multi-faceted and significant.”

“Firstly, it could lead to a more standardized approach to immunotherapy duration for NSCLC, which is beneficial for both clinicians and patients,” he said.

“Secondly, by potentially limiting the duration of immunotherapy to two years, we can reduce the risk of treatment-related adverse events, improving the patient’s quality of life,” he added.

“Lastly, there is the economic aspect; immunotherapy is expensive, and limiting the duration could result in substantial cost savings for healthcare systems and patients,” Dr. Harb explaned.

“It’s important to note that while the study’s findings are promising, they are based on retrospective and observational data. Therefore, individualized treatment decisions should still be made considering various factors such as patient preferences, performance status, and specific tumor characteristics.”

— Dr. Wael Harb, hematologist and medical oncologist