麻豆传媒

Adding an immune checkpoint inhibitor (ICI) to chemotherapy for older patients with previously untreated advanced non-small cell lung cancer (NSCLC) provided no survival advantage compared with ICI therapy alone, according to results from a Japanese retrospective cohort study.

Among patients ages 75 and older at a median follow-up of 19.2 months, median overall survival (OS) was 20 months for the chemoimmunotherapy group and 19.8 months for the ICI-alone group, reported Hajime Asahina, MD, PhD, of Hokkaido University Graduate School of Medicine in Sapporo, and colleagues.

The median progression-free survival (PFS) was 7.7 months in both groups, they noted in .

After propensity score matching, the researchers found no differences in OS and PFS between the patients receiving ICI-chemotherapy versus ICI alone. Significance was also not reached when separately analyzing patients with lower or higher PD-L1 expression (1-49% or ≥50%).

Furthermore, the incidence of grade 3 and higher immune-related adverse events (AEs) was higher in patients treated with a chemoimmunotherapy combination.

"Based on these results, ICI alone may be recommended for older adult patients with PD-L1-positive NSCLC," Asahina and colleagues wrote.

In an , Elad Sharon, MD, MPH, of Dana-Farber Cancer Institute and Harvard Medical School in Boston, noted that these efforts to evaluate outcomes in a population often overlooked in clinical trials are "needed by both patients and clinicians and are often sorely lacking in oncology."

However, he also advised that practice-changing results "should still be the domain of randomized clinical trials, rather than observational studies based on clinical practice."

Clinical trials and data from clinical practice should support and complement each other, Sharon said, adding that "through the use of both clinical trial and clinical practice evidence, we have the potential to advance therapies for diverse patient populations."

This retrospective cohort study included 1,245 patients (median age 78 years, 78% male) across 58 centers in Japan. PD-L1 expression of less than 1% occurred in 22% of tumors, 1% to 49% in 31% of tumors, 50% and higher in 33% of tumors, and unknown expression in 14% of tumors.

A total of 354 patients received ICI-chemotherapy combination treatment, 34% received ICI alone, 25% received platinum-doublet chemotherapy, and 12% received single-agent chemotherapy.

Median OS was 12.8 months with platinum-doublet chemotherapy and 9.5 months with single-agent chemotherapy, while median PFS was 5.4 months and 3.4 months, respectively.

Using propensity score matching to compare the ICI-chemotherapy and ICI-alone groups, Asahina and colleagues determined that the OS of patients with a PD-L1 tumor proportion score of 1% and higher was not significantly different between these two groups (22.3 vs 19.2 months, HR 0.98, 95% CI 0.67-1.42). The results were comparable for PFS (8.6 vs 8.0 months, HR 0.92, 95% CI 0.67-1.25).

By multivariate analysis, adding chemotherapy to ICI did not significantly prolong PFS (HR 0.99, 95% CI 0.72-1.36) or OS (HR 1.07, 95% CI 0.73-1.56).

Grade 3 or higher immune-related AEs occurred in 24.3% of patients in the ICI-chemotherapy group and 17.9% of patients in the ICI-alone group, while 32.5% and 24.7% required steroids for immune-related AEs.

Pneumonitis was reported in 23.4% and 15.6% of patients in the two groups, respectively, with 11.6% and 6.8% having grade 3 and higher pneumonitis.

Asahina and colleagues acknowledged several limitations to their study, namely that differences in baseline characteristics can affect the results of retrospective studies. While they attempted to compensate for this with propensity score matching, they suggested factors such as comorbidities could have affected the results of this study.

"Therefore, accurate comparison of each group to answer which regimen should be selected remains a challenge," they wrote.

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