Extending the dosing interval of immune checkpoint inhibitors (ICIs) does not appear to impact the efficacy of ICIs or increase the risk of severe toxicity for patients with non-small cell lung cancer (NSCLC), according to research published in Clinical Lung Cancer.
Extended-interval (EI) dosing was implemented due to the COVID-19 pandemic as a way to reduce clinic visits for patients with stage III and IV NSCLC receiving ICI treatment.
Researchers compared patients who received EI and those who received standard dosing of ICIs at a single center. The retrospective study included 205 consecutive patients with stage III/IV NSCLC. There were 117 patients in the EI group and 88 in the standard dosing group.
Baseline characteristics were largely similar between the groups. However, the standard group included more patients who received nivolumab and fewer who received durvalumab.
There was no significant difference in progression-free survival (PFS) or overall survival (OS) between the dosing groups for patients who received pembrolizumab monotherapy or those who received adjuvant durvalumab.
For patients who received pembrolizumab alone, the median follow-up was 93.7 weeks. The median PFS was 152 weeks in the EI group and 118 weeks in the standard group. The median OS was not reached and 189 weeks, respectively.
For patients who received adjuvant durvalumab, the median follow-up was 54.6 weeks. The median PFS and OS were not reached in either dosing group.
For patients who received nivolumab alone, PFS and OS were better in the EI group. At a median follow-up of 98.6 weeks, the median PFS was not reached in the EI group and was 29.8 weeks in the standard group. The median OS was not reached and 87.8 weeks, respectively.
The researchers were unable to compare PFS and OS for patients who received pembrolizumab plus chemotherapy due to patient numbers.
There were significantly more adverse events (AEs) in the EI group than in the standard dosing group — 237 and 118 AEs, respectively (P =.02).
There were no significant differences in AEs between the dosing groups for patients who received nivolumab alone, pembrolizumab plus chemotherapy, or adjuvant durvalumab. The only significant difference was seen in patients who received pembrolizumab monotherapy (P =.02).
For the entire cohort, the incidence of grade 3 or higher AEs was lower in the EI group than in the standard group, but this difference was not significant — 8.9% and 17.0%, respectively (P =.42).
The proportion of patients who required treatment adjustments due to AEs was similar between the dosing groups, at 26.5% in the EI group and 26.1% in the standard group.
“Based on our safety and efficacy data, EI dosing for ICI seems a safe and effective strategy and should be continued beyond the COVID-19 pandemic,” the researchers concluded.
Hijmering-Kappelle LBM, Hiltermann TJN, Bensch F. Safety and efficacy of extended interval dosing for immune checkpoint inhibitors in non-small cell lung cancer during the COVID-19 pandemic. Clin Lung Cancer. Published online December 24, 2021. doi:10.1016/j.cllc.2021.12.005