Low-Dose Nivolumab in Various Cancers: A Real-World Exploratory Analysis in Resource-Constrained Settings.

Abstract

Background: Immune checkpoint inhibitors (ICIs), including nivolumab, have significantly improved cancer care. However, due to high costs, there is a significant financial barrier to their widespread access. Emerging evidence shows biological plausibility as well as efficacy of low-dose nivolumab across different cancers.

Aims: This exploratory study aims to investigate the clinical outcomes of low-dose nivolumab in cancer treatment to explore the potential to improve its access by reducing costs, especially in resource-limited settings.

Methods and results: Data on patients with various malignancies treated with fixed 20 or 40 mg of nivolumab every 3 weeks were retrospectively analyzed. Response to the treatment, including the best objective response rate, best disease control rate, and adverse events, was reported. The Kaplan-Meier method was used to determine progression-free survival and overall survival. The patient cohort of 31 patients with various tumors received a median of 9 cycles (range, 2-20) of low-dose nivolumab therapy for 5.7 months (range, 0.7-17.1). Median follow-up was 8.6 months (95% CI, 7.1-12.9). Disease control was achieved in 21/31 (67.7%) patients, with the best objective response rate of 51.6%. The median progression-free survival was 8.8 months (95% CI, 6.6-not reached) and overall survival was 14.8 months (95% CI, 11.1-not reached). At the end of the study period, 3/31 patients had a radiologic complete response, 9/31 had a partial response, 4/31 had stable disease, and 6/31 had progressive disease, and 3/31 were not evaluable; 6 patients died during this period. The responses achieved were sustainable for a median of 4 months (range, 0.8-8.2). Only 5 patients developed adverse events of grade 2 or 3.

Conclusions: Low-dose nivolumab shows preliminary efficacy in resource-constrained settings. Further research should explore optimal dosing and scheduling for low-dose immunotherapy and evaluate its efficacy and safety through larger, homogeneous studies.