The time may have come to rethink the standard dose of pembrolizumab for treating metastatic non-small cell lung cancer (NSCLC). A new study published in the Journal of the National Cancer Institute indicates that the customary pembrolizumab dose for treating metastatic NSCLC may be higher than is needed for effective treatment in a significant number of patients.
Pembrolizumab was established as a first-line treatment of metastatic NSCLC tumors expressing programmed death ligand-1 (PD-L1) in at least 50% of cells in October 2016. The standard dosage for pembrolizumab was based on the KEYNOTE 024 trial. The dosage used in the trial was 200 mg for all patients (fixed dosing) every 3 weeks. As a result, this was the dose recommended by the US Food and Drug Administration (FDA).
However, multiple studies have demonstrated equivalent efficacy with lower weight-based doses (personalized dosing). The objective of this study was to compare the economic impact of using personalized dosing (2 mg/kg) vs fixed dosing (200 mg).
The researchers suspected that using the FDA-approved dose of 200 mg for all patients may be an unnecessarily high dose, given that the average weight in the United States is 82 kg. If dosed at 2 mg/kg, an appropriate dose for the average American adult would be 164 mg.
For this study, a budget impact analysis was performed to compare fixed dosing with personalized dosing. They found that the total annual cost of pembrolizumab with fixed dosing is $3.4 billion. However, with personalized dosing it would be $2.6 billion. The use of personalized dosing would likely lead to a 24% annual savings, more than $825 million, according to the researchers.
1. Goldstein DA, Gordon N, Davidescu M, et al. A phamacoeconomic analysis of personalized dosing vs fixed dosing of pembrolizumab in firstline PD-L1-positive non-small cell lung cancer [published online June 3, 2017]. J Natl Cancer Inst. doi: 10.1093/jnci/djx063