Cost effectiveness of immune checkpoint inhibitors in NSCLC according to PD-L1 expression

Immune checkpoint inhibitors are active in the treatment of patients with non–small-cell lung cancer (NSCLC); since PD-L1 receptor expression is related to the mechanism of action of immune checkpoint inhibitors, expression of PD-L1 is being studied as a predictive biomarker for this therapy. Aguiar and colleagues evaluated the cost-effectiveness of nivolumab and pembrolizumab with and without the use of PD-L1 as a biomarker in patients with NSCLC.¹ A systematic literature review of online databases and oncology conference presentations was performed, and all studies that assessed PD-L1 expression as a biomarker were included regardless of the design of the trial, the agent used, tumor histology, or number of previous treatments. A decision-analytic model was developed to determine the cost-effectiveness of PD-L1 testing and second-line treatment with the 2 FDA-approved agents, nivolumab (nivo) and pembrolizumab (pembro), versus docetaxel (doce), in patients with advanced NSCLC. Health effects were expressed as quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) were calculated. A total of 13 studies (4 of which were randomized) with 2700 patients were retrieved and included in the model. PD-L1 expression was associated with a greater likelihood of response (relative risk [RR], 2.08; confidence interval [CI], 1.49-2.91), and this effect was more intense among nonsquamous (NSQ) tumors (RR, 3.13; CI, 2.15-4.54) than among those with squamous (SQ) histology (RR, 2.12; CI, 1.37-3.29). PD-L1 expression was also correlated with longer progression-free survival (hazard ratio [HR], 0.83; 95% CI, 0.74-0.93) and better overall survival (HR, 0.86; 95% CI, 0.76-0.97). Regarding cost-effectiveness, PD-L1 ≥1% improved incremental QALY of nivo versus doce for patients with NSQ tumors by 67%, (from 0.124 to 0.208) leading to a 40% reduction in the ICER (from US$ 176K to US$ 105K). Interestingly, this effect was not observed among patients with SQ tumors. For pembro, using a 50% cutoff instead of a 1% cutoff increased the incremental QALY by 18% (from 0.138 to 0.164), leading to a 15% reduction in ICER (from $163K to $138K). The authors concluded that use of PD-L1 expression as a biomarker was associated with higher activity with immune checkpoint inhibitors and may increase the cost-effectiveness of treatment with these agents, but this effect was less robust among patients with SQ NSCLC.

1. Aguiar PN, et al. ASCO 2016. Abstract 9033.