What impacts the cost-effectiveness of PD-L1 testing in non-small cell lung cancer?

Programmed Death Ligand 1(PD-L1) testing is recommended for patients with Non-Small Cell Lung Cancer (NSCLC) at stage IIIB and IV, adenocarcinoma and squamous cell carcinoma. Up to now, no clinical-pathological parameters are perfectly able to select a positive PD-L1-patient. For this reason PD-L1 testing is mandatory for patients with advanced NSCLC for whom an immune checkpoint inhibitor treatment is appropriate. Several studies on the cost-effectiveness of immune checkpoint inhibitors in this subset of patients have been published. Chouaid et al. (Lung Cancer 127, 2019, 44-52) assessed the cost-effectiveness of pembrolizumab versus standard of care platinum-based chemotherapy from the French health care system perspective. The authors did not, however, mention that the type of PD-L1 testing used can impact the cost of therapy, which varies according to methods used and to the country where PD-L1 testing is performed. The lack of specific guidelines can lead to discrepancies in technical and/or clinical validation procedures of PD-L1 testing, and that this also impacts the cost of therapy. In conclusion, the effect of PD-L1 testing on cost-effectiveness of immune checkpoint inhibitors depends on the antibody and platform used for patient selection. The barriers to overcome are the limited quantity of biological material available and lack of standardization of the PD-L1 IHC test methods.