TEST:

AmoyDx® PD-L1 Expression Detection Kit

For patients with metastatic triple-negative breast cancer (TNBC), treatment with pembrolizumab is dependent on the accurate determination of programmed death ligand 1 (PD-L1) expression using immunohistochemistry (IHC)...In conclusion, concordance between E1L3N and 22C3 testing using CPS for PD-L1 in metastatic TNBC was >90%. However, certain cases were challenging to agree upon using current threshold criteria, highlighting the need for more standardized evidence-based methods to assess PD-L1 expression.

"Recently, the 'Chinese Expert Consensus on Clinical Testing standards of PD-L1 Expression Clinical Detection in Non-Small Cell Lung Cancer (2023 Edition)' was officially released in the Chinese Journal of Pathology. It aims to provide better guidance for the standardized use of PD-L1 detection in the clinical diagnosis and treatment process of non-small cell lung cancer (NSCLC). In this updated consensus, the AmoyDx®PD-L1 (E1L3N) assay (NMPA approval number 20223400313) was prioritized as companion diagnostics for Pembrolizumab."

These results indicate that the overall 84% concordance is driven by concordant negative results. In PD-L1 positive cancers, within-tumor heterogeneity in PD-L1 expression exists.

E1L3N can be used as a reliable alternative antibody clone to evaluate PD-L1 expression status not only in NSCLC patients but also in other cancer types.

Our study provides clinical evidence on the concordance of PD-L1 TPS scores between clones E1L3N and 22C3. Moreover, the treatment responses to pembrolizumab are also comparable between the PDL1-E1L3N and PDL1-22C3. These findings indicate that E1L3N is a reliable and cost-effective assay and may serve as an alternative to 22C3.

However, due to the overall low incidence of PD-L1 positivity, it seems unlikely that the benefit of immunotherapy in early-stage breast cancer would be simply explained by sampling error. Further studies are required to investigate effective predictive biomarkers of response to immunotherapy, as well as to standardize PD-L1 assessment in breast cancer.

Within the prospective ADAPT-IT trial (NCT03122522) testing an abbreviated course of nivolumab (nivo) + ipilimumab (ipi) in patients with unresectable stage III or IV melanoma, we investigated PD-L1 PET imaging in a 10-patient expansion cohort at baseline and after 6 weeks of treatment. The signal of PD-L1 positivity by PET imaging with 18F-BMS-986229 at baseline appears associated with early efficacy from nivo + ipi in this small cohort and may offer additional information than PD-L1 IHC. The ability to assess PD-L1 on a whole patient level at multiple timepoints on treatment may have future implications in how best to sequence and combine immunotherapies but further study in larger patient cohorts is needed.

"Amoy Diagnostics Co., Ltd...announced that China’s National Medical Products Administration (NMPA) recently granted Approval to AmoyDx® PD-L1 Expression Detection Kit (IHC) for guiding the first-line treatment of Pembrolizumab in non-small cell lung cancer patients."