ANGLE plc announced the launch of its Portrait® PD-L1 test for the evaluation of PD-L1 protein expression on CTCs following extensive development and optimisation. The test is provided as a service from ANGLE's Onc-ADaPT® GCP-compliant laboratories and is conducted by an expert team with over 10 years' experience in CTC analysis. PD-L1 is an immune-related biomarker that can be expressed on the surface of tumour cells across a range of cancer types, and expression of this biomarker enables cancer cells to evade immune response mechanisms that would typically keep abnormal cell growth in check.

Consequently, PD-1/PD-L1 inhibitors have emerged as the leading immunotherapy treatment option with over 2,800 active interventional studies in progress involving 430,000 patients. Theoutputof current tumour tissue-based PD-L1tests varies considerably, with poor performance often unavoidable due to the elapsed time between tissue biopsy (generally taken at diagnosis and difficult or impossible to repeat) and disease progression (which may be months or years later) when immunotherapies are considered, during which time PD-L1 status can change. ANGLE has developed its immunofluorescence (IF) based test for the determination of PD-L1 status on CTCs to allow real-time assessment of biomarker status, which may address this fundamental flaw in current PD-L1 tests via a simple blood test.