Solid Tumors

PD-L1 IHC 22C3 is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein. PD-L1 IHC 22C3 is indicated as an aid in identifying NSCLC patients for treatment with KEYTRUDA® (pembrolizumab).

disease state indication(s)
Non-Small Cell Lung Cancer (NSCLC), gastric/gastroesophageal (GEJ) adenocarcinoma

clinical use
PD-L1 is the protein product of the CD274 gene, and is expressed on the plasma membrane of a variety of both hematopoietic and solid tissue cells. PD-L1 interacts with the PD-1 receptor, which is found on the surface of leukocytes, including T- and B-lymphocytes and some myeloid cells. PD-L1/PD-1 binding triggers signal transduction cascades that ultimately result in self-tolerance and immune system suppression, which normally serves as an immune checkpoint that prevents overstimulation and autoimmunity. Research has shown that tumor infiltrating lymphocytes often exhibit upregulation of PD-1 expression; correspondingly, enhanced PD-L1 expression can be found on many tumor cells, and it is thought that this represents a possible mechanism of escape from immune-mediated tumor destruction. Blockade of PD-L1 stimulation of PD-1 impedes immune inhibition and allows for recognition of tumor as abnormal, with ensuing cytotoxicity. Clinical trials have demonstrated that PD-L1 status may predict benefit from treatment with immune modulators. Pembrolizumab (also called lambrolizumab or MK-3475) is a humanized monoclonal antibody targeting PD-1 that has been FDA-approved for advanced non-small cell lung carcinoma (NSCLC) with increased PD-L1 expression on the basis of data showing increased objective response rate and improved progression free and overall survival in these patients. Studies of other PD-1 inhibitors and anti-PD-L1 agents are ongoing in NSCLC as well as other tumor types.

methodology/product platform
Immunohistochemistry (IHC)

specimen type and requirements
Preferred:
Formalin-fixed, paraffin-embedded (FFPE) tissue containing sufficient tissue containing sufficient tumor cells for analysis. A single, best representative specimen will be tested. Specimens should be fixed in 10% neutral buffered formalin for 12 to 72 hours for PD-L1 testing.
Acceptable alternative:
At least 4 unstained slides cut at 4-5 µm thickness containing sufficient tumor cells, plus accompanying H&E stained slide. If an H&E slide is not available, 5 unstained slides cut at 4-5 µm thickness. Slides should be received at Genoptix within 5 weeks of being sectioned. Date of sectioning must be specified.
Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact with specimen.
DO NOT FREEZE.

turnaround time
Tech-only (TC): 2 days
Global (TC & PC): 3 days

cpt code(s)
88360 (x1)

medicare moldx cpt code
Not applicable

regulatory classification
FDA approved/cleared

ordering option
Global (TC & PC) or Tech-only (TC)