PD-L1

PD-L1 is a protein that protects normal cells from destruction when T-cells are activated. Some cancer cells take advantage of this protective role by highly expressing PD-L1 to evade the immune system. PD-1/PD-L1 inhibitor therapy blocks PD-L1 function, thereby enabling the immune system to attack cancer cells that express PD-L1. Therapies that target PD-L1 function belong to a class of drugs called checkpoint inhibitors.

1. Keytruda^® (pembrolizumab): FDA-approved for treating patients with certain types of cancers, such as non–small cell lung cancer (NSCLC), melanoma, head and neck squamous cell cancer, classical Hodgkin lymphoma, primary mediastinal B-cell lymphoma, urothelial carcinoma, MSI-high or dMMR solid tumors, colorectal cancer, gastroesophageal junction (GEJ), squamous cell carcinoma of the esophagus, cervical cancer, hepatocellular carcinoma, Merkel cell carcinoma, renal cell carcinoma, cutaneous squamous cell carcinoma, or triple negative breast cancer. See the package insert for a complete list of FDA-approved indications and prescribing information.¹
2. Opdivo^® (nivolumab): FDA-approved for treating patients with certain types of cancers, such as melanoma, NSCLC, malignant pleural mesothelioma, renal cell carcinoma, classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, urothelial carcinoma, colorectal cancer, hepatocellular carcinoma, and esophageal squamous cell carcinoma. May be used in combination with YERVOY^® (ipilimumab). See the package insert for a complete list of FDA-approved indications and prescribing information.²
3. Tecentriq^® (atezolizumab): FDA-approved for treating patients with certain types of cancers, such as urothelial carcinoma, NSCLC, triple-negative breast cancer, small cell lung cancer, hepatocellular carcinoma, and melanoma.See the package insert for a complete list of FDA-approved indications and prescribing information.³
4. Bavencio^® (avelumab): FDA-approved for treating patients with certain types of cancer, such as Merkel cell carcinoma, urothelial carcinoma, and renal cell carcinoma. See the package insert for a complete list of FDA-approved indications and prescribing information.⁴
5. Imfinzi^® (durvalumab): FDA-approved for treating patients with certain types of cancer, such as NSCLC and extensive-stage small cell lung cancer. See the package insert for a complete list of FDA-approved indications and prescribing information.⁵
6. Libtayo^® (cemiplimab-rwlc): FDA-approved for treating patients with certain types of cancer, such as cutaneous squamous cell carcinoma, basal cell carcinoma, and NSCLC. See the package insert for a complete list of FDA-approved indications and prescribing information.⁶

Yes, clinical studies are ongoing for other drugs and other indications. 

Some therapies that target PD-L1 function are indicated only for patients whose tumors express PD-L1 or elevated levels of PD-L1. Testing for PD-L1 expression in tumors can help determine whether a patient is a candidate for such therapies. For other therapies, testing for PD-L1 expression is not required but may provide additional information.

In addition to PD-L1 IHC testing, other tests may also provide information for selecting PD-1/PD-L1 inhibitor therapy. Microsatellite instability (MSI) analysis or mismatch repair deficiency testing can be used to identify patients with unresectable or metastatic solid tumors in whom frontline therapy has failed, and who may be candidates for certain PD-1/PD-L1 inhibitor therapies (Table 2).

If you have a question regarding this test or a patient report, you can call one of the following numbers:

• Oncology Client Services at San Juan Capistrano, CA: 1.866.894.6920.
• Oncology Client Services at Chantilly, VA: 1.866.677.0742 Opt.1.
• PhenoPath Client Services, Seattle, WA: 1.888.92.PHENO (1.888.927.4366).
• AmeriPath: Please contact your sales representative.
• If you are not sure what lab you order from, please contact your Quest sales representative. Call 1.866.MYQUEST (1.866.697.8378), or visit QuestDiagnostics.com.