The expanded label approved is indicated for use in identifying PD-L1 expression status to inform treatment in metastatic NSCLC with Merck's KEYTRUDA (pembrolizumab).

With this expanded use, PD-L1 IHC 22C3 pharmaDX test can be used for determining PD-L1 expression in a range of patients who have a PD-L1 tumour proportion score (TPS) of 1% or more.

Apart from this, the FDA had also approved KEYTRUDA for first-line treatment of metastatic NSCLC patients, with tumours of high level PD-L1 (TPS of 50% or more) or for previously treated metastatic NSCLC patients where tumour level show PD-L1 (TPS 1% or more).

The updated approval of PD-L1 IHC 22C3 pharmDx can also be used in identifying previously untreated patients with metastatic NSCLC with high levels of PD-L1 to be treated with KEYTRUDA. Prior to this, chemotherapy was the standard first-line treatment for most NSCLC patients.

KEYTRUDA is a humanised monoclonal antibody which works by increasing the body’s immune system and helps in detecting and fighting tumour cells.

It blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2 and activates T lymphocytes which could affect both tumour cells and regular cells.

Updated label can mean that patients in second line or later treatment settings including PD-L1 expression of 1% or more can also be treated with KEYTRUDA.

Agilent Diagnostics and Genomics Group president Jacob Thaysen said: “This expanded intended use for our FDA-approved PD-L1 IHC 22C3 pharmDx assay is a step towards providing first-line metastatic NSCLC patients with immunotherapy as an option.

“PD-L1 IHC 22C3 pharmDx allows pathologists to confidently determine, and report PD-L1 expression status for a patient’s tumor. This critical diagnostic information informs oncologists’ treatment decisions around KEYTRUDA.

“Pathologists recognize the need for approved and validated tests, and our companion diagnostic gives them a highly accurate tool to inform oncologists on PD-L1 expression.”