12 July 2019 - - The US Food and Drug Administration has accepted for review six supplemental Biologics License Applications (sBLAs) to update the dosing frequency for Keytruda, Merck's anti-PD-1 therapy, to include an every-six-weeks dosing schedule option, US-based biopharmaceutical company Merck (NYSE: MRK) said.
Merck is seeking FDA approval of a 400 mg Q6W dose infused over 30 minutes for Keytruda indications in melanoma, classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, gastric cancer, hepatocellular carcinoma and Merkel cell carcinoma. 
If approved by the FDA, the Q6W dose would be available for use in adults in addition to the currently approved dose of Keytruda 200 mg every three weeks infused over 30 minutes.
The FDA has set a Prescription Drug User Fee Act (PDUFA), or target action, date of Feb. 18, 2020.
In the EU, 400 mg Q6W dosing for Keytruda monotherapy was approved by the European Commission on March 28, 2019.
Keytruda is an anti-PD-1 therapy that works by increasing the ability of the body's immune system to help detect and fight tumor cells. Keytruda is a humanised monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.
Merck has the industry's largest immuno-oncology clinical research program. There are currently more than 1,000 trials studying Keytruda across a range of cancers and treatment settings.
The Keytruda clinical programme seeks to understand the role of Keytruda across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with Keytruda, including exploring several different biomarkers.