New Keytruda dosing schedule rejected in six cancers by the FDA

MSD’s blockbuster immunotherapy Keytruda has been stopped in its tracks by the FDA after the US regulator rejected its application for a new dosing regimen in six different cancers: melanoma, classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, gastric cancer, hepatocellular carcinoma, and Merkel cell carcinoma.

The therapy is already approved in those cancers when taken at 200mg dose every three weeks; the manufacturer was seeking to add the new dosing schedule of 400mg every six weeks on the grounds that it would provide patients with greater flexibility and make their trips to receive infusion more infrequent.  

Keytruda already secured approval in Europe for this dosing regimen on the back of positive data. However, the FDA met these same data with a Complete Response Letter, explaining that it could not approve the drug. In response, MSD confirmed it was “reviewing” the letter “and will discuss next steps with the FDA”.

Matt Fellows