Halozyme wins preliminary injunction against Merck’s Keytruda SC in Germany

Halozyme Therapeutics (HALO) announced that a German court has granted its request for a preliminary injunction ordering Merck (MRK) to refrain from distributing and offering Keytruda SC in Germany. The Munich Regional Court’s 7th Civil Division found that there is imminent infringement for Keytruda SC in Germany regarding one of Halozyme’s MDASE patents in Europe, European Patent No. 2 797 622. As a consequence, Merck’s launch activities for Keytruda SC in Germany that are within the scope of the order must be halted. Although the preliminary injunction decision is appealable, Halozyme believes the order will withstand attack if appealed. Separate nullity proceedings against this patent initiated by Merck in August 2025 are pending before the German Federal Patent Court. Patients who want to use Keytruda will have access to the IV version of Keytruda, which is not covered by Halozyme’s patent or the court’s injunction order. “We are very pleased the German court followed our arguments on the validity and infringement of one of our European MDASE patents and granted a preliminary injunction against Merck’s imminent infringement of our patent. The MDASE technology was developed through years of rigorous research to enable rapid, high-volume subcutaneous drug delivery,” said Mark Snyder, chief legal officer of Halozyme. The German proceedings are part of Halozyme’s global enforcement of its MDASE patents against infringement by Merck’s Keytruda SC. Halozyme has also sued Merck for patent infringement in U.S. federal district court in New Jersey. In that case, Halozyme alleges the subcutaneous formulation of Keytruda, which is being marketed in the U.S. as QLEX, infringes 15 patents that Halozyme filed beginning in 2011 to protect its MDASE technology. The patents at issue arise from Halozyme’s extensive research into nearly 7,000 modifications to human hyaluronidases. The MDASE patents are not included in Halozyme’s ENHANZE licensing program and are distinct from its ENHANZE patents. Therefore, the outcome of the infringement lawsuit against Merck will not impact ENHANZE, the ability of any licensee to use ENHANZE, or revenues Halozyme receives from ENHANZE licensees.