A German court has ordered a halt to the sale of Merck’s subcutaneous formulation of Keytruda after ruling in favor of Halozyme in a broader patent dispute. The decision stops commercial distribution in Germany and represents a legal win for Halozyme, which licenses hyaluronidase technology used to enable subcutaneous biologic delivery. The ruling underscores patent risks tied to formulation technologies and highlights how IP disputes can disrupt commercialization plans for major oncology products. Merck is likely to pursue appeals and alternative routes to market while assessing the decision’s implications for other jurisdictions. Subcutaneous formulations are intended to simplify administration and reduce infusion burdens; patent protection around enabling enzymes like Halozyme’s hyaluronidase is therefore strategically important for both originators and third‑party partners.