Halozyme Therapeutics is strengthening its position in subcutaneous drug delivery through two developments announced within a day of each other : a Dutch court ruling that restricts Merck’s Keytruda SC activities across multiple European markets and an expansion of its collaboration with argenx to develop subcutaneous formulations for two additional targets using Halozyme’s ENHANZE® technology.
On October 7, 2026, Halozyme announced that the specialized Dutch patent court in The Hague found Merck to be infringing Halozyme’s MDASE™ patent EP 2,797,622. The court ordered Merck’s central European Market Authorization Holder and worldwide packaging and distribution hub, MSD BV, to refrain from manufacturing, having manufactured, offering, placing on the market, using, importing or stocking Keytruda SC for these purposes in Belgium, Denmark, France, Ireland, Italy, Sweden, Switzerland and the Netherlands. The court also rejected Merck’s arguments challenging the validity of the patent.
The ruling concerns Keytruda SC, the subcutaneous version of Merck’s pembrolizumab. Halozyme said the injunction does not affect patients' access to the intravenous version of Keytruda, which is not covered by the company's patent or the court's order. The Dutch proceedings form part of Halozyme's broader global patent enforcement efforts concerning its MDASE™ technology. Halozyme previously obtained a preliminary injunction in Germany in December 2025 and has also filed a patent infringement lawsuit against Merck in the United States.
Importantly, Halozyme clarified that its MDASE™ patents involved in the Merck litigation are separate from the patents supporting its ENHANZE® licensing program. The company said the outcome of its global enforcement actions against Merck will therefore not affect licensees' ability to use ENHANZE® or the license fees associated with ENHANZE® patents.
Just one day earlier, on October 6, Halozyme announced an expansion of its global collaboration and license agreement with argenx. Under the expanded agreement, argenx will gain exclusive access to ENHANZE® for two additional targets, increasing the number of exclusive targets under the collaboration from six to eight. The companies intend to develop subcutaneous formulations using ENHANZE® technology.
The expansion builds on the companies' existing collaboration around VYVGART Hytrulo, a subcutaneous formulation that has provided an alternative administration option for patients with myasthenia gravis and chronic inflammatory demyelinating polyneuropathy. Halozyme said it will be eligible for milestone payments under the expanded agreement and royalties on net sales of products using ENHANZE®.
ENHANZE® uses Halozyme's proprietary recombinant human hyaluronidase, rHuPH20, to facilitate subcutaneous delivery of injected drugs and fluids. According to Halozyme, the technology has been used in ten commercialized products across more than 100 markets and has reached more than one million patients.
Taken together, the two developments highlight different aspects of Halozyme's subcutaneous drug-delivery strategy: the company is actively protecting its intellectual property in the market while simultaneously expanding the number of pharmaceutical programs using its drug-delivery technology. The developments also underscore the growing industry focus on subcutaneous formulations designed to provide more convenient alternatives to intravenous administration.
