Halozyme Sues Merck for Patent Infringement over Subcutaneous Keytruda Formulation

Complaint filed in New Jersey alleges Merck uses Halozyme's patented MDASE technology to develop SC Keytruda

Halozyme is seeking damages and injunctive relief to stop the infringement

SAN DIEGO, April 24, 2025 /PRNewswire/ -- Halozyme Therapeutics, Inc. (NASDAQ: HALO) (Halozyme), a biotechnology company that pioneered the use of human hyaluronidase for subcutaneous drug delivery, today filed a patent infringement lawsuit against Merck Sharp & Dohme Corp. (Merck) in U.S. District Court in New Jersey.

Halozyme believes the subcutaneous formulation of Merck's cancer medicine, Keytruda, infringes multiple patents that Halozyme filed beginning in 2011 to protect its groundbreaking MDASE subcutaneous delivery technology. Subcutaneous (SC) Keytruda has completed phase 3 clinical testing and Merck has publicly commented on its intention to launch the SC product in 2025. Merck has used Halozyme's technology to develop SC Keytruda without Halozyme's permission.

"We are filing this lawsuit to protect the innovative technology that we pioneered through years of painstaking research and development," said Dr. Helen Torley, president and chief executive officer of Halozyme. "Our technology can ease the burden of treatment and improve patient outcomes by making possible rapid, high-volume subcutaneous drug delivery for patients with serious medical conditions."

Halozyme partners with pharmaceutical companies to make subcutaneous versions of important medicines available for the benefit of patients. Halozyme's MDASE hyaluronidase technology is protected by a robust patent portfolio. Halozyme expected Merck to obtain a commercial license for the intellectual property it is using, but Merck has failed to do so and instead plans to launch SC Keytruda while knowingly infringing on Halozyme's MDASE patents.

The patents at issue arise from Halozyme's extensive research into nearly 7,000 modifications to human hyaluronidases. Among their uses, these hyaluronidases pioneered by Halozyme provide a mechanism for the rapid subcutaneous administration of therapeutic drugs. Halozyme's research and development resulted in a roadmap for selecting potential modifications to human hyaluronidases that can impact their activity and stability. Halozyme's comprehensive studies and innovations were a significant advancement to the field of human-derived hyaluronidases. 

"Merck has long been aware of Halozyme's patents and still proceeded to appropriate Halozyme's technology in order to develop SC Keytruda," said Halozyme's Chief Legal Officer, Mark Snyder. "Based on their public comments, it appears they intend to launch SC Keytruda later this year despite the clear infringement of our patents. In our lawsuit, we are seeking damages and injunctive relief to stop the infringement."

None of the MDASE patent rights which Halozyme is seeking to enforce in this suit relate to the Company's ENHANZE^® licensing program. The MDASE patents are not licensed to any of Halozyme's licensees. Therefore, the outcome of this dispute will not impact ENHANZE^®, the ability of any licensee to use ENHANZE^®, or revenues Halozyme receives from ENHANZE^® licensees.

About Halozyme

Halozyme is a biopharmaceutical company advancing disruptive solutions to improve patient experiences and outcomes for emerging and established therapies. As the innovators of ENHANZE^® drug delivery technology with the proprietary enzyme rHuPH20, Halozyme's commercially-validated solution is used to facilitate the subcutaneous delivery of injected drugs and fluids, with the goal of improving the patient experience with rapid subcutaneous delivery and reduced treatment burden. Having touched more than one million patient lives in post-marketing use in ten commercialized products in at least one major region and across more than 100 global markets, Halozyme has licensed its ENHANZE^® technology to leading pharmaceutical and biotechnology companies including Roche, Takeda, Pfizer, Janssen, AbbVie, Eli Lilly, Bristol-Myers Squibb, argenx, ViiV Healthcare, Chugai Pharmaceutical and Acumen Pharmaceuticals.

Halozyme also develops, manufactures and commercializes, for itself or with partners, drug-device combination products using its advanced auto-injector technologies that are designed to provide commercial or functional advantages such as improved convenience, reliability and tolerability, and enhanced patient comfort and adherence. The Company has two commercial proprietary products, Hylenex^® and XYOSTED^®, partnered commercial products and ongoing product development programs with Teva Pharmaceuticals and McDermott Laboratories Limited, an affiliate of Viatris, Inc.

Halozyme is headquartered in San Diego, CA and has offices in Ewing, NJ and Minnetonka, MN. Minnetonka is also the site of its operations facility.

For more information visit www.halozyme.com and connect with us on LinkedIn and Twitter.

Safe Harbor Statement

In addition to historical information, the statements set forth above include forward-looking statements including, without limitation, statements concerning the possible activity, benefits and attributes of Halozyme's ENHANZE^® and MDASE™ drug delivery technologies, the possible method of action of these technologies, their potential application to aid in the dispersion and absorption of other injected therapeutic drugs, and statements concerning certain other potential benefits of these technologies including facilitating more rapid delivery of high-volume injectable medications through subcutaneous delivery and potentially easing the treatment burden for patients and improving patient outcomes.  These forward-looking statements also include statements with respect to Halozyme's patent infringement suit against Merck Sharp & Dohme, Corp., to enforce Halozyme's patent rights, including Halozyme's belief that Merck's SC Keytruda infringes multiple Halozyme patents, Merck's public statements with respect to the timing of the commercial launch of SC Keytruda and Halozyme's belief that the suit will not impact its ENHANZE^® licensing program. These forward-looking statements involve risks and uncertainties beyond Halozyme's control that could cause actual results to differ materially from those in the forward-looking statements. The forward-looking statements are typically, but not always, identified through use of the words "expect," "believe," "enable," "may," "will," "could," "intends," "estimate," "anticipate," "plan," "predict," "probable," "potential," "possible," "should," "continue," and other words of similar meaning. Actual results could differ materially from the expectations contained in forward-looking statements as a result of several factors and Halozyme can offer no assurance with respect to such forward-looking statements and cautions the reader not to place undue reliance on these forward-looking statements.  In particular, there can be no assurance as to developments related to the litigation referred to in this press release, the outcome of the litigation or any remedies that could be awarded in connection with the litigation.  Actual results could also differ materially from expectations contained in this press release as a result of other risks and uncertainties including those related to the enforceability and validity of our patents, the cost of litigation, unexpected adverse events or patient experiences or outcomes from being treated with the ENHANZE® co-formulated treatments and competitive conditions. These and other factors that may result in material differences from the forward-looking statements contained in this press release are discussed in greater detail in Halozyme's most recent Annual and Quarterly Reports filed with the Securities and Exchange Commission. Except as required by law, Halozyme undertakes no duty to update forward-looking statements to reflect events after the date of this release.

Contacts:

Tram Bui
VP, Investor Relations and Corporate Communications
609-359-3016
[email protected]

Paul Gallagher
Teneo
917-573-5051
[email protected] 

SOURCE Halozyme Therapeutics, Inc.