Untitled case

In a significant pharmaceutical patent infringement litigation, Halozyme, Inc., a biotechnology company specializing in drug delivery technologies, has accused Merck Sharp & Dohme Corp. (Merck), a global pharmaceutical giant, of infringing multiple patents related to Halozyme's proprietary enzyme technology. The case, 2:25-cv-03179, was filed in the District of New Jersey on April 24, 2025. Halozyme asserts that Merck's development and impending commercialization of SC KEYTRUDA, a subcutaneous version of its blockbuster cancer immunotherapy KEYTRUDA, infringes Halozyme's patents. Merck has reportedly pursued the subcutaneous formulation to extend the market life of KEYTRUDA before its existing patent protection expires in 2028.

The lawsuit targets Merck's SC KEYTRUDA, which allegedly utilizes Halozyme's patented "MDASE™ technology" to enable rapid subcutaneous administration of therapeutic drugs. The asserted patents, a family of fifteen patents including US Patent No. 12,195,773, generally relate to modified PH20 hyaluronidase polypeptides that exhibit increased stability and/or activity, along with their compositions, formulations, and uses in drug products. Specifically, US Patent No. 12,195,773 details claims directed to modified PH20s with modifications to residue 320.

The case is currently in the District of New Jersey, with Magistrate Judge Jose R. Almonte overseeing initial proceedings, including a scheduled in-person status conference on January 28, 2026. The District of New Jersey is a particularly relevant venue for this dispute, as it has become a primary hub for pharmaceutical patent litigation, especially cases falling under the Hatch-Waxman Act, known for its specialized local patent rules designed to streamline complex intellectual property disputes. The notability of this case stems from its potential impact on the pharmaceutical industry, showcasing a common strategy by pharmaceutical companies to maintain market exclusivity through new drug formulations and the critical role of enabling technologies like Halozyme's MDASE™ in such developments.

Here's a summary of the key legal developments and outcomes for the patent infringement litigation in Halozyme, Inc. v. Merck Sharp & Dohme Corp., Case No. 2:25-cv-03179, filed in the New Jersey District Court, which involves US patent 12195773, among others.

Chronological Legal Developments:

• 2025-01-17: Merck Sharp & Dohme LLC (Merck) filed a Petition for Post-Grant Review (PGR2025-00017) with the Patent Trial and Appeal Board (PTAB) challenging U.S. Patent No. 12,110,520, one of the patents later asserted in the district court litigation.
• 2025-04-24: Halozyme, Inc. (Halozyme) filed a patent infringement complaint against Merck Sharp & Dohme Corp. in the U.S. District Court for the District of New Jersey (Case No. 2:25-cv-03179). The complaint alleges infringement of numerous patents related to modified PH20 hyaluronidase polypeptides, including US Patent No. 12,195,773. The asserted patents are crucial for Merck's subcutaneous version of its drug, Keytruda Qlex™.
• 2025-06-06: Merck filed a Petition for Post-Grant Review (PGR2025-00053) specifically challenging U.S. Patent No. 12,195,773, which is a patent at issue in the district court litigation. This was part of a broader strategy by Merck, which began filing PGR petitions in November 2024 against at least 14 Halozyme patents, all related to the modified PH20 hyaluronidase polypeptides.
• 2025-08-04: Halozyme filed an Updated Power of Attorney in various PGR proceedings, including PGR2025-00046, explicitly listing Case 2:25-cv-03179 (D.N.J.) as a related civil action.
• 2025-09-08: The PTAB instituted PGR2025-00017 against Halozyme's U.S. Patent No. 12,110,520. Prior to this decision, Halozyme disclaimed multiple claims (claims 3-5, 16, and 31-35) of the '520 patent.
• 2025-10-01 to 2025-10-02: The PTAB instituted PGR2025-00033 and PGR2025-00039 against Halozyme's U.S. Patent No. 12,049,652 and U.S. Patent No. 12,104,185, respectively. In these and other PGRs, Merck alleged invalidity based on obviousness, lack of written description, and enablement failures.
• 2025-10-10: The PTAB instituted PGR2025-00046 against Halozyme's U.S. Patent No. 12,091,692. Halozyme disclaimed claims 3-4, 6, and 27-28 of this patent before the institution decision.
• 2025-10-16: The PTAB instituted PGR2025-00052 against Halozyme's U.S. Patent No. 12,264,345; PGR2025-00024 against U.S. Patent No. 12,060,590; and PGR2025-00030 against U.S. Patent No. 12,054,758.
• 2025-11-19: The PTAB instituted PGR2025-00053 against U.S. Patent No. 12,195,773.
• Late 2025 - Early 2026: Discussions regarding a proposed Discovery Confidentiality Order indicate early stages of discovery in the district court case. The PTAB proceedings frequently reference the New Jersey District Court litigation as a related matter.

Current Posture:

The district court case, Halozyme, Inc. v. Merck Sharp & Dohme Corp., 2:25-cv-03179 (D.N.J.), is currently active and open. Given the number of instituted PGR proceedings against the asserted patents, it is highly probable that Merck has filed or will file a motion to stay the district court litigation pending the outcome of these PTAB reviews, though specific docket entries for such a motion were not found in the provided snippets. The extensive PTAB activity indicates that the validity of many of Halozyme's patents is being challenged in parallel. The outcome of these PTAB proceedings could significantly impact the district court case. No Markman hearing, trial, or final judgment has been reached in the district court.

Halozyme, Inc., the plaintiff in case 2:25-cv-03179 in the New Jersey District Court, is represented by attorneys from Walsh Pizzi O'Reilly Falanga LLP and Quinn Emanuel Urquhart & Sullivan, LLP.

The counsel of record for Halozyme, Inc. includes:

Liza M. Walsh

• Role: Local Counsel
• Firm: Walsh Pizzi O'Reilly Falanga LLP, Newark, New Jersey
• Experience Note: Ms. Walsh is a founding partner of her firm and has extensive experience in complex litigation, including pharmaceutical and intellectual property matters.

Lauren R. Malakoff

• Role: Local Counsel
• Firm: Walsh Pizzi O'Reilly Falanga LLP, Newark, New Jersey
• Experience Note: Ms. Malakoff is involved in various litigation matters, including intellectual property disputes.

David A. Nelson

• Role: Lead Counsel (pro hac vice forthcoming)
• Firm: Quinn Emanuel Urquhart & Sullivan, LLP, Chicago, Illinois
• Experience Note: Mr. Nelson is a partner at Quinn Emanuel and focuses on intellectual property litigation, particularly patent litigation in the pharmaceutical and biotechnology sectors.

Jeffrey S. Gerchick

• Role: Lead Counsel (pro hac vice forthcoming)
• Firm: Quinn Emanuel Urquhart & Sullivan, LLP, Washington, D.C.
• Experience Note: Mr. Gerchick is a partner at Quinn Emanuel specializing in high-stakes intellectual property and commercial litigation, frequently handling patent disputes.

Zachariah B. Summers

• Role: Lead Counsel (pro hac vice forthcoming)
• Firm: Quinn Emanuel Urquhart & Sullivan, LLP, Los Angeles, California
• Experience Note: Mr. Summers is a partner at Quinn Emanuel with experience in complex intellectual property and patent litigation.

Lauren Martin

• Role: Lead Counsel (pro hac vice forthcoming)
• Firm: Quinn Emanuel Urquhart & Sullivan, LLP, Boston, Massachusetts
• Experience Note: Ms. Martin is an attorney at Quinn Emanuel focusing on intellectual property litigation, including patent infringement cases.

In case 2:25-cv-03179, Halozyme, Inc. is the plaintiff and Merck Sharp & Dohme Corp. (now Merck Sharp and Dohme LLC) is the defendant.

The counsel of record representing the defendant, Merck Sharp & Dohme Corp. n/k/a Merck Sharp and Dohme LLC, includes:

Brian M. Goldberg

• Role: Lead Counsel
• Firm: Dechert LLP, Philadelphia, Pennsylvania
• Experience Note: Mr. Goldberg is an attorney at Dechert LLP. Dechert LLP has a notable intellectual property practice, particularly in patent litigation, including pharmaceutical and biotechnology cases.