Untitled case

Unified Patents has initiated an Inter Partes Review (IPR) against U.S. Patent No. 11,066,656 at the Patent Trial and Appeal Board (PTAB) under case number IPR2026-00314. The Petitioner, Unified Patents, is a member-based organization dedicated to deterring patent assertions by Non-Practicing Entities (NPEs) and reducing frivolous patent litigation by challenging the validity of patents through IPRs. The Patent Owner for the '656 patent is Halozyme Inc., a biotechnology company specializing in therapeutic enzymes. The patent at issue, U.S. Patent No. 11,066,656, titled "PH20 polypeptide variants, formulations and uses thereof," describes modified PH20 hyaluronidase polypeptides designed for increased stability and/or activity, which are utilized in pharmaceutical compositions and formulations, particularly for therapeutic applications such as enhancing drug absorption or treating conditions associated with hyaluronic acid.

The case is currently pending before the PTAB, an administrative tribunal within the U.S. Patent and Trademark Office. IPRs offer an alternative, often more streamlined process for challenging patent validity compared to district court litigation. This specific IPR is notable due to Unified Patents' active role in challenging patents they perceive as low-quality or prone to abusive assertion. While Unified Patents typically targets NPEs, the challenge against Halozyme Inc., an operating biotechnology company, suggests this IPR may be linked to broader commercial disputes or licensing issues within the pharmaceutical industry that impact one of Unified Patents' members. The outcome could have implications for the development and commercialization of enzyme-based therapeutics.

The patent litigation involving U.S. Patent No. 11,066,656 is part of a broader dispute between Halozyme, Inc. and Merck Sharp & Dohme Corp. in federal district court, with parallel inter partes review (IPR) proceedings at the Patent Trial and Appeal Board (PTAB).

Correction Regarding IPR Petitioner:
The initial case metadata incorrectly identifies Unified Patents as the petitioner for IPR2026-00314. Public records confirm that Merck Sharp & Dohme LLC is the Petitioner and Halozyme Inc. is the Patent Owner for IPR2026-00314, challenging U.S. Patent No. 11,066,656.

Here are the key legal developments in chronological order:

• 2025-04-24: District Court Complaint Filed
  Halozyme, Inc. filed a patent infringement lawsuit against Merck Sharp & Dohme Corp. in the U.S. District Court for the District of New Jersey, Case No. 2:25-cv-03179. Halozyme asserted infringement of fifteen related patents, including U.S. Patent No. 11,066,656, 10,865,400, 11,041,149, 11,952,600, 12,018,298, 12,037,618, 12,049,652, 12,054,758, 12,077,791, 12,091,692, 12,104,185, 12,110,520, 12,152,262, 12,195,773, and 12,264,345. Halozyme alleges that Merck's "SC KEYTRUDA" product infringes these patents, which relate to modified PH20 polypeptides used for subcutaneous administration of therapeutic drugs.

• 2025 (Various Dates): Merck Files Multiple Post-Grant Reviews (PGRs)
  In response to Halozyme's infringement suit, Merck Sharp & Dohme LLC filed numerous PGRs against the asserted patents at the PTAB. These include, but are not limited to:

  • PGR2025-00003 (U.S. Patent No. 11,952,600)
  • PGR2025-00004 (U.S. Patent No. 12,018,298)
  • PGR2025-00006 (U.S. Patent No. 12,152,262)
  • PGR2025-00009 (U.S. Patent No. 12,123,035)
  • PGR2025-00017 (U.S. Patent No. 12,110,520)
  • PGR2025-00024 (U.S. Patent No. 12,060,590)
  • PGR2025-00030 (U.S. Patent No. 12,054,758)
  • PGR2025-00033 (U.S. Patent No. 12,049,652)
  • PGR2025-00039 (U.S. Patent No. 12,104,185)
  • PGR2025-00042 (U.S. Patent No. 12,037,618)
  • PGR2025-00046 (U.S. Patent No. 12,091,692)
  • PGR2025-00050 (U.S. Patent No. 12,077,791)
  • PGR2025-00052 (U.S. Patent No. 12,264,345)
  • PGR2025-00053 (U.S. Patent No. 12,195,773)

• 2025-10-02: Institution of PGR2025-00039
  The PTAB instituted post-grant review for claims 1-11 of U.S. Patent No. 12,104,185 (PGR2025-00039).

• 2025-10-10: Institution of PGR2025-00046
  The PTAB instituted post-grant review for U.S. Patent No. 12,091,692 (PGR2025-00046). This patent is identified as a continuation of U.S. Patent No. 11,066,656.

• 2025-10-16: Institution of PGR2025-00030
  The PTAB instituted post-grant review for U.S. Patent No. 12,054,758 (PGR2025-00030), after Halozyme filed a statutory disclaimer for some claims.

• 2025-11-13: Institution of PGR2025-00042
  The PTAB instituted post-grant review for U.S. Patent No. 12,037,618 (PGR2025-00042), after Halozyme filed a statutory disclaimer for some claims.

• 2026-02-19: District Court Addresses Discovery and PTAB Status
  The District Court for the District of New Jersey issued a text order regarding ongoing discovery disputes in the Halozyme v. Merck litigation. The court ordered the parties to submit a joint letter by June 9, 2026, advising on the status of the matter following the Final Written Decision of the PTAB. This indicates the court is aware of and considering the impact of the parallel PTAB proceedings on the litigation.

• 2026-03-23: IPR2026-00314 Filed Against Patent 11,066,656
  Merck Sharp & Dohme LLC filed IPR2026-00314 against U.S. Patent No. 11,066,656, owned by Halozyme Inc. The IPR challenges claims 1-25 of the patent. The petition argues, among other grounds, that the '656 patent lacks priority due to deficiencies in written description and enablement in its parent application, making a prior art publication anticipatory.

Current Posture (as of 2026-05-30):
The district court litigation (Halozyme, Inc. v. Merck Sharp & Dohme Corp., 2:25-cv-03179 (D.N.J.)) is ongoing, with discovery matters being addressed. The court has explicitly linked its scheduling to the outcomes of the PTAB proceedings. Many PGRs and IPRs, including IPR2026-00314 against patent 11,066,656, are currently pending before the PTAB. The IPR2026-00314 is awaiting an institution decision, as it was filed recently on March 23, 2026. Final Written Decisions have not yet been issued for the various IPRs/PGRs, and no claim construction, trial, or final judgment has occurred in the district court litigation.

Halozyme, Inc., the plaintiff in Halozyme, Inc. v. Merck Sharp & Dohme Corp., Case No. 2:25-cv-03179 (D.N.J.), is represented by a team including lead counsel from Quinn Emanuel Urquhart & Sullivan, LLP, and local counsel from Walsh Pizzi O'Reilly Falanga LLP, along with in-house legal support.

The following counsel of record represent Halozyme, Inc. in the district court litigation:

Lead Counsel:

• David A. Nelson (Lead Counsel)
  • Firm: Quinn Emanuel Urquhart & Sullivan, LLP (Los Angeles, CA; New York, NY; or other offices)
  • Note: David Nelson is a partner at Quinn Emanuel and is noted as a lead attorney for Halozyme in the US litigation. He has extensive experience in high-stakes intellectual property litigation, particularly in the biotechnology and pharmaceutical sectors.
• Zachariah B. Summers (Lead Counsel)
  • Firm: Quinn Emanuel Urquhart & Sullivan, LLP (Los Angeles, CA; New York, NY; or other offices)
  • Note: Zachariah Summers is a partner at Quinn Emanuel and is identified as a lead attorney for Halozyme. He focuses on patent litigation, particularly in life sciences.

Local Counsel:

• Liza M. Walsh (Local Counsel)
  • Firm: Walsh Pizzi O'Reilly Falanga LLP (Newark, NJ)
  • Note: Liza Walsh is a founding partner of Walsh Pizzi O'Reilly Falanga LLP, with experience in complex commercial litigation, including intellectual property disputes.
• Lauren Ruth Malakoff (Local Counsel)
  • Firm: Walsh Pizzi O'Reilly Falanga LLP (Newark, NJ)
  • Note: Lauren Malakoff is an attorney at Walsh Pizzi O'Reilly Falanga LLP, assisting with litigation in the District of New Jersey.

In-house Counsel:

• Mark Snyder (Chief Legal Officer, In-house)
  • Firm: Halozyme, Inc. (San Diego, CA)
  • Note: Mark Snyder serves as Halozyme's Chief Legal Officer and has been quoted regarding the company's stance on the litigation.
• Josh Mack (Executive Director and Patent Litigation Counsel, In-house)
  • Firm: Halozyme, Inc. (San Diego, CA)
  • Note: Josh Mack is involved in patent litigation strategy for Halozyme.
• Aubrey Haddach (Executive Director Intellectual Property, In-house)
  • Firm: Halozyme, Inc. (San Diego, CA)
  • Note: Aubrey Haddach handles intellectual property matters for Halozyme and has been identified in related PTAB proceedings as an email contact for Halozyme.

Other attorneys listed as "Counsel Not Admitted To Usdc - Nj Bar" on PacerMonitor for this case, such as Elliot Choi, Nancy L. Zhang, Anastasia M. Fernands, and Lauren Martin, are likely members of the Quinn Emanuel team or other out-of-state counsel working on the case, who would appear pro hac vice once formally admitted to the District of New Jersey.

Halozyme Inc., the patent owner (defendant), is represented by both in-house counsel and outside counsel for IPR2026-00314.

Halozyme Inc. (In-House Counsel):

• Mark Snyder
  • Role: Senior Vice President, General Counsel, Chief Compliance Officer, and Corporate Secretary.
  • Firm: Halozyme Therapeutics, Inc. (San Diego, CA)
  • Note: Mr. Snyder leads litigation strategy for the company, and previously led litigation strategy for Qualcomm Incorporated, managing intellectual property, licensing, antitrust, and litigation matters.
• Josh Mack
  • Role: Executive Director, Patent Litigation Counsel.
  • Firm: Halozyme Therapeutics, Inc. (San Diego, CA)
  • Note: Mr. Mack leads all litigation matters for Halozyme and has experience in patent litigation from both in-house (Amgen) and outside counsel positions (Wilson Sonsini Goodrich & Rosati).
• Aubrey Haddach
  • Role: Executive Director, Intellectual Property.
  • Firm: Halozyme Therapeutics, Inc. (San Diego, CA)

Outside Counsel:

Sterne, Kessler, Goldstein & Fox P.L.L.C.
(Likely counsel for PTAB proceedings, based on service lists in related IPRs involving Halozyme and Merck Sharp & Dohme LLC. Firm's main office is in Washington, D.C.)

• Eldora L. Ellison
  • Role: Director.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Regularly involved in inter partes review (IPR) proceedings.
• R. Wilson Powers III
  • Role: Director.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Frequently represents patent owners in IPRs.
• Jennifer Meyer Chagnon
  • Role: Director.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Focuses on patent litigation and inter partes review proceedings.
• David H. Holman
  • Role: Director.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Experienced in post-grant proceedings before the PTAB.
• Tyler C. Liu
  • Role: Director.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Practice includes patent litigation and PTAB trials.
• Louis P. Panzica, Jr.
  • Role: Associate.
  • Firm: Sterne, Kessler, Goldstein & Fox P.L.L.C. (Washington, D.C.)
  • Note: Works on patent office litigation, including IPRs.

While not directly identified as counsel for this specific IPR in the available records, Quinn Emanuel Urquhart & Sullivan, LLP represents Halozyme in related patent infringement litigation against Merck Sharp & Dohme Corp. in U.S. federal district court concerning Halozyme's MDASE technology.

• David Nelson
  • Role: Partner.
  • Firm: Quinn Emanuel Urquhart & Sullivan, LLP (US offices)
  • Note: Leads US litigation for Halozyme against Merck regarding MDASE patents.
• Zach Summers
  • Role: Partner.
  • Firm: Quinn Emanuel Urquhart & Sullivan, LLP (US offices)
  • Note: Leads US litigation for Halozyme against Merck regarding MDASE patents.