DCT

1:26-cv-01001

Immunase Bio LLC v. CSL Behring LLC

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-01001, D. Del., 08/07/2026
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant CSL Behring LLC is a Delaware corporation and resides in the district. Venue is alleged to be proper for Defendant CSL Behring GmbH as it is a foreign defendant whose claims arise from U.S. conduct.
  • Core Dispute: Plaintiff alleges that Defendants' promotion and facilitation of the off-label use of their drug Zemaira® to treat or prevent Graft-versus-Host Disease infringes two patents covering methods of using alpha-1 antitrypsin for those specific purposes.
  • Technical Context: The technology involves the administration of alpha-1 antitrypsin (AAT) as a therapeutic method to treat or prevent Graft-versus-Host Disease (GvHD), a life-threatening complication of bone marrow and stem cell transplantation.
  • Key Procedural History: The complaint alleges that Defendants were aware of the asserted patents through multiple channels prior to the lawsuit, including the 2016 hiring of the university's former licensing manager who prosecuted the patents, licensing negotiations that began in 2016, and Defendants' own 2018 European patent application that cited the asserted patents.

Case Timeline

Date Event
2003-07-01 Zemaira® receives initial FDA approval
2004-03-31 CSL Limited acquires Aventis Behring
2005-06-07 Priority Date for '070 and '096 Patents
2016-01-01 CSL hires former University of Colorado licensing manager (alleged)
2016-10-04 U.S. Patent No. 9,457,070 Issues
2018-02-06 U.S. Patent No. 9,884,096 Issues
2018-03-22 "2018 Blood Publication" on AAT for GvHD is published
2018-11-30 CSL files European patent application EP '220 citing Asserted Patents
2019-10-22 CSL obtains Orphan Drug Designation for AAT for GvHD treatment
2020-10-20 CSL investor briefing projects Zemaira® launch for GvHD
2024-01-02 New Zemaira® vials become commercially available
2025-08-05 Plaintiff's licensor (University of Colorado) sends notice letter to CSL
2026-08-07 Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,457,070 - Compositions, Methods and Uses of Alpha 1-Antitrypsin for Early Intervention in Bone Marrow Transplantation and Treatment of Graft Versus Host Disease

  • Patent Identification: U.S. Patent No. 9,457,070, issued October 4, 2016 (the "'070 Patent").

The Invention Explained

  • Problem Addressed: The patent addresses Graft-versus-Host Disease (GvHD), a significant complication of bone marrow transplantation where donor immune cells attack the recipient's tissues, and notes the inadequacy and toxicity of conventional immunosuppressant therapies Compl. ¶2 '070 Patent, col. 3:1-26
  • The Patented Solution: The invention provides a method for treating acute GvHD by administering a composition containing alpha-1 antitrypsin (AAT) to a human subject Compl. ¶21 The patent specification suggests that AAT modulates the immune response by suppressing pro-inflammatory cytokines and altering the balance between effector and regulatory T cells, thereby mitigating the disease process '070 Patent, col. 4:46-65
  • Technical Importance: The use of AAT, a naturally occurring protein with a long history of clinical safety for other indications, offered a potentially novel and safer therapeutic strategy for managing GvHD compared to existing treatments '070 Patent, col. 4:62-65

Key Claims at a Glance

  • The complaint asserts infringement of, at minimum, Claim 1 of the '070 Patent Compl. ¶5
  • Independent Claim 1 recites:
    • A method for treating acute graft versus host disease (GvHD) in a human subject in need thereof,
    • said method comprising administering to the human subject a composition comprising alpha 1-antitrypsin (AAT)
    • and treating GvHD in the human subject.

U.S. Patent No. 9,884,096 - Compositions and Methods Related to Graft Versus Host Disease and Treatments Thereof

  • Patent Identification: U.S. Patent No. 9,884,096, issued February 6, 2018 (the "'096 Patent").

The Invention Explained

  • Problem Addressed: Similar to the '070 Patent, this patent addresses GvHD as a major complication of transplantation, but focuses on the challenge of preventing its onset rather than treating it after it has developed '096 Patent, background
  • The Patented Solution: The invention is a prophylactic method for reducing the risk of GvHD onset in a subject who has received a non-organ transplant (e.g., a stem cell transplant) by administering a composition comprising AAT '096 Patent, abstract The patent suggests this prophylactic administration helps to prevent the alloreactive immune response that causes GvHD '096 Patent, col. 4:20-43
  • Technical Importance: This preventative approach represents a potential shift from reactive treatment to proactive mitigation, aiming to stop GvHD before it can cause significant patient morbidity or mortality '096 Patent, col. 4:20-23

Key Claims at a Glance

  • The complaint asserts infringement of, at minimum, Claim 1 of the '096 Patent Compl. ¶5
  • Independent Claim 1 recites:
    • A method for reducing risk of onset of graft versus host disease (GvHD) in a human subject having a non-organ transplant and at risk of developing GvHD,
    • comprising administering to the human subject a composition comprising alpha-1 antitrypsin (AAT) or a recombinant molecule thereof, and a pharmaceutically acceptable excipient,
    • and reducing the risk of developing GvHD in the human subject.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentality is the use of Defendants' product Zemaira®, also referred to as CSL964, for the off-label treatment or prevention of GvHD Compl. ¶¶3-5

Functionality and Market Context

  • Zemaira® is a lyophilized, human plasma-derived alpha-1 proteinase inhibitor (AAT) for intravenous administration Compl. ¶90 It is FDA-approved for treating chronic AAT deficiency and emphysema Compl. ¶3 It is not approved for the treatment or prevention of GvHD Compl. ¶39
  • The complaint alleges Defendants are actively positioning Zemaira® for the GvHD indication by sponsoring Phase III clinical trials for both treatment (NCT04167514) and prevention (NCT03805789) of GvHD Compl. ¶4 A screenshot from ClinicalTrials.gov shows CSL Behring as the sponsor for trials titled "Treatment of GVHD" and "Prevention of Graft-versus-host Disease" using AAT Compl. p. 3
  • Further allegations state Defendants obtained an Orphan Drug Designation for AAT for the "Treatment of graft versus host disease" in 2019 Compl. ¶39 The complaint includes a chart from a 2020 investor briefing that lists "CSL964 AAT (GvHD Treatment)" under "Significant Target Launch Dates" for 2023-2025 Compl. p. 4

IV. Analysis of Infringement Allegations

The complaint's central theory is that Defendants induce infringement by actively and intentionally encouraging healthcare providers to use Zemaira® in a manner that directly infringes the asserted method patents Compl. ¶¶88 Compl. ¶107

'070 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for treating acute graft versus host disease (GvHD) in a human subject in need thereof, Defendants allegedly induce infringement by promoting the use of Zemaira® for the treatment of GvHD, including through sponsorship of clinical trial NCT04167514, "Treatment of GVHD in Hematopoietic Stem Cell Transplant (HSCT) Recipients." ¶89 col. 73:1-7
said method comprising administering to the human subject a composition comprising alpha 1-antitrypsin (AAT) Zemaira® is a composition comprising purified alpha-1 antitrypsin (AAT) that is administered to human subjects in clinical trials and for off-label use. ¶90 col. 73:1-7
and treating GvHD in the human subject. Defendants' alleged promotional activities, clinical research, and efforts to secure insurance coverage are all directed at the express purpose of treating GvHD with Zemaira®. ¶89 col. 73:1-7
  • Identified Points of Contention:
    • Legal Question (Inducement): A central issue will be whether Defendants' alleged activities-sponsoring clinical trials Compl. ¶4, publicizing results Compl. ¶¶52-54, engaging physician consultants Compl. ¶44, and facilitating insurance coverage for an off-label use Compl. ¶¶60-65-collectively constitute active inducement of infringement under 35 U.S.C. § 271(b).
    • Factual Question (Causation): The analysis may focus on what evidence demonstrates that physicians prescribe Zemaira® for GvHD because of Defendants' alleged encouraging acts, as opposed to other sources of information or independent medical judgment. The complaint provides a dosing regimen diagram from a presentation by a CSL consultant specifically identifying "AAT (Zemaira®)" for the "First-line Treatment SR-aGVHD" Compl. p. 14

'096 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for reducing risk of onset of graft versus host disease (GvHD) in a human subject having a non-organ transplant and at risk of developing GvHD, Defendants allegedly induce infringement by promoting the use of Zemaira® to prevent GvHD in patients with non-organ transplants (i.e., hematopoietic cell transplants), including through sponsorship of clinical trial NCT03805789, "Prevention of Graft-versus-host Disease." ¶108 col. 57:1-7
comprising administering to the human subject a composition comprising alpha-1 antitrypsin (AAT) or a recombinant molecule thereof, and a pharmaceutically acceptable excipient, Zemaira® is a composition of purified AAT that contains pharmaceutically acceptable excipients (e.g., mannitol) and is administered to human subjects. ¶¶109-110 col. 57:1-7
and reducing the risk of developing GvHD in the human subject. Defendants are allegedly developing and promoting Zemaira® specifically to reduce the risk of GvHD in human subjects. ¶111 col. 57:1-7
  • Identified Points of Contention:
    • Scope Question: The analysis may raise the question of whether the claim phrase "reducing the risk of onset" covers administration in a clinical trial setting where the prophylactic efficacy is still investigational, or if it requires a proven risk-reduction benefit.
    • Technical Question: Similar to the '070 patent, a key question will be whether the evidence supports a finding of induced infringement. The complaint points to Defendants' sponsorship of a preventative GvHD trial and efforts to secure compendia listings and insurance policies that cover Zemaira® for GvHD, such as a Keystone First policy bulletin covering Zemaira® for acute GvHD Compl. p. 34, as evidence of intent to encourage the claimed preventative method.

V. Key Claim Terms for Construction

  • The Term: "treating" ('070 Patent, Claim 1)

  • Context and Importance: The entirety of the infringement case hinges on the off-label use of Zemaira® for treating or preventing GvHD. Practitioners may focus on this term because the core allegation is that Defendants induce infringement of a method of "treating." The construction of "treating" will be critical to determining the scope of the claimed method that Defendants are alleged to have induced others to perform.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent specification uses broad language, stating methods are provided for "ameliorating symptoms or signs experienced by a subject having or in need of a transplant" '070 Patent, col. 4:5-8 This could support a construction that includes any administration intended to alleviate GvHD symptoms, even in an experimental context.
    • Evidence for a Narrower Interpretation: The specification also ties treatment to specific outcomes, such as reducing the "incidence of or...mortality of a subject" '070 Patent, col. 3:42-45 This language may support a narrower construction requiring a demonstrated therapeutic outcome beyond mere administration.

  • The Term: "reducing risk of onset" ('096 Patent, Claim 1)

  • Context and Importance: This term defines the prophylactic nature of the '096 Patent's asserted claim. The infringement allegation relies on Defendants' sponsorship of a clinical trial for the prevention of GvHD. The interpretation of "reducing risk" will determine whether performing or inducing the performance of such an investigational method falls within the claim's scope.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent abstract describes methods for "preventing transplantation and side effects." The specification also broadly discloses methods to "prevent a subject from developing GvHD" '096 Patent, col. 4:22-23 This could support a construction covering any administration intended to have a prophylactic effect.
    • Evidence for a Narrower Interpretation: The patent also states the findings "suggest that administration of AAT represents a novel and viable strategy to mitigate clinical GvHD" '096 Patent, col. 3:56-58 This may support a narrower view that "reducing risk" implies a known, viable risk reduction, not just an investigational attempt.

VI. Other Allegations

  • Indirect Infringement: The complaint's primary theory is inducement of infringement under 35 U.S.C. § 271(b). It alleges Defendants took affirmative steps with the intent to cause infringement by encouraging the off-label use of Zemaira® for GvHD. These alleged steps include sponsoring and publicizing clinical trials, leveraging the results to secure favorable listings in medical compendia, facilitating insurance coverage, and using physician consultants to promote the off-label use (Compl. ¶5; Compl. ¶6; Compl. ¶7; Compl. ¶8; Compl. ¶9; Compl. ¶10; Compl. ¶11; Compl. ¶12; Compl. ¶13; Compl. ¶14; Compl. ¶15; Compl. ¶16; Compl. ¶17; Compl. ¶18; Compl. ¶19; Compl. ¶20; Compl. ¶21; Compl. ¶22; Compl. ¶23; Compl. ¶24; Compl. ¶25; Compl. ¶26; Compl. ¶27; Compl. ¶28; Compl. ¶29; Compl. ¶30; Compl. ¶31; Compl. ¶32; Compl. ¶33; Compl. ¶34; Compl. ¶35; Compl. ¶36; Compl. ¶37; Compl. ¶38; Compl. ¶39; Compl. ¶40; Compl. ¶41; Compl. ¶42; Compl. ¶43; Compl. ¶44; Compl. ¶45; Compl. ¶46; Compl. ¶47; Compl. ¶48; Compl. ¶49; Compl. ¶50; Compl. ¶51; Compl. ¶52; Compl. ¶53; Compl. ¶54; Compl. ¶55; Compl. ¶56; Compl. ¶57; Compl. ¶58; Compl. ¶59; Compl. ¶60; Compl. ¶61; Compl. ¶62; Compl. ¶63; Compl. ¶64; Compl. ¶65; Compl. ¶66; Compl. ¶67; Compl. ¶68; Compl. ¶69; Compl. ¶70; Compl. ¶71; Compl. ¶72; Compl. ¶73; Compl. ¶74; Compl. ¶75; Compl. ¶76; Compl. ¶77; Compl. ¶78; Compl. ¶79; Compl. ¶80; Compl. ¶81).
  • Willful Infringement: The complaint alleges willful infringement based on Defendants' purported knowledge of the asserted patents long before the suit was filed Compl. ¶103 Compl. ¶122 The allegations of pre-suit knowledge are based on: (1) Defendants' hiring of the University of Colorado's former licensing manager who prosecuted the patents in 2016 Compl. ¶¶46-47; (2) licensing negotiations beginning in 2016 Compl. ¶48; (3) Defendants' own 2018 European patent application that explicitly cited the asserted patents Compl. ¶55; and (4) direct notice from the patent owner's licensor in 2022 and 2025 Compl. ¶¶57-59

VII. Analyst's Conclusion: Key Questions for the Case

  • A core issue will be one of inducement and intent: Does the evidence show that Defendants' activities-sponsoring trials, publishing data, and seeking insurance coverage for an off-label use-were not merely steps toward seeking future FDA approval but were instead part of a deliberate strategy to cultivate a profitable off-label market, thereby demonstrating the specific intent required to find induced infringement?
  • A central evidentiary question will be one of pre-suit knowledge: Can Plaintiff prove that Defendants, through their hiring of a key university licensing manager and their own patent filings citing the patents-in-suit, possessed actual knowledge of the patents and their applicability to Zemaira®'s use for GvHD, which would be critical for establishing willful infringement?
  • A key legal question will be one of off-label promotion: Where is the line between permissible dissemination of scientific information about an unapproved use to entities like payors and compendia, as the FDA may allow, and impermissible promotion that actively encourages and induces infringement of a method patent?
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