Calliditas Therap Ab v. Qilu Pharmaceutical Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Calliditas Therapeutics AB (Sweden)
  • Defendant: Qilu Pharmaceutical Co., Ltd. (China) and Qilu Pharma Inc. (Pennsylvania)
  • Plaintiff's Counsel: Morris, Nichols, Arsht & Tunnell LLP
• Case Identification: 1:26-cv-00197, D. Del., 02/24/2026
• Venue Allegations: Plaintiff alleges venue is proper in the District of Delaware because Defendant Qilu Ltd. is a foreign entity that may be sued in any judicial district, and both Defendants intend to market and sell the accused product throughout the United States, including in Delaware. Plaintiff further alleges personal jurisdiction based on Defendants' systematic contacts with Delaware, derivation of substantial revenue from the district, and previous consent to jurisdiction in prior Delaware court cases.
• Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of Plaintiff's TARPEYO® (budesonide) product constitutes an act of infringement of four patents covering specific oral dosage forms and methods of use for treating IgA nephropathy.
• Technical Context: The technology concerns pharmaceutical formulations of the corticosteroid budesonide, specifically engineered for delayed and modified release to target the ileum region of the small intestine for the treatment of IgA nephropathy, an autoimmune kidney disease.
• Key Procedural History: This action was initiated under the Hatch-Waxman Act following Plaintiff's receipt of a notice letter from Defendants regarding the filing of ANDA No. 221134, which included a Paragraph IV certification challenging the asserted patents. The complaint notes that Defendants have previously consented to personal jurisdiction in the District of Delaware in other patent litigation matters.

Case Timeline

Date	Event
2022-01-24	Earliest Priority Date for '719, '882, '883, and '057 Patents
2024-02-13	U.S. Patent No. 11,896,719 Issued
2024-12-24	U.S. Patent No. 12,171,882 Issued
2024-12-24	U.S. Patent No. 12,171,883 Issued
2025-05-27	U.S. Patent No. 12,311,057 Issued
2026-01-12	Defendants' "January 12 Notice Letter" sent to Plaintiff
2026-02-24	Complaint Filed

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

U.S. Patent No. 11,896,719 ("the '719 Patent"), "Pharmaceutical Compositions," Issued February 13, 2024

The Invention Explained

• Problem Addressed: The patent addresses IgA nephropathy (IgAN), a progressive autoimmune kidney disease for which no approved, direct treatment existed '719 Patent, col. 1:24-34 '719 Patent, col. 1:56-2:10 While systemic corticosteroids could be used, they are associated with a wide range of adverse side effects '719 Patent, col. 2:25-30 The patent identifies a need for a new treatment that provides an effective, localized immunosuppressive effect without these systemic side effects '719 Patent, col. 2:36-40
• The Patented Solution: The invention is a method of treating IgAN using an oral budesonide composition with a modified-release profile specifically designed to deliver the drug to the ileum, the final part of the small intestine '719 Patent, col. 2:41-55 This region contains Peyer's patches, lymphatic tissue believed to be the origin of the pathogenic IgA antibodies that cause IgAN '719 Patent, col. 1:40-47 The composition is formulated to resist dissolution in the stomach's acid and then delay release in the upper intestine, ensuring the drug payload is delivered to the targeted distal ileum region '719 Patent, abstract The manufacturing process for the coated beads that achieve this release profile is detailed in the specification '719 Patent, Fig. 1
• Technical Importance: This targeted delivery mechanism is designed to concentrate the therapeutic action at the site of disease pathogenesis, thereby reducing the formation of pathogenic antibodies while minimizing the systemic exposure and side effects common to conventional corticosteroid therapies '719 Patent, col. 2:55-60

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶44
• Claim 1 is a method of treatment claim with the following essential elements:
  • (i) Identifying a pharmaceutically acceptable composition for treating IgA nephropathy comprising budesonide and excipients that provide for a modified release.
  • The composition must fulfill a three-part requirement in a standard in vitro dissolution test:
    • (a) no more than about 10% of the budesonide is released within about 120 minutes in a medium with a pH of about 1.2;
    • (b) no more than about 10% of the budesonide is released into a "pharmaceutically-relevant dissolution medium" within about 30 minutes; and
    • (c) at least about 70% of the budesonide is released into the "pharmaceutically-relevant dissolution medium" within about 120 minutes.
  • (ii) Administering said composition to a patient with IgA nephropathy.
• The complaint does not explicitly reserve the right to assert dependent claims but makes a general allegation of infringement of "one or more claims" Compl. ¶44

U.S. Patent No. 12,171,882 ("the '882 Patent"), "Pharmaceutical Compositions," Issued December 24, 2024

The Invention Explained

• Problem Addressed: The '882 Patent, a continuation of the application leading to the '719 Patent, addresses the same problem: the need for a targeted IgAN treatment to avoid the significant adverse side effects associated with high-dose systemic corticosteroids '882 Patent, col. 1:25-2:40
• The Patented Solution: The solution is a pharmaceutical composition of budesonide engineered for modified release in the distal ileum to act locally on Peyer's patches, the site of pathogenic IgA production '882 Patent, abstract '882 Patent, col. 2:41-60 A flow diagram illustrates the multi-step coating process used to create beads with the desired release characteristics '882 Patent, Fig. 1
• Technical Importance: By targeting the gut's immune tissue, the composition aims to treat the underlying cause of IgAN while limiting systemic drug exposure, thus offering a more favorable safety profile compared to existing off-label treatments '882 Patent, col. 2:55-3:2

Key Claims at a Glance

• The complaint asserts at least independent claim 1 Compl. ¶55
• Claim 1 is a pharmaceutical composition claim with the following essential elements:
  • A plurality of cores comprising budesonide, encapsulated within a capsule.
  • The cores are coated with an extended release blend comprising a water-insoluble polymer (ethylcellulose) and a pore-forming polymer (hydroxypropylmethyl cellulose).
  • The capsule comprises an enteric coating.
  • The composition meets a specific three-part dissolution profile in a standard in vitro test.
• The complaint does not explicitly reserve the right to assert dependent claims but alleges infringement of "one or more claims" Compl. ¶55

Multi-Patent Capsule: U.S. Patent No. 12,171,883 ("the '883 Patent")

• Patent Identification: U.S. Patent No. 12,171,883, "Pharmaceutical Compositions," Issued December 24, 2024 Compl. ¶34
• Technology Synopsis: As a continuation of the same parent application, the '883 Patent covers pharmaceutical compositions of budesonide designed for modified release '883 Patent, abstract It addresses the need for a targeted treatment for IgA nephropathy that acts locally in the ileum to reduce pathogenic antibody production while minimizing systemic side effects associated with conventional corticosteroids '883 Patent, col. 1:25-2:40
• Asserted Claims: At least independent claim 1 Compl. ¶66
• Accused Features: The complaint alleges that Defendants' ANDA Product, a proposed generic version of TARPEYO®, infringes the '883 Patent Compl. ¶67

Multi-Patent Capsule: U.S. Patent No. 12,311,057 ("the '057 Patent")

• Patent Identification: U.S. Patent No. 12,311,057, "Pharmaceutical Compositions," Issued May 27, 2025 Compl. ¶35
• Technology Synopsis: This patent, also in the same family, is directed to methods of treating IgA nephropathy using modified-release budesonide compositions '057 Patent, abstract The technology aims to solve the problem of systemic corticosteroid side effects by delivering budesonide locally to the Peyer's patches in the ileum, the site of disease pathogenesis in IgAN '057 Patent, col. 1:24-2:40
• Asserted Claims: At least independent claim 1 Compl. ¶77
• Accused Features: The complaint alleges that the use of Defendants' ANDA Product in accordance with its product label will infringe the method claims of the '057 Patent Compl. ¶78

III. The Accused Instrumentality

• Product Identification: The accused instrumentality is Defendants' proposed generic drug product, identified by Abbreviated New Drug Application (ANDA) No. 221134 ("Defendants' ANDA Product") Compl. ¶1
• Functionality and Market Context: The accused product is a 4 mg delayed-release capsule of budesonide intended as a generic version of Plaintiff's brand-name drug, TARPEYO® Compl. ¶¶1-2 The complaint alleges that by filing the ANDA, Defendants have represented to the FDA that their product has the same active ingredient, dosage form, route of administration, and strength as TARPEYO® Compl. ¶41 It is further alleged that the product is bioequivalent to TARPEYO® and is seeking approval for the same indications, namely the treatment of adults with primary IgA nephropathy (Compl. ¶¶37; Compl. ¶41). The core functionality at issue is the product's delayed and modified-release mechanism, which is designed to deliver budesonide to a specific region of the gastrointestinal tract Compl. ¶36

IV. Analysis of Infringement Allegations

The complaint alleges that the very act of submitting the ANDA to seek FDA approval for a generic drug before patent expiration is an act of infringement under 35 U.S.C. § 271(e)(2)(A) Compl. ¶44 The specific infringement allegations are made on "information and belief" and state that the accused ANDA product and its use as directed by its label will meet every element of the asserted claims Compl. ¶45 Compl. ¶56 A chart from the '719 patent's specification shows the dissolution profile of Nefecon-Budesonide (the patented formulation) compared to other budesonide products, illustrating the claimed release characteristics '719 Patent, Fig. 5

'719 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
(i) identifying a pharmaceutically acceptable composition intended to treat IgA nephropathy comprising budesonide...which composition fulfils the following requirements...	Defendants' ANDA submission identifies a product for treating IgA nephropathy, which the complaint alleges has the claimed dissolution profile.	¶¶41; ¶45	col. 7:1-9
(a) the composition fulfils the requirement that no more than about 10% of the budesonide is released into the dissolution medium within about 120 minutes, when the dissolution medium is aqueous and has a pH of about 1.2;	The complaint alleges on information and belief that Defendants' ANDA Product meets this specific dissolution profile limitation for acidic conditions.	¶45	col. 7:4-9
(b) the composition fulfils the requirement that no more than about 10% of the budesonide is released into a pharmaceutically-relevant dissolution medium within about 30 minutes; and	The complaint alleges on information and belief that Defendants' ANDA Product meets this specific initial delayed-release limitation in a relevant medium.	¶45	col. 7:9-12
(c) the composition fulfils the requirement that at least about 70% of the budesonide is released into the pharmaceutically-relevant dissolution medium within about 120 minutes, then	The complaint alleges on information and belief that Defendants' ANDA Product meets this specific extended-release limitation in a relevant medium.	¶45	col. 7:12-16
(ii) administering said composition to a patient with IgA nephropathy in need of said treatment...	The complaint alleges that Defendants' product label will instruct physicians and patients to administer the ANDA Product for the treatment of IgA nephropathy.	¶¶37; ¶41; ¶48	col. 7:17-19

'882 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A pharmaceutical composition comprising a plurality of cores comprising budesonide...	Defendants' ANDA Product is alleged to be a composition comprising budesonide formulated into cores.	¶¶41; ¶56	col. 28:59-60
wherein the one or more cores are coated with an extended release pharmaceutically-acceptable polymeric blend comprising an alkyl cellulose and a pore-forming polymer...	The complaint alleges on information and belief that the cores of the ANDA Product are coated with polymers matching the claim description to achieve a modified release.	¶56	col. 27:1-20
wherein the pharmaceutical composition is orally administered as a capsule that comprises an enteric coating...	The complaint alleges Defendants' ANDA Product is an orally administered capsule with an enteric coating designed for delayed release.	¶¶1; ¶41; ¶56	col. 25:40-49
wherein the pharmaceutical composition meets the following release profile in a standard in vitro USP<711> dissolution test...	The complaint alleges on information and belief that Defendants' ANDA Product will exhibit the specific three-part dissolution profile recited in the claim.	¶56	col. 31:49-65

• Identified Points of Contention:
  • Technical Question: The central dispute will be factual and technical: does the Defendants' proposed generic product actually exhibit the specific, multi-part dissolution profile required by the claims when subjected to a standard in vitro test (e.g., less than 10% release at 30 minutes in a relevant medium, and at least 70% release at 120 minutes)? The complaint provides no test data for the accused product, relying on statutory infringement allegations and "information and belief."
  • Scope Question: A likely point of contention will be the proper interpretation of "pharmaceutically-relevant dissolution medium" as used in the claims of the '719 Patent. The parties may dispute what specific buffer, pH, and surfactant conditions constitute a "relevant" medium for testing infringement, as different conditions could yield different release profiles.

V. Key Claim Terms for Construction

• The Term: "pharmaceutically-relevant dissolution medium"

• Context and Importance: This term appears in the method claims of the '719 and '057 patents and is critical for determining infringement, as it defines the conditions under which the claimed dissolution profile must be met. The definition will dictate the parameters of the infringement analysis, and a broader or narrower construction could determine the outcome of the case. Practitioners may focus on this term because infringement hinges entirely on whether the accused product's performance meets the claimed profile under these specific, but potentially ambiguous, test conditions.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification lists several potential media, stating the medium "may be a phosphate buffer medium at a pH of about 6.2, a Level 1 Fasted State Simulated Intestinal Fluid (FaSSIF) at a pH of about 6.5..., a phosphate buffer medium at a pH of about 6.8..., or a phosphate buffer medium at a pH of about 7.2 or about 7.5" '719 Patent, col. 7:27-36 This language may support an interpretation that any of these, or functionally similar media, qualify as "pharmaceutically-relevant."
  • Evidence for a Narrower Interpretation: Defendants may argue that the specific examples and figures in the patent, which demonstrate the invention's performance, implicitly limit the term's scope. For instance, Example 3 uses a 50 mM sodium phosphate buffer at pH 6.8 with Tween 80 '719 Patent, col. 35:35-39, which could be argued to define the required medium more narrowly than the general list of possibilities.

• The Term: "about"

• Context and Importance: This term is used to qualify all numerical limitations in the dissolution profiles (e.g., "about 10%," "about 120 minutes"). The scope of "about" is a classic claim construction issue that will be central to determining whether test results showing minor deviations from the recited numbers still constitute infringement.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: A plaintiff may argue that "about" should be interpreted to encompass the normal range of variability observed in pharmaceutical manufacturing and testing. The patent itself shows results from different batches with some variation (e.g., 88%, 87%, and 84% release at 2.0h in Table 1) which could be used to argue for a broader meaning of "about" '719 Patent, Table 1
  • Evidence for a Narrower Interpretation: A defendant may argue for a more restrictive interpretation, possibly tying the scope of "about" to the precision of the measurement techniques or the standard deviation reported for a single batch ('719 Patent, Table 1, SD values of 2.2-3.5). They could argue that the term is not an open-ended license to deviate from the claimed values but covers only minor, insignificant variations.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement for the method patents ('719, '883, and '057 Patents), stating that upon FDA approval, Defendants will "intentionally encourage acts of direct infringement with knowledge of the... Patent" Compl. ¶48 Compl. ¶70 Compl. ¶81 The basis for inducement is the allegation that the product's prescribing information will instruct physicians and patients to administer the ANDA product to treat IgAN, thereby performing the steps of the claimed methods Compl. ¶38 The complaint also alleges contributory infringement, asserting the ANDA product is especially adapted for an infringing use and has no substantial non-infringing use Compl. ¶49 Compl. ¶71 Compl. ¶82
• Willful Infringement: The complaint alleges that "Defendants had knowledge of the... Patent[s] prior to filing their ANDA with the FDA" Compl. ¶52 Compl. ¶63 Compl. ¶74 Compl. ¶85 Based on this alleged pre-suit knowledge, the complaint asserts that the case is "exceptional" and seeks an award of attorneys' fees under 35 U.S.C. § 285, which is the statutory basis for enhanced damages due to willful infringement Compl. ¶53 Compl. ¶64 Compl. ¶75 Compl. ¶86

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

• A central evidentiary question will be one of technical performance: does the Defendants' proposed generic product, when physically tested under the conditions specified in the patents, actually exhibit the multi-part dissolution profile that defines the invention? As an ANDA case, the litigation will likely focus on empirical testing and expert disputes over whether the accused product's release rate of budesonide infringes the numerical boundaries set by the claims.
• A core legal question will be one of definitional scope: how will the court construe the term "pharmaceutically-relevant dissolution medium" and the numerical qualifier "about"? The outcome of the infringement analysis will hinge on the precise test conditions (e.g., pH, buffer composition) and the degree of numerical flexibility the court allows, which could either capture or exclude the measured performance of the accused product.
• A key distinction in the infringement case will be between the composition and method claims: while infringement of the composition claims (e.g., '882 Patent) depends on the physical properties of the ANDA product itself, infringement of the method claims (e.g., '719 Patent) will depend on whether Defendants' proposed product label instructs or encourages physicians and patients to use the product in the patented way.