Litigation Details for Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd. (Fed. Cir. 2023)

Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd. (Fed. Cir. 2023)

Docket		Date Filed	2023-02-28
Court	Court of Appeals for the Federal Circuit	Date Terminated
Cause		Assigned To
Jury Demand		Referred To
Parties	ALKEM LABORATORIES LTD.
Patents	10,039,745; 10,039,800; 10,046,000; 10,154,987; 10,265,370; 10,406,199; 10,695,329; 10,772,868; 10,786,482; 10,799,453; 11,179,402; 11,179,403; 6,028,222; 6,869,939; 6,977,257; 8,236,782; 8,241,664; 8,343,995; 8,492,369; 8,568,747; 8,778,366; 8,778,916; 8,835,407; 8,853,236; 9,028,005; 9,399,067; 9,463,183; 9,616,096; 9,669,008; 9,808,442; 9,814,751; 9,855,214; 9,968,553
Link to Docket	External link to docket

Biologic Drugs cited in Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd.

Details for Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd. (Fed. Cir. 2023)

Date Filed	Document No.	Description	Snippet	Link To Document
2023-02-28				External link to document
2023-02-28	15		No. 10,039,745, 10,039,745, which …dictionary.thefreedictionary.com/hypertension 10,039,745 B2 10,039,745 … No. 10,039,745, 10,039,745, issued … No. 10,039,745, 10,039,745, which …802,341, filed Nov. 2, 2017 (now U.S. Pat. No. 10,039, 745, issued 745, issued Aug.Aug. 7, 7, 2018)	External link to document
2023-02-28	20		’442 patent”), 10,039,745 (“’745 patent”), 10,154,987 (“’987 patent”), 10,772,868 (“’868 patent”), 10,786,482…Constructions for U.S. Patent Nos. 9,669,008, 9,808,442, 10,039,745, 10,154,987, 10,772,868…of U.S. patent application Ser. No. 15/802,341, filed Nov. 2, 2017 (now U.S. Pat. No. 10,039,745, issued… 9,669,008 B1 ;9,808,442 B2 ;10,039,745 B2 ;10,154,987 B2. (sam) (Entered: … 9,669,008 ;9,808,442 ;10,039,745 ;10,154,987 ;10,772,868 ;10,786,482 ;10,918,621 .	External link to document

Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd.: A Comprehensive Litigation Summary and Analysis

Case Overview

The litigation between Azurity Pharmaceuticals, Inc. and Alkem Laboratories Ltd. involves multiple patent infringement disputes, particularly focusing on pharmaceutical formulations. Here, we will delve into the key aspects of the case, including the patents in question, the legal issues, and the court's decisions.

Patents in Question

Enalapril Formulations (U.S. Patent Nos. 10,786,482 and 10,918,621)

In one part of the litigation, Azurity's patents (U.S. Patent Nos. 10,786,482 and 10,918,621) relate to liquid formulations of enalapril, a medication used to treat high blood pressure. These patents claim a liquid formulation that maintains at least 95% of the initial enalapril amount over a 12-month storage period at a specific temperature[1].

Vancomycin Formulations (U.S. Patent Nos. 10,493,028, 10,688,046, and 10,959,948)

In another part, the patents (U.S. Patent Nos. 10,493,028, 10,688,046, and 10,959,948) pertain to non-sterile stable liquid formulations of vancomycin, an antibiotic used to treat clostridium difficile infections. These patents specify formulations consisting of various ingredients such as buffering agents, sweeteners, preservatives, flavoring agents, and vancomycin hydrochloride[5].

Infringement Claims and Court Decisions

Enalapril Formulations

Azurity alleged that Alkem's Abbreviated New Drug Application (ANDA) infringed the '482 and '621 patents. The district court found that the ANDA did indeed infringe these patents but also determined that the patents were invalid due to obviousness and insufficient written description. The Federal Circuit affirmed this decision, upholding the district court's findings on obviousness and declining to address the issue of written description[1].

Vancomycin Formulations

In the case involving vancomycin formulations, Azurity claimed that Alkem's ANDA product infringed the '028, '046, and '948 patents. The key issue was whether Alkem's product fit within the claimed ingredients without any unlisted ingredients, given the "consisting of" preamble limitation.

• Propylene Glycol and Claim Construction: Alkem argued that its product did not infringe because it described propylene glycol as a co-solvent, which was not a claimed function. The court found that Azurity had disclaimed propylene glycol during patent prosecution, preventing it from arguing that propylene glycol could function as a flavoring agent. This disclaimer was crucial in determining that Alkem's product did not infringe the '948 patent[2][3].

• Literal Infringement and Doctrine of Equivalents: Alkem's ANDA formulation differed from the claimed ingredients in several respects, including the absence of sodium benzoate and the presence of methyl paraben and ethyl paraben. The court denied Alkem's motion for judgment on the pleadings, allowing Azurity to potentially prove that the unlisted ingredients were unrelated to the claimed invention. However, the court ultimately found that Alkem's product did not infringe the patents, partly due to the absence of sodium benzoate and the presence of propylene glycol, which Azurity had disavowed during prosecution[5].

Legal Issues and Arguments

Obviousness

The Federal Circuit upheld the district court's determination that the '482 and '621 patents were invalid due to obviousness. Obviousness is a mixed question of fact and law, and the court found substantial evidence to support this conclusion[1].

Claim Construction and Disclaimer

In the vancomycin case, the court's decision hinged on claim construction and the doctrine of disclaimer. Azurity's arguments during patent prosecution, where it distinguished its invention by the absence of propylene glycol, were deemed to disclaim the inclusion of propylene glycol in the claimed invention. This disclaimer prevented Azurity from later arguing that propylene glycol could be part of the claimed formulation[2][3].

Consisting Of Preamble Limitation

The "consisting of" preamble in the vancomycin patents was critical. This limitation means that no ingredient can be present in the formulation other than those listed in the claims. Azurity's inability to fit all of Alkem's ANDA ingredients within the claimed ingredients led to the conclusion that Alkem's product did not infringe[2][3].

Key Takeaways

• Patent Validity: The '482 and '621 patents were found invalid due to obviousness and insufficient written description.
• Claim Construction: Azurity's disavowal of propylene glycol during prosecution was a decisive factor in the vancomycin case, preventing it from arguing that propylene glycol could function as a flavoring agent.
• Infringement Analysis: The court's strict interpretation of the "consisting of" preamble limitation in the vancomycin patents meant that any unlisted ingredients in Alkem's ANDA product precluded literal infringement.
• Doctrine of Equivalents: Azurity's potential path to infringement under the doctrine of equivalents was blocked by the court's findings on literal infringement and the application of prosecution history estoppel.

FAQs

What were the main patents involved in the litigation between Azurity and Alkem?

The main patents involved were U.S. Patent Nos. 10,786,482 and 10,918,621 for enalapril formulations, and U.S. Patent Nos. 10,493,028, 10,688,046, and 10,959,948 for vancomycin formulations.

Why were the enalapril patents found invalid?

The enalapril patents were found invalid due to obviousness and insufficient written description, as determined by the district court and affirmed by the Federal Circuit.

How did the court interpret the "consisting of" preamble limitation in the vancomycin patents?

The court interpreted the "consisting of" preamble strictly, meaning that no ingredients other than those listed in the claims could be present in the formulation for it to be considered infringing.

What role did propylene glycol play in the vancomycin case?

Propylene glycol was a critical ingredient in the vancomycin case. Azurity's disavowal of propylene glycol during patent prosecution prevented it from arguing that propylene glycol could function as a flavoring agent, which was a claimed ingredient.

Can Azurity still pursue infringement claims under the doctrine of equivalents?

In the vancomycin case, Azurity's path to infringement under the doctrine of equivalents was blocked due to the court's findings on literal infringement and the application of prosecution history estoppel.

Cited Sources

1. United States Court of Appeals for the Federal Circuit, Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd., No. 23-1540, 2023 WL 3254117 (Fed. Cir. Sept. 14, 2023).
2. JDSupra, Azurity Pharms., Inc. v. Alkem Labs. Ltd., October 3, 2023.
3. Robins Kaplan LLP, Azurity Pharms., Inc. v. Alkem Labs. Ltd., May 4, 2023.
4. Justia, Azurity Pharmaceuticals, Inc. v. Alkem Laboratories Ltd., No. 1:2019cv02100, Document 213 (D. Del. 2023).
5. Robins Kaplan LLP, Azurity Pharms., Inc. v. Alkem Labs., Ltd., January 31, 2022.