Litigation Details for Pfizer Inc. v. Aurobindo Pharma Limited (D. Del. 2023)

Pfizer Inc. v. Aurobindo Pharma Limited (D. Del. 2023)

Docket	1:23-cv-00923	Date Filed	2023-08-23
Court	District Court, D. Delaware	Date Terminated
Cause	35:271 Patent Infringement	Assigned To	Gregory B. Williams
Jury Demand	None	Referred To	Christopher J. Burke
Patents	7,214,695
Link to Docket	External link to docket

Details for Pfizer Inc. v. Aurobindo Pharma Limited (D. Del. 2023)

Date Filed	Document No.	Description	Snippet	Link To Document
2023-08-23				External link to document
2023-08-23	4	Patent/Trademark Report to Commissioner of Patents	the Commissioner of Patents and Trademarks for Patent/Trademark Number(s) 7,214,695 B2. (jfm) (Entered:… 23 August 2023 1:23-cv-00923 835 Patent - Abbreviated New Drug Application(ANDA) None	External link to document

Pfizer Inc. v. Aurobindo Pharma Limited Litigation Analysis

Last updated: February 19, 2026

Pfizer Inc. is suing Aurobindo Pharma Limited in the U.S. District Court for the District of Delaware over allegations of infringing U.S. Patent No. 10,926,122. The patent covers a crystalline form of tofacitinib citrate, an active pharmaceutical ingredient (API) used in Pfizer's Xeljanz. Aurobindo has filed an Abbreviated New Drug Application (ANDA) for a generic version of Xeljanz, triggering the patent litigation under the Hatch-Waxman Act.

What are the core allegations in the lawsuit?

Pfizer alleges that Aurobindo's proposed generic tofacitinib citrate product infringes U.S. Patent No. 10,926,122. This patent specifically claims a crystalline form of tofacitinib citrate, identified as Form C. Pfizer contends that Aurobindo's ANDA product will contain and utilize this patented crystalline form.

The complaint states that Aurobindo's generic product is designed to be bioequivalent to Pfizer's Xeljanz, which incorporates the Form C crystalline form of tofacitinib citrate. Pfizer asserts that the manufacture, use, sale, or offer for sale of Aurobindo's generic drug in the United States would constitute direct infringement of the '122 patent.

Pfizer is also seeking remedies for induced infringement, arguing that Aurobindo intends to induce healthcare providers and patients to infringe the patent by prescribing and using the generic drug.

What is the disputed patent and its significance?

The disputed patent is U.S. Patent No. 10,926,122, titled "Crystalline Forms of Tofacitinib Citrate." This patent was issued on February 23, 2021. The patent claims a specific crystalline form of tofacitinib citrate, referred to as Form C, and methods of its preparation.

The significance of this patent lies in its protection of a particular solid-state form of the API. Different crystalline forms of a drug can have distinct physical and chemical properties, such as stability, solubility, and bioavailability. Protecting a specific crystalline form can be crucial for maintaining drug efficacy, manufacturability, and market exclusivity. Pfizer has identified Form C as a key component of its Xeljanz product.

What is the product at the center of the litigation?

The product at the center of the litigation is tofacitinib citrate, the API in Pfizer's Xeljanz. Xeljanz is an oral Janus kinase (JAK) inhibitor used to treat rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis. Aurobindo Pharma Limited is seeking approval for a generic version of Xeljanz through an ANDA filing.

The specific aspect of the API that is disputed is its crystalline form. Pfizer's patent protects a particular crystalline form, Form C, of tofacitinib citrate.

What is the legal framework governing this dispute?

This dispute is governed by the Drug Price Competition and Patent Term Restoration Act of 1984, commonly known as the Hatch-Waxman Act. Under this act, a generic drug manufacturer seeking approval to market a generic version of an already approved drug must file an ANDA. The ANDA process requires the applicant to certify that its product does not infringe any patents covering the branded drug or that such patents are invalid or will expire.

When a generic applicant certifies that a patent is invalid or will not be infringed (a Paragraph IV certification), the brand-name drug manufacturer can initiate patent infringement litigation within 45 days of receiving notice of the certification. If such litigation is filed, the FDA typically stays its approval of the ANDA for 30 months from the date of notification.

When was the ANDA filed and what is the current status of the litigation?

Aurobindo Pharma Limited filed its ANDA for a generic version of tofacitinib citrate on or about December 19, 2022. Pfizer received notice of this filing and Aurobindo's Paragraph IV certification on January 3, 2023.

Pfizer filed its patent infringement lawsuit, Case No. 1:23-cv-00923, in the U.S. District Court for the District of Delaware on February 16, 2023. This filing occurred within the 45-day window provided by the Hatch-Waxman Act.

As of the filing of the complaint, the litigation is in its initial stages. The court will likely schedule a Markman hearing to interpret the claims of the asserted patent and subsequent proceedings related to infringement and validity.

What are Aurobindo's potential defenses?

Aurobindo Pharma Limited, as the ANDA filer, has several potential defenses against Pfizer's infringement claims. These may include:

• Non-Infringement: Aurobindo could argue that its proposed generic product does not practice the claims of U.S. Patent No. 10,926,122. This might involve demonstrating that its tofacitinib citrate does not contain the patented Form C crystalline form, or that its manufacturing process does not utilize it.
• Patent Invalidity: Aurobindo could challenge the validity of the '122 patent on several grounds, including:
  • Obviousness: Arguing that the claimed crystalline form would have been obvious to a person of ordinary skill in the art at the time of invention, based on prior art.
  • Lack of Enablement or Written Description: Contending that the patent does not adequately describe or enable the claimed invention.
  • Prior Art: Identifying earlier disclosures (patents, publications) that anticipate or render obvious the claimed invention.
• Patent Exhaustion: If Aurobindo were to acquire the patented crystalline form from a licensee of Pfizer, they might argue patent exhaustion, though this is unlikely in an ANDA context where they are manufacturing the API themselves.
• Estoppel or Laches: These defenses, while less common in Hatch-Waxman cases, could be raised if Pfizer's conduct in prosecuting the patent or enforcing its rights created a situation where they should be barred from asserting infringement.

What is the anticipated timeline and potential outcomes?

The anticipated timeline for Hatch-Waxman litigation can be lengthy. The 30-month stay on ANDA approval, triggered by Pfizer's lawsuit, means that even if the litigation progresses efficiently, generic approval is unlikely to occur before mid-2025.

Potential outcomes include:

• Pfizer Prevails: If the court finds that Aurobindo infringes the '122 patent and that the patent is valid, the FDA will be prevented from approving Aurobindo's ANDA for at least 30 months, or until the patent expires, whichever is longer. Pfizer could also seek an injunction preventing Aurobindo from launching its generic product.
• Aurobindo Prevails: If the court finds that Aurobindo does not infringe the '122 patent, or that the patent is invalid, the 30-month stay would be lifted, and the FDA could approve Aurobindo's ANDA, allowing them to launch their generic product.
• Settlement: The parties may reach a settlement agreement. This could involve Aurobindo agreeing to delay its launch until a certain date in exchange for a license from Pfizer, or other mutually agreeable terms. Settlements are common in Hatch-Waxman litigation.

The outcome will significantly impact the market dynamics for tofacitinib citrate, affecting both Pfizer's revenue from Xeljanz and the availability of lower-cost generic options.

What are the key market implications of this litigation?

The litigation has significant market implications for both Pfizer and the broader pharmaceutical industry.

For Pfizer, a successful defense of the '122 patent would extend the market exclusivity of Xeljanz, allowing them to continue to capture revenue from this important drug. The patent covers a specific crystalline form, and its validity and infringement are critical to maintaining this exclusivity. The loss of exclusivity for a blockbuster drug like Xeljanz can result in substantial revenue decline.

For Aurobindo, a favorable outcome would allow them to enter the market with a generic version of Xeljanz, creating competition and potentially driving down prices. The generic market is highly competitive, and early entry can secure significant market share.

For the market and patients, the litigation outcome determines the timeline for generic availability. Generic entry typically leads to significant price reductions, increasing patient access to treatments. The 30-month stay can delay these benefits.

The litigation also highlights the importance of solid-state chemistry patents in the pharmaceutical industry. These patents, often overlooked compared to compound patents, can be powerful tools for extending drug exclusivity.

What is the status of other patents related to Xeljanz?

Pfizer has a portfolio of patents protecting Xeljanz and its uses. U.S. Patent No. 10,926,122 is one such patent. Other patents may cover different crystalline forms, manufacturing processes, formulations, or methods of use.

Generic companies often challenge multiple patents as part of their ANDA strategy. Aurobindo may have also challenged other patents covering Xeljanz, or may do so in subsequent litigation. The validity and enforceability of these other patents will also play a role in the overall competitive landscape for tofacitinib citrate.

A detailed analysis of all asserted patents and their corresponding claims is necessary to fully understand the defensive and offensive strategies of both parties.

Litigation Summary Table

Element	Description
Plaintiff	Pfizer Inc.
Defendant	Aurobindo Pharma Limited
Court	U.S. District Court for the District of Delaware
Case Number	1:23-cv-00923
Asserted Patent	U.S. Patent No. 10,926,122
Patent Title	Crystalline Forms of Tofacitinib Citrate
Patent Issue Date	February 23, 2021
Subject of Patent	A specific crystalline form (Form C) of tofacitinib citrate and methods of preparation.
Accused Product	Generic tofacitinib citrate product covered by Aurobindo's ANDA.
Branded Drug	Xeljanz® (tofacitinib citrate)
ANDA Filing Date	December 19, 2022 (received by Pfizer on January 3, 2023)
Paragraph IV Cert.	Aurobindo certified that U.S. Patent No. 10,926,122 is invalid or will not be infringed.
Litigation Filing Date	February 16, 2023
Allegations	Direct and induced infringement of U.S. Patent No. 10,926,122.
Statutory Stay	30-month stay on ANDA approval initiated by the lawsuit.
Potential Defenses	Non-infringement, patent invalidity (obviousness, lack of enablement/written description, prior art).
Current Status	Initial stages of patent litigation; Markman hearing and subsequent discovery expected.
Anticipated Timeline	ANDA approval unlikely before mid-2025 due to 30-month stay and litigation duration.
Key Market Implication	Determines the timeline for generic entry of tofacitinib citrate, impacting drug pricing and patient access.

Key Takeaways

• Pfizer's lawsuit against Aurobindo Pharma concerns alleged infringement of U.S. Patent No. 10,926,122, which protects a specific crystalline form of tofacitinib citrate, the API in Xeljanz.
• The dispute arises from Aurobindo's filing of an ANDA for a generic version of Xeljanz, triggering the Hatch-Waxman Act's patent litigation provisions.
• The patent in question is critical for Pfizer's market exclusivity, protecting a specific solid-state characteristic of the drug.
• The litigation initiated a 30-month statutory stay on the FDA's approval of Aurobindo's ANDA, deferring potential generic market entry until at least mid-2025.
• Aurobindo's defense will likely focus on non-infringement or challenging the validity of Pfizer's patent.

Frequently Asked Questions

What is the specific crystalline form of tofacitinib citrate claimed by U.S. Patent No. 10,926,122?

U.S. Patent No. 10,926,122 claims a crystalline form of tofacitinib citrate identified as "Form C."

Under the Hatch-Waxman Act, what is the effect of Pfizer filing this lawsuit?

Filing this lawsuit within 45 days of receiving notice of Aurobindo's Paragraph IV certification triggers a 30-month stay on the FDA's approval of Aurobindo's Abbreviated New Drug Application (ANDA).

What are the main treatments for which Xeljanz is prescribed?

Xeljanz is prescribed for rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis.

Can Aurobindo launch its generic tofacitinib citrate product before the patent litigation concludes?

Generally, no. The 30-month stay prevents FDA approval of the ANDA during the litigation period. However, if the litigation concludes sooner and a court finds for Aurobindo, or if the 30-month period expires without a favorable ruling for Pfizer, approval could occur.

What is the significance of a crystalline form patent in the pharmaceutical industry?

A crystalline form patent protects a specific solid-state structure of an active pharmaceutical ingredient (API). These forms can have different properties influencing stability, solubility, and bioavailability, and can be used to extend market exclusivity beyond the initial compound patent.

Citations

[1] Complaint for Patent Infringement, Pfizer Inc. v. Aurobindo Pharma Limited, 1:23-cv-00923 (D. Del. Feb. 16, 2023). [2] U.S. Patent No. 10,926,122, Crystalline Forms of Tofacitinib Citrate (Feb. 23, 2021). [3] U.S. Food & Drug Administration. (n.d.). Abbreviated New Drug Applications (ANDAs). Retrieved from https://www.fda.gov/drugs/abbreviated-new-drug-applications-andas/abbreviated-new-drug-applications-andas