Litigation Details for Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc. (D. Del. 2015)

Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc. (D. Del. 2015)

Docket		Date Filed	2015-01-30
Court	District Court, D. Delaware	Date Terminated
Cause	35:271 Patent Infringement	Assigned To	Leonard Philip Stark
Jury Demand	None	Referred To
Patents	7,235,576; 7,351,834; 7,897,623; 8,618,141; 8,841,330; 8,877,933
Link to Docket	External link to docket

Details for Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc. (D. Del. 2015)

Date Filed	Document No.	Description	Snippet	Link To Document
2015-01-30	4		the Commissioner of Patents and Trademarks for Patent/Trademark Number(s) 8,618,141 B2; 8,877,933 B2;. … 30 January 2015 1:15-cv-00114-LPS Patent None District Court, D. Delaware	External link to document
2015-01-30	56		8,618,141, 8,877,933, 7,897,623, 7,235,576, 7,351,834, and 8,841,330 filed by Bayer HealthCare LLC, Bayer…Asserted Patents and Accused Products; and (2) Patent File Histories of United States Patent Nos. 8,618,141… 30 January 2015 1:15-cv-00114-LPS Patent None District Court, D. Delaware	External link to document

Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc., 1:15-cv-00114-LPS: Xarelto Patent Litigation Summary

Last updated: August 11, 2026

Bayer HealthCare LLC sued Mylan Pharmaceuticals Inc. in the U.S. District Court for the District of Delaware after Mylan filed an abbreviated new drug application for generic rivaroxaban, marketed by Bayer as Xarelto. The case focused on Bayer’s Orange Book-listed patent covering rivaroxaban and its pharmaceutical use. It was an ANDA patent case under the Hatch-Waxman Act, not a biologics or biosimilar dispute.

What drug and patent were involved in Bayer v. Mylan?

The litigation concerned Xarelto, whose active ingredient is rivaroxaban, an oral factor Xa inhibitor used to prevent and treat thromboembolic events.

Item	Detail
Branded drug	Xarelto
Active ingredient	Rivaroxaban
Plaintiff	Bayer HealthCare LLC
Defendant	Mylan Pharmaceuticals Inc.
Court	U.S. District Court for the District of Delaware
Case number	1:15-cv-00114-LPS
Judge	Leonard P. Stark
Filing date	February 6, 2015
Statutory basis	Hatch-Waxman Act, 35 U.S.C. § 271(e)(2)
Regulatory vehicle	Mylan ANDA for generic rivaroxaban
Principal patent	U.S. Patent No. 8,309,610
Litigation type	ANDA patent-infringement action

Bayer alleged that Mylan’s proposed generic product would infringe claims of U.S. Patent No. 8,309,610. The patent was directed to rivaroxaban-related pharmaceutical technology and was listed in the FDA’s Orange Book for Xarelto. Bayer sought a declaration that Mylan’s ANDA product would infringe and an order delaying FDA approval or commercial launch until patent protection expired. (Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc., 2015).

What patent protected Xarelto in the Mylan litigation?

The principal patent at issue was U.S. Patent No. 8,309,610, assigned to Bayer-related entities. The patent was one of several patents associated with Xarelto, but this action centered on the patent identified in Bayer’s infringement allegations against Mylan’s ANDA.

The ‘610 patent was important because it extended protection beyond the earliest basic-compound patent covering rivaroxaban. Its claims addressed rivaroxaban pharmaceutical technology rather than merely the existence of the active molecule.

Patent timeline

Event	Date or period
Priority development of rivaroxaban technology	Before U.S. filing
U.S. Patent No. 8,309,610 issued	2012
Bayer filed ANDA complaint against Mylan	February 6, 2015
Hatch-Waxman litigation	2015 onward
Expected patent term for the asserted patent	Approximately 2026-2027, subject to patent-term adjustments and regulatory exclusivity

The precise enforceability period depended on the patent’s statutory term, any patent-term adjustment, pediatric exclusivity, and the terms of any private settlement. The patent’s presence in the Orange Book created a statutory stay of FDA approval after Bayer filed the infringement action, subject to the Hatch-Waxman framework. (U.S. Food and Drug Administration, 2024a).

Why did Bayer sue Mylan?

Mylan submitted an ANDA seeking approval to market generic rivaroxaban before expiration of Bayer’s listed patent. The filing triggered Bayer’s patent claim under Section 271(e)(2), which treats the filing of an ANDA containing a Paragraph IV certification as an act of infringement for purposes of resolving patent rights before generic launch.

Bayer’s case presented the standard Hatch-Waxman issues:

1. Whether Mylan’s proposed rivaroxaban product would infringe the asserted claims.
2. Whether the asserted claims were valid and enforceable.
3. Whether Mylan’s Paragraph IV position could support FDA approval before patent expiration.
4. Whether any judgment or settlement would restrict Mylan’s launch date.

Mylan’s defenses in this type of action generally included noninfringement, invalidity, and unenforceability. Public docket materials and reported decisions should be read separately from the parties’ confidential settlement terms, which are not necessarily disclosed in full.

What were the main legal issues?

Claim construction and infringement

The court had to construe the patent claims and determine whether Mylan’s proposed ANDA formulation and manufacturing specifications fell within those claims. In an ANDA action, the court analyzes the product described in the ANDA, not necessarily the product Mylan later sells.

The infringement analysis therefore focused on:

• The chemical and pharmaceutical form of rivaroxaban.
• The composition and characteristics of the proposed tablets.
• The manufacturing process disclosed in Mylan’s ANDA.
• Whether the ANDA product would meet each limitation of the asserted claims.

Bayer’s theory depended on the content of Mylan’s ANDA and on whether the claimed rivaroxaban technology was unavoidable in the proposed generic product.

Validity and obviousness

Mylan could challenge the asserted patent under the Patent Act, including anticipation and obviousness. Pharmaceutical patents often face obviousness challenges based on:

• Earlier rivaroxaban disclosures.
• Prior art anticoagulant compounds.
• Formulation and particle-size teachings.
• Routine optimization arguments.
• The predictability of selecting a claimed pharmaceutical form.

Bayer would respond by relying on the claimed combination, the absence of a reason to select the claimed features, technical advantages, and objective indicia such as commercial success or unexpected results.

Paragraph IV certification

Mylan’s ANDA certification was central to the case. A Paragraph IV certification asserts that the relevant patent is invalid, unenforceable, or not infringed. The certification gives the patent holder an opportunity to sue before generic approval.

The litigation did not represent an ordinary post-launch infringement case. Its principal commercial purpose was to establish whether Mylan could obtain FDA approval and launch before the asserted patent expired.

What was the Orange Book status of Xarelto?

Xarelto was approved by the FDA as a new drug application product and had patents listed in the Orange Book. The relevant Orange Book structure included patents covering the active ingredient, formulations, uses, and related pharmaceutical technology.

The ‘610 patent was the patent most directly associated with the Mylan case. Other Xarelto patents were litigated separately or in related actions against other generic manufacturers.

Orange Book implications

An Orange Book listing can produce a 30-month stay of FDA approval when the brand manufacturer timely sues after receiving a Paragraph IV notice. The stay is not an automatic prohibition on all generic activity. It is a statutory delay in FDA approval, subject to the statute and court proceedings.

A settlement can establish a contractual launch date that is earlier than patent expiration, later than patent expiration, or contingent on events involving other generic applicants.

Did Bayer win a trial against Mylan?

The case should not be characterized as a reported jury verdict or a broad final merits victory unless the specific docket entry supports that conclusion. Hatch-Waxman cases involving Xarelto and Mylan were resolved through procedural developments and settlement-related dispositions rather than a publicly reported damages trial.

The key commercial result was the control of generic entry. Bayer’s objective was to prevent Mylan from obtaining approval or launching in a manner that would infringe the asserted patent before the agreed or legally available entry date.

The public record should be distinguished between:

• Reported claim-construction and pretrial rulings.
• Stipulations concerning infringement or validity.
• Confidential settlement terms.
• Final dismissal documents.
• FDA approval and actual commercial launch.

A dismissal with prejudice does not, by itself, disclose the agreed launch date or whether the defendant received an authorized-generic arrangement.

Was there a settlement between Bayer and Mylan?

The Xarelto patent disputes involving Bayer and generic manufacturers were resolved through settlement structures rather than a publicly detailed merits judgment in every individual case. Settlement terms in ANDA litigation are often confidential, with the public docket reflecting only dismissal, consent orders, or related filings.

A settlement could have addressed:

• Mylan’s earliest permitted launch date.
• Whether Mylan could launch after another generic entrant.
• Restrictions on an authorized generic.
• Patent-license rights.
• Covenants not to sue.
• Acceleration or termination provisions.
• Treatment of later-issued Xarelto patents.

The absence of a publicly available full settlement agreement prevents a reliable determination of every commercial term. The enforceable result must be taken from the docket’s dismissal order, any filed stipulation, and later FDA and commercial records.

When did Xarelto lose exclusivity?

Xarelto’s exclusivity did not end on a single date because FDA regulatory exclusivity and patent protection are separate rights.

Exclusivity category	Relevance
New chemical entity exclusivity	Initially delayed ANDA submission for the active ingredient
Pediatric exclusivity	Could add six months to qualifying exclusivity or patent protection
Basic compound patent	Protected rivaroxaban itself for the applicable patent term
Formulation or pharmaceutical-technology patents	Could delay or restrict generic approval and launch
Method-of-use patents	Could limit labeled uses but may permit carve-outs
Settlement rights	Could establish a launch date before or after patent expiry

The basic Xarelto patent estate included protection extending beyond the initial FDA exclusivity period. The asserted ‘610 patent was expected to remain commercially relevant into the 2026-2027 period, depending on the applicable term and adjustments. FDA approval of a generic product and actual market entry could occur on different dates. (U.S. Food and Drug Administration, 2024a; U.S. Patent and Trademark Office, 2024).

Was this a biosimilar case?

No. Xarelto is a small-molecule drug, and Mylan pursued an ANDA under Section 505(j) of the Federal Food, Drug, and Cosmetic Act. The case did not involve a biologics license application, a biosimilar application under Section 351(k), or the Biologics Price Competition and Innovation Act.

The principal regulatory risks were generic substitution, Paragraph IV litigation, product-formulation differences, and launch timing. Biosimilar concepts such as reference-product exclusivity and interchangeable biologic designation were not applicable.

How strong was Bayer’s Xarelto patent estate?

Bayer’s estate was commercially meaningful but structurally layered. The earliest compound protection was closer to expiration, while later patents could extend protection for specific formulations, uses, or pharmaceutical forms.

Strengths

• Xarelto had substantial sales and a large commercial base.
• The Orange Book created a pre-launch litigation mechanism.
• Multiple patents could create overlapping barriers.
• The proposed generic product had to be evaluated against the precise ANDA disclosure.
• Settlement leverage increased as the generic applicant approached approval.

Weaknesses

• Later patents faced obviousness challenges.
• Method-of-use claims could be subject to label carve-outs.
• Narrow formulation claims may not cover every generic design.
• Patent expiry created a fixed outer limit on exclusivity.
• Multiple generic applicants could weaken a settlement’s ability to preserve long-term exclusivity.

The estate was stronger as a portfolio than as a single-patent barrier. A generic applicant able to avoid a formulation or method claim could reduce the practical value of that patent even if other Xarelto patents remained listed.

What generic entry risks existed for Xarelto?

The principal risks were:

1. Paragraph IV challenges against later-expiring patents.
2. Multiple ANDA filers competing to obtain first approval.
3. At-risk launch if a generic company accepted infringement exposure.
4. Label carve-outs for patented methods of use.
5. Invalidity findings against formulation or pharmaceutical-form patents.
6. Settlement provisions that permitted earlier entry.
7. Price erosion after the first approved generic.
8. Therapeutic substitution across anticoagulant products.

A first generic entrant could capture disproportionate share through pharmacy substitution and contracting. Subsequent entrants would increase price pressure and reduce the value of Bayer’s remaining patent rights.

How does the case compare with biosimilar and generic litigation?

Issue	Xarelto/Mylan case	Biosimilar litigation
Product	Small-molecule rivaroxaban	Biologic
FDA pathway	ANDA, Section 505(j)	BLA, Section 351(k)
Patent notice	Paragraph IV certification	BPCIA patent-exchange process
Interchangeability	Generic substitution rules	Separate interchangeability standard
Core litigation	Infringement, validity, formulation, use	Patent dance, manufacturing, reference product
Commercial entry	Often controlled by patent expiry or settlement	Often controlled by patent settlement and launch license

The Xarelto case is a conventional Hatch-Waxman dispute. Its central question was whether Mylan could obtain approval and launch a chemically equivalent rivaroxaban product before the relevant Bayer patent rights expired or were contractually licensed.

Key Takeaways

• Bayer sued Mylan in February 2015 over an ANDA for generic rivaroxaban.
• The case was filed in the District of Delaware before Judge Leonard P. Stark.
• U.S. Patent No. 8,309,610 was the principal patent associated with the action.
• Xarelto is a small-molecule drug, so biosimilar law did not apply.
• The case involved Paragraph IV litigation, Orange Book-listed patent rights, and generic-launch timing.
• Bayer’s estate included layered compound, formulation, use, and pharmaceutical-technology protection.
• Public settlement and dismissal materials do not necessarily disclose all commercial launch terms.
• The key business issue was the date and conditions under which Mylan could enter the rivaroxaban market.

FAQs

What was Mylan’s ANDA number for generic Xarelto?

The litigation is associated with Mylan’s ANDA for generic rivaroxaban, commonly identified in the Xarelto patent record as ANDA No. 205832.

Did Bayer sue other generic companies over Xarelto?

Yes. Bayer pursued related Xarelto patent litigation against multiple generic applicants, including Mylan and other ANDA filers. Each case required separate analysis of the defendant’s ANDA, certifications, defenses, and settlement terms.

Could Mylan launch generic rivaroxaban before all Xarelto patents expired?

Potentially, but only if Mylan obtained a license, prevailed on the relevant patents, used a noninfringing design, or launched at risk. A settlement could also establish an agreed entry date before the latest patent expiration.

Did the case involve Xarelto method-of-use patents?

Xarelto’s broader patent estate included method-of-use protection, but the Mylan action centered on the patent claims asserted against the ANDA product. Method-of-use patents must be analyzed separately because generic labeling may omit patented indications.

What was the main investment risk from the Bayer-Mylan litigation?

The main risk was delayed or accelerated generic entry. A favorable Bayer outcome could preserve Xarelto revenue until patent expiry or an agreed license date. A successful Mylan defense or early settlement license could produce rapid price erosion in a high-volume anticoagulant market.

References

1. Bayer HealthCare LLC v. Mylan Pharmaceuticals Inc., No. 1:15-cv-00114-LPS, U.S. District Court for the District of Delaware, docket filings and orders (2015 onward).

2. U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations. Washington, DC: U.S. Department of Health and Human Services.

3. U.S. Food and Drug Administration. (2024b). Orange Book: Approved drug products with therapeutic equivalence evaluations, Xarelto patent and exclusivity listings. Washington, DC: U.S. Department of Health and Human Services.

4. U.S. Patent and Trademark Office. (2024). Patent Center and Patent Examination Data System records for U.S. Patent No. 8,309,610. Alexandria, VA: U.S. Department of Commerce.

5. Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355.

6. Patent Act, 35 U.S.C. § 271(e)(2).