US Patent 9,889,144: Abiraterone Acetate Formulation Scope, Expiration, and Patent Landscape

US Patent 9,889,144 protects a specific 125 mg abiraterone acetate solid oral dosage form that uses controlled particle size, defined excipients, rapid dissolution, and pharmacokinetic performance comparable to a 1,000 mg dose of Zytiga. The patent is directed to a low-dose, bioavailability-enhanced formulation rather than to abiraterone acetate as a molecule.

The central commercial implication is a four-tablet, 500 mg dosing configuration capable of replacing the historical 1,000 mg Zytiga dose. A competing product could avoid literal infringement by changing the formulation, particle-size distribution, dissolution profile, or measurable pharmacokinetic results. That design-around path is technically available but commercially constrained because the claims combine multiple formulation and performance limitations.

What patents protect the 125 mg abiraterone acetate formulation?

US 9,889,144 protects a unit dosage form containing 125 mg of abiraterone acetate with a defined excipient system and specified in vitro and in vivo performance.

Patent element	Requirement in independent claims 1 and 12
Dosage form	Solid oral unit dosage form
Active ingredient	125 mg abiraterone acetate
Particle size	D50 greater than 100 nm and less than 1,200 nm
Excipients	Lactose monohydrate, sodium lauryl sulfate, microcrystalline cellulose, croscarmellose sodium, sodium stearyl fumarate, BHA and BHT
Dissolution medium	900 mL pH 4.5 phosphate buffer with 0.12% sodium lauryl sulfate
Dissolution apparatus	USP Apparatus II at 75 rpm
Dissolution result	At least 70% dissolved between five and 15 minutes
Pharmacokinetics	500 mg dose produces mean Cmax of 50-120 ng/mL
Pharmacokinetics	500 mg dose produces mean AUC(0-∞) of 240-650 h×ng/mL
Comparator	1,000 mg Zytiga tablets in fasted healthy male subjects

The claims do not cover every abiraterone acetate tablet. They require a combination of:

A specified dose per unit;
A defined particle-size range;
A named excipient set;
A dissolution result under a precise test method; and
Pharmacokinetic results within stated ranges.

A product lacking one required limitation would not literally satisfy the relevant claim, although infringement could still turn on claim construction and the doctrine of equivalents.

How broad are the independent claims in US 9,889,144?

Claims 1 and 12 are the principal barriers. They are substantially similar, but claim 1 includes a specific bioequivalence limitation comparing the 500 mg formulation with 1,000 mg of Zytiga. Claim 12 states the pharmacokinetic ranges but does not expressly repeat the bioequivalence requirement.

This creates two practical claim groups:

Claim 1 and its dependents: narrower because of the express Zytiga comparison.
Claim 12 and its dependents: potentially broader because the claim focuses on the absolute Cmax and AUC ranges rather than an express comparative bioequivalence finding.

The independent claims also use population-based pharmacokinetic language. A formulation must produce the claimed mean values in a population of healthy male subjects under fasted conditions. That limitation creates proof issues. In litigation, the patent owner would likely need clinical or regulatory data showing that the accused product meets the stated Cmax and AUC ranges. The accused party could challenge whether the claim language defines a reproducible product characteristic or an uncertain result-dependent limitation.

What particle-size limitations are protected?

Claims 4, 5, 13 and 14 narrow the active ingredient by particle-size distribution:

Dependent limitation	Range
D50	Greater than 100 nm and below 1,000, 800, 500, 400 or 300 nm
D90	Greater than 300 nm and below 3,000, 2,000, 900, 800 or 700 nm
D4,3	Greater than 300 nm and below 1,100, 900 or 800 nm

The use of D50, D90 and D4,3 makes particle characterization central to freedom-to-operate analysis. Different analytical instruments, dispersion methods, sampling procedures and calculation models can produce different results. A competitor would need validated particle-size testing under conditions likely to withstand litigation scrutiny.

What formulation compositions are protected?

Claims 10, 11, 19 and 20 define weight-percent ranges for each component.

The broader composition range includes:

Component	Broad range
Abiraterone acetate	5-50 wt.%
Lactose monohydrate	5-80 wt.%
Sodium lauryl sulfate	0.1-10 wt.%
Microcrystalline cellulose	5-80 wt.%
Croscarmellose sodium	1-15 wt.%
Sodium stearyl fumarate	0.01-10 wt.%
BHA	0.001-1 wt.%
BHT	0.001-1 wt.%

The narrower composition claim requires:

Abiraterone acetate at 10-30 wt.%;
Lactose monohydrate at 20-40 wt.%;
Sodium lauryl sulfate at 1-5 wt.%;
Microcrystalline cellulose at 20-60 wt.%;
Croscarmellose sodium at 2-10 wt.%;
Sodium stearyl fumarate at 0.1-2 wt.%;
BHA at 0.01-2 wt.; and
BHT at 0.01-2 wt.

The narrower claim has an apparent drafting issue because the BHA and BHT ranges in claims 11 and 20 extend to 2 wt.%, while the independent claims recite 0.001-1 wt.%. The practical scope remains the intersection with the incorporated independent limitations. A product using more than 1 wt.% BHA or BHT would present a substantial argument that it falls outside the independent claim, subject to the claim language and prosecution history.

When does US Patent 9,889,144 lose exclusivity?

The patent was granted on February 20, 2018. Its term is generally calculated from the earliest effective nonprovisional U.S. filing date, subject to patent-term adjustment, terminal disclaimers and any applicable regulatory extension. The patent record, rather than the grant date alone, controls the enforceable expiration date.[1]

The patent appears to belong to the abiraterone acetate formulation family associated with Sun Pharma’s low-dose product Yonsa. Related family members and continuation patents must be reviewed separately because a continuation can carry a different claim set while sharing substantially the same priority chain.

Exclusivity category	Relevance
Abiraterone compound patent	The original abiraterone patent is no longer the principal U.S. barrier
Zytiga formulation and use patents	Historically affected generic 250 mg and 500 mg products
US 9,889,144	Targets the 125 mg low-dose formulation architecture
Regulatory exclusivity	Depends on the relevant NDA, approval date and FDA designation
Patent-term adjustment	Must be confirmed from the USPTO patent record
Terminal disclaimer	Must be checked against related Sun Pharma patents

The patent should not be treated as expiring simply 20 years after its issue date. A definitive expiration analysis requires the USPTO term data and any terminal-disclaimer information. FDA Orange Book listing does not itself extend the patent term.

What is the Orange Book status of US 9,889,144?

The relevant FDA product is Yonsa, a 125 mg abiraterone acetate tablet approved under NDA 210461. Zytiga is a separate abiraterone acetate product approved under NDA 202379.[2][3]

Orange Book relevance depends on whether US 9,889,144 is listed against the Yonsa NDA and whether the listing includes a method-of-use code or a formulation-related patent listing. A patent may be enforceable under ordinary patent law even if it is not listed in the Orange Book. Conversely, Orange Book listing creates an FDA regulatory pathway for notice and a potential 30-month stay following a qualifying Paragraph IV certification, but it does not determine ultimate infringement or validity.[4]

For diligence purposes, the critical distinction is:

Zytiga’s Orange Book patents primarily relate to its approved product, formulation, or use.
US 9,889,144 is directed to a 125 mg dosage form with Yonsa-like performance.
A generic applicant seeking approval for a 125 mg product may face a different patent set from an applicant seeking approval for 250 mg or 500 mg abiraterone acetate tablets.

Which companies are challenging the abiraterone acetate patent estate?

The principal competitive pressure has historically come from generic manufacturers filing ANDAs for abiraterone acetate tablets. Generic applicants targeting Zytiga generally challenge listed patents through Paragraph IV certifications or seek approval after listed patent expiration.

The most relevant potential challengers to a 125 mg formulation patent are companies developing:

A 125 mg tablet intended to be dosed as four tablets daily;
A micronized abiraterone acetate formulation;
A noninfringing particle-size distribution;
A formulation using alternative surfactants, lubricants or antioxidants; or
A product relying on a different bioavailability-enhancement mechanism.

Public patent litigation involving abiraterone acetate has included challenges by generic companies to Janssen’s Zytiga-related patents. Those cases do not automatically establish a challenge to US 9,889,144. Each notice letter, ANDA certification and complaint must identify the specific patent and NDA at issue.

What patent litigation affects US 9,889,144?

The patent presents several litigation issues:

Literal infringement

A plaintiff would need to prove that the accused product has the required 125 mg strength, excipient system, particle-size limitation, dissolution behavior and pharmacokinetic profile. The claim is difficult to assess from a public product label alone because particle size, dissolution data and clinical PK data may not appear in the labeling.

Inherent infringement

The patent owner could argue that the claimed dissolution or PK characteristics necessarily result from the accused formulation. That theory would require reliable testing across representative batches. Variability in manufacturing and analytical methods could weaken an inherent-infringement case.

Validity

Likely validity issues include:

Obviousness based on micronization, surfactant use and conventional tablet excipients;
Written-description support for the full particle-size and composition ranges;
Enablement across the broad formulation and PK ranges;
Indefiniteness of population-based pharmacokinetic limitations; and
Anticipation by earlier abiraterone acetate formulations or clinical studies.

The strongest patentability argument is the claimed combination of low dose, rapid dissolution and exposure comparable to a higher Zytiga dose. The strongest invalidity argument is that each individual feature may have been known, making the combination vulnerable to an obviousness challenge.

How strong is the patent estate for Yonsa compared with Zytiga?

Issue	Yonsa and US 9,889,144	Zytiga
Dose	125 mg per tablet	Historically 250 mg tablets; later 500 mg presentations
Dose strategy	Four tablets provide 500 mg	Four 250 mg tablets historically provided 1,000 mg
Core protection	Formulation and performance	Product, formulation and method-of-use patents
Particle-size role	Central to the claims	Relevant to formulation but not the sole focus of the original product
Bioequivalence limitation	Central to claim 1	Used as a regulatory comparison
Design-around potential	Moderate to high technically	Higher after core patents expired
Manufacturing barrier	Controlled milling and blend uniformity	Conventional tablet manufacturing plus product-specific controls

US 9,889,144 is narrower than a composition-of-matter patent but can be commercially meaningful because it protects a marketed dosage architecture. Its enforceability depends heavily on whether a generic product reproduces the claimed excipients and performance profile.

What generic launch risks exist for abiraterone acetate?

A generic launch can follow several paths:

Launch scenario	Risk profile
250 mg or 500 mg generic Zytiga-equivalent	May avoid US 9,889,144 if it does not use the claimed 125 mg form
125 mg generic Yonsa-equivalent	High risk of direct formulation-patent challenge
Alternative excipient formulation	Lower literal-infringement risk, but dissolution and bioequivalence must be demonstrated
Nonmicronized active ingredient	May fail the claimed particle-size limitations, but may create bioavailability problems
At-risk launch after Paragraph IV litigation	Potential damages, injunction and market-share liability
Launch after patent expiration	Lower legal risk, subject to other listed patents and regulatory exclusivity

The key commercial question is whether a generic company needs to copy the low-dose product. If a 250 mg or 500 mg product can obtain approval without infringing the low-dose formulation claims, US 9,889,144 may have limited blocking power against that product. It is more consequential for a direct 125 mg substitute.

What manufacturing and geographic IP barriers apply?

The principal manufacturing barriers are particle-size control, content uniformity at a relatively low active load, surfactant distribution, rapid disintegration and reproducible dissolution. BHA and BHT introduce additional formulation-control requirements because they are present at low concentrations.

U.S. protection does not automatically extend to Europe, Canada, Japan, China or other markets. Patent-family members must be reviewed jurisdiction by jurisdiction. Regulatory approval, patent term, supplementary protection certificates, national-phase prosecution and local litigation can materially differ. A global launch plan should treat US 9,889,144 as one jurisdiction-specific asset within a broader family.

What are the revenue implications?

Zytiga generated multibillion-dollar global revenue during its peak commercial period, with U.S. sales representing a major portion before generic erosion. Johnson & Johnson reported worldwide Zytiga sales of approximately $1.4 billion in 2018, with subsequent declines as generic competition expanded.[5]

Yonsa addresses a smaller but strategically important segment because it reduces the daily abiraterone dose from 1,000 mg to 500 mg. The patent’s value depends on:

The share of prescriptions using the 125 mg product;
Whether payers prefer the lower-dose formulation;
The timing of generic 250 mg and 500 mg entry;
Whether generic firms elect to copy the Yonsa format; and
The enforceability of related patents.

Key Takeaways

US 9,889,144 protects a 125 mg abiraterone acetate tablet, not abiraterone acetate generally.
The claims require a defined excipient set, particle-size range, rapid dissolution and specified fasted-state pharmacokinetics.
Claims 1 and 12 are the principal independent claims; claim 1 has the more explicit Zytiga bioequivalence limitation.
Claims 4, 5, 13 and 14 make D50, D90 and D4,3 particle-size measurements central to infringement analysis.
Claims 10, 11, 19 and 20 protect broad and narrower excipient weight-percent ranges.
A 250 mg or 500 mg generic may avoid this patent without copying the 125 mg Yonsa formulation.
A direct 125 mg generic substitute faces greater Paragraph IV and infringement exposure.
Patent expiration must be confirmed from the USPTO term record, including patent-term adjustment and any terminal disclaimer.
Orange Book listing affects FDA approval procedure but does not decide patent validity or infringement.
The formulation estate is commercially meaningful but narrower and more design-around-sensitive than a composition-of-matter patent.

FAQs About US Patent 9,889,144

Does US 9,889,144 cover Zytiga 250 mg tablets?

No. The independent claims require a unit dosage form containing 125 mg of abiraterone acetate. A conventional 250 mg Zytiga tablet would not satisfy that limitation.

Does the patent cover a 500 mg abiraterone tablet?

Not literally under the independent claims quoted here, which require 125 mg per unit dosage form. A 500 mg tablet would need to be assessed against other patents and could implicate related family claims.

Is micronized abiraterone acetate alone infringing?

No. Micronization alone is insufficient. The claims also require the specified dose, excipients and dissolution or pharmacokinetic limitations.

Can a generic use different antioxidants?

A generic using antioxidants other than BHA and BHT may have a stronger noninfringement position against the quoted claims. It would still need to assess related patents and possible equivalents theories.

Does FDA approval establish infringement of US 9,889,144?

No. FDA approval establishes regulatory authorization, not patent infringement. Patent liability depends on the asserted claims, the accused product and the relevant patent-law record.

References

United States Patent and Trademark Office. (2018). U.S. Patent No. 9,889,144, Abiraterone acetate formulations.
U.S. Food and Drug Administration. (2011). Zytiga (abiraterone acetate) tablets, NDA 202379: Prescribing information.
U.S. Food and Drug Administration. (2018). Yonsa (abiraterone acetate) tablets, NDA 210461: Prescribing information.
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations.
Johnson & Johnson. (2019). 2018 annual report.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sun Pharm	YONSA	abiraterone acetate	TABLET;ORAL	210308-001	May 22, 2018		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	095480	⤷ Start Trial
Australia	2014232508	⤷ Start Trial
Australia	2015317466	⤷ Start Trial
Australia	2018241103	⤷ Start Trial
Brazil	112015023629	⤷ Start Trial
Brazil	112017003219	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,889,144

Which drugs does patent 9,889,144 protect, and when does it expire?

Summary for Patent: 9,889,144