Details for Patent: 11,160,751

Which drugs does patent 11,160,751 protect, and when does it expire?

Patent 11,160,751 protects XYOSTED (AUTOINJECTOR) and is included in one NDA.

This patent has nine patent family members in five countries.

Summary for Patent: 11,160,751

Title:	Hematocrit modulation through needle assisted jet injection of testosterone
Abstract:	The present invention provides compositions and methods for treating a subject in need of treatment with testosterone, including introducing testosterone into the subject subcutaneously, intradermally, or intramuscularly, from a needle assisted jet injection device.
Inventor(s):	Paul K. WOTTON, Jonathan Jaffe
Assignee:	Antares Pharma Inc
Application Number:	US15/027,387
Patent Claim Types: see list of patent claims	Use; Dosage form;

United States Patent 11,160,751: Scope, Claim Construction, and Testosterone Patent Landscape

U.S. Patent No. 11,160,751 claims a narrow administration method for testosterone or a testosterone ester delivered subcutaneously in sesame oil through a powered autoinjector. The method combines formulation, dose, device, injection-time, pharmacokinetic, hematocrit, patient-population, and injection-performance limitations. The patent does not broadly claim testosterone, testosterone enanthate, sesame-oil formulations, or autoinjectors in isolation.

The principal commercial product implicated by the claim architecture is XYOSTED, testosterone enanthate injection, marketed by Antares Pharma and later associated with Halozyme following Halozyme’s acquisition of Antares. XYOSTED is a subcutaneous, single-dose autoinjector product supplied in 50 mg, 75 mg, and 100 mg strengths in 0.5 mL of sesame oil.[1]

What does U.S. Patent 11,160,751 claim?

The independent claim requires every element below:

Claim element	Scope
Active ingredient	Testosterone or a pharmaceutically acceptable ester or salt
Route	Subcutaneous administration
Vehicle	Sesame oil
Device	Powered autoinjector
Injection time	About 5 to about 20 seconds
Drug concentration	About 50 to about 400 mg/mL
Serum or plasma concentration	Increases to a second concentration within about 300 to about 1,800 ng/dL
Duration	Maintained for approximately 2 hours through at least 5 days
Hematocrit	Does not exceed 70% of a packed-cell measurement volume
Claimed objective	Modulating or controlling hematocrit

The claim is a method-of-treatment claim. It does not cover a product merely because that product contains testosterone enanthate in sesame oil. An accused product or use would need to satisfy the claimed administration conditions.

The claim language also contains several relative and approximate terms, including “about,” “maintained,” “increases,” and “does not exceed.” Their construction would affect both infringement and validity analysis.

How should claim 1 of Patent 11,160,751 be construed?

“Testosterone or a pharmaceutically acceptable ester or salt”

The claim is not limited expressly to testosterone enanthate. It potentially reaches other testosterone esters or salts if they satisfy the remaining limitations. Commercial testosterone products use different esters, including testosterone enanthate, cypionate, undecanoate, and acetate-related forms.

The claim’s practical commercial relevance is narrower than this chemical breadth because the remaining limitations are tailored to a subcutaneous depot injection in sesame oil delivered through a powered device.

“In sesame oil”

The sesame-oil limitation excludes products using other vehicles unless the accused formulation also contains sesame oil. This limitation is important because many testosterone products use alternative excipients, oil vehicles, gels, creams, or oral delivery systems.

The claim does not specify the exact quantity or purity of sesame oil. A formulation containing sesame oil would likely satisfy the vehicle limitation if sesame oil is the relevant carrier rather than an incidental excipient.

“Powered autoinjector”

The claim requires a powered autoinjector. A conventional syringe, manual needle, vial-and-syringe system, or transdermal applicator would not ordinarily satisfy this limitation.

Claim 13 narrows the device requirement further by requiring a needle-assisted jet injector. That dependent claim creates a more specific device subgroup. It does not convert the entire patent into a device patent because the claims remain directed to use of the device to administer testosterone.

“About 5 seconds to about 20 seconds”

This limitation targets the delivery profile. It creates potential infringement exposure for powered injectors programmed to deliver the dose in approximately that interval.

The word “about” introduces a range beyond the literal numerical endpoints. The legally relevant range would depend on the specification, prosecution history, technical meaning, and evidence regarding measurement conditions.

“300 ng/dL to 1,800 ng/dL”

The claim requires the testosterone concentration in serum or plasma to rise to and remain at a second concentration within a very broad range. The claim does not require the same exact concentration for every patient. It also does not specify whether the concentration is total testosterone, free testosterone, or another analytical measure. The patent specification and prosecution record would be important in resolving that issue.

A product could satisfy the claim even if its labeled dose is the same as a competing product, because the claim focuses on the resulting pharmacokinetic profile as well as the administration method.

What do the dependent claims add?

Claims	Added limitation
2-8	Patient age, including at least 60, 65, 70, or 75 years and age ranges from 60 to 75 or 60 to 70
9	Hematocrit above baseline but below 160% of baseline
10	Male subject
11	Female subject
12	Newborn subject
13	Needle-assisted jet injector
14	Hematocrit upper limit from 110% through 160% of baseline
15	Dose mass of approximately 5 mg to 400 mg
16	Preservative-free dose
17	Specified conditions, including hypogonadism, reduced fertility, erectile dysfunction, osteoporosis, and anemia
18	Treatment of the condition in claim 17
19	Testosterone concentration maintained for approximately five days to one month
20	Medicament-chamber pressure of approximately 80 to 1,000 psi
21	Leakback below approximately 6% of total dose volume

Claims 2 through 8 are unusual because they divide the population by age. Claims 10 through 12 separately cover male, female, and newborn subjects. These limitations may support narrower infringement theories but can also create written-description and enablement questions if the specification does not provide adequate support across all listed populations.

What formulations are protected by Patent 11,160,751?

The patent protects use of testosterone or a testosterone ester in sesame oil when the formulation is administered under the claimed conditions. Claim 1 requires a concentration of approximately 50 to 400 mg/mL. Claim 15 separately requires a dose mass of approximately 5 to 400 mg, while claim 16 covers a preservative-free dose.

The commercial XYOSTED formulation is supplied in 50 mg/mL, 75 mg/mL, and 100 mg/mL-equivalent strengths based on a 0.5 mL injection volume.[1] Those strengths fall within the concentration range recited in claim 1.

The patent therefore has a potentially relevant formulation-use overlap with XYOSTED, but the overlap depends on the entire claim combination. A formulation that matches the concentration and sesame-oil limitations but is administered manually, intramuscularly, or outside the claimed injection interval would not necessarily infringe claim 1.

How does Patent 11,160,751 compare with XYOSTED’s FDA-approved use?

XYOSTED is FDA-approved for testosterone replacement therapy in adult males for conditions associated with a deficiency or absence of endogenous testosterone.[1] Its labeled administration is subcutaneous, once weekly, using a single-dose autoinjector. The label identifies a 0.5 mL delivery volume and 50 mg, 75 mg, and 100 mg dosage strengths.[1]

The patent claim is broader and narrower than the approved label in different respects.

Issue	Patent 11,160,751	XYOSTED labeling
Route	Subcutaneous	Subcutaneous
Vehicle	Sesame oil	Sesame-oil formulation
Device	Powered autoinjector	Single-dose autoinjector
Dose strengths	Approximately 5-400 mg	50, 75, and 100 mg
Injection time	Approximately 5-20 seconds	Device-specific delivery profile
Population	Male, female, newborn, and age-defined groups in dependent claims	Adult males
Testosterone range	Approximately 300-1,800 ng/dL	Testosterone-replacement dosing and monitoring
Hematocrit ceiling	Up to 70% in claim 1	FDA labeling includes hematocrit monitoring and clinical intervention thresholds
Treatment period	Approximately 2 hours to at least 5 days; claim 19 extends to one month	Weekly dosing regimen

The overlap is strongest for subcutaneous testosterone enanthate delivered through a powered autoinjector in sesame oil. The patent’s broader population and hematocrit language does not mean that FDA-approved use extends to women, newborns, or all listed conditions.

What is the patent’s strongest infringement theory?

The strongest theory would involve a product or treatment protocol that uses:

1. Testosterone enanthate or another testosterone ester;
2. Sesame oil;
3. A powered autoinjector;
4. A dose within approximately 5 to 400 mg;
5. A drug concentration within approximately 50 to 400 mg/mL;
6. A delivery time of approximately 5 to 20 seconds; and
7. A resulting testosterone concentration and hematocrit profile within the claimed parameters.

A product resembling XYOSTED is more exposed than a conventional intramuscular testosterone injection because it may satisfy the route, vehicle, dose-form, and device limitations simultaneously.

The most difficult infringement elements are likely to be the pharmacokinetic and hematocrit limitations. Those elements require patient-specific or clinical evidence. A label alone may not establish that every administration produces the claimed serum or plasma range or hematocrit result.

What are the principal validity risks?

Written description and enablement

The claims span multiple testosterone esters, a wide concentration range, multiple device pressures, several age groups, male and female subjects, newborns, and treatment durations extending to one month. A validity challenge could argue that the specification does not demonstrate possession of the full claimed genus or enable the full scope without undue experimentation.

The newborn and female-subject claims may receive particular scrutiny if the disclosure and examples focus primarily on adult men with hypogonadism.

Indefiniteness

Potentially disputed terms include:

• “About”;
• “maintained”;
• “second concentration”;
• “packed cell measurement volume”;
• “baseline level of hematocrit”; and
• “leak back.”

Claim 21 is especially dependent on how leakback is measured, including whether the measurement is taken immediately after injection, after a defined observation period, or under specified device and tissue conditions.

Lack of written support for the hematocrit relationship

Claim 1 uses an absolute ceiling of 70%, while claims 9 and 14 use a percentage of baseline hematocrit. These are different measurement frameworks. The relationship between the absolute and relative thresholds could be contested if the specification does not explain how they operate across different baseline values.

Obviousness

The patent combines known elements that may individually have been present in the prior art:

• Testosterone replacement;
• Subcutaneous testosterone delivery;
• Sesame-oil depot formulations;
• Powered autoinjectors;
• Controlled injection times;
• Pharmacokinetic monitoring; and
• Hematocrit monitoring.

The patent’s defense would depend on whether the claimed combination produced an unexpected clinical or pharmacokinetic result and whether the prior art gave a reason to combine the elements. Evidence concerning reduced injection burden, dose consistency, leakback reduction, and hematocrit control would be material.

When does Patent 11,160,751 lose exclusivity?

A U.S. patent normally expires 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable extension.[2] The issue date, November 2, 2021, does not determine the expiration date.

Patent 11,160,751 should therefore be evaluated through:

• The earliest effective nonprovisional priority date;
• Any continuation or divisional relationship;
• Patent-term adjustment;
• Terminal disclaimers;
• Patent-term extension;
• Maintenance-fee status; and
• Any disclaimer or post-grant proceeding.

The patent document and USPTO Patent Center record control the term calculation. A precise expiration date cannot be established from the claims alone.

What is the Orange Book status of Patent 11,160,751?

The relevant listed drug is XYOSTED, NDA 208088. FDA Orange Book listing is separate from patent issuance. A patent may be relevant to the product without being listed for the NDA, and an Orange Book listing may cover a formulation, method of use, or device-related patent depending on FDA’s listing framework.[3]

For an ANDA strategy, the key questions are whether Patent 11,160,751 is listed against NDA 208088, whether the listed claims correspond to the proposed generic’s use, and whether the applicant must submit a Paragraph IV certification.

A Paragraph IV challenge would be directed to listed patent claims, not to every patent that may have commercial relevance. If the patent is listed, an ANDA applicant could assert that the claims are invalid, unenforceable, or not infringed. A timely patent-owner suit under the Hatch-Waxman framework could trigger the statutory 30-month stay, subject to the applicable procedural conditions.[4]

Which companies are most likely to challenge the patent?

The likely challengers are generic or specialty pharmaceutical companies seeking approval for subcutaneous testosterone enanthate or a therapeutically equivalent testosterone product. The commercial threat depends on whether the proposed product uses:

• A powered autoinjector;
• Sesame oil;
• A concentration within the claimed range;
• The claimed injection duration; and
• A label that encourages a use within the method claims.

A generic applicant may reduce exposure by using a different device, a different route, a different vehicle, or a label that omits the patented method where legally permissible. That strategy is more difficult if the claimed method is the core approved use or if the product design necessarily practices the patented delivery method.

What generic entry risks exist for XYOSTED?

Early entry

Early entry would most likely require a successful Paragraph IV challenge, a finding of noninfringement, invalidity, or unenforceability, or a settlement permitting launch before patent expiration.

Carve-out entry

A skinny-label strategy may be available for method-of-use claims if the patented indication can be carved out without removing the core approved use. The feasibility depends on the FDA-approved labeling and the exact scope of the listed claims.

Device substitution

A generic could attempt to avoid claims 1, 13, and 20 by using a manual syringe or a powered device with a different pressure or delivery profile. That approach may create regulatory, human-factors, and commercial disadvantages because the autoinjector is part of XYOSTED’s product differentiation.

Formulation substitution

Changing the vehicle from sesame oil could avoid the principal formulation limitation, but the substitution would require separate FDA development and compatibility work. Testosterone depot formulations also face solubility, viscosity, tissue-tolerability, and injection-volume constraints.

How strong is the patent estate?

Patent 11,160,751 has meaningful commercial relevance but a narrower scope than a composition-of-matter patent. Its value comes from the combination of delivery system and clinical-use limitations.

Strength factor	Assessment
Composition-of-matter protection	Low; the claim does not broadly claim testosterone enanthate
Formulation protection	Moderate; sesame oil and concentration are required
Device protection	Moderate to strong for matching powered autoinjectors
Method-of-use protection	Stronger where the approved product practices every limitation
Design-around risk	Material; route, vehicle, device, injection time, and label can potentially change
Proof burden	High for pharmacokinetic, hematocrit, pressure, and leakback limitations
Generic litigation value	Significant if listed and tied to the principal XYOSTED use
Biosimilar relevance	None in the conventional sense; testosterone is a chemically synthesized small molecule

The patent is not a biosimilar barrier. Biosimilar procedures apply to biological products, while testosterone products proceed through the small-molecule drug framework, generally including abbreviated new drug applications where the statutory requirements are met.[5]

What litigation and settlement issues matter?

A litigation review should focus on:

• ANDA filings referencing XYOSTED;
• Paragraph IV notices;
• District court complaints;
• Declaratory-judgment actions;
• Inter partes review petitions;
• Claim-construction rulings;
• Settlement terms and launch dates;
• Covenants not to sue; and
• Any license or authorized-generic arrangement.

A settlement could permit entry before patent expiration while preserving the patent’s formal validity. The economic impact would depend on the launch date, royalty terms, supply arrangements, and whether the agreement restricts competing testosterone products.

No license or settlement right is created by Patent 11,160,751 itself. Those rights arise only from separate agreements or court orders.

What manufacturing and IP barriers affect competing products?

A competing product must solve more than the active-ingredient issue. The relevant barriers include:

• High-concentration testosterone ester formulation;
• Sterility and particulate control;
• Sesame-oil compatibility;
• Autoinjector dose accuracy;
• Injection-force and viscosity management;
• Needle penetration and tissue retention;
• Leakback control;
• Container-closure integrity;
• Device reliability;
• Human-factors validation; and
• Pharmacokinetic comparability.

Claim 20’s pressure range and claim 21’s leakback limitation create technical evidence points that may be difficult to evaluate from public labeling. A competitor that changes device pressure or injection speed may avoid some claims but still face separate device patents, trade secrets, or regulatory comparability challenges.

Key Takeaways

• Patent 11,160,751 is a method patent focused on subcutaneous testosterone administration using a powered autoinjector.
• Sesame oil, a 50-400 mg/mL concentration, a 5-20 second injection, specified testosterone exposure, and hematocrit control are central limitations.
• XYOSTED is the principal commercial product implicated by the claim structure.
• The patent does not broadly claim testosterone enanthate, sesame oil, or autoinjectors independently.
• Infringement analysis requires evidence of the full claimed method, including pharmacokinetic and hematocrit results.
• The broad age, sex, newborn, pressure, duration, and leakback limitations create potential validity and proof issues.
• Generic risk depends heavily on Orange Book listing, Paragraph IV certification, device design, and the feasibility of a label or formulation design-around.
• Testosterone is a small-molecule drug, so biosimilar litigation is not the relevant competitive framework.
• The precise expiration date requires the USPTO term record, including priority, patent-term adjustment, and any terminal disclaimer.

FAQs

Does Patent 11,160,751 cover intramuscular testosterone injections?

No. Claim 1 requires subcutaneous administration. A conventional intramuscular testosterone injection would generally fall outside the independent claim unless another asserted claim has materially different language.

Does a testosterone gel infringe Patent 11,160,751?

A testosterone gel would not ordinarily satisfy the sesame-oil, powered-autoinjector, and subcutaneous-injection limitations. It would generally be outside the claim scope.

Can a competitor avoid the patent by using testosterone cypionate instead of testosterone enanthate?

Not automatically. Claim 1 covers testosterone or a pharmaceutically acceptable ester or salt. Testosterone cypionate could fall within the active-ingredient language if the remaining limitations are also met.

Does the 70% hematocrit limitation mean the product must be tested in every patient?

The claim requires the claimed administration to produce the specified hematocrit result. Whether clinical testing is required to prove infringement depends on the evidence and the applicable infringement theory, but the hematocrit limitation creates a material proof issue.

Is Patent 11,160,751 a device patent?

No. It is directed to a method of administering testosterone. The autoinjector, pressure, injection time, and leakback requirements limit the method claims but do not create a standalone claim to the injector hardware.

References

1. U.S. Food and Drug Administration. (2023). XYOSTED (testosterone enanthate) injection, prescribing information.
2. United States Patent and Trademark Office. (2024). Patent term adjustment and patent term provisions.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Food and Drug Administration. (2024). Hatch-Waxman amendments and abbreviated new drug applications.
5. U.S. Food and Drug Administration. (2024). Biosimilar and interchangeable biosimilar products.

Drugs Protected by US Patent 11,160,751

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Antares Pharma Inc	XYOSTED (AUTOINJECTOR)	testosterone enanthate	SOLUTION;SUBCUTANEOUS	209863-001	Sep 28, 2018		RX	Yes	Yes			Y			METHOD OF ADMINISTERING TESTOSTERONE ENANTHATE SUBCUTANEOUSLY
Antares Pharma Inc	XYOSTED (AUTOINJECTOR)	testosterone enanthate	SOLUTION;SUBCUTANEOUS	209863-002	Sep 28, 2018		RX	Yes	Yes			Y			METHOD OF ADMINISTERING TESTOSTERONE ENANTHATE SUBCUTANEOUSLY
Antares Pharma Inc	XYOSTED (AUTOINJECTOR)	testosterone enanthate	SOLUTION;SUBCUTANEOUS	209863-003	Sep 28, 2018		RX	Yes	Yes			Y			METHOD OF ADMINISTERING TESTOSTERONE ENANTHATE SUBCUTANEOUSLY

Foreign Priority and PCT Information for Patent: 11,160,751

PCT Information
PCT Filed	October 07, 2014	PCT Application Number:	PCT/US2014/059443
PCT Publication Date:	April 16, 2015	PCT Publication Number:	WO2015/054213

International Family Members for US Patent 11,160,751

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Canada	2926439
European Patent Office	3054957
European Patent Office	3653213