US Patent 11,160,779: Solriamfetol Renal-Dosing Claims, Exclusivity and Patent Landscape

US Patent 11,160,779 protects renal-function-based dosing of solriamfetol, also identified in the claims as [R]-2-amino-3-phenylpropylcarbamate or APC. The patent covers Sunosi treatment protocols for excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea in patients with mild, moderate, or severe renal impairment.

The central commercial risk is a method-of-use patent that maps closely to the FDA-approved renal dosing instructions. A generic applicant could challenge the patent under Paragraph IV, attempt a label carve-out, or wait for patent expiry. The patent does not protect the solriamfetol molecule itself, a particular tablet formulation, or the manufacturing process.

What does US Patent 11,160,779 protect?

US 11,160,779 protects a dosing algorithm that combines four elements:

Excessive daytime sleepiness.
A specified eGFR range.
A defined dose-escalation schedule.
A maximum daily dose based on renal function.

The patent covers APC, the free-base equivalent of solriamfetol, and APC hydrochloride, the salt form used in Sunosi tablets.

eGFR range	Covered condition	Initial dose	Escalation	Maximum dose
60 to 89 mL/min/1.73 m²	Narcolepsy	75 mg APC	150 mg APC after at least 3 days	150 mg APC
60 to 89 mL/min/1.73 m²	Obstructive sleep apnea	37.5 mg APC	75 mg, then 150 mg APC, each after at least 3 days	150 mg APC
30 to 59 mL/min/1.73 m²	Excessive daytime sleepiness	37.5 mg APC for at least 5 days	75 mg APC beginning on the next day	75 mg APC
15 to 29 mL/min/1.73 m²	Excessive daytime sleepiness	37.5 mg APC	No escalation	37.5 mg APC

Claim 1 focuses on moderate and severe renal impairment. Claim 12 is broader because it also covers mild impairment and separates narcolepsy from obstructive sleep apnea.

The patent is assigned to Jazz Pharmaceuticals-related interests, with the invention directed to renal dosing of solriamfetol rather than discovery of the active pharmaceutical ingredient itself. The patent issued on November 2, 2021. [1]

How do the claims operate?

Claim 1: moderate and severe renal impairment

Claim 1 requires treatment of a patient with excessive daytime sleepiness and either:

an eGFR of approximately 30 to 59 mL/min/1.73 m², receiving 37.5 mg APC for at least five days followed by 75 mg APC; or
an eGFR of approximately 15 to 29 mL/min/1.73 m², receiving 37.5 mg APC without exceeding that dose.

The phrase “n1 is an integer equal to or greater than 5” means the low dose must continue through at least day five. The 75 mg dose begins on day six or later. Claim 11 narrows the first pathway by requiring at least seven days before escalation.

Claim 12: mild, moderate and severe impairment

Claim 12 is an independent claim. It incorporates:

the 30 to 59 eGFR regimen;
the 15 to 29 eGFR regimen;
the narcolepsy regimen for eGFR 60 to 89; and
the obstructive sleep apnea regimen for eGFR 60 to 89.

This claim is important because it captures the full renal dosing framework reflected in the Sunosi prescribing information. [2]

Claims 2 and 3: therapeutic indications

Claim 2 limits the excessive daytime sleepiness to narcolepsy. Claim 3 limits it to obstructive sleep apnea.

These claims create separate infringement positions depending on the generic label. A label that includes both indications and the patented renal dosing instructions would create a stronger inducement theory than a label that omits one indication.

Claims 4 through 6: hydrochloride salt dosing

Claims 4 through 6 cover APC hydrochloride quantities corresponding to the free-base doses:

APC free-base equivalent	APC hydrochloride amount
37.5 mg	Approximately 44.7 mg
75 mg	Approximately 89.3 mg

The salt conversion is commercially relevant because Sunosi tablets are labeled by solriamfetol hydrochloride strength, while the patent expresses the therapeutic dose by APC equivalent.

Claims 4 and 5 cover individual strength conversions. Claim 6 covers use of both strengths during the escalation regimen.

Claims 7 and 8: administration timing

Claim 7 requires administration upon awakening. Claim 8 requires administration more than nine hours before bedtime.

These limitations narrow the claims but may align with the approved product labeling. A generic applicant would need to assess whether the proposed label recommends the same timing or merely permits it.

Claims 9 through 11: patient, renal calculation and titration

Claim 9 limits the patient to a human. Claim 10 requires eGFR determination using the Modification in Diet in Renal Disease equation. Claim 11 requires at least seven days at the lower dose before escalation in the 30 to 59 eGFR group.

The MDRD limitation may create a construction issue. Current clinical practice may use other equations, including CKD-EPI. A dosing instruction that uses eGFR without specifying MDRD may not literally meet claim 10, although other claims do not contain that limitation.

What is the FDA regulatory status of solriamfetol?

The FDA approved Sunosi on June 17, 2019, under NDA 211230 for excessive daytime sleepiness associated with narcolepsy or obstructive sleep apnea. The active ingredient is solriamfetol hydrochloride. [2,3]

The FDA label includes renal-dose restrictions:

mild renal impairment: dose escalation with a lower maximum than patients with normal renal function;
moderate renal impairment: initiation at 37.5 mg and a 75 mg maximum;
severe renal impairment: 37.5 mg maximum;
end-stage renal disease: use is not recommended.

The label also identifies morning administration and warns against dosing close to bedtime because of the risk of insomnia. These instructions increase the overlap between the approved label and claims 1, 7, 8 and 12.

Sunosi received five-year new chemical entity exclusivity. Because approval occurred on June 17, 2019, the NCE exclusivity period generally ran until June 17, 2024, subject to FDA regulatory calculations and any applicable pediatric extension. NCE exclusivity did not prevent a patent challenge after the relevant statutory period, but it blocked FDA approval of an ANDA or 505(b)(2) application during the exclusivity period. [3,4]

What is the Orange Book status of US Patent 11,160,779?

US Patent 11,160,779 is a method-of-use patent relevant to Sunosi. Orange Book treatment depends on whether the patent is listed against NDA 211230 and whether the listed claims correspond to an approved use.

The practical implications of listing are:

an ANDA applicant must certify to the patent;
a Paragraph IV certification can trigger notice and patent litigation;
a timely infringement action can create a 30-month FDA approval stay under the Hatch-Waxman framework;
a section viii statement or labeling carve-out may be available if the generic omits the patented use.

The Orange Book does not determine validity or infringement. It identifies patents submitted by the NDA holder or patent owner as covering the drug, its formulation, or an approved method of use. [4]

The relevant analysis should distinguish this patent from patents covering the active ingredient, formulations, and manufacturing processes. A generic applicant may face several independent Orange Book-listed patents even if it succeeds against the renal-dosing patent.

When does US Patent 11,160,779 lose exclusivity?

The patent issued in 2021 from an application claiming priority to an earlier filing directed to renal dosing of solriamfetol. Its ordinary 20-year patent term is expected to extend into approximately 2038, subject to the official USPTO term calculation, patent-term adjustment, terminal disclaimers, and any other recorded term limitation. [1,5]

The relevant commercial date is the patent’s calculated expiration date in USPTO Patent Center and the current Orange Book, not the grant date. The patent does not appear to be a patent-term-extension asset based on the drug’s regulatory approval date. Any pediatric exclusivity would add six months to applicable regulatory exclusivity, not alter the underlying patent expiration date.

The exclusivity timeline is therefore:

Event	Date or period
Sunosi FDA approval	June 17, 2019
Five-year NCE exclusivity	Generally through June 17, 2024
US Patent 11,160,779 grant	November 2, 2021
Expected ordinary patent expiry	Approximately 2038, subject to USPTO term calculation
Earliest practical generic pathway	After regulatory exclusivity, subject to patents, certifications and litigation

What patent claims are most vulnerable to a Paragraph IV challenge?

The strongest potential challenge points are claim construction, written description, obviousness and enablement.

Obviousness

A challenger could combine:

known solriamfetol dosing in patients with normal renal function;
renal pharmacokinetic data;
standard dose-reduction principles;
known eGFR classifications; and
clinical guidance for stimulant or wake-promoting agents.

The patent holder would likely argue that the specific dosing thresholds, escalation intervals and maximum doses were not predictable from general renal pharmacology. The renal dose-response relationship and the distinction between narcolepsy and obstructive sleep apnea would be central to that dispute.

Written description and enablement

The claims cover dose schedules across multiple eGFR ranges and two disease settings. A challenger could argue that the specification does not adequately support every claimed combination, particularly the full set of escalation schedules in claim 12.

The patent holder would rely on renal pharmacokinetic studies and clinical data showing that exposure rises as renal clearance declines. [1,6]

Claim construction

Several terms may generate disputes:

“about” in the eGFR and dose ranges;
“equivalent to” APC;
“providing to a subject”;
“not provided a daily dose exceeding”;
“upon the subject’s awakening”; and
“more than nine hours in advance” of bedtime.

The use of approximate eGFR ranges may make the claims more tolerant of measurement variation. By contrast, the five-day and three-day escalation periods are more objectively measurable.

MDRD limitation

Claim 10 is narrower because it specifies the MDRD equation. A generic label that relies on eGFR without naming MDRD may avoid literal infringement of claim 10. That limitation does not avoid claims 1, 2, 3, 4, 5, 6, 7, 8, 9 or 12.

Which companies are challenging the Sunosi patent estate?

No publicly established commercial generic launch of solriamfetol has displaced Sunosi in the US market based solely on the information available in the cited patent and FDA materials. A company that files an ANDA with a Paragraph IV certification would typically become identifiable through FDA notice, a patent complaint, or both.

The principal potential challengers are generic manufacturers with CNS portfolios and controlled-substance distribution capabilities. The commercial attractiveness is limited by:

the need to reproduce the solriamfetol hydrochloride active ingredient;
potential compound, formulation and process patents;
the relatively specialized narcolepsy and obstructive sleep apnea markets;
controlled-substance compliance;
the need to establish a commercially viable product without infringing method-of-use claims.

A label carve-out may be difficult if the patented dosing instructions are embedded in the FDA-approved treatment directions for both listed indications.

How strong is the patent estate for Sunosi?

US Patent 11,160,779 is strongest as a regulatory-label patent. Its value comes from the close relationship between the claimed renal dosing algorithm and the approved Sunosi prescribing information.

Its principal strengths are:

direct coverage of the FDA renal dosing categories;
independent claim 12 covering mild, moderate and severe impairment;
separate claims for narcolepsy and obstructive sleep apnea;
coverage of both APC and APC hydrochloride dosing;
objective eGFR thresholds and escalation periods.

Its limitations are:

it does not cover every use of solriamfetol;
it does not claim the active molecule;
it does not claim a tablet formulation;
some dependent claims require narrow timing or renal-calculation limitations;
infringement may depend on the exact generic label and physician conduct;
method-of-use claims remain subject to conventional validity attacks.

The patent is a meaningful barrier to a full-label generic, but it is not a complete substitute for compound, formulation and process protection.

What other patent categories affect generic solriamfetol entry?

Compound patents

Earlier patents may protect the R-enantiomer of solriamfetol, related carbamate compounds, or pharmaceutical salts. The key expiration date for any compound patent is likely to be earlier than the renal-dosing patent because compound discovery predates the clinical renal-dosing work.

Formulation patents

Formulation patents may cover tablet composition, excipients, dissolution, stability or salt handling. Such patents can remain relevant even if a generic defeats a method-of-use patent.

Method-of-use patents

Other method patents may cover treatment of excessive daytime sleepiness, narcolepsy or obstructive sleep apnea without renal impairment. These claims may create separate Paragraph IV exposure.

Manufacturing and process patents

Process claims can cover:

preparation of the R-enantiomer;
resolution or asymmetric synthesis;
conversion to APC hydrochloride;
crystallization and solid-state forms;
impurity control; and
tablet manufacture.

These patents may affect supply economics even where they do not appear in the Orange Book.

Geographic coverage

US Patent 11,160,779 has no direct legal effect outside the United States. Corresponding PCT, European, Canadian or other national applications must be assessed separately. Foreign claims may differ materially because of national standards for medical-use claims, Swiss-type claims, dosage regimens and patentable subject matter.

Does solriamfetol have biosimilar risk?

No. Solriamfetol is a small-molecule drug, not a biologic. The relevant competition is an ANDA generic or, in some circumstances, a 505(b)(2) product. Biosimilar provisions under the Biologics Price Competition and Innovation Act do not apply.

The principal regulatory pathway is an ANDA demonstrating pharmaceutical equivalence and bioequivalence to Sunosi. The applicant may use Paragraph IV, Paragraph III, or a section viii statement depending on the applicable patent and use claims.

What generic launch scenarios exist?

Full-label launch after patent expiry

A generic could launch with narcolepsy and obstructive sleep apnea indications after expiration or successful resolution of the relevant patent barriers.

Paragraph IV launch

A challenger could certify that US Patent 11,160,779 is invalid, unenforceable or not infringed. Litigation could delay approval for up to 30 months if the patent holder files a timely action.

Carved-out launch

A generic could remove a patented method from its label under a section viii statement. The viability of this approach would depend on whether the renal dosing instructions are separable from the remaining approved uses and whether the FDA accepts the proposed labeling.

At-risk launch

A generic could launch before final resolution of litigation. That would expose the applicant to damages, injunction risk and potential enhanced damages if infringement were found.

Key Takeaways

US Patent 11,160,779 covers renal-function-based solriamfetol dosing for excessive daytime sleepiness.
Claim 12 is the broadest practical claim because it covers mild, moderate and severe renal impairment.
The patent maps closely to FDA-approved Sunosi renal dosing and therefore has substantial label-based enforcement value.
APC hydrochloride doses of approximately 44.7 mg and 89.3 mg correspond to 37.5 mg and 75 mg APC equivalents.
The patent covers method of treatment, not the solriamfetol molecule, tablet formulation or manufacturing process.
Five-year NCE exclusivity for Sunosi generally ended in June 2024.
The patent’s expected ordinary term extends into approximately 2038, subject to the official USPTO term calculation.
Generic risk will depend on the complete Sunosi patent estate, Paragraph IV certifications, possible label carve-outs and any Hatch-Waxman litigation.
Solriamfetol has generic rather than biosimilar competition risk.

FAQs about US Patent 11,160,779 and Sunosi

Is US Patent 11,160,779 a formulation patent?

No. It is a method-of-treatment patent directed to renal dosing, eGFR categories, dose escalation and maximum daily doses.

What dose does the patent protect for severe renal impairment?

For eGFR of approximately 15 to 29 mL/min/1.73 m², the claims protect a 37.5 mg APC-equivalent daily dose without escalation above that amount.

Does the patent cover normal renal function?

The independent claim covering the full dosing framework includes mild impairment at eGFR 60 to 89. It does not generally cover patients with eGFR of 90 or higher.

Can a generic launch with only one Sunosi indication?

Potentially, but the applicant would need to evaluate the listed method-of-use patents and whether the FDA-approved narcolepsy and obstructive sleep apnea indications can be cleanly separated through a section viii labeling carve-out.

Is solriamfetol controlled by a biosimilar pathway?

No. Solriamfetol is a small molecule. Generic competition would proceed primarily through the ANDA pathway, not a biosimilar application.

References

United States Patent and Trademark Office. (2021). US Patent No. 11,160,779, methods of treating excessive daytime sleepiness in subjects with renal impairment. USPTO Patent Center.
U.S. Food and Drug Administration. (2023). Sunosi (solriamfetol) prescribing information. Jazz Pharmaceuticals.
U.S. Food and Drug Administration. (2019). FDA approves new treatment for excessive daytime sleepiness in adults with narcolepsy or obstructive sleep apnea. FDA.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. FDA.
United States Patent and Trademark Office. (2024). Patent term adjustment and patent term calculation resources. USPTO.
U.S. Food and Drug Administration. (2019). Sunosi clinical pharmacology review and application materials for NDA 211230. FDA.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Axsome Malta	SUNOSI	solriamfetol hydrochloride	TABLET;ORAL	211230-001	Jun 17, 2019	AB	RX	Yes	No	11,160,779	⤷ Start Trial				TREATMENT OF EXCESSIVE DAYTIME SLEEPINESS BY ADMINISTERING SOLRIAMFETOL TO A SUBJECT HAVING MILD, MODERATE, OR SEVERE RENAL IMPAIRMENT	⤷ Start Trial
Axsome Malta	SUNOSI	solriamfetol hydrochloride	TABLET;ORAL	211230-002	Jun 17, 2019	AB	RX	Yes	Yes	11,160,779	⤷ Start Trial				TREATMENT OF EXCESSIVE DAYTIME SLEEPINESS BY ADMINISTERING SOLRIAMFETOL TO A SUBJECT HAVING MILD, MODERATE, OR SEVERE RENAL IMPAIRMENT	⤷ 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

Summary for Patent: 11,160,779