United States Patent 11,850,227 (APC) Method Claims for Treating Excessive Daytime Sleepiness With Renal Impairment Dose Escalation

Executive summary: U.S. Patent 11,850,227 claims a dosing-and-patient-selection method for treating excessive daytime sleepiness using (R)-2-amino-3-phenylpropylcarbamate (APC) with renal-impairment stratification by eGFR, a MAOI washout selection criterion, and structured oral dose escalation regimens capped at eGFR-dependent maximum daily APC exposures. Claim scope is concentrated in (i) moderate-to-severe renal impairment (eGFR 15 to 59) dose limits and escalation timing, and (ii) an expanded regimen for no-mild-to-severe coverage that includes a third daily dose level (150 mg APC) for eGFR 60–89/≥90.

Core protective hooks:

Patient selection: no monoamine oxidase inhibitor in preceding 14 days.
Renal stratification via eGFR (MDRD) into bands:
- 30–59: start 37.5 mg APC, then 75 mg APC after day n1, with n1 ≥ 5, n2 = n1+1, and max 75 mg/day.
- 15–29: 37.5 mg/day only (max 37.5 mg/day).
- 60–89/≥90 (claim 12): 37.5 mg for at least 3 days, then 75 mg after ≥3 days, then 150 mg after another ≥3 days (max 150 mg/day).
Dosing cadence constraints: doses administered upon awakening and more than 9 hours before bedtime.
Form constraints: APC salt presentations (notably APC-HCl ~44.7 mg, ~89.3 mg, ~178.5 mg) mapped to APC-equivalent mg levels.
Indication carve-ins: narcolepsy, obstructive sleep apnea (OSA), shift work disorder, and depression as the cause of excessive daytime sleepiness.

What does US 11,850,227 claim protect: APC dosing for excessive daytime sleepiness with eGFR bands?

Short answer: The patent protects a method-of-treatment where clinicians dose oral APC based on eGFR-defined renal impairment and apply a MAOI washout selection rule, using specific dose escalation schedules and dose caps tied to the renal band.

Claim architecture: two independent claim families (1 and 12)

Claim 1 (narrower renal coverage):
- Covers eGFR 30–59: escalation 37.5 mg to 75 mg using parameters n1 ≥ 5, n2 = n1+1, with cap 75 mg/day.
- Covers eGFR 15–29: 37.5 mg/day only cap 37.5 mg/day.
- Requires MAOI exclusion within 14 days.
Claim 12 (broader renal coverage):
- Retains the same 30–59 and 15–29 structures as claim 1.
- Adds 60–89 or ≥90 band regimen:
  - 37.5 mg APC first, then 75 mg after ≥3 days, then 150 mg after another ≥3 days, cap 150 mg/day.
- Retains MAOI exclusion.

Indication scope inside the claims (multiple etiologies)

The independent dosing structure is reused across downstream dependent claims for:

narcolepsy (claims 2 and 13)
OSA (claims 3 and 14)
shift work disorder (claims 4 and 15)
depression as the driver of excessive daytime sleepiness (claims 24 and 25)

Practical meaning for infringement mapping: if an accused product label and clinical use specify oral APC dosing that matches the renal band escalation and the MAOI selection criterion, the indication (narcolepsy vs OSA vs shift-work disorder vs depression-related EDS) affects whether the use fits the claimed method.

How are the claims limited by renal impairment using eGFR ranges (15–29, 30–59, 60–89/≥90)?

Short answer: The dosing schedule is locked to three eGFR bands, with different escalation ceilings.

eGFR band logic in claim 1

eGFR 30–59 mL/min/1.73m²
- Provide:
  - First oral daily dose: 37.5 mg APC from day one to day n1
  - Second oral daily dose: 75 mg APC starting day n2
    - n1 ≥ 5
    - n2 = n1 + 1
- Hard cap: no daily dose exceeding 75 mg APC
eGFR 15–29
- Provide:
  - Oral daily dose: 37.5 mg APC
- Hard cap: no daily dose exceeding 37.5 mg APC

eGFR band logic added in claim 12

eGFR 60–89 or ≥90
- Provide:
  - First oral daily dose: 37.5 mg APC
  - After at least 3 days, second oral daily dose: 75 mg APC
  - After at least 3 days, third oral daily dose: 150 mg APC
- Hard cap: no daily dose exceeding 150 mg APC

eGFR calculation method limitation

Dependent claim 10 and 22 require eGFR determined using MDRD equation.

IP consequence: An infringement theory must address not only the dose schedule but also the clinician’s method of eGFR calculation if MDRD is treated as an additional limitation in the asserted dependent claim.

What is the MAOI washout requirement and how does it narrow method coverage?

Short answer: The claims require selecting a subject who has not been treated with a monoamine oxidase inhibitor within the preceding 14 days.

Where it applies

Present in claim 1 and claim 12 as a gating step.
It functions as a selection criterion before any APC dosing regimen.

Practical coverage effect

If an accused method is used in a population that is not screened for MAOI washout, or the clinical protocol allows MAOI within a window shorter than 14 days, it may fall outside the literal requirements of the claimed method.

When does dose escalation occur: how are n1 and n2 defined for eGFR 30–59?

Short answer: For eGFR 30–59, the shift from 37.5 mg APC to 75 mg APC is defined by integers n1 ≥ 5 and n2 = n1 + 1.

Claim 1 escalation timing

Day 1 through Day n1: 37.5 mg APC daily
Starting Day n2: 75 mg APC daily
Constraints:
- n1 ≥ 5
- n2 = n1 + 1
- daily maximum 75 mg APC

Dependent tightening: n1 ≥ 7

Dependent claim 11 increases the floor: n1 ≥ 7.
This narrows the escalation earlier boundary.

eGFR 60–89/≥90 uses “at least 3 days”

In claim 12 (no/mild to moderate renal impairment band as defined):

37.5 mg for ≥3 days
then 75 mg for ≥3 days
then 150 mg This timing is not tied to an integer parameter; it is a day-count minimum.

Which dosage forms and salt equivalents are explicitly covered (APC vs APC-HCl mg conversions)?

Short answer: The claims include dependent limitations that map APC-equivalent doses to APC-HCl mass units.

Salt-mapped dose equivalents

Claim 5: first oral daily dose ~44.7 mg APC-HCl (equivalent to 37.5 mg APC)
Claim 6: second oral daily dose ~89.3 mg APC-HCl (equivalent to 75 mg APC)
Claim 18: third oral daily dose ~178.5 mg APC-HCl (equivalent to 150 mg APC)

Practical effect on claim scope

A literal method infringement theory that asserts dependent claims 5/6/18 must match both:

the APC dose equivalence, and
the administered salt form as claimed.

If an accused protocol uses a different salt form or a different formulation not matching the dependent limitation, it may only be reachable via the broader independent claims (1 or 12), if those do not restrict salt identity.

How are administration timing constraints (awakening; >9 hours before bedtime) likely to affect infringement?

Short answer: Multiple dependent claims require administration:

upon awakening, and
more than nine hours in advance of bedtime.

Covered cadence limitations

Claim 7 (for claim 1 regimen): all daily doses administered upon awakening.
Claim 8 (for claim 1 regimen): all daily doses administered >9 hours before bedtime.
Claim 19 and 20 mirror the same timing requirements for claim 12’s three-level regimen.

Practical effect

These are likely to be among the most operationally specific limitations:

a dosing schedule that stays within the same APC daily mg and renal timing but administers outside the >9-hour window could avoid dependent-claim coverage.
an accused clinician protocol that documents dosing after the >9-hour window would be relevant to non-infringement defenses if those dependent claims are asserted.

What indications are covered: narcolepsy, obstructive sleep apnea, shift work disorder, and depression-related EDS?

Short answer: The patent uses “excessive daytime sleepiness” caused by specific underlying conditions, with dependent claims adding etiologies.

Indication-by-dependent-claim map

Narcolepsy:
- claim 2 (with claim 1 dosing)
- claim 13 (with claim 12 dosing)
Obstructive sleep apnea (OSA):
- claim 3
- claim 14
Shift work disorder:
- claim 4
- claim 15
Depression (as cause of excessive daytime sleepiness):
- claim 24 (with claim 1 dosing)
- claim 25 (with claim 12 dosing)

Operational implication: If a label or clinical use defines indication differently (for example “EDS in OSA” vs “treatment of excessive daytime sleepiness due to OSA”), the method’s mapping depends on how the claims are construed and how the treated population is characterized.

How strong is the US 11,850,227 patent estate for the key product question: do its claims block generic entry or only specific dosing protocols?

Short answer: The claims are strong against generic “copycat use” only to the extent the generic product is used exactly in the claimed APC oral dosing pattern, with renal eGFR-based stratification, MAOI washout, and the specific escalation timing and dose caps.

What is actually protected

Method-of-treatment steps, not a composition claim in the provided claim set.
The scope is fundamentally defined by:
- selection criterion (MAOI washout),
- eGFR band stratification (including MDRD if dependent),
- dose escalation and maximum daily APC caps per band,
- optional salt form constraints and administration timing.

Where a generic/competitor can create design-around space

Common pathways to reduce exposure in method claims:

avoid matching the renal-band escalation parameters (for example, alter the escalation schedule so the switch is not at day n2 defined by n1≥5 and n2=n1+1, or for the 60–89/≥90 band alter the “≥3 days” structure),
cap daily doses differently than claimed,
implement administration outside the “upon awakening” and “>9 hours” timing limits if dependent claims are asserted,
change eGFR determination method (relevant if MDRD-dependent claims are asserted).

What patent-claim “coverage gaps” exist inside the shown claim set itself?

Short answer: Some clinically plausible variations are not explicitly captured in the shown claims, based strictly on the claim text provided.

Potential coverage gaps (as written)

No explicit allowance for:
- intermittent dosing or non-daily schedules,
- alternative renal assessment equations in the asserted independent claims (dependent claims do lock MDRD),
- titration rules that are not day-based (e.g., lab-response-based or symptom-response-based titration).
The independent claim 1 excludes coverage for eGFR 60–89/≥90; those uses are covered by claim 12 only.

Indication coverage is dependent

The etiologies (narcolepsy, OSA, shift work disorder, depression) are dependent, so the “base” independent method covers “excessive daytime sleepiness,” but the specific causal basis is a limitation only in dependent claims.

What would an Orange Book and FDA exclusivity check likely show for APC/related EDS indications?

Short answer: The claims you provided look like post-approval clinical method dosing restrictions, which in practice often appear as patents listed in the Orange Book tied to a drug product for a particular NDA with method claims. However, the provided materials do not include the FDA NDA/ANDA number, drug label, or Orange Book entry.

Implication for diligence: Without the Orange Book listing details, it is not possible to map 11,850,227 to:

the specific NDA,
the listed claim type (1 vs 2 vs 3 vs method-of-use vs PK),
and the corresponding patent expiration and exclusivity timeline in the way required for a full freedom-to-operate view.

(Per constraints, no further inference is produced.)

What would Paragraph IV ANDA or biosimilar-style risk look like against method claims like these?

Short answer: If an ANDA or other generic is approved, the most realistic risk is not composition substitution but induced or contributory infringement theories based on label instructions and expected prescribing that match the claimed renal band escalation and MAOI washout selection criteria.

Method claim enforcement levers

Labeling that explicitly instructs eGFR-based dosing with specific day escalation parameters increases exposure.
If clinical practice follows the label strictly, generic entry could trigger method infringement theories for the “off label” boundary depending on how the claims are construed.

Defensive space

If the label or prescribing patterns do not enforce the same day-count escalation constraints, a generic could argue non-infringement of method steps.

How does US 11,850,227 compare with typical EDS patent estates: where are the likely “related” claim clusters?

Short answer: Based on the shown claims alone, 11,850,227 is concentrated in:

renal impairment stratification,
MAOI washout selection,
structured oral escalation regimens,
and administration timing.

Likely neighboring protections in a coordinated estate (based only on claim themes)

A complete landscape usually also includes:

compound and polymorph/formulation patents,
additional method-of-use claims (different etiologies, different renal bands, or alternative titration algorithms),
and safety-related labeling claims (drug-drug contraindications, washout windows, dose adjustments).

No other specific patents are named in your prompt, so no cross-citation is possible here.

Key claim-by-claim scope checklist (for infringement mapping)

Element	Claim 1	Claim 12
Excessive daytime sleepiness treatment	Yes	Yes
MAOI washout: no MAOI within prior 14 days	Yes	Yes
Measure eGFR	Yes	Yes
eGFR band 30–59 dosing	Yes	Yes
eGFR band 15–29 dosing	Yes	Yes
eGFR band 60–89 or ≥90 dosing	No	Yes
APC dose levels	37.5 → 75 (max 75)	37.5 → 75 → 150 (max 150)
n1 and n2 definitions (30–59)	n1≥5; n2=n1+1	same
Day-count minima (60–89/≥90)	n/a	≥3 days then ≥3 days
Salt equivalents (dependent)	APC-HCl ~44.7 and ~89.3	adds ~178.5
Administration upon awakening (dependent)	Yes (claim 7)	Yes (claim 19)
>9 hours before bedtime (dependent)	Yes (claim 8)	Yes (claim 20)
eGFR via MDRD (dependent)	Yes (claim 10)	Yes (claim 22)
Indication etiologies (dependent)	narcolepsy/OSA/shift work/depression	narcolepsy/OSA/shift work/depression

Key Takeaways

U.S. Patent 11,850,227 protects a method-of-treatment using oral APC with renal-impairment eGFR stratification, a 14-day MAOI washout selection rule, and specific dose escalation schedules with hard daily caps.
Claim 1 covers eGFR 30–59 (37.5 mg days 1–n1 with n1≥5, then 75 mg starting n2=n1+1) and eGFR 15–29 (37.5 mg only).
Claim 12 expands coverage to eGFR 60–89/≥90 using ≥3-day steps to reach 150 mg/day.
Dependent claims tighten scope via APC-HCl dose equivalents, MDRD eGFR calculation, and administration timing (upon awakening; >9 hours before bedtime).
For competitive entry risk, the controlling question is whether the challenged prescribing/labeling protocol matches the claimed stepwise renal titration and MAOI screening requirements.

FAQs

1. Does US 11,850,227 cover APC dosing in patients with eGFR ≥60?
No for claim 1; yes for claim 12 with escalation to 150 mg/day after ≥3-day intervals.

2. What is the maximum APC daily dose the claims allow by renal band?
eGFR 15–29: 37.5 mg/day; eGFR 30–59: 75 mg/day; eGFR 60–89/≥90: 150 mg/day.

3. What does “n1 is an integer equal to or greater than 5” control?
It sets the minimum number of days the patient stays on 37.5 mg before escalation; escalation occurs on day n2 = n1+1.

4. Are narcolepsy and OSA treated as separate claim limitations?
Yes. They appear in dependent claims that specify the cause of excessive daytime sleepiness.

5. How can an accused regimen reduce risk against dependent claims 7–8 and 19–20?
By dosing outside “upon awakening” and the >9 hours before bedtime timing constraints.

References

United States Patent 11,850,227, claims as provided by user.

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	⤷ Start Trial	⤷ Start Trial				TREATMENT OF EXCESSIVE DAYTIME SLEEPINESS BY ADMINISTERING SOLRIAMFETOL TO A SUBJECT HAVING NO, MILD, MODERATE, OR SEVERE RENAL IMPAIRMENT	⤷ Start Trial
Axsome Malta	SUNOSI	solriamfetol hydrochloride	TABLET;ORAL	211230-002	Jun 17, 2019	AB	RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial				TREATMENT OF EXCESSIVE DAYTIME SLEEPINESS BY ADMINISTERING SOLRIAMFETOL TO A SUBJECT HAVING NO, 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: 11,850,227