US Patent 9,486,437 Scope and Claims: Doxepin Methods for Sleep Maintenance Insomnia (8th Hour, Fragmentation/Early Awakening, 0.5–6 mg)

US 9,486,437 is directed to method-of-treatment claims for sleep maintenance insomnia with a specific timing window in the patient’s sleep schedule (the “8th hour” and the final 60 minutes), paired with a doxepin dosing range (0.5–6 mg) administered before sleep onset. The asserted claim structure is narrow in (i) clinical phenotype (fragmentation or early awakening during the final part of the 8-hour period) and (ii) dosing parameters (range and “prior to start” administration), while broadening through dependent claim variations for insomnia chronicity and sleep termination timing (final 45/30 minutes) and through dose-specific dependent claims (about 1 mg, 3 mg, 6 mg).

What patents protect doxepin sleep maintenance insomnia methods like US 9,486,437?

Core claim elements in US 9,486,437 (independent claim 1 and 11):

Indication/phenotype: sleep maintenance insomnia defined by events during the 8th hour of an 8-hour desired sleep period.
Event type:
- Claim 1: fragmented sleep during the final 60 minutes.
- Claim 11: early awakenings during the final 60 minutes.
Dose: doxepin (or pharmaceutically acceptable salt) at 0.5 to 6 mg.
Timing of administration: dose is administered prior to the start of the sleep period.
Method orientation: “method for treating” the insomnia by giving the dose under those conditions.

Practical scope implication:

The claims are built to track a label-like clinical characterization used in insomnia drug development: maintenance symptoms are defined by sleep-wake disruption late in the night, not sleep onset.
The method is defined by both patient outcome timing (final 60 minutes of the 8th hour) and administration timing (before sleep onset), which becomes a non-trivial constraint for generic/designer drug products and for non-doxepin comparators.

What jurisdictional coverage does US 9,486,437 imply for related patent families?

The user-provided text specifies United States Drug Patent 9,486,437, so the analysis here is limited to the US claim set as supplied. No family or foreign application numbers were provided in the prompt; therefore, the landscape below focuses on US claim scope logic and typical adjacent US patent estate boundaries that intersect with this claim structure (dose range, doxepin salts, timing, and maintenance-insomnia phenotype). The landscape cannot be enumerated claim-by-claim across other patents without the missing bibliographic data and document text (specifically: publication/application numbers, assignee, specification, and cited references).

How broad are the claims of US 9,486,437? What are the key claim limitations?

Scope anchor 1: “8th hour” and “final 60 minutes”

Both independent claims hinge on a specific timing framework:

An 8-hour period of desired sleep is assumed.
The insomnia disorder is characterized by symptoms occurring in the 8th hour, specifically:
- fragmented sleep during the final 60 minutes (claim 1), or
- early awakenings during the final 60 minutes (claim 11).

This creates a built-in argument for infringement/non-infringement based on whether the treated patient population fits the defined pattern. For generic or competing method regimens, the strongest defense would target:

a different modeled sleep duration window, or
a disorder defined by earlier-night disruptions (sleep onset or early sleep) rather than late-night maintenance symptoms.

Scope anchor 2: Doxepin dosage range of 0.5 to 6 mg

The independent claims cover:

doxepin and pharmaceutically acceptable salts, and
dosage between 0.5 and 6 mg.

This range is broad enough to encompass typical low-dose doxepin regimens used for insomnia maintenance, but it is still bounded. Competitors staying outside the range (below 0.5 mg or above 6 mg) aim to avoid literal infringement.

Scope anchor 3: administration “prior to the start of the sleep period”

This limitation is often decisive in method patents:

even if dose is within the claimed range,
a competitor’s regimen that administers doxepin after sleep onset, or uses a different administration schedule relative to sleep initiation, can avoid literal capture.

Scope anchor 4: method improvement tied to minimization of next-day residual sedation

This appears as a dependent claim in claim 2 and claim 12:

“dosage is effective to improve sleep maintenance insomnia while minimizing next day residual sedation.”

Because it is dependent, literal infringement is limited to those additional features when asserting dependent claims. Still, dependent claims can influence claim construction, since the independent claims are already limited by timing/phenotype/dose.

What do dependent claims in US 9,486,437 add to infringement risk?

Claim set for dependent scope: chronic vs non-chronic vs transient (claims 3–5 and 13–15)

Claim 3: chronic insomnia (claim 1 dependent)
Claim 4: non-chronic insomnia (claim 1 dependent)
Claim 5: transient insomnia (claim 1 dependent)
Claim 13: chronic insomnia (claim 11 dependent)
Claim 14: non-chronic insomnia (claim 11 dependent)
Claim 15: transient insomnia (claim 11 dependent)

These dependent clauses broaden practical capture by covering multiple clinical durability categories. For litigation, this means the patentee is not forced into one chronicity model; a defendant cannot avoid infringement simply by reclassifying the marketed indication as “non-chronic” or “transient,” assuming all other limitations are met.

Claim set for sleep termination timing: final 45 minutes and final 30 minutes (claims 6–7)

Claim 6: patient experiences sleep period terminates during final 45 minutes.
Claim 7: terminates during final 30 minutes.

These are narrower than claim 1’s “final 60 minutes fragmented sleep” requirement, but they are additional phenotype constraints tied to the same “8th hour” frame. They can matter where clinical endpoints or patient diaries are mapped differently between studies.

Dose-specific dependent claims: about 1 mg, 3 mg, 6 mg (claims 8–10 and 16–18)

Claim 8: about 1 mg
Claim 9: about 3 mg
Claim 10: about 6 mg
Claim 16: about 1 mg (dependent on claim 11)
Claim 17: about 3 mg (dependent on claim 11)
Claim 18: about 6 mg (dependent on claim 11)

These provide additional infringement hooks for products positioned at common discrete dose strengths within the broader 0.5–6 mg range. In practice, a competitor cannot rely on “our dose is not exactly in the range” if it uses a marketed unit strength that maps to these “about” values.

How does US 9,486,437 define sleep maintenance insomnia differently from sleep onset insomnia patents?

The independent claims define insomnia by:

late-night disruption (8th hour, final 60 minutes),
with a maintenance symptom type (fragmentation or early awakenings).

This contrasts with sleep onset insomnia method patents, which typically:

focus on latency to persistent sleep,
define endpoints at sleep initiation (e.g., time to sleep onset or latency measures).

US 9,486,437 therefore has a built-in differentiation:

it targets the maintenance portion of an 8-hour sleep schedule,
not initiation.

That distinction matters when comparing enforcement risk against alternative hypnotics, because many insomnia method patents are drafted around different endpoints.

What does “fragmented sleep” vs “early awakenings” cover in US 9,486,437?

The patent splits the independent claims into two clinically adjacent but separable event definitions:

Claim 1: fragmented sleep (implies multiple awakenings or sleep interruptions).
Claim 11: early awakenings.

From a construction standpoint, a defendant could argue that the clinical concept differs (e.g., fragmentation includes brief interruptions without full awakening; early awakening implies waking before the target sleep end). Yet, because each independent claim is separately drawn, the patentee can choose the better fit to evidence from clinical trials or post-marketing data.

How strong is the patent estate for US 9,486,437’s specific dosing and timing concept?

From the claim text provided, the patent’s strength is anchored in:

a tight dose range (0.5–6 mg),
a timing requirement relative to sleep onset (“prior to the start”),
and a late-night symptom definition tied to the 8th hour and final 60 minutes.

That combination reduces the number of plausible “design-around” paths:

changing dose outside 0.5–6 mg,
changing administration timing to after sleep onset,
or shifting the clinical endpoint away from the 8th hour/final 60 minutes phenotype.

However, without the specification text and file history, it is not possible here to assess:

whether the patent has strong support for the full range,
whether “about” is defined,
whether salts are expressly enabled,
or whether claims are vulnerable on written description/enablement for all embodiments.

When does US 9,486,437 lose exclusivity?

No filing date, priority date, or term adjustment data is provided in the prompt for US 9,486,437. Without those bibliographic inputs, exclusivity timing cannot be stated accurately.

What is the Orange Book status of US 9,486,437?

No Orange Book listing data, reference drug name, application number, or listed drug/NDA/BLA identifier is provided in the prompt. Without that, Orange Book status cannot be produced.

Could generics launch with a Paragraph IV challenge against US 9,486,437?

A Paragraph IV challenge would typically target:

non-infringement by changing dose, timing, or patient phenotype definition,
or invalidity based on anticipation/obviousness relative to prior art on low-dose doxepin for sleep maintenance.

But the prompt includes only the asserted claims, not:

the patent’s cited references,
the assignee and prosecution record,
or the claim construction history.

Therefore, a legally actionable Paragraph IV risk assessment cannot be generated from claim text alone.

How does US 9,486,437 compare with other doxepin insomnia method patents?

What can be inferred from this patent’s claim construction is that it occupies a specific “slice” of doxepin insomnia IP:

it is a method-of-treatment patent (not a composition claim as written),
focused on maintenance symptom timing in the 8th hour,
and tied to low-dose (0.5–6 mg) administered before sleep onset.

Other doxepin IP commonly clusters around:

formulation/composition (e.g., controlled release),
kit/regimen structures,
use for specific endpoints (latency vs maintenance),
or different dose schedules.

A direct comparison requires knowing the other patents’ independent claim elements and priority dates, which are not provided.

Which companies are likely licensed or challenging US 9,486,437?

The prompt provides no assignee, licensees, litigation parties, or FDA product tied to the patent. Company-level landscape cannot be derived.

What generic entry risks exist for doxepin sleep maintenance insomnia at 1 mg, 3 mg, 6 mg?

The presence of dose-specific dependent claims (about 1 mg, 3 mg, 6 mg) increases risk for a competitor product that:

uses a doxepin salt delivered at those nominal strengths, and
is labeled or evidenced as treating sleep maintenance insomnia defined by fragmented sleep or early awakenings in the final 60 minutes of the 8th hour,
with administration prior to sleep onset.

A competitor’s key risk management levers are:

non-literal approach through different dosing range (outside 0.5–6 mg),
different administration timing relative to sleep onset,
and avoiding the claimed maintenance-definition phenotype in labeling and study endpoints.

Timeline: what the claim structure implies about evidentiary proof in litigation

If US 9,486,437 is asserted, the proof model aligns to the claim’s modular limitations:

Claim element	What plaintiffs typically use	What defendants typically attack
Sleep maintenance insomnia defined by 8th hour/final 60 minutes	Clinical diary endpoints, polysomnography segmentation, label/labeling claims mapped to “final” window	Redefining endpoints, using different sleep window assumptions
Fragmented sleep vs early awakenings	Trial data mapping to fragmentation/awakening metrics	Distinguishing fragmentation from early awakening definitions
Doxepin dosage 0.5–6 mg	Product strength, dose instructions, trial dosing	Use dose outside range; “about” disputes
Administration prior to sleep onset	Labeling regimen “take before bed”	Alternative schedule (after onset), different regimen instructions
Next-day residual sedation minimization (dependent claims 2/12)	Safety/tolerability endpoints	Residual effects not minimized or not tied to insomnia improvement

Key Takeaways

US 9,486,437 is a method-of-treatment patent for sleep maintenance insomnia defined specifically by late-night symptom timing (8th hour, final 60 minutes).
It covers doxepin (or salts) at 0.5–6 mg, administered before the start of the sleep period.
Claim breadth is driven by the combination of (i) timing of symptoms within the sleep schedule, (ii) administration timing, and (iii) dose range.
Dependent claims broaden clinical applicability across chronic, non-chronic, and transient insomnia categories and add dose-specific hooks at about 1 mg, 3 mg, and 6 mg.
Without the patent bibliographic data (priority/filing dates) and Orange Book and prosecution records, exclusivity and Orange Book status cannot be computed from the provided material.

FAQs

Does US 9,486,437 require fragmented sleep to occur exactly in the final 60 minutes of the 8th hour?
The independent claim requires fragmented sleep during the final 60 minutes of the 8-hour desired sleep period (for claim 1) or early awakenings during that same window (for claim 11).
Can a dosing regimen outside 0.5–6 mg avoid US 9,486,437?
If the dosage is truly outside the claimed range (and not within “about” constructions for the dependent dose strengths), it is a principal non-infringement design-around lever.
What is the litigation significance of “administered prior to the start of the sleep period”?
It ties the method to a regimen timing relative to sleep onset, enabling arguments based on alternative administration schedules.
Do dependent claims on chronic vs transient insomnia expand the method beyond one patient subgroup?
Yes. The dependent claims explicitly cover chronic, non-chronic, and transient insomnia for both fragmented sleep and early awakening formulations of the independent claims.
Which dependent claims are most useful for asserting against specific dose strengths?
The “about 1 mg,” “about 3 mg,” and “about 6 mg” dependent claims provide strength-specific infringement anchors within the broader 0.5–6 mg independent claim range.

References (APA)

Provided patent claim text for United States Patent 9,486,437 (claims 1–18).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Currax	SILENOR	doxepin hydrochloride	TABLET;ORAL	022036-001	Mar 17, 2010	AB	RX	Yes	No	9,486,437	⤷ Start Trial				TREATMENT OF INSOMNIA	⤷ Start Trial
Currax	SILENOR	doxepin hydrochloride	TABLET;ORAL	022036-002	Mar 17, 2010	AB	RX	Yes	Yes	9,486,437	⤷ Start Trial				TREATMENT OF INSOMNIA	⤷ 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
Canada	2687118	⤷ Start Trial
Canada	2687124	⤷ Start Trial
European Patent Office	2026792	⤷ Start Trial
Japan	2009537553	⤷ Start Trial
Japan	2009537554	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 9,486,437

Which drugs does patent 9,486,437 protect, and when does it expire?

Summary for Patent: 9,486,437