United States Patent 4,940,731: Sertraline Premature Ejaculation Claims, Scope, Expiry, and Patent Landscape

U.S. Patent No. 4,940,731 covers the use of sertraline, specifically the cis stereoisomer identified in the claim, to delay ejaculation in patients with premature ejaculation. It is a method-of-use patent, not a composition-of-matter patent. The patent issued July 10, 1990, and its ordinary 17-year term expired July 10, 2007. It therefore presents no current U.S. patent barrier to generic sertraline or to use of sertraline for premature ejaculation.

The claim is narrow in chemical identity but broad in clinical implementation. It does not specify dose, dosage form, route, treatment duration, or a particular diagnostic definition of premature ejaculation.

What does U.S. Patent 4,940,731 protect?

The sole claim protects:

A method of treating premature ejaculation by administering an effective amount of (1S-cis)-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-N-methyl-1-naphthalenamine, or a pharmaceutically acceptable salt, to a patient in need of treatment.

The claimed compound is sertraline, the active pharmaceutical ingredient in Zoloft. The claim is directed to the therapeutic use of sertraline rather than to sertraline itself.

Patent identity and key dates

Item	Data
U.S. patent	4,940,731
Title	Treatment of premature ejaculation using sertraline
Assignee	Pfizer Inc.
Priority date	January 29, 1988
U.S. filing date	January 27, 1989
Issue date	July 10, 1990
Original term	17 years from issue for this pre-URAA patent
Ordinary expiration	July 10, 2007
Claim type	Method of treatment
Active ingredient	Sertraline
Covered salt	Any pharmaceutically acceptable salt of the claimed stereoisomer
Current status	Expired

The chemical name in the claim corresponds to the active cis stereoisomer of sertraline. The commercially used form is generally sertraline hydrochloride.

How broad is the single claim?

The claim has several limiting elements:

A patient must have premature ejaculation.
The administered compound must be the specified sertraline stereoisomer.
The compound may be administered as a pharmaceutically acceptable salt.
The amount must be effective in delaying ejaculation.
The conduct must constitute treatment through administration to the patient.

The claim does not expressly limit:

Oral, buccal, sublingual, injectable, or other administration routes.
Immediate-release or modified-release dosage forms.
A particular dose.
Daily or on-demand administration.
Treatment duration.
A required ejaculation latency threshold.
Use only in lifelong or acquired premature ejaculation.
Use only in adults.
A particular salt, although the salt must be pharmaceutically acceptable.

Chemical scope

The claim does not cover all selective serotonin reuptake inhibitors. It does not expressly cover paroxetine, fluoxetine, citalopram, escitalopram, dapoxetine, clomipramine, or other antidepressants.

It also does not extend to every sertraline-related molecule. A compound with a different stereochemical configuration, a changed N-substituent, or a materially modified ring system would not fall within the literal chemical definition solely because it had a similar pharmacologic effect.

The reference to the (1S-cis) form is material. A racemic mixture or the opposite stereoisomer would create a claim-construction issue and could avoid literal infringement if the accused product did not contain the claimed stereoisomer. A formulation containing sertraline hydrochloride would generally remain within the salt language.

Functional limitation

The phrase “effective in delaying ejaculation” is a functional limitation. The claim requires more than administering sertraline to a patient who happens to have premature ejaculation. The treatment must be effective in delaying ejaculation.

The absence of a numerical delay threshold creates potential interpretation issues. In an infringement dispute, clinical data, labeling, prescribing instructions, patient records, and expert testimony could be relevant to whether the administered amount was effective. Those issues have no practical significance for current U.S. enforcement because the patent has expired.

When did U.S. Patent 4,940,731 lose exclusivity?

The patent lost enforceable exclusivity on July 10, 2007, assuming no unusual term adjustment or disclaimer altered the term. The patent was issued before the Uruguay Round Agreements Act changed the standard U.S. patent term from 17 years after issuance to 20 years from the earliest effective nonprovisional filing date.

Exclusivity timeline

Date	Event
January 29, 1988	Reported priority date
January 27, 1989	U.S. application filing
July 10, 1990	Patent issued
July 10, 2007	Ordinary patent expiration
After July 10, 2007	No enforceable rights under the patent

The patent’s expiration means that a company can now manufacture, sell, prescribe, or promote a sertraline product for a premature-ejaculation indication without infringing this patent. Other legal restrictions, including FDA approval requirements and false-labeling rules, remain separate from patent rights.

Was sertraline protected by earlier composition patents?

Sertraline’s principal composition-of-matter protection was associated with U.S. Patent No. 4,536,518, also assigned to Pfizer. That patent covered sertraline and related chemical subject matter. Its term expired before or around the period when generic sertraline entered the U.S. market.

U.S. Patent 4,940,731 was therefore an indication patent layered onto an older compound patent. Its commercial purpose was to protect an additional medical use after the underlying antidepressant compound had already been developed and marketed.

Patent category	Representative patent	Subject matter	Current relevance
Composition of matter	U.S. 4,536,518	Sertraline and related compounds	Expired
Premature-ejaculation use	U.S. 4,940,731	Administration of sertraline to delay ejaculation	Expired
Product and formulation rights	Various later filings and applications	Dosage forms, solutions, manufacturing, or product presentation	Must be reviewed separately; no current barrier is established by the 4,940,731 claim

The existence of later formulation or manufacturing patents would not revive the expired method claim. A later patent would need independent validity and enforceability and would have to cover the specific product, process, or use at issue.

What is the FDA regulatory status of sertraline for premature ejaculation?

Sertraline is FDA-approved for psychiatric indications, including major depressive disorder, obsessive-compulsive disorder, panic disorder, post-traumatic stress disorder, social anxiety disorder, and premenstrual dysphoric disorder, depending on the approved product labeling.

Premature ejaculation is not an FDA-approved indication for sertraline. Use for premature ejaculation is therefore generally off-label in the United States.

FDA approval position

Regulatory issue	Status
Active ingredient	Sertraline hydrochloride
Original branded product	Zoloft
FDA-approved product categories	Tablets, capsules, and oral solution products have been marketed
Premature ejaculation indication	Not FDA-approved
Generic sertraline	FDA-approved for approved sertraline indications
FDA-approved dapoxetine product in the United States	No
Need for new approval for a labeled PE product	Yes, if a company seeks to market sertraline with premature ejaculation labeling

A company may market an approved generic sertraline product for its approved indications, but it generally cannot add premature ejaculation claims to labeling without FDA authorization. Patent expiry removes the patent obstacle; it does not create regulatory approval for a new indication.

What is the Orange Book status of U.S. Patent 4,940,731?

U.S. Patent 4,940,731 should not be treated as a current Orange Book barrier to generic sertraline.

The patent was a use patent for premature ejaculation, while the FDA-approved Zoloft indications were psychiatric disorders and premenstrual dysphoric disorder. An Orange Book listing would have depended on whether the patent claimed an approved use of the reference drug and whether the NDA holder submitted the patent for listing.

Because the patent expired in 2007, it cannot presently block approval or marketing. Current generic sertraline applicants are not required to wait for this patent to expire, and the patent does not support a current Paragraph IV challenge strategy.

Paragraph IV implications

A Paragraph IV certification is relevant when an applicant challenges an unexpired listed patent. For U.S. Patent 4,940,731:

A new Paragraph IV challenge has no practical commercial purpose because the patent is expired.
The patent cannot generate a 30-month stay against an ANDA.
The patent cannot support a current automatic generic-entry date.
The patent’s historical expiry date is the relevant exclusivity event.

If the patent had been listed against an approved indication, a generic applicant might historically have used a section viii statement to carve out the patented use rather than challenge the patent. That pathway is now academic for this patent.

Does the claim cover sertraline formulations?

Yes, but only indirectly.

The claim covers administration of the specified compound or a pharmaceutically acceptable salt. A tablet, capsule, oral solution, or other dosage form can be the vehicle for practicing the method if it contains the claimed sertraline form and is administered to treat premature ejaculation.

The claim does not independently claim:

A tablet composition.
A capsule composition.
An oral solution.
A particular excipient system.
A controlled-release profile.
A specific particle size.
A particular manufacturing process.
A combination of sertraline with another active ingredient.

A formulation patent could contain narrower claims directed to one of those features. Such claims would be separate from the method claim in U.S. Patent 4,940,731 and would require separate validity and expiration analysis.

What patent litigation and settlement agreements affected the patent?

No current U.S. litigation can be based on U.S. Patent 4,940,731 because the patent expired in 2007. The patent therefore cannot support a new infringement action, injunction, damages claim, or generic-entry settlement.

There is no apparent current settlement issue that affects U.S. market access under this patent. Any historical litigation or licensing arrangement would not extend the statutory patent term. A private license could allocate commercial rights during the patent term, but it could not create patent exclusivity after expiration.

Pfizer’s ownership of the sertraline franchise is commercially relevant to the patent’s history. It does not give Pfizer continuing exclusivity over off-label use of sertraline for premature ejaculation.

How strong was the patent estate for sertraline premature ejaculation?

The estate was narrow and strategically dependent on use protection.

Strengths

It identified the active sertraline stereoisomer precisely.
It covered pharmaceutically acceptable salts.
It did not restrict the method to a particular dose or route.
It applied to treatment of a distinct sexual-medicine indication.
It could have captured use of generic-quality sertraline during its term if the use was practiced with the required therapeutic purpose.

Limitations

It contained only a single method claim.
It did not cover the sertraline molecule itself.
It did not cover other SSRIs or alternative pharmacologic agents.
It did not claim a formulation or manufacturing process.
The PE indication was not an FDA-approved sertraline indication.
Enforcement against prescribing or patient use would have raised practical and divided-infringement issues.
The entire claim expired in 2007.

The patent was materially weaker than a live composition-of-matter patent. Its value depended on the ability to identify and enforce the specific off-label use before expiration.

What generic entry risks exist today?

There is no patent-based generic entry risk under U.S. Patent 4,940,731. Generic sertraline products have been marketed for years, and the expired patent does not prevent:

Generic sertraline manufacture.
Generic sertraline sale.
Off-label prescribing for premature ejaculation.
Development of a new sertraline product targeting sexual-medicine use, subject to FDA requirements.
Development of competing premature-ejaculation therapies.

The principal current barriers are regulatory and commercial rather than patent-based. A company seeking an FDA-approved premature-ejaculation indication would need clinical development and an appropriate FDA submission. A company selling an existing generic sertraline product cannot rely on patent expiry alone to add that indication to its label.

How does this patent compare with competing premature-ejaculation products?

Sertraline’s patent position differs from products specifically developed for premature ejaculation.

Product or approach	U.S. approval for PE	Patent position relevant to U.S. PE market
Sertraline	No	U.S. PE use patent expired
Dapoxetine	No U.S. approval	International patent history differs; no U.S. approved product franchise
Topical anesthetics	Some products and combinations may be marketed under different regulatory pathways	Product-specific patents and regulatory status must be assessed
Behavioral therapy	Not applicable	No drug patent barrier
Other SSRIs	Generally off-label for PE	Separate compound and formulation estates; no automatic coverage from 4,940,731

Sertraline competes clinically with other off-label SSRIs and with topical or behavioral approaches. U.S. Patent 4,940,731 does not create exclusivity for the broader treatment category.

What is the geographic coverage of U.S. Patent 4,940,731?

The patent provides rights only under U.S. law. It does not establish protection in Europe, Canada, Japan, China, or other jurisdictions.

Foreign family members would require separate review for:

Filing and priority dates.
Grant status.
National patent term.
Supplementary protection certificates.
Local claim language.
Local rules governing medical-use claims.
Expiration and post-grant status.

The U.S. expiration date cannot be applied automatically to foreign counterparts.

Key Takeaways

U.S. Patent 4,940,731 is a method-of-use patent covering sertraline treatment for premature ejaculation.
The claimed compound is the (1S-cis) sertraline stereoisomer or a pharmaceutically acceptable salt.
The claim does not cover all SSRIs, all sertraline analogs, or a specific formulation.
The patent issued July 10, 1990, and ordinarily expired July 10, 2007.
Sertraline is not FDA-approved for premature ejaculation in the United States.
The patent is not a current Orange Book or Paragraph IV barrier.
Generic sertraline entry is not restricted by this patent.
Any current exclusivity analysis must examine later formulation, manufacturing, labeling, or foreign patents separately.
There is no current U.S. infringement, injunction, or settlement risk under this expired patent.

FAQs

Can a generic sertraline manufacturer market the drug for premature ejaculation?

It can manufacture and sell generic sertraline after complying with FDA requirements, but it cannot add an unapproved premature-ejaculation indication to its labeling without appropriate FDA authorization.

Does U.S. Patent 4,940,731 cover sertraline hydrochloride?

Yes. The claim covers the specified sertraline compound and pharmaceutically acceptable salts, which includes sertraline hydrochloride.

Does the patent cover dapoxetine?

No. Dapoxetine is a different chemical compound and is outside the literal compound definition in the claim.

Could a new sertraline formulation infringe the patent?

Not today, because the patent expired. During its term, a formulation containing the claimed sertraline compound could have been relevant if administered for the claimed treatment purpose.

Can Pfizer enforce the patent against current off-label sertraline use?

No. The patent expired in 2007, so it cannot support a current patent infringement claim.

References

United States Patent and Trademark Office. (1990). Treatment of premature ejaculation using sertraline (U.S. Patent No. 4,940,731). https://patents.google.com/patent/US4940731A/en
United States Patent and Trademark Office. (1985). Tetralin derivatives (U.S. Patent No. 4,536,518). https://patents.google.com/patent/US4536518A/en
U.S. Food and Drug Administration. (2024). Zoloft (sertraline hydrochloride) prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
U.S. Food and Drug Administration. (2024). ANDA approvals and generic drug information. https://www.fda.gov/drugs/generic-drugs.contains

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	110958	⤷ Start Trial
Australia	609664	⤷ Start Trial
Canada	2024188	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,940,731

Summary for Patent: 4,940,731