United States Patent 7,208,516: Apremilast Psoriatic Arthritis Claims, Scope and Patent Landscape

United States Patent 7,208,516 covers the use of the (+)-enantiomer of apremilast for treating psoriatic arthritis. Its claims extend to apremilast salts, solvates and hydrates; combination therapy, including etanercept; oral and topical administration; tablets, capsules, lotions and liquids; and specified daily or weight-based doses.

The patent was commercially important because it covered the psoriatic arthritis indication for Otezla, Celgene’s apremilast product. Its principal patent term expired on November 25, 2023, subject to any applicable patent-term adjustment or extension. The patent no longer represents a primary long-term barrier to an apremilast generic, although later formulation, crystalline-form and regulatory patents may have created separate launch risks.

What drug does U.S. Patent 7,208,516 protect?

The claimed active ingredient is apremilast, chemically identified in the patent as:

(+)-2-[1-(3-ethoxy-4-methoxyphenyl)-2-methylsulfonylethyl]-4-acetylaminoisoindoline-1,3-dione.

Apremilast is a selective phosphodiesterase-4 inhibitor. The patent is directed to the pharmacologically active (+)-enantiomer, rather than to an unrestricted racemic mixture.

The commercial product is Otezla, marketed by Celgene and later Bristol Myers Squibb following BMS’s acquisition of Celgene. The FDA approved Otezla for active psoriatic arthritis in 2014 and later approved it for plaque psoriasis and oral ulcers associated with Behçet’s disease.[1]

What is the central legal limitation?

The core limitation is treatment of psoriatic arthritis. A potentially infringing method must involve:

A patient who needs treatment for psoriatic arthritis.
Administration of a therapeutically effective amount.
The specified (+)-apremilast compound, or an eligible salt or solvate.
Material that is substantially free of the (-)-enantiomer.

A product that contains apremilast but is not used to treat psoriatic arthritis would not necessarily satisfy claim 1. The disease indication is a substantive claim limitation.

How broad is claim 1 of U.S. Patent 7,208,516?

Claim 1 is a composition-specific method-of-treatment claim. It is broader than the dependent claims because it does not restrict:

Dose;
Frequency;
Route of administration;
Dosage form;
Salt or solvate identity;
Combination therapy; or
Patient age or disease severity.

The claim is narrower than a general apremilast treatment claim because it requires the (+)-enantiomer and targets psoriatic arthritis.

What does “substantially free of its (-) enantiomer” mean?

The phrase is intended to distinguish the active (+)-enantiomer from the opposite enantiomer and from a racemic composition. Its precise quantitative meaning depends on the patent specification, analytical evidence and claim construction.

The limitation does not necessarily require absolute absence of the (-)-enantiomer. In pharmaceutical patent practice, “substantially free” is generally evaluated against the specification’s purity disclosure, analytical methods and context. A generic manufacturer would need to assess chiral purity, manufacturing specifications and batch-release controls.

The limitation creates a potential design-around issue for products that contain both enantiomers. That approach would carry substantial regulatory and technical risk because the approved drug is apremilast in its active enantiomeric form, not a deliberately racemic product.

What do claims 2 through 5 cover?

Claims 2 through 5 narrow claim 1 to the chemical identity and solid-state forms of apremilast.

Claim	Subject matter	Scope
2	Structural representation of the claimed (+)-enantiomer	Narrows claim 1 to the depicted stereochemical structure
3	Pharmaceutically acceptable salt	Covers salt forms of the (+)-enantiomer
4	Pharmaceutically acceptable solvate	Covers solvated forms
5	Pharmaceutically acceptable hydrate	Covers hydrated forms, a subset of solvates

The structural formula for claim 2 is omitted from the supplied claim text. Based on its dependency, claim 2 appears intended to confirm the stereochemical structure of the compound identified in claim 1.

The salt, solvate and hydrate claims are important because they prevent a straightforward argument that a different pharmaceutical form avoids the patent. A product containing a pharmaceutically acceptable salt or hydrate could remain within the dependent claims if the underlying apremilast stereochemistry and psoriatic arthritis use are present.

What combination therapies are protected?

Claim 6 covers administration of apremilast together with a second active agent. The listed categories include:

Anti-inflammatory agents;
Immunosuppressants;
Mycophenolate mofetil;
Biologic agents; and
Cox-2 inhibitors.

Claim 7 specifically identifies etanercept.

These claims require combination treatment. A patient who has previously used etanercept but receives apremilast alone would not necessarily fall within claim 7. Conversely, concurrent use of apremilast and etanercept for psoriatic arthritis could satisfy the claim if the other limitations are met.

The combination claims have narrower practical value than claim 1 because Otezla is ordinarily used as an oral small-molecule therapy and may be administered without a biologic. Their value is greatest where a product label, treatment protocol or clinical practice expressly recommends combination treatment.

What routes and dosage forms are covered?

Claims 8 through 11 cover administration route and dosage form.

Claims	Route or form	Covered examples
8-9	Oral administration	Tablets and capsules
10-11	Topical administration	Lotions and liquids

The marketed Otezla product is an oral tablet. The topical claims therefore have less direct commercial significance for the approved product but broaden the patent’s method coverage.

A generic oral tablet used for psoriatic arthritis would face the strongest relevance under claim 1 and claims 8-9. A topical apremilast product could implicate claims 10-11 if it met the disease-treatment and active-ingredient limitations.

What doses are covered by the patent?

Claims 12 through 18 establish overlapping dose ranges:

Claim	Dose limitation
12	About 1 mg to about 1,000 mg per day
13	About 5 mg to about 500 mg per day
14	About 10 mg to about 200 mg per day
15	About 20 mg per day
16	About 20 mg per day, once or twice daily
17	About 0.01 mg/kg to about 100 mg/kg/day
18	About 1, 5 or 25 mg/kg/day

The claims use “about,” which can provide some numerical flexibility. The precise boundary depends on claim construction, specification disclosure and the relevant prosecution history.

The 20 mg claim is commercially relevant because the approved Otezla maintenance dose for most adult indications is 30 mg twice daily, while dose-reduction regimens can involve lower doses. The patent’s broad claims are therefore more important than the 20 mg dependent claim for evaluating ordinary commercial use.

The supplied text contains “0.0 1 mg,” which is evidently a formatting error for “0.01 mg.”

When did U.S. Patent 7,208,516 expire?

The patent’s ordinary twenty-year term ran from the relevant nonprovisional filing date and expired on November 25, 2023, based on the patent family’s 2003 filing chronology.[2]

Event	Date
Priority filing	November 25, 2002
U.S. filing chronology	November 25, 2003
Patent grant	April 24, 2007
Nominal expiration	November 25, 2023

The provisional priority date does not ordinarily establish the expiration date for a later nonprovisional application. Patent-term adjustment, patent-term extension and terminal-disclaimer issues must be checked in the official USPTO record before relying on a final expiration calculation.

For commercial planning, the patent should be treated as an expired or near-expired method patent after November 2023, subject to the official register and any applicable statutory extension.

What was the Orange Book status of U.S. Patent 7,208,516?

U.S. Patent 7,208,516 was associated with Otezla and the apremilast product franchise. It was relevant to the FDA Orange Book listing for the approved product and to generic certification analysis.

An applicant filing an abbreviated new drug application could address a listed patent through:

Paragraph I certification, if the patent information was not applicable;
Paragraph II certification, if the patent had expired;
Paragraph III certification, accepting delayed approval until expiration; or
Paragraph IV certification, asserting that the patent was invalid, unenforceable or not infringed.

After the patent’s nominal expiration, a Paragraph II certification would ordinarily become the relevant route for that patent. A Paragraph IV challenge could still have been used before expiration if a generic applicant sought approval before the patent term ended.

The Orange Book does not itself determine infringement. It records patent information submitted for approved drug products and affects FDA approval timing under the Hatch-Waxman framework.[3]

Which companies challenged apremilast patents?

Apremilast generic competition involved ANDA applicants challenging the Otezla patent estate. Public litigation and regulatory records identify generic manufacturers and applicants in the apremilast market, including companies such as Amneal Pharmaceuticals, Teva Pharmaceuticals and other ANDA sponsors.

The principal dispute structure was conventional:

A generic applicant filed an ANDA for apremilast tablets.
The applicant certified against one or more listed Otezla patents.
The patent holder asserted infringement under 35 U.S.C. § 271(e)(2).
The litigation addressed validity, enforceability, infringement and the timing of FDA approval.
Settlement agreements could establish an agreed generic entry date before or after patent expiration.

The existence of a Paragraph IV certification does not establish that a patent is invalid. It creates litigation exposure and can trigger a statutory stay of FDA approval, subject to the Hatch-Waxman framework.[4]

What later patents protected apremilast?

The commercial patent estate extended beyond U.S. Patent 7,208,516. The relevant categories included:

Compound and enantiomer patents

Earlier Celgene patent families covered substituted isoindolinone and phthalimide compounds, including apremilast and related molecules. These patents were directed more closely to the active compound and chemical genus than to psoriatic arthritis treatment.

Method-of-use patents

U.S. Patent 7,208,516 was the key psoriatic arthritis method patent. Other method patents addressed psoriasis, inflammatory disorders or specific dosing and patient populations.

Formulation and solid-state patents

Later patents and applications addressed pharmaceutical compositions, crystalline forms, particle properties, manufacturing processes and dosage forms. These patents can create launch barriers even after an earlier method patent expires.

A generic may avoid an expired method patent but still face claims covering:

A particular crystalline form;
A specific tablet formulation;
A manufacturing process;
A particle-size distribution;
A pharmaceutical composition; or
A method of administering a defined regimen.

The legal and commercial value of these later patents depends on whether the generic’s proposed product necessarily practices the claimed technology.

How strong is the patent estate for Otezla?

The estate was strongest while three factors overlapped:

The product had an FDA-approved psoriatic arthritis indication.
The method patent remained unexpired.
The Orange Book contained additional unexpired product or formulation patents.

U.S. Patent 7,208,516 had strong product-label relevance because the patented disease indication was an approved use of Otezla. Its weakness was temporal: the patent’s term ended in 2023, leaving later patents to carry the principal exclusivity burden.

Estate component	Commercial strength
Active enantiomer identity	High before compound-patent expiration
Psoriatic arthritis treatment	High while U.S. Patent 7,208,516 was enforceable
Salt and hydrate coverage	Moderate to high, depending on product form
Combination therapy	Narrower practical coverage
Oral tablet claims	Directly relevant to commercial Otezla
Topical formulations	Limited current relevance without a marketed topical product
Later formulation and solid-state patents	Potentially material after method-patent expiry

Is biosimilar competition relevant to apremilast?

No. Apremilast is a chemically synthesized small molecule, not a biologic. Competitive products proceed through the generic drug pathway, usually an ANDA under Section 505(j) of the Federal Food, Drug, and Cosmetic Act.

Biosimilar litigation under the Biologics Price Competition and Innovation Act is not the applicable pathway. The relevant risks are:

ANDA filing;
Paragraph IV certification;
Hatch-Waxman litigation;
FDA approval timing;
Label carve-outs;
Formulation patents; and
Manufacturing-process patents.

What generic launch scenarios existed?

The main scenarios were:

Launch after expiration of U.S. Patent 7,208,516

Once the method patent expired, a generic applicant could seek approval for apremilast, subject to other listed patents and regulatory requirements.

Skinny-label launch

A generic could seek approval for indications not covered by enforceable method patents, omitting patented uses from its labeling where FDA rules permit. This strategy depends on the remaining approved indications, patent listings and the feasibility of a lawful label carve-out.

Launch after settlement date

A Paragraph IV settlement could provide a contractual entry date earlier than the last listed patent expiration. The actual date would depend on the settlement terms and FDA approval status.

At-risk launch

A generic could launch before final patent resolution, accepting potential damages or injunctive exposure if the patent holder prevailed. This strategy is commercially significant but legally hazardous.

What licensing and ownership issues affect the patent?

Celgene was the principal commercial developer and patent holder associated with Otezla. Bristol Myers Squibb acquired Celgene in 2019 and became the relevant owner of the Otezla business and associated intellectual-property interests.[5]

The key transaction was an acquisition rather than a narrowly defined apremilast license. Any freedom-to-operate review must distinguish:

Patent ownership;
Exclusive licenses;
Co-development rights;
Settlement licenses;
Manufacturing agreements; and
Distribution arrangements.

Ownership of a patent does not by itself establish that every related patent family, regulatory exclusivity right or litigation settlement has the same owner.

What is the geographic scope?

U.S. Patent 7,208,516 is enforceable only under U.S. law. It does not directly block generic or local manufacture in Europe, Japan, China or other jurisdictions.

International protection required separate national or regional patents. The relevant analysis must compare:

Priority dates;
National-phase filings;
Patent-term rules;
Supplementary protection certificates;
Patent-term extensions;
Orange Book or equivalent listings;
Local generic approval rules; and
Litigation outcomes.

A generic manufacturer could face different launch dates by country because apremilast compound, formulation and method patents did not necessarily expire simultaneously worldwide.

Key Takeaways

U.S. Patent 7,208,516 covers treating psoriatic arthritis with the substantially enantiopure (+)-enantiomer of apremilast.
The claims include salts, solvates, hydrates, combination therapy, etanercept, oral and topical delivery, tablets, capsules, lotions, liquids and broad dose ranges.
The psoriatic arthritis limitation is central. The patent is not a general claim to every use of apremilast.
The patent’s nominal term expired on November 25, 2023, subject to official confirmation of any term adjustment or extension.
Generic competition is governed by the ANDA and Hatch-Waxman framework, not the biosimilar pathway.
Later formulation, crystalline-form, manufacturing and method patents may have remained relevant after the expiration of the ’516 patent.
BMS became the relevant commercial owner after acquiring Celgene.
The strongest historical infringement theory involved a generic oral apremilast product carrying or inducing the patented psoriatic arthritis use.

FAQs

Does U.S. Patent 7,208,516 cover all apremilast products?

No. It covers specified methods of treating psoriatic arthritis using the (+)-enantiomer of apremilast or an eligible salt or solvate. It does not automatically cover every disease use, formulation or manufacturing process.

Can a generic sell apremilast for psoriasis after this patent expired?

Potentially, subject to other unexpired patents, FDA approval requirements and applicable method-of-use listings. Expiration of the ’516 patent removes one barrier but does not eliminate the entire Otezla patent estate.

Does a racemic apremilast product avoid the patent?

It may raise a non-infringement argument against the “substantially free” limitation, but regulatory, pharmacological and other patent issues would remain. A racemic product would not necessarily be substitutable for the approved active enantiomer.

Does claim 7 prohibit using apremilast with any biologic?

No. Claim 7 specifically identifies etanercept. Claim 6 is broader but still requires the claimed apremilast treatment and a qualifying second active agent.

Are apremilast generic companies biosimilar applicants?

No. Apremilast generics use the ANDA pathway for chemically synthesized drugs. Biosimilar applications are designed for biological products and do not apply to apremilast.

References

U.S. Food and Drug Administration. (2014). Otezla (apremilast) prescribing information. FDA.
United States Patent and Trademark Office. (2007). U.S. Patent No. 7,208,516, Methods of treating psoriatic arthritis. U.S. Department of Commerce.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355(j); 35 U.S.C. § 271(e)(2).
Bristol Myers Squibb. (2019). Bristol Myers Squibb completes acquisition of Celgene. Company transaction announcement.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	2962690	⤷ Start Trial	300994	Netherlands	⤷ Start Trial
European Patent Office	2962690	⤷ Start Trial	LUC00125	Luxembourg	⤷ Start Trial
European Patent Office	2962690	⤷ Start Trial	122019000070	Germany	⤷ Start Trial
European Patent Office	2962690	⤷ Start Trial	CA 2019 00033	Denmark	⤷ Start Trial
European Patent Office	2962690	⤷ Start Trial	2019C/008	Belgium	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,208,516

Summary for Patent: 7,208,516