Details for Patent: 11,622,959

Which drugs does patent 11,622,959 protect, and when does it expire?

Patent 11,622,959 protects SOHONOS and is included in one NDA.

This patent has twenty-eight patent family members in eighteen countries.

Summary for Patent: 11,622,959

Title:	Methods for treating heterotopic ossification
Abstract:	The invention features dosing regimens and pharmaceutical formulations for oral administration of palovarotene. The dosing regimens can reduce heterotopic ossification, reduce the number of flare-ups, and/or reduce the severity of flare-ups in subjects suffering from fibrodysplasia ossificans progressiva.
Inventor(s):	Clarissa Desjardins, Donna Roy GROGAN, Jeffrey Neal PACKMAN, Mark Harnett
Assignee:	Clementia Pharmaceuticals Inc
Application Number:	US16/950,604
Patent Claim Types: see list of patent claims	Use;

United States Patent 11,622,959: Palovarotene FOP Claims, Exclusivity, Litigation and Patent Landscape

U.S. Patent No. 11,622,959 protects a flare-up dosing regimen for palovarotene in patients with fibrodysplasia ossificans progressiva, or FOP. The independent claim requires sequential oral dosing: approximately 20 mg daily for 20 to 40 days, followed by approximately 10 mg daily for 14 to 112 days. The claim is directed to treatment conduct, not to palovarotene as a molecule, capsule composition, or manufacturing process.

The patent is commercially relevant to Sohonos, Ipsen's palovarotene product approved by the FDA for reducing the formation of heterotopic ossification in adults and skeletally mature females aged 8 years and older with FOP. A generic competitor would need to avoid the claimed regimen, challenge patent validity or enforceability, or wait for patent and regulatory exclusivity to expire. Because palovarotene is a small molecule, biosimilar law does not apply.

What does U.S. Patent 11,622,959 protect?

The patent protects a two-stage, flare-up-specific palovarotene regimen:

Required element	Claim 1 requirement
Disease	Fibrodysplasia ossificans progressiva
Treatment objective	Reducing heterotopic ossification
Clinical status	Subject is experiencing at least one flare-up symptom
Administration route	Oral
First dose	20 mg ± 1.0 mg daily, equivalent to 19-21 mg
First treatment period	20-40 days
Second dose	10 mg ± 1.0 mg daily, equivalent to 9-11 mg
Second treatment period	14-112 days
Active ingredient	Palovarotene or a pharmaceutically acceptable salt

Every limitation in claim 1 must be met for literal infringement. A regimen using 20 mg for 28 days followed by 10 mg for 56 days would fall within the express language of claim 1 and the narrower dependent claims 5 and 9. A regimen using 20 mg for 28 days followed by 10 mg for 56 days plus another 28 days if symptoms persist would correspond to claim 6.

The claims do not require a specific capsule, excipient, formulation, brand, manufacturer, diagnostic test, or flare-up trigger. They focus on dose, sequence, duration, patient characteristics, symptoms, and adjunctive treatment.

How broad is independent claim 1?

Claim 1 is moderately broad as a method claim but narrow as a clinical regimen claim. Its main breadth comes from the alternative duration ranges:

• The first treatment period may last 20, 21, 22, through 40 days.
• The second treatment period may last 14 through 112 days.
• The dose tolerances cover 19-21 mg and 9-11 mg.

The claim is narrowed by several mandatory conditions:

1. The patient must have FOP.
2. The patient must be experiencing at least one flare-up symptom during the treatment period.
3. Palovarotene must be administered orally.
4. The regimen must begin with the approximately 20 mg dose.
5. The regimen must then transition to the approximately 10 mg dose.
6. Both dosing stages must occur in the specified sequence.

A chronic maintenance regimen using 10 mg alone would not satisfy claim 1. A flare-up regimen using 20 mg for fewer than 20 days or more than 40 days would fall outside the literal scope of claim 1. A regimen beginning at 10 mg and escalating to 20 mg also would not satisfy the claim as written.

The doctrine of equivalents could create risk for dosing schedules that vary modestly from the express ranges, but equivalence would depend on the facts, prosecution history, claim construction, and any estoppel arising during prosecution.

What do claims 2 through 9 add?

Claims 2 through 9 create overlapping duration positions around the second-stage 10 mg dose.

Claim	Additional limitation
2	10 mg daily for 14-84 days
3	After 84 days, an additional 28 days if symptoms continue
4	10 mg daily for 14-56 days
5	10 mg daily for 56 days
6	10 mg daily for 56 days, plus 28 additional days if symptoms continue
7	10 mg daily for 112 days
8	20 mg daily for 28 ± 4 days, equivalent to 24-32 days
9	20 mg daily for exactly 28 days

Claims 5, 6, 8 and 9 are commercially important because they track the practical 28-day loading period and 56-day continuation period associated with flare-up treatment. Claim 6 adds a symptom-dependent extension and may be relevant where treatment continues after the initial 56-day period.

The claims are nested rather than mutually exclusive. For example, a 28-day first stage followed by 56 days of 10 mg treatment may fall within claims 1, 2, 4, 5, 8 and 9. A 28-day first stage followed by 84 days of 10 mg treatment may fall within claims 1, 2, 8 and 9.

Which patient populations are covered?

Claims 10 and 11 narrow the regimen to specific patient characteristics:

• Claim 10 covers a subject weighing more than 60 kg.
• Claim 11 covers a subject with skeletal maturity of 90% or greater.

These limitations may be important for adult and skeletally mature patients. They do not restrict claim 1, which remains broader because claim 1 does not require a particular body weight or maturity level.

The patient qualification in claim 11 is technically different from a simple age threshold. Skeletal maturity must be assessed under the applicable clinical or regulatory standard. A generic label that uses age alone could create interpretation issues if the dosing instructions are applied to patients near a maturity cutoff.

How do claims 12 through 18 expand the patent scope?

Claims 12 through 15 cover adjunctive treatment:

• Claim 12 requires administration of an antihistamine.
• Claim 13 limits the antihistamine to topical administration.
• Claim 14 limits the antihistamine to systemic administration.
• Claim 15 requires administration of an emollient to the skin.

Claims 16 through 18 address symptom and product-form limitations:

• Claim 16 identifies flare-up symptoms as swelling, pain, erythema, warmth, stiffness, or decreased range of motion.
• Claim 17 specifies palovarotene itself.
• Claim 18 specifies a pharmaceutically acceptable salt of palovarotene.

These claims do not independently cover antihistamine therapy, emollient therapy, or symptom monitoring. Each remains dependent on the full regimen of claim 1.

Claim 16 is useful for infringement analysis because it supplies an express list of qualifying flare-up symptoms. A patient need not present every listed symptom. The phrase "at least one" means that a single listed symptom may satisfy the limitation, subject to claim construction and the factual record.

What is the Orange Book status of palovarotene?

Sohonos is an FDA-approved small-molecule drug marketed by Ipsen. Its regulatory pathway is an NDA, not a biologics license application. Relevant regulatory protections include:

Regulatory protection	Relevance
New chemical entity exclusivity	Restricts certain ANDA submissions for the statutory NCE period
Orphan-drug exclusivity	FOP is a rare disease indication and can receive seven years of indication-specific exclusivity
Patent listings	Method-of-use patents may be listed in the Orange Book if they meet FDA listing requirements
Pediatric exclusivity	May add six months if granted based on qualifying pediatric study obligations

FDA approval of Sohonos was announced on December 15, 2023. The FDA-approved indication covers reduction of heterotopic ossification in adults and skeletally mature females aged 8 years and older with FOP.[1]

The Orange Book, rather than the patent document alone, controls whether U.S. Patent 11,622,959 is listed against the relevant Sohonos NDA and what use code is associated with it. A patent can be legally relevant to a product without appearing in the Orange Book, and an Orange Book listing does not establish ultimate validity or infringement.

When does palovarotene lose exclusivity?

Palovarotene exclusivity has several potentially overlapping components:

1. Patent exclusivity. The expiration date depends on the earliest effective nonprovisional or international filing date in the relevant family, patent-term adjustment, terminal disclaimers, and any patent-term extension.
2. NCE exclusivity. The five-year NCE period generally limits ANDA filing during the first four years, subject to Paragraph IV provisions.
3. Orphan-drug exclusivity. The FOP indication may receive seven years of market exclusivity from approval, subject to the scope of the orphan indication.
4. Pediatric exclusivity. A qualifying six-month extension can apply to otherwise expiring patents and regulatory exclusivities.

The issue date of U.S. Patent 11,622,959, April 11, 2023, does not by itself determine expiration. Patent term is ordinarily measured from the applicable earliest filing date, not from issuance. The exact patent expiration should therefore be taken from the USPTO Patent Examination Data System, the patent-front-page term information, and the Orange Book listing for the approved product.[2][3]

What generic entry risks exist for Sohonos?

A generic palovarotene applicant could pursue several strategies.

Paragraph IV challenge

An ANDA applicant may certify that a listed patent is invalid, unenforceable, or not infringed. A Paragraph IV notice can trigger patent litigation and a potential 30-month stay of FDA approval under the Hatch-Waxman framework.[4]

For this patent, the most plausible Paragraph IV positions would concern:

• Obviousness of the 20 mg-to-10 mg sequence.
• Written description and enablement for the full 14-112 day second-stage range.
• Support for dose tolerances of ±1.0 mg.
• Adequacy of disclosure for treating flare-ups across the claimed patient population.
• Claim construction of "during a period when the subject is experiencing at least one flare-up symptom."
• Whether the clinical evidence supports reducing heterotopic ossification across all claimed durations.
• Double patenting or terminal-disclaimer issues within the palovarotene family.
• Noninfringement based on a label that omits the claimed flare-up regimen.

Skinny-label strategy

A generic company could seek approval for uses that omit the patented method, provided the FDA-approved labeling and marketing conduct do not encourage the protected use. This strategy is difficult where the main commercial use of palovarotene is the patented FOP flare-up regimen.

A label omitting the words "flare-up" may not eliminate risk if the overall labeling, dosage instructions, promotional materials, or distribution controls direct physicians to the patented sequence. Induced-infringement exposure would depend on the final label and conduct.

Design-around dosing

Potential design-around concepts include:

• Using a first-stage dose below 19 mg or above 21 mg.
• Using the first-stage dose for fewer than 20 or more than 40 days.
• Starting with the 10 mg dose.
• Using a second-stage dose below 9 mg or above 11 mg.
• Avoiding a sequential transition from 20 mg to 10 mg.
• Treating outside a documented flare-up period.

Each design-around must be evaluated against other patents, regulatory labeling, clinical evidence, and the doctrine of equivalents. Avoiding claim 1 does not establish freedom to operate for the full palovarotene product.

Are there formulation or manufacturing patents?

U.S. Patent 11,622,959 is not a formulation patent. It does not require:

• A particular capsule composition.
• Particle size.
• Solid-state form.
• Excipient.
• Dissolution profile.
• Packaging system.
• Manufacturing process.
• Salt-selection process.

A broader palovarotene patent estate may contain separate families directed to the active compound, pharmaceutical compositions, solid forms, therapeutic uses, and manufacturing methods. Those families create independent freedom-to-operate issues. A manufacturer that avoids the 20 mg-to-10 mg regimen could still face infringement risk from a composition or process patent.

The claims also do not require a particular commercial strength. A 10 mg capsule and two 5 mg capsules could both satisfy a 10 mg dose limitation if the total administered amount meets the claim. The same analysis applies to a 20 mg dose supplied as multiple units.

Which companies are challenging the palovarotene patent estate?

No Paragraph IV challenger or patent settlement can be inferred from U.S. Patent 11,622,959 or from the claim text alone. Public assessment requires review of FDA Orange Book updates, Paragraph IV notices, federal court dockets, ANDA litigation complaints, and Ipsen disclosures.

The principal commercial parties are:

Party	Role
Ipsen Biopharmaceuticals, Inc.	Commercial sponsor and holder of Sohonos rights
Clementia Pharmaceuticals	Original developer of palovarotene, acquired by Ipsen
FDA	NDA approval, labeling, exclusivity and Orange Book administration
Potential ANDA sponsors	Future generic applicants and Paragraph IV challengers

No biosimilar competitors are relevant because palovarotene is a chemically synthesized small molecule rather than a biologic.

What patent litigation affects palovarotene?

The principal litigation risk is future Hatch-Waxman litigation over listed method-of-use patents. The relevant trigger would be an ANDA filing containing a Paragraph IV certification against a listed palovarotene patent.

Litigation issues would likely include:

• Whether the proposed generic label induces use of the patented FOP regimen.
• Whether the claims are obvious in view of prior retinoid dosing and FOP studies.
• Whether the claimed duration ranges are adequately supported.
• Whether clinical evidence establishes a reduction in heterotopic ossification.
• Whether prosecution amendments narrowed the scope of equivalents.
• Whether any continuation patent is subject to obviousness-type double patenting.
• Whether the patent is enforceable after conduct during prosecution.

A settlement would typically address launch timing, authorized-generic rights, royalties, or license terms. No settlement date or entry date should be assumed without a filed agreement, court docket, SEC disclosure, or FDA record.

How strong is the patent estate for palovarotene?

The asserted strength of U.S. Patent 11,622,959 is concentrated in regimen specificity rather than molecule exclusivity.

Strength factor	Assessment
Clinical specificity	Strong: the claims map to a defined flare-up regimen
Dose and duration detail	Strong: multiple overlapping dependent claims
Product coverage	Limited: no composition or manufacturing limitation
Label-infringement exposure	Potentially significant if the generic label mirrors the approved regimen
Design-around potential	Moderate, because the claims use fixed dose and duration boundaries
Validity risk	Depends on prior art, clinical disclosure and prosecution history
Biosimilar barrier	None; the product is a small molecule
Regulatory barrier	Meaningful because NCE, orphan and patent protections may overlap

The claims are commercially stronger when the approved label recommends the same sequence and durations. They are weaker if a competitor can obtain approval for a non-infringing indication or if the FDA label does not require the patented regimen.

How does palovarotene compare with competing FOP therapies?

Palovarotene is the first FDA-approved therapy specifically indicated to reduce heterotopic ossification in FOP. The competitive landscape remains driven by investigational agents and supportive care rather than by an established generic or biosimilar substitute.

Other approaches may target activin receptor signaling, inflammation, flare-up control, or surgical and supportive management. These products would not automatically infringe U.S. Patent 11,622,959 unless they use palovarotene in the claimed regimen. A competing FOP drug with a different active ingredient would generally fall outside this patent, although it could be subject to separate patents.

What is the revenue exposure from this patent?

The patent protects a central use of Sohonos in a very small patient population. Commercial exposure is therefore driven less by broad primary-care prescribing and more by:

• Lifetime treatment duration.
• Patient weight and maturity.
• Frequency of flare-ups.
• Geographic approvals.
• Reimbursement and rare-disease pricing.
• Physician adoption.
• Generic timing.
• Orphan exclusivity and patent listing status.

A generic launch that avoids the patented flare-up regimen may capture limited volume if the principal clinical demand is tied to that regimen. A successful Paragraph IV challenge could affect the entire commercial product if the approved use cannot be effectively carved out.

What geographic coverage does the patent provide?

U.S. Patent 11,622,959 provides rights only in the United States. It does not directly block palovarotene use, sale, or manufacture in Canada, Europe, Japan, or other markets.

International protection must be assessed separately through the corresponding PCT and national-phase families. The relevant questions include:

• Whether the same dosing regimen was granted abroad.
• Whether foreign claims retained the 20 mg-to-10 mg sequence.
• Whether national claims cover the same patient population.
• Whether supplementary protection certificates or pediatric extensions apply.
• Whether local regulatory exclusivity overlaps with patent term.

Manufacturing outside the United States can still create U.S. exposure if product is imported, offered for sale, or used in the United States. U.S. law also includes specific provisions governing certain activities related to regulatory submissions.

Key Takeaways

• U.S. Patent 11,622,959 is a method-of-treatment patent for palovarotene in FOP.
• Claim 1 requires oral administration of 19-21 mg daily for 20-40 days, followed by 9-11 mg daily for 14-112 days.
• Claims 5, 6, 8 and 9 provide commercially important protection for 28-day loading and 56-day continuation regimens.
• Claims 10 and 11 narrow coverage to patients weighing more than 60 kg or having at least 90% skeletal maturity.
• Claims 12-15 cover regimens that add antihistamines or emollients.
• The patent does not claim palovarotene itself, a formulation, a solid form, or a manufacturing process.
• Palovarotene is a small molecule, so biosimilar competition is irrelevant; generic ANDA competition is the applicable pathway.
• Paragraph IV litigation would likely focus on obviousness, written description, enablement, claim construction and label-induced infringement.
• Orange Book listing, use codes, patent-term information and any Paragraph IV challenge must be assessed independently from the patent claims.
• The patent's commercial value depends on how closely the approved Sohonos labeling tracks the claimed flare-up regimen.

FAQs

Does U.S. Patent 11,622,959 cover all palovarotene use?

No. It covers the specified sequential dosing regimen for a patient with FOP experiencing a flare-up symptom. It does not claim every palovarotene dose, every duration, or every indication.

Can a generic use palovarotene at 10 mg without infringing this patent?

Possibly, if it does not practice the full claimed sequence. A 10 mg-only regimen would not literally satisfy claim 1, but other patents, regulatory provisions, or induced-infringement theories could remain relevant.

Does a 21 mg palovarotene dose fall within the claims?

Yes. The 20 mg ± 1.0 mg limitation covers 19-21 mg, assuming the dose is administered under the other conditions in the claim.

Does the patent cover treatment when the patient has pain but no swelling?

Claim 16 lists pain as one qualifying flare-up symptom. Because the claim requires at least one listed symptom, pain can satisfy that dependent claim if the other claim elements are met.

Is an authorized generic the same as a biosimilar competitor?

No. An authorized generic is a chemically equivalent small-molecule product marketed under the brand owner's authorization. A biosimilar is a biological product evaluated under the abbreviated biologics pathway. Palovarotene competition would proceed through generic-drug mechanisms.

References

1. U.S. Food and Drug Administration. (2023, December 15). FDA approves first treatment for patients with rare disease that causes abnormal bone growth. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-patients-rare-disease-causes-abnormal-bone-growth

2. United States Patent and Trademark Office. (2023, April 11). U.S. Patent No. 11,622,959, methods of treating fibrodysplasia ossificans progressiva. U.S. Department of Commerce.

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

4. U.S. Food and Drug Administration. (2024). Approved drug products and therapeutic equivalence evaluations: Patent and exclusivity information. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book/approved-drug-product-patent-and-exclusivity-information

5. U.S. Food and Drug Administration. (2023). Sohonos (palovarotene) prescribing information. Ipsen Biopharmaceuticals, Inc. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/215559s000lbl.pdf

6. U.S. Congress. (1984). Drug Price Competition and Patent Term Restoration Act of 1984, 21 U.S.C. § 355(j); 35 U.S.C. §§ 156, 271(e), 282.

Drugs Protected by US Patent 11,622,959

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Ipsen	SOHONOS	palovarotene	CAPSULE;ORAL	215559-001	Aug 16, 2023		RX	Yes	No	11,622,959					REDUCTION OF HETEROTOPIC OSSIFICATION IN PATIENTS WITH FIBRODYSPLASIA (MYOSITIS) OSSIFICANS PROGRESSIVA
Ipsen	SOHONOS	palovarotene	CAPSULE;ORAL	215559-002	Aug 16, 2023		RX	Yes	No	11,622,959					REDUCTION OF HETEROTOPIC OSSIFICATION IN PATIENTS WITH FIBRODYSPLASIA (MYOSITIS) OSSIFICANS PROGRESSIVA
Ipsen	SOHONOS	palovarotene	CAPSULE;ORAL	215559-003	Aug 16, 2023		RX	Yes	No	11,622,959					REDUCTION OF HETEROTOPIC OSSIFICATION IN PATIENTS WITH FIBRODYSPLASIA (MYOSITIS) OSSIFICANS PROGRESSIVA
Ipsen	SOHONOS	palovarotene	CAPSULE;ORAL	215559-004	Aug 16, 2023		RX	Yes	No	11,622,959					REDUCTION OF HETEROTOPIC OSSIFICATION IN PATIENTS WITH FIBRODYSPLASIA (MYOSITIS) OSSIFICANS PROGRESSIVA
Ipsen	SOHONOS	palovarotene	CAPSULE;ORAL	215559-005	Aug 16, 2023		RX	Yes	Yes	11,622,959					REDUCTION OF HETEROTOPIC OSSIFICATION IN PATIENTS WITH FIBRODYSPLASIA (MYOSITIS) OSSIFICANS PROGRESSIVA

International Family Members for US Patent 11,622,959

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2017276835
Australia	2022202148
Brazil	112018075422
Canada	3025854
Chile	2018003502
China	109562099
China	120204216