US Patent 11,406,638: Scope, Claims, Expiration, Litigation Risk, and Patent Landscape for PDE4B Inhibitor–Nintedanib Combinations
US Patent No. 11,406,638 protects a combination-treatment concept for progressive fibrosing interstitial lung diseases, including idiopathic pulmonary fibrosis. Its claims cover: (1) a fixed pharmaceutical composition containing a PDE4B inhibitor and nintedanib, (2) separate dosage forms packaged as a kit, and (3) methods using both agents simultaneously, sequentially, alternately, or separately. The patent does not claim nintedanib monotherapy, a PDE4B inhibitor alone, or every possible pulmonary-fibrosis combination.[1]
What does US Patent 11,406,638 claim?
The patent has three operative claim categories.
| Claim category |
Claims |
Protected subject matter |
| Combination composition |
1-2 |
A composition containing a PDE4B inhibitor of formula III and nintedanib, including nintedanib monoethanesulfonate |
| Combination kit |
3-6 |
Separate PDE4B-inhibitor and nintedanib dosage forms, with package instructions for use in PF-ILD or IPF |
| Combination treatment method |
7-10 |
Administration of the PDE4B inhibitor and nintedanib to treat PF-ILD or IPF |
The central limitation is the required pairing of two pharmacological components:
- A PDE4B inhibitor defined by formula III or a pharmaceutically acceptable salt; and
- Nintedanib or a pharmaceutically acceptable salt.
Claim 2 and claim 4 narrow the nintedanib component to its monoethanesulfonate form. Nintedanib monoethanesulfonate is the active pharmaceutical ingredient used in Ofev.[2]
What is the significance of the formula III limitation?
Formula III is the chemical genus that defines the PDE4B inhibitor component. The supplied claims do not reproduce the chemical structure or substituent definitions for formula III. The practical breadth of the patent therefore depends heavily on the full structural definition in the patent specification and on the identity of the commercial or clinical PDE4B inhibitor that falls within that formula.
The likely commercial relevance is BI 1015550, also known as nerandomilast, a selective PDE4B inhibitor developed by Boehringer Ingelheim for fibrotic lung disease. The claim language should not be treated as covering BI 1015550 unless the compound falls within formula III as issued and the relevant claim construction confirms that result.
How broad is the composition protection?
Claim 1: fixed combination composition
Claim 1 requires a single pharmaceutical composition containing both active agents. The claim is broad as to:
- Relative amounts of the two active ingredients.
- Dosage form, unless restricted elsewhere in the specification.
- Pharmaceutical carriers and excipients.
- The particular pharmaceutically acceptable salt of the PDE4B inhibitor.
- The particular pharmaceutically acceptable salt of nintedanib.
The claim is narrower as to the active ingredients. A product would need to contain a PDE4B inhibitor within formula III and nintedanib or a covered salt.
A product containing nintedanib with a PDE4A inhibitor, an unrelated anti-fibrotic, or a PDE4B inhibitor outside formula III would not literally satisfy claim 1. A formulation containing the two active ingredients in separate compartments may also raise a claim-construction issue because claim 1 uses the term “pharmaceutical composition,” while claims 3-6 expressly address a kit containing separate dosage forms.
Claim 2: nintedanib monoethanesulfonate
Claim 2 narrows claim 1 to nintedanib monoethanesulfonate. This is commercially important because the approved Ofev product uses nintedanib as the ethanesulfonate salt.[2] Claim 2 may be easier to apply to a commercial product than claim 1 if the PDE4B inhibitor and nintedanib are formulated together.
The claim does not require a particular tablet strength, release profile, excipient system, dosing ratio, or fixed-dose presentation. Those limitations could be relevant in validity or infringement analysis if the patent specification or prosecution history narrowed the claims.
What does the kit protection cover?
Claims 3-6 cover a two-product arrangement rather than a single combined formulation.
The kit must contain:
- A first pharmaceutical composition or dosage form containing the formula III PDE4B inhibitor; and
- A second pharmaceutical composition or dosage form containing nintedanib or a covered salt.
Claims 5 and 6 require package-insert instructions directing use in PF-ILD or IPF. The instructions can specify simultaneous, concurrent, sequential, successive, alternate, or separate administration.
This language creates a broad delivery architecture. It can reach a commercial package containing two independently manufactured products, even if the actives are never physically combined. The package-insert requirement also gives the patentee a potential infringement theory focused on labeling and distribution materials.
Does a co-packaged Ofev and PDE4B product create risk?
Potentially. A co-packaged product could implicate claims 3-6 if:
- The PDE4B product contains a covered formula III inhibitor;
- The second product contains nintedanib or nintedanib monoethanesulfonate;
- The products are supplied as a kit; and
- The labeling directs the claimed use in PF-ILD or IPF.
A physician independently prescribing the two products does not automatically establish infringement by the manufacturers. Liability would depend on the defendant’s acts, labeling, inducement evidence, and the specific statutory and case-law framework applied.
What methods of treatment does the patent protect?
Claims 7-10 cover treatment of PF-ILD and IPF by administering both agents in therapeutically effective amounts.
Claim 7 is the broad method claim. Claim 8 narrows the disease to IPF. Claim 9 covers multiple administration schedules. Claim 10 narrows nintedanib to the monoethanesulfonate.
The method claims do not require:
- A specific dose of either agent;
- A specified treatment duration;
- A specified sequence;
- A particular patient biomarker;
- A particular severity of fibrosis;
- A stated reduction in forced vital capacity decline; or
- A particular formulation.
The absence of a specific dosing limitation expands literal scope but may create validity and enforcement issues involving written description, enablement, anticipation, obviousness, and clinical support. The patent’s specification and prosecution record would control those issues.
Which diseases are within scope?
PF-ILD is broader than IPF. It can include non-IPF interstitial lung diseases that develop a progressive fibrosing phenotype. Depending on the patent’s definitions, relevant disease categories may include:
- Progressive systemic-sclerosis-associated interstitial lung disease;
- Chronic hypersensitivity pneumonitis;
- Autoimmune-related interstitial lung disease;
- Fibrotic nonspecific interstitial pneumonia; and
- Other progressive fibrosing interstitial lung diseases.
The claims expressly identify PF-ILD and IPF. The patent does not, based on the supplied claims, cover all pulmonary diseases or all forms of fibrosis.
When does US Patent 11,406,638 lose exclusivity?
US Patent 11,406,638 issued on August 9, 2022.[1] The patent’s ordinary term is generally measured from the earliest effective nonprovisional or international filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and other statutory adjustments.[3]
The public patent number alone does not establish the final expiration date. A reliable term calculation requires the patent’s priority chain, filing history, PTA statement, and any terminal disclaimer. The ordinary baseline for a patent with a 2019 effective nonprovisional filing would be approximately 2039, before any adjustment.
| Event |
Date or status |
| US patent grant |
August 9, 2022 |
| Patent term framework |
20 years from applicable earliest nonprovisional filing date |
| PTA |
Must be taken from the issued patent and USPTO record |
| PTE |
No basis is apparent from the supplied claims |
| Terminal disclaimer |
Must be checked in the USPTO file |
| Practical baseline |
Approximately 2039 if the relevant filing date was in 2019 |
The patent should not be treated as expiring in 2042 merely because it issued in 2022. US utility patent term normally runs from the effective filing date, not the grant date.
What is the Orange Book status of US Patent 11,406,638?
US Patent 11,406,638 is directed to a combination of a PDE4B inhibitor with nintedanib for PF-ILD or IPF. Ofev is approved as nintedanib capsules for the treatment of IPF, chronic fibrosing ILDs with a progressive phenotype, and systemic sclerosis-associated ILD.[2]
The patent does not claim Ofev monotherapy. Its claims require the additional PDE4B inhibitor. For that reason, it is not a conventional composition, formulation, or method-of-use patent for approved nintedanib monotherapy. A listing against Ofev would require the patent to claim an approved method or approved product in a manner satisfying the FDA’s Orange Book listing rules.[4]
The relevant regulatory distinction is:
| Issue |
Assessment |
| Approved nintedanib product |
Ofev |
| Approved active ingredient |
Nintedanib, administered as nintedanib ethanesulfonate |
| Patent’s claimed product |
PDE4B inhibitor plus nintedanib |
| Coverage of Ofev monotherapy |
No, based on the supplied claims |
| Coverage of an approved fixed-dose PDE4B/nintedanib product |
Potentially, if approved and within the claims |
| Orange Book relevance |
Limited unless the combination receives FDA approval and the patent is properly listable |
A patent can create commercial or litigation risk without being an Orange Book-listed patent against the existing Ofev NDA. The patent may become more relevant if a PDE4B/nintedanib combination product reaches an approved regulatory pathway.
Does the patent create Paragraph IV risk for nintedanib generics?
Risk to generic Ofev
The patent presents limited direct risk to a generic seeking approval for nintedanib monotherapy because the supplied claims require a PDE4B inhibitor. A conventional ANDA applicant for nintedanib alone would not practice the combination claims merely by selling nintedanib monotherapy.
The principal Paragraph IV risks would instead arise if:
- The generic label encourages coadministration with a covered PDE4B inhibitor;
- The applicant markets a co-packaged PDE4B/nintedanib product;
- The applicant seeks approval for a combination product; or
- The patent is listed against a later-approved combination NDA.
Certification scenarios
| Applicant product |
Likely patent issue |
| Nintedanib monotherapy |
Generally outside the supplied claims |
| PDE4B inhibitor monotherapy |
Outside the supplied combination claims |
| Fixed-dose PDE4B/nintedanib product |
Direct composition claim risk |
| Separate co-packaged products |
Kit claim risk |
| Label directing combined use for IPF or PF-ILD |
Method and inducement risk |
| Nintedanib generic with neutral monotherapy labeling |
Lower risk under these claims |
A Paragraph IV certification is relevant only if the patent is listed for the reference product and the applicant’s proposed product falls within the listed patent’s scope. The existence of US 11,406,638 alone does not establish a Paragraph IV obligation for a nintedanib-only ANDA.
What formulation patents are relevant to this estate?
The supplied claims are combination claims, not conventional formulation claims. They do not specify:
- Tablet or capsule architecture;
- Immediate-release or sustained-release delivery;
- Particle size;
- Amorphous or crystalline form;
- Solubility-enhancing excipients;
- Enteric coating;
- Food-effect mitigation;
- Specific dissolution limits; or
- A fixed-dose ratio.
The patent may contain dependent claims or specification support for these features, but they are not present in claims 1-10 as supplied.
A competitive freedom-to-operate review should separate four patent layers:
- PDE4B inhibitor composition-of-matter patents;
- PDE4B inhibitor formulation and dosing patents;
- Nintedanib compound, salt, polymorph, formulation, and method patents; and
- Combination, kit, and treatment-method patents such as US 11,406,638.
The fourth layer is the focus of this patent. It may remain relevant after earlier compound patents expire because combination patents can have later priority dates.
How does this patent compare with the main nintedanib patent estate?
| Patent estate |
Primary subject |
Relevance to US 11,406,638 |
| Nintedanib compound patents |
Active molecule and chemical synthesis |
Separate from the combination claims |
| Nintedanib salt and formulation patents |
Ethan esulfonate, dosage forms, stability, delivery |
Overlap only if a covered product also contains the PDE4B inhibitor |
| Ofev method-of-use patents |
Nintedanib monotherapy in IPF or other ILDs |
Distinct from the dual-agent method claims |
| PDE4B inhibitor patents |
Formula III compound and related uses |
Necessary to identify the first active agent |
| US 11,406,638 |
PDE4B inhibitor plus nintedanib |
Combination layer |
The patent’s commercial value depends on the development of the PDE4B inhibitor, not solely on the size of the nintedanib market. If the PDE4B inhibitor is approved for PF-ILD or IPF, the combination claims could constrain coformulation, co-packaging, and combination labeling. If the PDE4B program fails, the standalone legal scope remains but its commercial leverage declines.
Which companies are likely to face competitive or licensing issues?
Boehringer Ingelheim is the central commercial entity in the nintedanib market through Ofev and has also developed PDE4B inhibitor programs, including BI 1015550 and nerandomilast.[2,5] The patent therefore has potential strategic importance in:
- Internal combination development;
- Partnering around PDE4B inhibitors;
- Licensing of combination rights;
- Co-development of anti-fibrotic regimens;
- Combination clinical trials; and
- Negotiations with generic or specialty pharmaceutical companies.
No licensing deal, settlement agreement, or active litigation can be established from the claim text alone. The patent does not, by itself, show that any company has challenged it or that a court has adjudicated its validity.
How strong is the patent estate?
The patent has meaningful structural breadth but depends on several technical and legal conditions.
| Strength factor |
Assessment |
| Combination requirement |
Narrows scope to dual-agent use |
| PDE4B genus |
Potentially broad, but full formula III must be reviewed |
| Nintedanib limitation |
Clear and commercially identifiable |
| Salt coverage |
Broad in claims 1, 3, and 7; monoethanesulfonate expressly covered in dependent claims |
| Disease scope |
Broad PF-ILD language, narrowed by claim 8 to IPF |
| Administration schedule |
Broad under claim 9 |
| Dosage limitations |
Not specified in supplied claims |
| Single-product protection |
Present in claims 1-2 |
| Co-packaging protection |
Present in claims 3-6 |
| Monotherapy protection |
Absent |
| Biosimilar protection |
Not relevant |
The strongest practical claims may be claims 3-6 and 7-10 if the PDE4B agent is clinically developed alongside nintedanib. The method claims cover multiple administration schedules, while the kit claims can reach commercial packaging and labeling. Claim 1 may face greater technical scrutiny if the patent does not provide adequate support across the full formula III genus.
What generic launch scenarios exist?
Nintedanib-only generic launch
A nintedanib-only generic would generally target Ofev monotherapy. On the supplied claims, it would not necessarily practice the patented combination because it would lack the PDE4B inhibitor.
PDE4B inhibitor generic or follow-on launch
A PDE4B product sold alone would not fall within claims 1-10 unless its labeling or packaging directs use with nintedanib in the claimed manner.
Combination product launch
A fixed-dose combination would face the highest direct exposure. Claims 1, 2, 7, and 10 could apply depending on the active agent, salt, disease indication, and formulation.
Co-packaged launch
A co-packaged PDE4B inhibitor and nintedanib product could implicate claims 3-6, particularly if package instructions identify PF-ILD or IPF and prescribe combined use.
What geographic coverage does the patent provide?
US Patent 11,406,638 provides rights in the United States only. Parallel protection may exist in other jurisdictions through related national-phase or regional applications, but foreign coverage cannot be inferred from the US patent number or claims.
A global launch review should examine:
- PCT applications and national-phase entries;
- European Patent Office family members;
- Canadian, Japanese, Chinese, Korean, and Australian counterparts;
- Patent-term adjustments or extensions;
- Opposition or post-grant proceedings;
- Divisional and continuation applications; and
- Foreign claim differences.
US claim scope does not establish European, Chinese, or other national scope. The geographic risk must be assessed family member by family member.
What manufacturing and intellectual-property barriers exist?
Manufacturing a PDE4B/nintedanib combination may face barriers beyond the claims:
- Separate active pharmaceutical ingredient supply chains;
- Salt selection and solid-state control;
- Stability interactions between the two agents;
- Dose-ratio optimization;
- Dissolution and bioavailability requirements;
- Packaging and moisture protection;
- Clinical evidence for combined use; and
- Regulatory justification for a new combination product.
The patent does not require a particular manufacturing process in the supplied claims. A manufacturer could therefore avoid process infringement while still facing composition, kit, or method claims. Conversely, a noninfringing formulation may still be commercially blocked by regulatory requirements or separate patents covering the PDE4B inhibitor or nintedanib.
Key Takeaways
- US 11,406,638 is a combination patent, not a nintedanib monotherapy patent.
- It covers a formula III PDE4B inhibitor used with nintedanib or a covered salt.
- Nintedanib monoethanesulfonate is expressly covered in claims 2, 4, and 10.
- Claims 3-6 extend protection to kits, separate dosage forms, and package instructions.
- Claims 7-10 cover treatment of PF-ILD and IPF using both agents.
- A conventional nintedanib-only generic is not directly targeted by the supplied claims.
- The patent could materially affect a fixed-dose combination, co-packaged product, or combination label.
- The patent’s commercial strength depends on whether a commercially relevant PDE4B inhibitor falls within formula III.
- The final expiration date requires the priority chain, PTA, and terminal-disclaimer record.
- No biosimilar pathway applies because both nintedanib and PDE4B inhibitors are small molecules.
- The patent is not, based on the supplied claims, a conventional Orange Book patent for Ofev monotherapy.
- The patent provides US protection only unless corresponding foreign family members exist.
FAQs
Can a company sell nintedanib and a PDE4B inhibitor in separate prescriptions?
Separate prescriptions do not automatically fall within the kit claims. Risk increases if the manufacturer packages the products together or labels them for combined PF-ILD or IPF treatment.
Does claim 9 require the two drugs to be administered at the same time?
No. Claim 9 expressly covers simultaneous, concurrent, sequential, successive, alternate, or separate administration.
Does the patent cover pirfenidone combined with a PDE4B inhibitor?
Not under the supplied claims. Pirfenidone is not nintedanib and would not satisfy the tyrosine kinase inhibitor limitation.
Can a formulation avoid the patent by using a different nintedanib salt?
Possibly, but claims 1, 3, and 7 cover nintedanib and pharmaceutically acceptable salts generally. Claims 2, 4, and 10 specifically narrow to the monoethanesulfonate form.
Is BI 1015550 definitely covered by this patent?
That conclusion requires comparison of BI 1015550’s chemical structure with the complete formula III definition and the issued claim construction. The supplied claim text alone does not establish chemical identity.
References
- United States Patent and Trademark Office. (2022). U.S. Patent No. 11,406,638, pharmaceutical composition, kit and method of treatment comprising a PDE4B inhibitor and nintedanib.
- U.S. Food and Drug Administration. (2024). Ofev (nintedanib) prescribing information. Boehringer Ingelheim Pharmaceuticals, Inc.
- United States Code. (2024). 35 U.S.C. §§ 154, 156.
- U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.
- Boehringer Ingelheim. (2024). Nerandomilast and PDE4B inhibitor development information.
