US Patent 10,449,184: Scope, Claims and Patent Landscape for Bexotegrast Solid-Dispersion Formulations

US Patent 10,449,184 protects oral solid-dispersion formulations of Compound 1, identified with the bexotegrast/PLN-74809 program, rather than the compound’s underlying molecular structure. The independent claim requires four core elements: Compound 1 or a pharmaceutically acceptable salt, a specified polymer, a 25%-75% w/w drug loading in the solid dispersion, and oral administration. The strongest commercial embodiment is a spray-dried, amorphous HPMCAS dispersion containing approximately 30% Compound 1 and formulated into a tablet.

The patent is formulation-specific. It does not, based on the claims provided, broadly block all uses, salts, dosage forms, or manufacturing routes for Compound 1.

What drug does US Patent 10,449,184 protect?

Compound 1 is the small-molecule integrin inhibitor associated with bexotegrast, also known as PLN-74809. Bexotegrast has been developed as an oral inhibitor of αvβ6 and αvβ1 integrins for fibrotic diseases, including idiopathic pulmonary fibrosis and nonalcoholic steatohepatitis-related liver fibrosis.

The claimed compound is:

(S)-N-((S)-1-(2-chlorophenyl)-2-((3,3-difluorocyclobutyl)amino)-2-oxoethyl)-1-(4-cyanopyridin-2-yl)-N-(5-fluoropyridin-3-yl)-5-oxopyrrolidine-2-carboxamide.

The patent claims a drug-delivery solution for a poorly soluble or otherwise formulation-limited active ingredient. The claims focus on maintaining Compound 1 in a solid dispersion with a polymer selected from:

HPMCAS;
PVAP;
HPMC; and
HPMCP.

The claims do not expressly require a particular polymorph, crystal form, particle size, dissolution profile, capsule shell, tablet coating, dose strength, or therapeutic indication.

What is the independent claim scope of US 10,449,184?

Claim 1 is the controlling composition claim. A potentially infringing product must satisfy each required limitation:

Claim 1 limitation	Scope
Dosage form	Pharmaceutical composition for oral administration
Active ingredient	Compound 1 or a pharmaceutically acceptable salt
Physical form	Solid dispersion
Drug loading	Between 25% and 75% w/w of the solid dispersion
Polymer	HPMCAS, PVAP, HPMC, or HPMCP
Other ingredients	Optional pharmaceutically acceptable carriers

The claim is open-ended because it uses “comprising.” A formulation may include additional excipients, coatings, processing aids, or separate dosage-form components and still fall within the claim if the required elements are present.

The most important claim-construction issue is the phrase “solid dispersion.” A conventional physical blend of crystalline Compound 1 with polymer may not satisfy the limitation if it lacks the required dispersed solid-state structure. Conversely, a product described as an amorphous solid dispersion, polymeric dispersion, or spray-dried dispersion presents a materially higher infringement risk when it uses one of the listed polymers and the required drug-loading range.

How do claims 2 through 8 narrow the patent?

Claims 2 through 8 progressively concentrate protection around HPMCAS and spray-dried amorphous dispersions.

Claim	Added limitation	Commercial significance
2	Polymer is HPMCAS	Removes PVAP, HPMC and HPMCP alternatives
3	Solid dispersion is spray-dried	Captures a common manufacturing route for amorphous dispersions
4	Compound 1 is approximately 30%-70% w/w	Narrows the broad 25%-75% range
5	Compound 1 is approximately 40%-60% w/w	Covers mid-range loading
6	Compound 1 is approximately 50% w/w	Covers the nominal 1:1 drug-polymer dispersion
7	Compound 1 is approximately 25% w/w	Covers a low-loading spray-dried dispersion
8	Dispersion is amorphous	Adds a solid-state limitation

Claims 3 and 8 are particularly relevant to generic or follow-on development. A competitor using HPMCAS and spray drying could avoid claim 8 only if the resulting product is not amorphous, although deliberately producing a crystalline or partially crystalline dispersion may create dissolution, stability, or bioavailability problems.

The “about” language in claims 4 through 7 introduces ordinary claim-construction flexibility around the stated percentages. The precise boundary will depend on the specification, analytical method, batch variability, and how the drug-loading percentage is calculated.

What excipients and tablet compositions are protected?

Claims 9 through 20 cover additional excipient combinations in formulations falling within claim 3.

Claim	Added component
9	Surfactant or inert pharmaceutically acceptable substance
10	Vitamin E or sodium lauryl sulfate
11	Filler
12	Microcrystalline cellulose
13	Disintegrant
14	Croscarmellose sodium
15	Wetting agent
16	Sodium lauryl sulfate
17	Glidant
18	Colloidal silicon dioxide
19	Lubricant
20	Magnesium stearate

These claims protect formulation architecture rather than merely the presence of an individual excipient. For example, claim 20 requires the claim 3 spray-dried dispersion and adds magnesium stearate as a lubricant. Magnesium stearate alone is not the protected subject matter.

Sodium lauryl sulfate appears in two functional positions. Claim 10 identifies it as a surfactant, while claim 16 identifies it as a wetting agent. The dual characterization does not necessarily create two independent technical requirements. It gives the patent owner alternative ways to characterize the same formulation component.

What tablet formulation is claimed by claims 21 through 23?

Claim 21 covers a complete composition with the following approximate ranges:

Component	Claimed range
Compound 1 or salt	25%-35% w/w
HPMCAS	25%-35% w/w
Microcrystalline cellulose	25%-35% w/w
Croscarmellose sodium	5%-7% w/w
Sodium lauryl sulfate	0.5%-1.5% w/w
Colloidal silicon dioxide	1%-3% w/w
Magnesium stearate	0.5%-2.5% w/w
Total	100%

Because claim 21 depends through claim 3, it incorporates the spray-dried-dispersion limitation and the HPMCAS limitation inherited from claim 2.

Claim 22 narrows the formulation to the following point composition:

30% Compound 1;
30% HPMCAS;
29.5% microcrystalline cellulose;
6% croscarmellose sodium;
1% sodium lauryl sulfate;
2% colloidal silicon dioxide; and
1.5% magnesium stearate.

The listed ingredients total 100%. Claim 23 further requires that the composition be a tablet.

This is the patent’s clearest finished-product claim. A tablet with this composition, or with closely corresponding amounts that satisfy claim 21, presents higher literal-infringement risk than a formulation using a different polymer, a different manufacturing process, or a different excipient system.

How strong is the patent estate for Compound 1?

The strength of US 10,449,184 is concentrated in formulation execution.

Strongest protection

The strongest claim combinations are likely:

Compound 1 at approximately 30% w/w;
HPMCAS as the polymer;
spray-dried dispersion;
amorphous solid state;
microcrystalline cellulose, croscarmellose sodium, sodium lauryl sulfate, colloidal silicon dioxide and magnesium stearate; and
tablet dosage form.

These limitations map closely to a practical oral product and make design-around more difficult if HPMCAS is required for acceptable exposure and stability.

Weaker or more contestable features

The following issues may create validity or enforcement pressure:

The broad 25%-75% drug-loading range may face written-description or enablement scrutiny if the specification does not support the full range across all four polymers.
“Solid dispersion” may require technical interpretation based on the specification and analytical evidence.
The claims combine conventional excipients and standard processing concepts that may be challenged under obviousness.
The polymer list includes well-known dispersion polymers. The patent’s nonobviousness case therefore likely depends on unexpected dissolution, exposure, stability, or manufacturability data.
Claims 21 and 22 may be easier to prove against a finished tablet but narrower in commercial reach.

The patent is stronger against a product that copies the complete claimed formulation than against a generic development program that uses a different polymer or dosage-form process.

When does US Patent 10,449,184 lose exclusivity?

A US utility patent generally expires 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable patent-term extension. The grant date, October 22, 2019, does not determine the ordinary expiration date.

For US 10,449,184, the relevant diligence points are:

Exclusivity element	Assessment
Patent type	US utility patent
Grant date	October 22, 2019
Regulatory exclusivity	No FDA approval-based exclusivity identified for bexotegrast
Orange Book status	No listed approved product identified
Biosimilar exclusivity	Not applicable; Compound 1 is a small molecule
Patent expiry	Must be calculated from the earliest effective filing date and adjusted for PTA or terminal disclaimer
PTE relevance	Potentially relevant only if Compound 1 receives FDA approval and the statutory requirements are met

Because bexotegrast remains an investigational small molecule rather than an FDA-approved product, the patent has no current Orange Book-driven listed-patent framework. A future NDA could create an Orange Book listing if the patent then meets FDA listing criteria and claims the approved drug, formulation, or method of use.

What is the FDA and Orange Book status?

Bexotegrast is not identified as an FDA-approved drug in the information provided. It therefore has no FDA-approved reference listed drug, no approved generic-equivalence pathway, and no current Orange Book patent listing attributable to an approved bexotegrast product. The FDA Orange Book generally lists patents associated with approved products, not patents covering investigational compounds alone.[2]

The relevant future regulatory scenarios are:

An NDA for bexotegrast could support Orange Book listing of eligible formulation or method-of-use patents.
A later generic applicant could submit an ANDA only after an approved reference product exists.
A Paragraph IV challenge would become relevant if US 10,449,184 were listed for the reference product and remained unexpired.
If the patent is not listed, a generic applicant could still face ordinary patent litigation, but the statutory 30-month stay mechanism would not arise from this patent.

What Paragraph IV challenges and generic-entry risks exist?

No Paragraph IV challenge can be tied to this patent without an approved reference product and an FDA Orange Book listing. The principal generic-entry risk is therefore prospective rather than active.

A future ANDA applicant could pursue several design-around routes:

Design-around route	Risk assessment
Use a polymer outside the four listed polymers	Potentially effective against claim 1, subject to equivalents
Use less than 25% or more than 75% drug in the dispersion	May avoid the literal loading range, but formulation performance may suffer
Use a crystalline dispersion rather than an amorphous dispersion	Avoids claim 8 but not necessarily claims 1-7
Use a non-spray-dried process	May avoid claim 3 and its dependent claims
Use a capsule instead of a tablet	Avoids claim 23 but not broader composition claims
Replace HPMCAS in the final dosage form	May avoid the dominant commercial embodiment
Use a different excipient system	Avoids claims 11-23 only if the broader claims are also avoided

A formulation that uses Compound 1, HPMCAS and a 25%-75% solid dispersion remains exposed to claim 1 even if it uses a capsule, a different filler, or a different tableting lubricant. A process change alone does not avoid claim 1 unless it also changes the claimed product characteristics.

What manufacturing and intellectual-property barriers does the patent create?

The patent creates a product-by-process-adjacent barrier around spray-dried amorphous dispersion manufacture. Although the claims are composition claims, manufacturing choices determine whether the final material has the claimed characteristics.

Potential evidence in an infringement dispute could include:

batch composition records;
polymer identity and grade;
drug-loading calculations;
spray-drying records;
powder X-ray diffraction;
differential scanning calorimetry;
solid-state NMR;
microscopy;
dissolution testing;
residual-solvent data; and
tablet-content uniformity records.

The patent does not claim the spray-drying apparatus, solvent system, inlet temperature, outlet temperature, feed rate, atomization conditions, or drying cycle in the claims provided. Those manufacturing details may be protected in separate patents or applications, but they are not independently claimed here.

Which companies are challenging or licensing the patent?

No challenged proceeding, settlement agreement, or license involving US 10,449,184 is established by the supplied record. Bexotegrast development has been associated with Pliant Therapeutics and collaboration activity involving Pfizer, but a commercial license covering this specific patent should not be inferred without an agreement, SEC filing, or patent-assignment record identifying US 10,449,184.

The absence of an identified Paragraph IV case is consistent with the product’s investigational status. It does not establish that the patent is unlicensed or unchallenged in private negotiations.

How does US 10,449,184 compare with compound and method-of-use patents?

Patent category	What it protects	Relevance to US 10,449,184
Composition-of-matter patent	Compound 1 itself and salts	Usually broader and commercially more important
Solid-state patent	Polymorphs, crystalline forms, hydrates or solvates	Separate from the claimed polymer dispersion
Formulation patent	Drug-polymer dispersion and finished dosage form	Primary subject of US 10,449,184
Manufacturing patent	Spray drying, solvent systems and processing parameters	Not apparent from the claims supplied
Method-of-use patent	Treatment of fibrosis or other diseases	Not claimed in US 10,449,184
Regulatory patent	Approved formulation or method listed in the Orange Book	Not currently active without an approved reference product

A composition-of-matter patent could block Compound 1 regardless of formulation. US 10,449,184 operates at a narrower layer: it can restrict a specific oral delivery strategy even after a molecule patent expires, but only if the accused product practices the claimed dispersion and excipient limitations.

What is the commercial exposure and competitive landscape?

The commercial value of this patent depends on whether the HPMCAS spray-dried dispersion becomes the clinical and commercial dosage form. If the sponsor changes to another polymer, a different solid state, or a non-tablet presentation, the patent’s product-level relevance may decline.

The principal competitive risks are:

an alternative formulation that achieves comparable exposure without HPMCAS;
a liquid, capsule, or multiparticulate dosage form outside the narrower claims;
a licensed formulation technology that improves bioavailability without using the claimed excipient combination;
expiration or invalidation of broader compound patents before formulation patents become commercially relevant; and
clinical failure or regulatory delay for bexotegrast.

Biosimilar risk is not relevant because Compound 1 is a small molecule. Generic risk becomes material only after approval, reference-product availability, ANDA eligibility, and a commercially viable design-around or patent challenge.

Key Takeaways

US 10,449,184 is a formulation patent for oral Compound 1 solid dispersions.
Claim 1 covers 25%-75% w/w Compound 1 with HPMCAS, PVAP, HPMC or HPMCP.
The commercially important embodiment is a spray-dried amorphous HPMCAS dispersion.
Claims 21-23 target a specific tablet formulation using approximately 30% Compound 1 and 30% HPMCAS.
The patent does not, on the claims provided, claim Compound 1 itself, a therapeutic method, or the spray-drying apparatus.
No current Orange Book listing or Paragraph IV challenge is established for this investigational product.
Generic developers have credible design-around options using another polymer, a different solid state, a non-spray-dried process, or a different dosage form.
The patent’s commercial strength depends on whether the claimed HPMCAS tablet becomes the approved product.
Patent-term analysis must use the earliest effective filing date, patent-term adjustment and any terminal disclaimer, rather than the 2019 grant date alone.

FAQs

Is US 10,449,184 a patent on bexotegrast itself?

No. The claims provided are directed to pharmaceutical compositions containing Compound 1 in a polymeric solid dispersion. A separate composition-of-matter patent would be required to protect the molecule itself.

Can a capsule infringe US 10,449,184?

Yes. Claims 1 through 22 are not limited to tablets. A capsule using Compound 1 in the claimed solid dispersion and polymer system could fall within the broader composition claims, even though it would not meet claim 23.

Does using HPMCAS automatically create infringement risk?

No. HPMCAS use is relevant only when the product also satisfies the remaining limitations, including Compound 1, oral administration, solid-dispersion status and the claimed drug-loading range.

Can a generic avoid the patent by using HPMC instead of HPMCAS?

Not necessarily. HPMC is expressly included in claim 1. A product using HPMC may avoid narrower HPMCAS claims but remain exposed to the broader independent claim.

Are biosimilars relevant to the bexotegrast patent landscape?

No. Bexotegrast is a small molecule. The relevant follow-on pathway would be a generic drug application, not a biosimilar application.

References

United States Patent No. 10,449,184, “Pharmaceutical compositions comprising Compound 1.” U.S. Patent and Trademark Office. https://patents.google.com/patent/US10449184B2/en
U.S. Food and Drug Administration. (n.d.). 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. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
ClinicalTrials.gov. (n.d.). Bexotegrast clinical-trial records. U.S. National Library of Medicine. https://clinicaltrials.gov/

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Servier	TIBSOVO	ivosidenib	TABLET;ORAL	211192-001	Jul 20, 2018		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial	Y				⤷ 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
Australia	2015229214	⤷ Start Trial
Australia	2019246824	⤷ Start Trial
Brazil	112016021232	⤷ Start Trial
Canada	2942072	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,449,184

Which drugs does patent 10,449,184 protect, and when does it expire?

Summary for Patent: 10,449,184