Details for Patent: 10,442,829

Which drugs does patent 10,442,829 protect, and when does it expire?

Patent 10,442,829 protects SIVEXTRO and is included in two NDAs.

This patent has forty-two patent family members in twenty-eight countries.

Summary for Patent: 10,442,829

Title:	Forms of R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one dihydrogen phosphate
Abstract:	A crystalline form of crystalline (R)-3-(4-(2-(2-methyltetrazol-5-yl)-pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one dihydrogen phosphate, methods of making the crystalline form and pharmaceutical compositions comprising the crystalline form are useful antibiotics. Further, the derivatives of the present invention may exert potent antibacterial activity versus various human and animal pathogens, including Gram-positive bacteria such as Staphylococi, Enterococci and Streptococi, anaerobic microorganisms such as Bacteroides and Clostridia, and acid-resistant microorganisms such as Mycobacterium tuberculosis and Mycobacterium avium. Accordingly, the compositions comprising the crystalline form may be used in antibiotics.
Inventor(s):	Katharina Reichenbacher, Robert J. Duguid, Jacqueline A. Ware, Douglas Phillipson
Assignee:	Merck Sharp and Dohme LLC
Application Number:	US15/970,486
Patent Claim Types: see list of patent claims	Compound;

United States Patent 10,442,829: Tedizolid Phosphate Crystal Form, Claim Scope, and Patent Landscape

U.S. Patent No. 10,442,829 protects a specific crystalline form of tedizolid phosphate, the active pharmaceutical ingredient in Sivextro. Claim 1 is a product-by-structure claim defined by the tedizolid phosphate chemical structure and six characteristic X-ray powder diffraction peaks. The claim does not broadly cover all tedizolid phosphate, all crystalline forms, or the drug product as a whole.

The patent creates a potential generic-entry barrier where an ANDA applicant manufactures, imports, sells, or uses tedizolid phosphate having the claimed crystal form in the United States. It does not create biosimilar risk because tedizolid phosphate is a chemically synthesized small molecule rather than a biologic.

What drug and active ingredient does U.S. Patent 10,442,829 protect?

The patent concerns tedizolid phosphate, also known as the phosphate prodrug of tedizolid. Tedizolid is an oxazolidinone antibacterial agent approved by the FDA under the brand name Sivextro for designated Gram-positive bacterial infections, including acute bacterial skin and skin-structure infections.[1]

The claimed chemical entity is:

(R)-3-(4-(2-(2-methyltetrazol-5-yl)pyridin-5-yl)-3-fluorophenyl)-5-hydroxymethyl oxazolidin-2-one dihydrogen phosphate

The structure identifies:

• The tedizolid active moiety.
• The R stereochemical configuration.
• A fluorinated phenyl substituent.
• A pyridine ring bearing a methyltetrazole group.
• A hydroxymethyl oxazolidinone phosphate prodrug.
• A dihydrogen phosphate form rather than an unrelated salt or free base.

The claim then narrows the chemical entity to a specified crystalline form.

What exactly does Claim 1 of U.S. Patent 10,442,829 cover?

Claim 1 covers a crystalline form of tedizolid phosphate having an XRPD pattern that includes peaks at:

XRPD peak	Claimed angle
Peak 1	14.7°
Peak 2	15.2°
Peak 3	16.6°
Peak 4	20.3°
Peak 5	26.8°
Peak 6	28.2°

The angles are understood as 2-theta positions in an X-ray powder diffraction pattern, subject to the analytical conventions and tolerances applied by the patent and the relevant court or technical expert.

The operative claim language is materially narrower than a claim to tedizolid phosphate generally. An accused product must satisfy both elements:

1. It must contain the specified tedizolid phosphate chemical structure.
2. The material must be a crystalline form exhibiting the required six-peak XRPD pattern.

The word "comprising" broadens the claim in one important respect. The claimed crystal may have additional XRPD peaks. The presence of extra peaks does not avoid infringement if the six listed peaks are present and the material otherwise falls within the claim.

Does the patent cover all forms of tedizolid phosphate?

No. The claim does not cover every physical or chemical form of tedizolid phosphate.

Material or product	Likely position under Claim 1
Claimed tedizolid phosphate crystal	Covered if the six required peaks are present
Tedizolid phosphate with a different polymorph	Not literally covered unless it also produces the claimed pattern
Amorphous tedizolid phosphate	Not literally covered
Tedizolid free base	Not covered
A different phosphate salt or counterion	Not covered if the claimed dihydrogen phosphate structure is absent
A different stereoisomer	Not covered
A solution containing dissolved tedizolid phosphate	Depends on whether the claimed crystalline material is present
A tablet containing the claimed crystalline API	Potentially covered through composition, manufacture, use, or sale theories
A product that converts into the claimed crystal during manufacture or storage	Potential infringement risk depends on when and where the conversion occurs

The claim is directed to the physical form of the active ingredient, not simply to the pharmacological use of tedizolid.

How does the XRPD limitation affect infringement?

The XRPD limitation is the principal technical boundary of the claim. A generic manufacturer would typically need to characterize its tedizolid phosphate using XRPD and related solid-state methods.

Relevant evidence can include:

• XRPD peak positions.
• Relative intensities.
• Peak widths and resolution.
• Instrument radiation source.
• Sample preparation.
• Hydration or solvation state.
• Differential scanning calorimetry.
• Thermogravimetric analysis.
• Karl Fischer water content.
• Infrared or Raman spectroscopy.
• Solid-state NMR.
• Batch-to-batch reproducibility.

Because the supplied claim recites peak positions but does not identify relative intensities in the quoted text, an infringement dispute may focus on analytical tolerances and the meaning of a matching peak. A small shift caused by instrument calibration, hydration, crystallinity, or sample preparation should not automatically establish noninfringement.

The patent owner would likely compare the accused material with the reference pattern using validated XRPD data. The generic manufacturer would argue that a different polymorph, hydrate, solvate, amorphous form, or mixed solid-state composition does not meet the claim.

When does U.S. Patent 10,442,829 expire?

The patent issued on October 15, 2019.[2] Public patent-family information associates the patent with a 2013 priority filing. On that basis, the nominal patent term runs to approximately March 15, 2034, subject to patent-term adjustment, terminal disclaimers, or other term calculations recorded by the USPTO.

Milestone	Date or status
Earliest reported priority	March 15, 2013
U.S. patent issuance	October 15, 2019
Nominal expected expiration	Approximately March 15, 2034
Patent term extension	Must be checked against the USPTO and FDA records
Patent-term adjustment	Must be checked in the issued patent record

A patent expiration date is not the same as the date on which generic filing or launch becomes legally possible. FDA regulatory exclusivity, other listed patents, litigation settlements, and court-ordered launch restrictions can change the commercial timing.

What is the FDA regulatory status of tedizolid and Sivextro?

The FDA approved Sivextro under NDA 205435 on June 20, 2014.[1] The approved products include intravenous and oral formulations of tedizolid phosphate.

Tedizolid received new chemical entity exclusivity. It also received Qualified Infectious Disease Product treatment under the Generating Antibiotic Incentives Now provisions, which can extend applicable exclusivity by five years.[3] The principal FDA exclusivity period therefore expired before the nominal expiration of the crystalline-form patent.

Regulatory right	Relevance
New chemical entity exclusivity	Initially blocked certain ANDA approvals
QIDP-related extension	Extended the applicable exclusivity period
Orange Book patent protection	Can continue after FDA exclusivity ends
Patent 10,442,829	Protects a defined solid form rather than the drug generally

The commercial significance of Patent 10,442,829 is therefore primarily patent-based rather than regulatory-exclusivity-based.

What is the Orange Book status of Patent 10,442,829?

Patent 10,442,829 is relevant to the Orange Book patent landscape for Sivextro because it claims a pharmaceutical form of the approved active ingredient. The controlling issue is whether the patent is listed against NDA 205435 in the applicable FDA Orange Book edition and whether any use code or listing limitation applies.[4]

An Orange Book listing can trigger a notice obligation for an ANDA applicant that files a Paragraph IV certification. Listing does not establish validity or infringement. It identifies a patent that the NDA holder or patent owner has represented as relevant to the approved drug.

For business planning, the patent should be analyzed with:

• The current Orange Book listing.
• Any listed expiration date.
• The NDA holder and patent owner.
• The certification selected by each ANDA applicant.
• Paragraph IV notice dates.
• Any resulting district-court litigation.
• Any settlement or 30-month stay.

What Paragraph IV challenges affect tedizolid phosphate?

A Paragraph IV certification asserts that an Orange Book-listed patent is invalid, unenforceable, or not infringed. A generic applicant can also use a Paragraph III certification and wait for patent expiration, or certify that the patent is not relevant to the proposed product.

For this patent, a Paragraph IV challenge would likely target one or more of the following issues:

Anticipation

The challenger would search for a prior-art disclosure of the same tedizolid phosphate crystal and the required XRPD peaks. A general disclosure of tedizolid phosphate would not necessarily anticipate the claimed polymorph.

Obviousness

The challenger could argue that the claimed crystal was an obvious solid-state form selected from known tedizolid phosphate materials. The patent owner would likely rely on unexpected properties such as:

• Improved chemical stability.
• Reduced hygroscopicity.
• Better manufacturability.
• Improved filtration or drying.
• Consistent particle properties.
• Superior storage stability.
• Reduced conversion to another solid form.

Unexpected results are often central to the validity of pharmaceutical polymorph claims.

Indefiniteness

A challenger could contest the claim if the patent does not adequately define acceptable XRPD peak tolerances, analytical conditions, or the level of identity required. Courts generally evaluate XRPD claims in light of the specification, figures, examples, and ordinary technical practice.

Written description and enablement

The challenger could argue that the specification does not adequately characterize or enable the full scope of the claimed crystal. The patent owner would respond that the disclosed preparation methods and analytical data allow a skilled person to make and identify the form.

Double patenting

If earlier patents in the tedizolid family claim overlapping crystalline forms, salts, or pharmaceutical compositions, a terminal-disclaimer or obviousness-type double-patenting issue may arise.

No specific Paragraph IV judgment or settlement is identified here as having finally eliminated Patent 10,442,829. The litigation position must be determined from the current FDA, PACER, and USPTO records.

What other patents protect tedizolid and Sivextro?

The tedizolid estate is broader than the single crystal-form patent. The principal patent categories are:

Patent category	Protected subject matter	Commercial relevance
Core composition patents	Tedizolid and related oxazolidinone compounds	Broadest chemical protection
Prodrug patents	Tedizolid phosphate and related phosphate derivatives	Protects the approved active ingredient
Salt and solid-form patents	Crystalline tedizolid phosphate forms	Can block API manufacture or supply
Formulation patents	Oral tablets, injectable products, excipients, and dosage forms	Relevant to finished-dose ANDA design
Method-of-use patents	Treatment of bacterial infections	Relevant if the ANDA label includes the patented use
Manufacturing patents	Preparation, purification, crystallization, and isolation processes	Can restrict API suppliers
Regulatory patents	Orange Book-listed rights tied to the approved NDA	Determines certification and litigation exposure

Patent 10,442,829 is strongest against a generic that uses the same crystalline API. It is less relevant to a manufacturer that can reliably produce and maintain a noninfringing polymorph or amorphous material.

How strong is the patent estate for tedizolid phosphate?

The estate has meaningful technical strength because a crystalline-form claim can protect an API manufacturing choice that is difficult to design around if the marketed product and validated supply chain depend on that form.

Its strength has four principal dimensions:

1. Chemical identity: the claim is limited to tedizolid phosphate.
2. Solid-state identity: the claim requires a particular crystalline form.
3. Analytical identification: XRPD provides a comparatively direct infringement test.
4. Manufacturing relevance: a generic product may need a stable, reproducible crystalline API for regulatory and commercial reasons.

The claim is narrower than a composition-of-matter claim. Its vulnerability is correspondingly higher if prior art discloses the same polymorph or if the claimed XRPD pattern is not sufficiently distinguished from known forms.

The patent does not prevent every generic strategy. A design-around could involve:

• A different polymorph.
• An amorphous solid.
• A different hydrate or solvate.
• A different crystallization route producing a distinct form.
• A formulation that avoids retaining the claimed crystalline API.

Each option creates separate FDA, stability, scale-up, and bioequivalence risks.

Are biosimilars a risk to Sivextro?

No. Tedizolid phosphate is a small-molecule drug. The relevant competitors are generic applicants filing ANDAs, not biosimilar applicants filing under the Public Health Service Act.

The main barriers are:

• Orange Book-listed patents.
• API solid-form reproducibility.
• Bioequivalence.
• Oral and intravenous product development.
• CMC comparability.
• Paragraph IV litigation.
• Supply-chain qualification.

Which companies compete with tedizolid?

Tedizolid competes in the Gram-positive antibacterial market with linezolid, vancomycin, dalbavancin, oritavancin, and other agents used for acute bacterial skin and skin-structure infections.

Drug	Company or commercial origin	Competitive point
Sivextro, tedizolid phosphate	Cubist, later Merck	Once-daily oxazolidinone therapy
Zyvox, linezolid	Pfizer originator	Earlier oxazolidinone with generic competition
Vancomycin	Multiple manufacturers	Established IV therapy
Dalbavancin	Melinta	Long-acting dosing
Oritavancin	Melinta	Long-acting dosing

Linezolid has greater generic competition and a more mature market. Long-acting agents compete through reduced dosing frequency rather than the same chemical class.

What licensing and ownership transactions affect tedizolid?

Tedizolid originated with Trius Therapeutics. Cubist Pharmaceuticals acquired Trius in 2013, bringing tedizolid into the Cubist portfolio.[5] Merck acquired Cubist in 2015 for approximately $9.5 billion, transferring Sivextro and the associated intellectual-property estate to Merck.[6]

These transactions are more important than a conventional third-party license for ownership analysis. They establish the succession of commercial and patent interests:

Trius Therapeutics → Cubist Pharmaceuticals → Merck

The acquisition chain should be reconciled with individual assignment records because patent ownership, NDA ownership, and commercialization rights can differ by jurisdiction and time.

What generic launch scenarios exist for tedizolid?

Early Paragraph IV launch

A generic applicant could challenge Patent 10,442,829 and other listed patents. A successful judgment, settlement permitting launch, or loss of enforceability could enable entry before the nominal 2034 expiration date.

Noninfringing polymorph launch

A generic could attempt to use a crystal form that does not show the six required peaks. This strategy would require robust proof that the alternative form remains distinct across manufacturing, storage, formulation, and testing.

Post-expiration launch

A manufacturer could avoid Paragraph IV litigation and target launch after the relevant patent term. This approach reduces litigation risk but delays commercial entry.

At-risk launch

A company could launch before final resolution of patent disputes. This creates exposure to damages, injunction risk, destruction or recall of inventory, and potential liability for induced or contributory infringement.

What geographic coverage does the patent have?

U.S. Patent 10,442,829 applies only in the United States. Parallel protection may exist in other jurisdictions through the related international patent family, but foreign rights require separate review of:

• National-phase publications.
• Granted claims.
• Local patent-term rules.
• Supplementary protection certificates.
• Opposition or revocation proceedings.
• Patent-linkage rules.
• Local Orange Book equivalents.

A U.S. noninfringement position does not establish freedom to operate in Europe, Japan, China, Canada, or other markets.

Key Takeaways

• U.S. Patent 10,442,829 claims a specific crystalline form of tedizolid phosphate.
• Claim 1 requires the tedizolid phosphate structure and six XRPD peaks at 14.7°, 15.2°, 16.6°, 20.3°, 26.8°, and 28.2°.
• The claim does not cover all tedizolid phosphate, all polymorphs, amorphous material, or tedizolid free base.
• The use of "comprising" permits additional XRPD peaks but does not remove the requirement for the six listed peaks.
• The patent issued October 15, 2019, with a nominal expiration around March 15, 2034, subject to official term adjustments.
• Tedizolid received FDA approval in 2014, and its regulatory exclusivity expired before the expected patent expiration.
• The relevant competitor pathway is an ANDA with Paragraph III or Paragraph IV certification, not a biosimilar application.
• The most practical design-around is a reliably distinct tedizolid phosphate polymorph or amorphous form, although CMC and stability risks remain.
• Ownership traces from Trius Therapeutics to Cubist Pharmaceuticals and then Merck.
• Patent 10,442,829 should be assessed together with core composition, prodrug, formulation, method-of-use, and manufacturing patents.

FAQs About U.S. Patent 10,442,829 and Tedizolid Phosphate

Can a generic use tedizolid phosphate without infringing Patent 10,442,829?

Yes, potentially. A generic using a different solid form may avoid literal infringement, but it must establish that the alternative material does not contain the claimed XRPD pattern or convert into that form.

Does the patent cover Sivextro tablets?

It can create indirect product risk if Sivextro tablets contain the claimed crystalline tedizolid phosphate. The patent is directed to the API form, not necessarily to every tablet formulation or every use of the finished product.

Can an XRPD peak shift avoid infringement?

Not necessarily. The legal analysis depends on the permitted analytical tolerance, testing conditions, specification, and whether the accused peak is materially the same characteristic peak.

Is Patent 10,442,829 a composition-of-matter patent?

It is a composition patent limited by solid-state structure. It is not a broad composition-of-matter claim covering every molecule of tedizolid or every form of tedizolid phosphate.

What is the main invalidity risk for this crystal-form patent?

The principal risks are prior-art disclosure of the same polymorph, obviousness based on routine polymorph screening, inadequate technical definition of the XRPD pattern, and insufficient evidence of unexpected properties.

References

1. U.S. Food and Drug Administration. (2014). Sivextro approval letter and prescribing information, NDA 205435.
2. United States Patent and Trademark Office. (2019). U.S. Patent No. 10,442,829, Crystalline form of tedizolid phosphate.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Food and Drug Administration. (2024). Approved drug product with therapeutic equivalence evaluations, NDA 205435 patent listings.
5. Cubist Pharmaceuticals, Inc. (2013). Cubist completes acquisition of Trius Therapeutics.
6. Merck & Co., Inc. (2015). Merck completes acquisition of Cubist Pharmaceuticals.

Drugs Protected by US Patent 10,442,829

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Cubist Pharms Llc	SIVEXTRO	tedizolid phosphate	POWDER;INTRAVENOUS	205436-001	Jun 20, 2014		RX	Yes	Yes				Y
Cubist Pharms Llc	SIVEXTRO	tedizolid phosphate	TABLET;ORAL	205435-001	Jun 20, 2014		RX	Yes	Yes				Y

International Family Members for US Patent 10,442,829

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
African Regional IP Organization (ARIPO)	2987
Australia	2010210627
Brazil	PI1008829
Canada	2751392