US Patent 10,532,047: Olutasidenib Solid-Form Scope, Exclusivity and Patent-Landscape Analysis

US Patent 10,532,047 protects a specific crystalline solid form of olutasidenib, the active ingredient in Rezlidhia. The patent is not a broad composition-of-matter patent. Its enforceable scope is concentrated on olutasidenib material exhibiting defined XRPD, DSC, and DVS characteristics. The strongest practical coverage is directed to the crystalline form identified by XRPD peaks at 6.3°, 12.8°, 13.8°, 23.6°, and 27.8° 2θ, with a DSC endotherm near 256.6°C and low water uptake of approximately 0.25% w/w at 25°C and 90% relative humidity. [1]

The patent can create a manufacturing and formulation barrier for a generic olutasidenib product if the proposed active pharmaceutical ingredient or finished dosage form uses the claimed crystalline form. It does not, on its face, prevent every olutasidenib product that uses a different polymorph, amorphous material, solvate, hydrate, salt, or other non-infringing solid form.

What drug does US Patent 10,532,047 protect?

US 10,532,047 protects a solid form of olutasidenib, also identified in the claims by its chemical name:

“((S)-5-((1-(6-chloro-2-oxo-1,2-dihydroquinolin-3-yl)ethyl)amino)-1-methyl-6-oxo-1,6-dihydropyridine-2-carbonitrile.”

Olutasidenib is an isocitrate dehydrogenase-1 inhibitor marketed by Rigel Pharmaceuticals as Rezlidhia. The FDA approved Rezlidhia in December 2022 for adults with relapsed or refractory acute myeloid leukemia with a susceptible IDH1 mutation. [2]

The patent protects physical-state characteristics of the molecule rather than the molecule’s therapeutic mechanism or all medical uses.

Patent identity and subject matter

Item	Analysis
Patent	US 10,532,047
Protected subject matter	Crystalline solid form of olutasidenib
Primary analytical tools	XRPD, DSC and DVS
Key XRPD peaks	6.3°, 12.8°, 13.8°, 23.6° and 27.8° 2θ
Additional XRPD peaks	5.7°, 8.5°, 10.6°, 17.3°, 22.0°, 22.8° and others
DSC marker	Endothermic event at approximately 256.6°C
Moisture marker	Maximum water uptake of approximately 0.25% w/w at 25°C/90% RH
Dosage-form limitation	The claims provided are not expressly limited to capsules, tablets or another finished dosage form
Product relationship	Relevant to the active ingredient and any dosage form containing the claimed solid form

How many claims does US 10,532,047 have?

The patent has 20 claims in the claim set provided. Claims 1 through 13 focus on “Compound 1” and then identify the compound through solid-state characteristics. Claims 14 through 20 expressly identify olutasidenib.

The claims are heavily nested. Claims 2 through 9 depend on claim 1, claims 11 through 13 depend on claim 10, and claims 15 through 20 create a second olutasidenib-specific chain.

Claim architecture

Claims	Main limitation	Practical function
1	Solid form with five specified XRPD peaks	Broadest XRPD-based independent claim in the first claim group
2	Claim 1 plus specified d-spacings	Adds corresponding crystallographic spacing
3	Claim 1 plus expanded XRPD pattern	Adds eleven identified peaks
4	Claim 3 plus expanded d-spacings	Adds crystallographic spacing for the expanded pattern
5	Claim 1 plus a substantially complete XRPD pattern	Most detailed XRPD fingerprint in the first group
6	Claim 1 plus DSC event near 256.6°C	Adds thermal characterization
7	Claim 2 plus DSC event	Combines XRPD, d-spacing and DSC
8	Claim 1 plus DVS water uptake	Adds humidity-response limitation
9	Claim 6 plus DVS water uptake	Combines XRPD, DSC and DVS
10	Independent compound-specific DSC claim	Covers olutasidenib identified by DSC conditions
11-13	Claim 10 combined with XRPD and DVS	Adds dependent analytical markers
14	Independent olutasidenib solid-form claim	Covers at least one of XRPD, DSC or DVS characteristics
15	Claim 14 plus five-peak XRPD pattern	Narrows the independent claim
16-18	Expanded XRPD pattern and d-spacings	Adds increasingly detailed fingerprint limitations
19	Claim 18 plus DSC	Combines full XRPD pattern and thermal event
20	Claim 19 plus DVS	Narrowest combined analytical claim

What is the broadest claim in US Patent 10,532,047?

Claim 14 is potentially the broadest olutasidenib-specific claim in the provided claim set. It covers a solid form of olutasidenib characterized by at least one of three properties:

The specified five-peak XRPD pattern;
A DSC endothermic event at approximately 256.6°C; or
Maximum water uptake of approximately 0.25% w/w at 25°C and 90% relative humidity.

This “at least one” structure is materially broader than the claims requiring simultaneous XRPD, DSC and DVS characteristics. A material could potentially fall within claim 14 based on only one qualifying analytical characteristic, assuming the claim survives construction and the accused material satisfies the applicable measurement parameters.

Claim 10 is also significant because it is an independent claim directed to olutasidenib characterized by the DSC event. It specifies the DSC method, including an aluminum pan, nitrogen purge, a 10°C/minute ramp rate and a temperature range beginning at approximately room temperature.

What XRPD pattern does the patent cover?

The core XRPD signature is:

2θ, ±0.2°	d-spacing, ±0.2 Å
6.3°	14.0 Å
12.8°	6.9 Å
13.8°	6.4 Å
23.6°	3.8 Å
27.8°	3.2 Å

The expanded pattern adds peaks at 5.7°, 8.5°, 10.6°, 17.3°, 22.0° and 22.8°. Claim 5 also lists additional peaks extending through 38.1° 2θ.

A key infringement issue is that XRPD peaks are not normally required to match with unlimited numerical precision. The claims use tolerances of ±0.2° 2θ and, in several claims, “same or substantially the same” peak positions. Differences caused by instrument calibration, sample preparation, preferred orientation, crystallite size, humidity, temperature or data-processing methods may become important in an infringement dispute.

Technical scope of the XRPD limitations

The XRPD claims can cover:

The isolated active pharmaceutical ingredient;
A drug substance used to manufacture capsules;
A partially processed intermediate retained in the final product;
A solid form recovered from a finished dosage form;
A crystalline material blended with excipients, if the claimed form remains present and analytically identifiable.

The claims do not expressly require a particular particle size, morphology, purity level, solvent content, excipient, capsule shell or manufacturing process.

Does the patent cover olutasidenib generally?

No. The claims provided do not cover every form of olutasidenib.

A product may avoid literal infringement if it uses:

A different polymorph with a materially different XRPD pattern;
An amorphous form;
A hydrate or solvate that does not exhibit the claimed characteristics;
A salt or co-crystal outside the claim language;
A material whose DSC profile does not show the claimed thermal event;
A form that does not meet the specified DVS limitation where DVS is required by the asserted claim.

That distinction matters for generic strategy. A generic sponsor could pursue a solid-form design-around, but the alternative form would need to satisfy pharmaceutical development, stability, bioavailability, scale-up and regulatory requirements. A technically non-infringing form that cannot support a reliable capsule product has limited commercial value.

When does US Patent 10,532,047 lose exclusivity?

The patent issued on January 14, 2020. Its ordinary patent term is generally measured from the applicable nonprovisional or international filing date, subject to patent-term adjustment and any terminal disclaimer. The claims provided do not include the front-page bibliographic data needed to state an exact expiration date.

The practical exclusivity date therefore depends on:

The earliest effective nonprovisional filing date;
Any priority claims;
Patent-term adjustment;
Any patent-term extension;
Any terminal disclaimer;
Whether the patent is listed for the approved Rezlidhia product;
The scope and timing of any settlement with a generic applicant.

Patent term and FDA regulatory exclusivity are separate. FDA approval of Rezlidhia in 2022 created regulatory exclusivity periods independent of the patent term. [2]

FDA exclusivity

For an approved small-molecule drug, relevant FDA exclusivities may include:

Exclusivity type	General duration	Relevance
New chemical entity exclusivity	5 years	Blocks abbreviated new drug applications during the applicable period, subject to statutory exceptions
Orphan-drug exclusivity	7 years	Applies to the same drug and indication if orphan designation and approval requirements are met
Three-year clinical-investigation exclusivity	3 years	May apply to certain changes supported by new clinical investigations
Pediatric exclusivity	6 months	Applies only if granted after completion of an FDA pediatric requirement

The applicable exclusivity status must be confirmed from FDA records. Patent expiry does not automatically establish generic launch eligibility if FDA exclusivity or other listed patents remain active.

What is the Orange Book status of US 10,532,047?

US 10,532,047 is potentially relevant to Orange Book protection for Rezlidhia because it claims a solid form of the active ingredient used in the approved drug. Orange Book listing, however, must be confirmed against the current FDA Approved Drug Products with Therapeutic Equivalence Evaluations database and the sponsor’s patent submission.

An Orange Book-listed patent can require an ANDA applicant to:

Certify that the patent information is not applicable;
Certify that the patent has expired;
Submit a Paragraph III certification stating that approval will wait until patent expiry;
Submit a Paragraph IV certification alleging that the patent is invalid, unenforceable or not infringed.

A solid-form patent may be listed if it claims the drug substance, drug product, formulation, or an approved method of use. The claims supplied here are drug-substance solid-form claims. They are not conventional method-of-use claims and do not expressly recite a capsule formulation.

What Paragraph IV challenges could target this patent?

A Paragraph IV challenge could attack US 10,532,047 on several grounds:

Non-infringement

The ANDA applicant could certify that its olutasidenib does not contain the patented form. This position would require analytical evidence showing that the proposed drug substance lacks the relevant XRPD peaks, DSC event or DVS behavior.

Anticipation

The applicant could argue that the claimed solid form was disclosed in a single earlier publication, patent, regulatory filing or other qualifying prior-art reference. For a polymorph patent, anticipation generally requires disclosure of the claimed form and its defining characteristics, not merely disclosure of the molecular structure.

Obviousness

The applicant could argue that the claimed form would have been obvious to a skilled person seeking a stable, manufacturable or low-hygroscopic olutasidenib form. Relevant evidence could include:

Routine polymorph screening;
Predictable crystallization behavior;
Prior disclosure of the same solvent system;
Known solid-state properties of structurally related IDH1 inhibitors;
Motivation to improve stability or moisture resistance.

Indefiniteness and written description

Terms such as “about,” “same or substantially the same,” and analytical limits may be challenged if the patent does not provide an objective boundary. The DSC claim may also raise questions concerning reproducibility across instruments, pans, purge conditions and heating rates.

The patent’s detailed analytical parameters strengthen reproducibility for the DSC limitation. The XRPD claims remain dependent on sample and instrument conditions, which could be central to litigation.

How strong is the patent estate for olutasidenib?

US 10,532,047 appears technically focused but commercially meaningful. Its strength is higher against a generic that uses the same development form as the reference product and lower against a sponsor that develops a genuinely different polymorph or amorphous form.

Factor	Assessment
Claim breadth	Moderate for the claimed form; narrow for olutasidenib generally
Product relevance	High if Rezlidhia uses the patented crystalline form
Detectability	High; XRPD, DSC and DVS provide established analytical tools
Design-around potential	Real but technically demanding
Manufacturing relevance	High because the claims attach to the drug substance
Method-of-use protection	Not provided by the supplied claims
Formulation protection	Not expressly provided by the supplied claims
Litigation leverage	Strongest where the generic copies the reference crystalline form
Prior-art vulnerability	Dependent on earlier solid-form disclosures and crystallization data

The patent’s low water uptake limitation may also support a commercial narrative around stability and handling. That property does not by itself establish non-obviousness, but it can help connect the claimed form to manufacturing and product-quality advantages.

What manufacturing barriers does the patent create?

A generic manufacturer may need to establish control over:

Polymorph identity;
Seeding and crystallization conditions;
Solvent composition;
Drying temperature and duration;
Milling conditions;
Storage humidity;
Conversion between polymorphs;
Lot-to-lot XRPD consistency.

Even if a generic sponsor selects a non-infringing solid form, manufacturing conditions can unintentionally produce the patented form as a minor component or conversion product. That creates a process-control risk. The sponsor would need validated solid-state specifications and stability data demonstrating that the alternative form remains outside the relevant claims throughout manufacture and storage.

What generic launch scenarios exist?

Scenario 1: Same-form launch

The generic uses the same crystalline form as Rezlidhia. This creates the highest infringement risk and is the most vulnerable path to a Paragraph IV suit.

Scenario 2: Alternative polymorph

The generic uses a distinct polymorph. This reduces literal infringement risk but creates development and regulatory burdens. The alternative form must demonstrate acceptable stability, dissolution, bioequivalence and manufacturing reproducibility.

Scenario 3: Amorphous or non-crystalline material

An amorphous approach may avoid XRPD claims directed to the crystalline pattern. It may introduce physical-stability, hygroscopicity, dissolution and shelf-life risks.

Scenario 4: Delayed launch after patent expiry

A Paragraph III strategy avoids litigation but delays market entry until the relevant patent and regulatory exclusivities have expired.

Scenario 5: Settlement-based entry

A Paragraph IV filing could result in a settlement providing an agreed launch date before patent expiry. The commercial value of that route depends on the patent estate beyond US 10,532,047, FDA exclusivity and the number of competing ANDA applicants.

Which companies are challenging olutasidenib exclusivity?

No company-specific Paragraph IV challenger or settlement can be identified from the claim text alone. Public litigation, ANDA certification and settlement records must be matched to the current Orange Book listing and federal court docket data before attributing a challenge to a particular generic manufacturer.

The competitive field is likely to include:

Large generic manufacturers with oncology portfolios;
Specialty generic companies capable of solid-state development;
Contract manufacturers supplying an ANDA sponsor;
Potential licensees pursuing non-infringing olutasidenib forms.

The absence of a known public challenger in the supplied material does not establish that no challenge exists.

What licensing deals affect the patent?

Forma Therapeutics developed olutasidenib, and Novo Nordisk acquired Forma in 2022. Rigel Pharmaceuticals later obtained rights to commercialize Rezlidhia in the United States. [3] The commercial rights arrangement is relevant to enforcement and product economics, but the claim text does not establish ownership of US 10,532,047, the patent’s assignment history, or the scope of any license.

Patent ownership, Orange Book submission rights and litigation rights should be determined from USPTO assignment records, FDA listing information and the applicable transaction agreements.

How does US 10,532,047 compare with a composition-of-matter patent?

Issue	Solid-form patent	Composition-of-matter patent
Protected subject	Specific physical form	Chemical compound or genus
Design-around	Often possible through another form	Usually more difficult
Detection	XRPD, DSC, DVS or related testing	Chemical identity and structure
Product relevance	Highest when reference drug uses the claimed form	Broad across forms and formulations
Manufacturing impact	Direct	Indirect unless process claims apply
Litigation focus	Form identity and analytical methods	Structure, claim construction and infringement
Commercial durability	Depends on alternative-form feasibility	Usually broader

US 10,532,047 should therefore be treated as a secondary patent barrier relative to a valid composition-of-matter patent, but it may still delay generic entry if the reference product’s crystalline form is copied or if no commercially viable alternative form exists.

Key Takeaways

US 10,532,047 is a solid-form patent for olutasidenib, not a broad claim to all olutasidenib products.
The principal protected form is identified by XRPD peaks at 6.3°, 12.8°, 13.8°, 23.6° and 27.8° 2θ.
The patent also uses a DSC endotherm near 256.6°C and DVS water uptake of approximately 0.25% w/w.
Claim 14 is potentially the broadest olutasidenib-specific claim because it requires at least one of the XRPD, DSC or DVS characteristics.
Claims 19 and 20 provide the most cumulative analytical limitations and are narrower.
A generic sponsor has a possible polymorph or amorphous-form design-around, but the alternative must satisfy manufacturing, stability and regulatory requirements.
Paragraph IV risk is highest where the ANDA product uses the reference product’s crystalline form.
The exact patent expiration date, Orange Book listing status, ownership chain, litigation record and any settlement require confirmation from current USPTO, FDA and court records.
The commercial rights history includes Forma Therapeutics, Novo Nordisk and Rigel Pharmaceuticals.

FAQs

Does US 10,532,047 cover the Rezlidhia capsule itself?

The supplied claims do not expressly recite a capsule, capsule shell, excipient or finished dosage-form composition. They cover the olutasidenib solid form that may be used in the capsule.

Can a generic avoid this patent by using a different polymorph?

Potentially. A genuinely different polymorph may avoid the claimed XRPD pattern, DSC event or DVS characteristic. The alternative form must remain distinct during manufacture and storage.

Is a DSC peak alone enough to infringe the patent?

Claim 10 and claim 14 make the DSC limitation important. Whether a DSC event is sufficient depends on the asserted claim, the required analytical conditions and whether the accused material meets the claim’s “about” limitation.

Does the patent protect olutasidenib treatment of IDH1-mutated AML?

The supplied claims do not recite a therapeutic method, AML, IDH1 mutation status or patient-treatment step. They are solid-form claims.

Can the patent block an olutasidenib API manufactured outside the United States?

US patent infringement can arise from importing into the United States or selling, offering for sale, or using the patented product in the United States. Foreign manufacturing alone does not remove US exposure where the patented product enters the US market.

References

United States Patent No. 10,532,047, claims 1-20 (2020).
U.S. Food and Drug Administration. (2022, December 1). FDA approves olutasidenib for relapsed or refractory acute myeloid leukemia with a susceptible IDH1 mutation. https://www.fda.gov/
Rigel Pharmaceuticals, Inc. (2023). Annual report on Form 10-K. U.S. Securities and Exchange Commission. https://www.sec.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
Rigel Pharms	REZLIDHIA	olutasidenib	CAPSULE;ORAL	215814-001	Dec 1, 2022		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
Cyprus	1126012	⤷ Start Trial
Denmark	3720442	⤷ Start Trial
European Patent Office	3720442	⤷ Start Trial
European Patent Office	4215197	⤷ Start Trial
Spain	2941079	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 10,532,047