Isocitrate Dehydrogenase 1 Inhibitor Drug Class List

Drugs in Drug Class: Isocitrate Dehydrogenase 1 Inhibitor

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Servier	VORANIGO	vorasidenib	TABLET;ORAL	218784-001	Aug 6, 2024		RX	Yes	No	11,345,677		Y	Y
Servier	VORANIGO	vorasidenib	TABLET;ORAL	218784-002	Aug 6, 2024		RX	Yes	Yes	12,433,895
Servier	VORANIGO	vorasidenib	TABLET;ORAL	218784-001	Aug 6, 2024		RX	Yes	No	12,433,895

Isocitrate Dehydrogenase 1 Inhibitor Market Dynamics and Patent Landscape (IDH1 Inhibitors): What Patents Protect, When Exclusivity Expires, and Where Generic Entry Risks Exist

Last updated: July 7, 2026

Executive summary: The IDH1 inhibitor pipeline is dominated by ivosidenib (Tibsovo; IDH1 mutant glioma and AML) and a smaller commercial footprint from other IDH1 programs. Patent estates cluster around (1) compound claims for mutant IDH1 inhibition, (2) formulation and crystallinity for oral dosing, and (3) method-of-use claims tied to specific IDH1-mutant indications. Market access is shaped by FDA labeling breadth, payer adoption in AML and second-line/relapsed settings, and exclusivity timing that governs generic and biosimilar substitution. Generic entry pressure is mainly an Orange Book paragraph IV and settlement-driven question for small molecules; the practical risk is not “biosimilar” substitution but whether challengers can avoid formulation and method-of-use claims and whether FDA approval can occur before patent expiry or via design-around.

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What is the current market for Isocitrate Dehydrogenase 1 (IDH1) inhibitors and how do patents shape pricing and share?

Answer: The market is led by ivosidenib (IDH1 inhibitor) in IDH1-mutant AML and IDH1-mutant cholangiocarcinoma and glioma cohorts where labeled use exists. The patent estate drives exclusivity duration, which in turn shapes generic timing and payer contracting. Near-term market dynamics depend on: (1) ongoing label expansions, (2) competitive sequencing versus other IDH1 inhibitors and IDH2 inhibitors, and (3) the ability of generic filers to clear formulation and method-of-use barriers.

How does exclusivity structure impact competition in IDH1 AML and solid tumors?

• Small molecule exclusivity model: exclusivity and patent blocking are handled through Orange Book-listed patents (composition, formulation, and methods) and FDA regulatory timelines.
• Where competition concentrates: relapsed/refractory AML and post-treatment solid tumor settings where patient volume and treatment duration sustain revenue and support continued patent value.
• Why method-of-use patents matter: even if a generic can replicate the compound, it may still be blocked from using the same indication-specific dosing or patient selection language if those claims are listed and enforceable.

Key revenue exposure drivers

• Label breadth: broader labeling increases the “design-around difficulty” for generic entrants because method-of-use and patient-selection language becomes harder to avoid.
• Treatment setting stability: if guidelines and payer pathways keep patients on IDH1 inhibitors beyond initial response, generic entry becomes a bigger threat once patents clear.
• Combination regimes: if IDH1 inhibitors are used in combination, settlement agreements and patent licenses can influence how quickly generic sponsors can launch and commercialize.

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What patents protect ivosidenib (Tibsovo) and other IDH1 inhibitors?

Answer: IDH1 inhibitor patent estates typically protect (1) mutant-IDH1 small-molecule compounds, (2) pharmaceutical compositions (solid oral dosage forms, specific excipients, and stability profiles), (3) crystalline forms and polymorphs where relevant, and (4) methods of treatment for IDH1-mutant malignancies (AML, glioma, cholangiocarcinoma).

Patent clusters commonly seen in IDH1 inhibitor estates

• Compound claims: core inhibitory chemistry for mutant IDH1.
• Crystallinity/polymorph claims: particular solid-state forms used to control bioavailability and manufacturability.
• Formulation claims: tablets/capsules, controlled release or specific dosage form compositions.
• Method-of-use claims: treatment regimens, patient genotypes (IDH1 mutation), and line-of-therapy definitions.

Where do challengers typically attack?

• Claim invalidity and noninfringement focused on compound scope (for composition claims) and on formulation differences (for composition-of-matter plus formulation claims).
• Design-around focused on substituting formulation excipients or manufacturing processes to reduce infringement risk while still meeting FDA chemistry, manufacturing, and controls requirements.

Note: A complete, product-specific patent table with expiration dates and listed Orange Book patents cannot be produced from the information provided.

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When does ivosidenib lose exclusivity and what are the patent expiry milestones?

Answer: For IDH1 inhibitors, exclusivity loss generally happens in layers: (1) regulatory exclusivity (if applicable), (2) composition/compound patent expiry, (3) formulation and polymorph patent expiry, and (4) method-of-use patent expiry for each labeled indication. The exact dates are determined by each Orange Book listing and by each listed patent’s expiration and any pediatric exclusivity extensions.

Exclusivity timeline mechanics that govern generic entry

• Orange Book listing gates: FDA cannot approve an ANDA or 505(j) application that attempts to launch before a listed patent expires without a paragraph IV certification and the associated litigation or settlement path.
• Patent term adjustments and PTA/TEA: delays or extends expiration and affects when a court or settlement triggers “safe harbor” launch dates.
• Pediatric exclusivity: can extend key expirations, shifting generic launch.

Note: Specific expiration and “last to expire” dates require Orange Book patent-by-patent extraction for each product in the class.

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How many patents cover IDH1 inhibitors and what is the strength of the patent estate by category?

Answer: IDH1 inhibitor estates typically include multiple patents across categories rather than a single “blocker” patent. Estate strength depends on whether the claims are broad and enforceable, whether polymorph/formulation claims are enforceable, and whether method-of-use claims remain active through the full labeled indication set.

How estate strength translates into launch delays

• Composition + formulation combination: makes it harder for challengers to launch quickly even if the compound is replicated.
• Method-of-use listing: increases the odds of negotiated restrictions (carve-outs, labeling limitations) or court blocking unless the generic challenger narrows the proposed indication.

What “strong estate” looks like in practice

• multiple active compound/formulation/patient-selection claims,
• limited ability for design-around without losing bioequivalence or therapeutic alignment,
• and settled paragraph IV challenges that delay launch.

Note: A defensible quantitative count of “how many patents” and an evidence-based “strength score” cannot be completed without the product-specific Orange Book and litigation record.

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Which generic and Paragraph IV challengers are targeting IDH1 inhibitors?

Answer: Paragraph IV challenges in small molecule oncology typically target the compound and key formulation patents listed in the Orange Book, with litigation or settlement driving launch timing. The class-specific challenger roster and case-by-case details must be derived from FDA Orange Book certifications and USPTO/PACER dockets for each product.

What patent targets are usually certified in IDH1 cases

• Claim-by-claim certifications for compound claims.
• Validity/expiry arguments for formulation and polymorph patents.
• Noninfringement through formulation or process distinctions.

Note: No challenger identities or docket outcomes can be reliably listed from the provided prompt.

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What patent litigation affects ivosidenib and other IDH1 inhibitors?

Answer: The litigation pattern in IDH1 inhibitors follows the standard ANDA paragraph IV framework: pharma companies enforce listed Orange Book patents through suit in the period after FDA acceptance of a paragraph IV ANDA. The practical impact is launch date deferral through TRO/preliminary injunctions or negotiated settlement “trigger” dates.

Common litigation outcomes that shift market entry

• Early settlements: often include agreed-for-launch dates and sometimes market labeling restrictions.
• Noninfringement wins: can remove a blocker quickly, reducing delay.
• Invalidity findings: collapse remaining barriers and accelerate entry.

Note: Litigation case names, court venues, and settlement trigger dates are not stated in the prompt and cannot be compiled without product-specific sources.

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What formulations are protected for IDH1 inhibitors and how do formulation patents block generics?

Answer: Formulation patents often cover the oral dosage form and solid-state form performance that ensures absorption and stability. For oral oncology small molecules, this frequently translates into patents on:

• tablet/capsule compositions and excipient blends,
• specific drug-to-excipient ratios,
• solid-state form (polymorph/crystal),
• and manufacturing controls that preserve consistent performance.

Where generic risk is highest

• Crystalline form claims: challengers must match the same polymorph or demonstrate noninfringement by using a different form.
• In-scope formulation claims: even if the compound is correct, excipient or processing differences can still fall within claim scope.
• Method-of-use coupling: if the patent list includes patient-selection language, generic labeling changes may be required.

Note: A product-specific formulation patent map requires Orange Book list retrieval and patent document review.

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What method-of-use patents protect IDH1 inhibitors and which indications are most at risk?

Answer: Method-of-use patents for IDH1 inhibitors typically cover treatment of cancers with IDH1 mutations, often stratified by:

• disease type (AML, glioma, cholangiocarcinoma),
• prior therapy setting (relapsed/refractory or first-line in certain subgroups),
• and sometimes dosing schedules.

Why method-of-use patents matter more than compound patents

Generic developers may be able to overcome compound scope, but method-of-use claims can block meaningful commercial launch by requiring label carve-outs, which can reduce market uptake and delay “full launch.”

Note: Indication-specific method-of-use claim mapping cannot be produced without identifying which patents are listed for each product and indication.

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How does ivosidenib compare with IDH2 inhibitors and other competing oncology strategies in terms of IP risk?

Answer: Compared with IDH2 inhibitors, IDH1 inhibitors face a similar small-molecule IP structure: compound + formulation + method-of-use. Differentiation usually comes from:

• distinct patent families and expiry dates,
• different labeled patient segments,
• and competition intensity from alternative targeted therapies.

IP-driven competitive sequencing

• If an IDH1 product clears patents later: generics face delayed entry in that segment; brand retention can stay strong even as clinical guidelines evolve.
• If method-of-use claims persist: even after compound expiry, launch can be “constrained” via labeling limits.

Note: A rigorous cross-class comparison requires product-specific patent timelines for the competing therapies.

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What is the Orange Book status of IDH1 inhibitors and how does it predict generic launch timelines?

Answer: Orange Book status is the operational predictor of generic launch: every Orange Book-listed patent creates a legal entry barrier for ANDA/505(j) approvals. Launch timing hinges on:

• the “blocking” status of listed patents,
• paragraph IV certification outcomes,
• and the presence of settlements that set launch trigger dates.

Orange Book elements to extract for decision-grade modeling

• Patent numbers, assignees, and claim categories (composition, formulation, method).
• Listed expiration dates and any extensions.
• Orange Book “patent status” relative to the ANDA certification route.

Note: The Orange Book listing itself is not provided in the prompt and must be extracted to produce a factual table.

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Key Takeaways

• IDH1 inhibitor markets are shaped by layered patent estates that typically include compound, formulation/solid-state, and method-of-use protections.
• Generic entry risk is primarily an Orange Book and paragraph IV question for small molecules, with settlement and labeling restrictions determining effective launch.
• The practical “last to expire” is often an interaction between compound expiry, formulation/polymorph expiry, and indication-specific method-of-use listings.
• Decision-grade modeling requires a patent-by-patent Orange Book timeline, plus any paragraph IV litigation/settlement records that control launch triggers.

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FAQs

1. Do method-of-use patents delay ANDA launches for IDH1 inhibitors even if compound patents expire?
2. How do polymorph and crystallinity patents affect the ability to file and launch generic IDH1 inhibitors?
3. What Orange Book patent categories are most frequently challenged in paragraph IV certifications for oncology small molecules?
4. Do settlement agreements in IDH1 inhibitor paragraph IV cases typically restrict labeling or set fixed launch dates?
5. How should investors compare patent estate risk across IDH1 inhibitors versus IDH2 inhibitors?

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References

1. U.S. Food and Drug Administration (FDA). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. FDA. (Database).
2. U.S. FDA. Drugs@FDA. (Database).
3. U.S. Patent and Trademark Office (USPTO). Patent Application Full Text and Patent Examination Data. (Database).