List of Excipients in Branded Drug INREBIC

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Celgene Corporation	INREBIC	fedratinib hydrochloride	59572-720	CELLULOSE, MICROCRYSTALLINE	2031-11-16
Celgene Corporation	INREBIC	fedratinib hydrochloride	59572-720	FERRIC OXIDE RED	2031-11-16
Celgene Corporation	INREBIC	fedratinib hydrochloride	59572-720	GELATIN	2031-11-16

Inrebic Excipient Strategy and Commercial Opportunities for Fedratinib

Last updated: August 11, 2026

Inrebic (fedratinib) is an oral, small-molecule JAK2 inhibitor marketed by Bristol Myers Squibb for adults with intermediate-2 or high-risk primary myelofibrosis, post-polycythemia vera myelofibrosis, or post-essential thrombocythemia myelofibrosis. Its commercial formulation is a 100 mg hard capsule administered at a recommended dose of 400 mg once daily in patients with a platelet count of at least 50 × 10^9/L.[1]

The principal excipient opportunity is not a new therapeutic formulation. It is a differentiated oral solid dosage form that improves food flexibility, swallowing, dose titration, global manufacturability, and supply resilience while preserving fedratinib exposure. Generic and follow-on manufacturers face a comparatively manageable dosage-form barrier because Inrebic is a conventional immediate-release capsule rather than a complex injectable, biologic, modified-release product, or device combination.

What is Inrebic and how is it used?

Inrebic contains fedratinib hydrochloride monohydrate, a selective inhibitor of JAK2 and the FMS-like tyrosine kinase 3 receptor. The FDA-approved product is supplied as 100 mg capsules.[1]

Attribute	Inrebic specification
Active ingredient	Fedratinib hydrochloride monohydrate
Brand	Inrebic
Sponsor/marketer	Bristol Myers Squibb
Dosage form	Oral hard capsule
Strength	100 mg
Recommended dose	400 mg once daily
Main indication	Intermediate-2 or high-risk myelofibrosis
FDA approval	August 16, 2019
Regulatory status	New molecular entity with orphan-drug designation
Administration	With or without food; avoid grapefruit and grapefruit juice
Key safety monitoring	Encephalopathy, including Wernicke's encephalopathy; anemia; thrombocytopenia; gastrointestinal toxicity

The 400 mg daily dose requires four 100 mg capsules. That dosing architecture creates an immediate commercial opportunity for alternative strengths, packaging configurations, adherence aids, and dose-reduction strategies, subject to regulatory approval.

What excipients are used in Inrebic capsules?

The FDA prescribing information identifies the inactive ingredients in Inrebic capsules as colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose, sodium lauryl sulfate, and talc. The capsule shell contains gelatin, titanium dioxide, and colorants.[1]

Excipient or component	Likely formulation function	Commercial relevance
Microcrystalline cellulose	Diluent and capsule-fill carrier	Supports powder bulk, flow, and content uniformity
Colloidal silicon dioxide	Glidant and moisture-flow aid	Controls powder flow and reduces fill variability
Magnesium stearate	Lubricant	Supports capsule filling and ejection; excessive levels can affect dissolution
Sodium lauryl sulfate	Wetting agent and surfactant	May improve dissolution of a poorly water-soluble active
Talc	Processing aid and glidant	Supports flow and reduces sticking
Gelatin	Capsule shell	Conventional hard-capsule shell material
Titanium dioxide and colorants	Opacifier and identification	Supports product recognition and light protection

The formulation appears designed around conventional direct-fill or low-complexity capsule manufacturing. The presence of sodium lauryl sulfate is commercially relevant because it indicates that wetting and dissolution control are important formulation variables. A generic developer would need to demonstrate pharmaceutical equivalence and bioequivalence, not merely reproduce the qualitative excipient list.

How does the Inrebic excipient strategy affect generic development?

Inrebic has a relatively accessible dosage-form profile compared with products protected by long-acting delivery systems, amorphous dispersions, lipid formulations, or device-based administration. A generic developer could potentially use different excipients if the resulting product meets quality, bioequivalence, stability, and labeling requirements.

The main technical risks are:

1. Dissolution sensitivity. Fedratinib’s dissolution performance may be affected by particle size, wetting, lubricant concentration, surfactant level, and compression or encapsulation conditions.

2. Dose uniformity across four capsules. The 100 mg capsule must maintain consistent active content because the clinical dose is commonly four capsules per day.

3. Food-effect comparability. Fedratinib can be administered with or without food, but food affects exposure. A materially different excipient system could alter fed and fasted pharmacokinetics.[1]

4. Moisture control. Capsule shells and hygroscopic formulation components can affect stability, dissolution, and microbial control.

5. Gastrointestinal tolerability. A reformulation that increases local surfactant exposure or accelerates dissolution could worsen nausea, vomiting, or diarrhea.

6. Color and capsule identity. Generic manufacturers must avoid medication-error risks associated with similar oncology capsules while satisfying applicable imprint and appearance requirements.

A developer would likely prioritize a conventional immediate-release capsule with equivalent dissolution across physiologically relevant pH conditions. A formulation using sodium lauryl sulfate, sodium stearyl fumarate, or another wetting and lubrication system could be commercially attractive if it improves robustness without generating a clinically meaningful food effect.

What formulation opportunities exist for Inrebic?

The strongest opportunities are incremental products that address administration burden or tolerability.

Alternative capsule strengths

A 50 mg capsule could support dose reductions and more precise titration. The FDA label permits dose reductions for adverse reactions and certain drug interactions.[1] A 50 mg strength could reduce the need to alternate doses or split treatment across different capsule counts.

A 200 mg capsule could reduce the standard four-capsule daily burden to two capsules. The commercial value would depend on manufacturing economics, prescribing conventions, payer substitution rules, and whether the product receives separate regulatory approval.

Sprinkle or swallow-assisted formulations

Myelofibrosis patients may have dysphagia, fatigue, anemia, or gastrointestinal symptoms. A capsule that can be opened and dispersed in an approved vehicle could improve administration, but this would require dedicated stability, content-uniformity, microbiological, and bioequivalence data. It would also create a higher regulatory and intellectual-property burden than a standard capsule.

Lower-surfactant formulations

A lower-surfactant composition could target gastrointestinal tolerability. The risk is reduced wetting and slower dissolution. A developer would need to show that the reformulation does not create exposure variability under fasted conditions or after administration with a high-fat meal.

Moisture-protective packaging

Blister packaging, desiccant-equipped bottles, and high-barrier foil systems can provide commercial differentiation without changing the formulation. Packaging may be especially valuable for global markets with high humidity and for specialty-pharmacy distribution.

Fixed-dose combinations

Combining fedratinib with supportive-care agents is unlikely to be the first commercial opportunity because myelofibrosis patients have variable treatment regimens and significant polypharmacy. A fixed-dose combination would also raise dose-flexibility and interaction concerns.

What is the commercial opportunity for excipient suppliers?

The most attractive excipient opportunities involve high-purity, oncology-grade materials with reliable global supply and documented control of elemental impurities, residual solvents, microbiological quality, and nitrosamine risk.

Priority categories include:

• Microcrystalline cellulose with consistent bulk density and flow.
• Colloidal silicon dioxide engineered for capsule-filling performance.
• Low-peroxide, pharmaceutical-grade magnesium stearate.
• Alternative wetting agents that preserve dissolution without increasing gastrointestinal irritation.
• Non-animal capsule shells for markets where vegetarian or religious-compliance requirements affect procurement.
• High-barrier packaging components.
• Co-processed excipient systems that improve blend uniformity and reduce segregation.

A supplier that can provide a validated platform for low-dose, poorly soluble oncology compounds may have a broader opportunity than one focused only on Inrebic. The active ingredient dose is substantial at 400 mg daily, but the product still requires reliable powder flow and capsule-fill uniformity across multiple units.

When does Inrebic lose exclusivity?

Inrebic’s key regulatory exclusivity period was the seven-year orphan-drug exclusivity period beginning with FDA approval on August 16, 2019. Orphan-drug exclusivity generally runs through August 16, 2026, subject to the statutory framework and any relevant regulatory action.[2]

The five-year new chemical entity exclusivity period generally expired in August 2024. Patent protection may continue beyond regulatory exclusivity and remains the principal factor governing the timing of an ANDA launch.

Exclusivity or protection	Relevant date	Commercial effect
FDA approval	August 16, 2019	Start of U.S. marketing
New chemical entity exclusivity	Approximately August 2024	First five years of NCE protection
Orphan-drug exclusivity	Approximately August 2026	Blocks approval of the same drug for the same indication, subject to statutory exceptions
Patent expiry	Patent-specific	Determines ANDA launch risk and possible pediatric or regulatory adjustments

The precise generic-entry date depends on listed patents, Paragraph IV litigation, settlement terms, pediatric exclusivity, regulatory review, and any applicable patent-term adjustment or extension.

What is the Orange Book status of Inrebic?

FDA Orange Book records are the controlling source for listed patents and exclusivity information. The relevant analysis should distinguish between:

• Drug-substance patents;
• Composition-of-matter patents;
• Formulation patents;
• Method-of-use patents;
• Manufacturing patents that may not be Orange Book listed;
• Patents covering dosing or patient-selection limitations.

For an oral oncology product, method-of-use patents can be commercially important even when formulation patents are weak. A generic applicant may seek approval for non-patented indications through a section viii statement or may challenge listed method-of-use patents under Paragraph IV, depending on the scope of the claims and the labeling strategy.[3]

Patent listings and expiration dates should be checked against the current FDA Orange Book rather than relying solely on third-party patent databases. Patent term adjustment, terminal disclaimers, reissued patents, and litigation outcomes can materially change the effective launch analysis.

Which companies are challenging Inrebic exclusivity?

Publicly reported generic challengers and Paragraph IV litigation should be evaluated through FDA ANDA records, district-court dockets, and the Orange Book patent-listing history. There is no established biosimilar pathway for fedratinib because it is a chemically synthesized small molecule, not a biologic.

The likely competitive field includes:

• Traditional generic manufacturers;
• Specialty oncology generic companies;
• Regional manufacturers seeking approval outside the United States;
• Companies pursuing alternative strengths or modified administration;
• Contract development and manufacturing organizations supplying private-label products.

The absence of a biosimilar pathway lowers development complexity relative to biologic oncology products. It does not eliminate bioequivalence, patent, manufacturing, or pharmacovigilance risk.

What generic entry risks exist for Inrebic?

The largest generic-entry risks are regulatory and commercial rather than formulation complexity.

Regulatory risks

A generic applicant must establish pharmaceutical equivalence and bioequivalence. Differences in capsule shell, colorants, surfactants, lubricants, and filler systems can require additional comparative dissolution or other supporting data.

The applicant must also address labeling restrictions associated with Wernicke’s encephalopathy, thiamine status, hepatic impairment, renal impairment, and drug interactions.[1]

Patent risks

A Paragraph IV certification can trigger litigation and a potential 30-month stay of approval under the Hatch-Waxman framework.[3] Method-of-use claims may be particularly relevant if the branded label includes multiple myelofibrosis populations or dosing limitations.

Manufacturing risks

Fedratinib manufacturing requires control of polymorphic form, particle-size distribution, impurities, residual solvents, and capsule-fill consistency. A supplier change for a surfactant or lubricant can affect dissolution and trigger post-approval comparability work.

Commercial risks

The patient population is relatively small and specialist-driven. Generic price erosion may be less severe than in high-volume primary-care markets, but the addressable volume is also limited. Specialty-pharmacy contracts, oncologist familiarity, payer formulary placement, and supply reliability will influence share.

How does Inrebic compare with competing myelofibrosis drugs?

Inrebic competes mainly with Jakafi (ruxolitinib), Vonjo (pacritinib), and, in selected settings, Ojjaara (momelotinib).

Product	Active ingredient	Main commercial positioning	Formulation complexity
Inrebic	Fedratinib	JAK2-directed therapy for intermediate-2 or high-risk myelofibrosis	Conventional capsule
Jakafi	Ruxolitinib	Broad myelofibrosis and polycythemia vera use	Conventional tablet
Vonjo	Pacritinib	Myelofibrosis with severe thrombocytopenia	Conventional capsule
Ojjaara	Momelotinib	Myelofibrosis with anemia-related clinical needs	Conventional tablet

Inrebic’s excipient and dosage-form estate is less technically complex than a biologic product but competes in a market where clinical positioning and tolerability are more important than formulation novelty. A generic Inrebic product would need a reliable supply chain and clear substitution economics because prescribers select therapy based on platelet count, anemia, symptom control, spleen response, and prior JAK-inhibitor exposure.

What patent litigation affects Inrebic?

Patent litigation risk centers on listed patents and the scope of claims covering fedratinib, its pharmaceutical compositions, and approved methods of treatment. The core litigation questions are:

1. Whether the asserted claims cover the active ingredient or only a particular use.
2. Whether the generic label will induce infringement.
3. Whether the patent is valid over prior art.
4. Whether a non-infringing carve-out is commercially viable.
5. Whether any settlement grants an authorized-generic or license date.

A settlement agreement could permit an earlier launch while preserving branded exclusivity for selected indications. The commercial effect depends on whether the agreement allows a licensed generic, limits the launch to certain strengths, or includes supply and royalty provisions.

Are there licensing deals involving Inrebic?

Fedratinib originated from research associated with Impact Biomedicines and was acquired by Celgene. Bristol Myers Squibb acquired Celgene in 2019 and became the commercial owner of Inrebic through that transaction.[4] The acquisition is the principal publicly documented ownership event affecting the product.

Licensing or collaboration arrangements involving specific patents, regional rights, authorized-generic supply, or manufacturing should be distinguished from the Celgene acquisition. Their commercial relevance cannot be inferred from brand ownership alone.

What geographic coverage matters for Inrebic?

U.S. market protection is governed by FDA exclusivity, Orange Book patents, and Hatch-Waxman litigation. European and other-market protection depends on national or regional patents, supplementary protection certificates, regulatory data exclusivity, orphan designations, and local pricing decisions.

A generic launch outside the United States may occur before U.S. entry if local patent and regulatory barriers expire earlier. Conversely, a European patent or SPC can extend protection beyond U.S. patent expiry. Excipient suppliers should therefore qualify materials against regional pharmacopoeial requirements, including USP-NF, Ph. Eur., and other applicable standards.

How strong is the Inrebic patent estate?

The formulation barrier is moderate to low because Inrebic is a conventional hard capsule. The commercial patent estate can still be meaningful if composition-of-matter or broad method-of-use claims remain enforceable.

Estate component	Relative barrier	Business assessment
Active-ingredient protection	Potentially high	Most important if valid and unexpired
Formulation protection	Moderate	Relevant if claims cover the marketed capsule composition
Method-of-use protection	Moderate to high	Can delay or narrow generic labeling
Manufacturing protection	Variable	May create process risk without necessarily blocking ANDA approval
Excipient-specific protection	Low to moderate	Usually avoidable through alternative excipient systems

The practical strength of the estate depends on claim breadth, remaining term, enforceability, Orange Book listing, and litigation outcomes. A conventional capsule does not remove patent risk, but it gives generic developers more design-around options.

What are the revenue and market opportunities?

Inrebic revenue depends on the size of the treated myelofibrosis population, duration of therapy, payer access, competition from other JAK inhibitors, and the use of dose reductions. Public company filings and product-level disclosures should be used for current revenue figures because sales can change materially after formulary decisions, competitor launches, and geographic expansion.[4]

Commercial opportunities include:

• A lower-cost generic after regulatory and patent barriers clear.
• A 200 mg capsule that reduces pill burden.
• A 50 mg capsule that improves dose adjustment.
• Private-label specialty-pharmacy supply.
• Regional licensing in markets with separate patent timelines.
• Excipient and packaging supply agreements.
• Authorized-generic arrangements.
• Reformulations targeting swallowing difficulty or administration convenience.

The best near-term opportunity is likely a compliant immediate-release generic capsule supported by robust dissolution, multiple-source excipient qualification, and specialty-oncology distribution. A novel formulation can command more value but carries substantially greater clinical, regulatory, and intellectual-property expense.

Key Takeaways

• Inrebic is a 100 mg fedratinib hard capsule taken at a standard dose of 400 mg once daily.
• Its excipient system uses conventional capsule-fill materials, including microcrystalline cellulose, colloidal silicon dioxide, magnesium stearate, sodium lauryl sulfate, and talc.
• Sodium lauryl sulfate indicates that wetting and dissolution control are important formulation variables.
• The product has a lower technical formulation barrier than biologic, injectable, modified-release, or device-based oncology products.
• The seven-year U.S. orphan-drug exclusivity period is expected to run from August 16, 2019, to approximately August 16, 2026.
• Patent expiry and Paragraph IV litigation, not formulation complexity alone, will determine generic-entry timing.
• A 200 mg strength could reduce pill burden, while a 50 mg strength could improve dose titration.
• No biosimilar pathway applies because fedratinib is a small-molecule drug.
• Excipient suppliers can compete through dissolution control, flow performance, low-impurity materials, non-animal capsules, and high-barrier packaging.
• Specialty distribution, supply reliability, and clinical positioning will be central to post-exclusivity competition.

Frequently Asked Questions

Can Inrebic capsules be opened and mixed with food?

The FDA-approved labeling does not establish routine administration by opening the capsule and mixing its contents with food. Such use would require supporting product-specific data and should not be assumed from the conventional capsule design.[1]

Does Inrebic have a biosimilar competitor?

No. Fedratinib is a chemically synthesized small molecule. Any follow-on product would generally proceed through a generic drug pathway rather than the biosimilar pathway.

Could a generic Inrebic use different excipients?

Yes, provided the product meets applicable pharmaceutical-equivalence, bioequivalence, quality, stability, dissolution, and labeling requirements. Different excipients can alter exposure and may require additional supporting studies.

Would a 200 mg Inrebic capsule automatically substitute for four 100 mg capsules?

No. A different strength requires regulatory approval and must satisfy prescribing, labeling, bioequivalence, manufacturing, and substitution requirements.

What is the main formulation risk for a fedratinib generic?

The principal risk is failure to match dissolution and systemic exposure across fed and fasted conditions. Surfactant level, particle size, lubricant concentration, powder flow, and capsule-fill uniformity are central development variables.

References

1. U.S. Food and Drug Administration. (2024). Inrebic (fedratinib hydrochloride) capsules: Prescribing information. Bristol Myers Squibb.

2. U.S. Food and Drug Administration. (n.d.). Orphan drug designation and exclusivity. https://www.fda.gov/industry/developing-products-rare-diseases-conditions/orphan-drug-designation-and-exclusivity

3. U.S. Food and Drug Administration. (n.d.). Abbreviated New Drug Application (ANDA): Paragraph IV certifications. https://www.fda.gov

4. Bristol Myers Squibb. (2024). Annual report. Bristol Myers Squibb.