Last updated: July 31, 2026
Kineret is the recombinant interleukin-1 receptor antagonist anakinra, marketed globally by Swedish Orphan Biovitrum (Sobi). The U.S. Food and Drug Administration (FDA) approves it for rheumatoid arthritis (RA), cryopyrin-associated periodic syndromes (CAPS), including neonatal-onset multisystem inflammatory disease (NOMID), and deficiency of interleukin-1 receptor antagonist (DIRA). Kineret remains commercially relevant because of its broad off-label use in hyperinflammatory disorders, short half-life, established pediatric experience, and relatively low manufacturing complexity compared with monoclonal antibodies.
The principal commercial risks are biosimilar or follow-on competition, price pressure in RA, and substitution by longer-acting interleukin-1 inhibitors such as Ilaris (canakinumab). Kineret has no FDA-approved COVID-19 indication, and its clinical-trial evidence in COVID-19 has not produced a broad U.S. regulatory expansion.
What is Kineret and how does anakinra work?
Kineret contains anakinra, a nonglycosylated recombinant form of the human interleukin-1 receptor antagonist. It blocks the activity of interleukin-1 alpha and interleukin-1 beta at the interleukin-1 receptor.
The FDA-approved dosage is generally 100 mg administered subcutaneously once daily for adults with RA. Dosing varies for pediatric and rare-disease indications. The product is supplied as a prefilled syringe and requires refrigerated storage. Its short elimination half-life, approximately four to six hours, allows rapid treatment interruption but creates a daily-administration burden [1].
Which diseases does Kineret treat?
| Indication |
Regulatory status |
Main patient population |
| Rheumatoid arthritis |
FDA-approved |
Adults with moderately to severely active disease after inadequate response to disease-modifying antirheumatic drugs |
| NOMID/CAPS |
FDA-approved |
Adults and children six months and older |
| DIRA |
FDA-approved |
Neonates, children and adults with genetically confirmed disease |
| COVID-19 |
Not FDA-approved |
Investigational and off-label use |
| Other autoinflammatory conditions |
Off-label or investigational |
Patients with Still's disease, macrophage activation syndrome and related disorders |
Kineret is also authorized in the European Union for several inflammatory diseases, including RA, CAPS, DIRA and Still's disease, subject to local labeling [2].
What clinical trials have evaluated Kineret?
Clinical evidence for Kineret is strongest in IL-1-driven autoinflammatory disease. Evidence in COVID-19 is mixed and does not establish a uniform treatment benefit across unselected hospitalized populations.
Kineret trials in COVID-19
The most commercially relevant COVID-19 study was the SAVE-MORE trial, a randomized controlled study evaluating anakinra in hospitalized patients with elevated soluble urokinase plasminogen activator receptor, or suPAR. The trial reported lower progression to severe respiratory failure and lower mortality with early anakinra treatment [3].
The European Medicines Agency authorized Kineret for treatment of COVID-19 in adults with pneumonia requiring supplemental oxygen who are at risk of developing severe respiratory failure, based on the SAVE-MORE evidence and subsequent regulatory review [4]. This authorization did not translate into a U.S. FDA approval.
Other studies produced less consistent results. The COV-AID randomized trial did not show a clinically meaningful benefit from anakinra, siltuximab or combination therapy in critically ill patients with COVID-19 [5]. Differences in biomarker selection, disease stage, background corticosteroid use, patient severity and treatment timing reduced comparability across trials.
| Trial or evidence set |
Population |
Result |
Commercial implication |
| SAVE-MORE |
Hospitalized adults selected using suPAR |
Positive clinical outcome signal |
Supports biomarker-guided use in selected European patients |
| COV-AID |
Critically ill hospitalized patients |
No significant overall benefit |
Limits broad positioning in intensive-care COVID-19 |
| REMAP-CAP and related platform studies |
Severe or critical COVID-19 |
Mixed or limited evidence for IL-1 blockade |
No broad global standard-of-care adoption |
| FDA regulatory review |
U.S. COVID-19 population |
No Kineret approval |
No U.S. COVID-19 exclusivity or labeled demand |
What are the latest Kineret clinical-development priorities?
Kineret’s current clinical value is concentrated in rare inflammatory disease, pediatric disease and selected hospital-based inflammatory syndromes rather than a large late-stage commercial pipeline. Key areas of study have included:
- Still's disease and systemic juvenile idiopathic arthritis.
- Macrophage activation syndrome and cytokine storm.
- Secondary hemophagocytic lymphohistiocytosis.
- Acute inflammatory complications associated with immune therapies.
- Cardiovascular and metabolic inflammatory disorders.
- Severe viral infection and COVID-19 subgroups defined by inflammatory biomarkers.
The main development constraint is that anakinra is already approved for several inflammatory conditions. New trials therefore tend to pursue label expansion, treatment algorithms or biomarker-defined populations rather than establish a new platform indication.
What is the FDA regulatory status of Kineret?
Kineret received its original U.S. approval in 2001 for RA. The FDA later approved it for NOMID in 2013 and DIRA in 2018 [1]. The NOMID approval was supported by the product’s clinical effectiveness in reducing disease activity and preventing ongoing organ damage in a rare, severe pediatric disorder.
Kineret is regulated as a biologic. It is therefore tracked through the FDA’s Purple Book framework rather than the conventional small-molecule Orange Book. The distinction matters for competition: a follow-on anakinra product would generally pursue a biosimilar or interchangeable biosimilar pathway under the Biologics Price Competition and Innovation Act, rather than an abbreviated new drug application under Hatch-Waxman [6].
What is the Orange Book status of Kineret?
Kineret does not have the same Orange Book patent-listing profile as a conventional chemical drug. Its relevant regulatory exclusivity and follow-on competition analysis belongs primarily in the biologics framework.
The U.S. reference product’s regulatory exclusivity periods have expired. Kineret’s commercial protection therefore depends mainly on manufacturing know-how, regulatory history, physician familiarity, supply reliability, rare-disease positioning and contractual or market-access barriers.
What patents protect Kineret and when does anakinra lose exclusivity?
The foundational intellectual property covering recombinant human interleukin-1 receptor antagonist was developed before Kineret’s current commercial period. Core U.S. patent protection has expired, and the product does not have a current U.S. composition-of-matter patent blocking biosimilar development.
The relevant protection categories are:
| Protection category |
Kineret position |
| Recombinant anakinra composition |
Core protection expired |
| Use in rheumatoid arthritis |
Historical method-of-use protection; no broad current barrier to biosimilar competition |
| NOMID and CAPS use |
Rare-disease clinical and regulatory protection has expired or is limited by indication |
| DIRA treatment |
Label and clinical-use value remain important, but broad molecule exclusivity does not block follow-on development |
| Formulation and syringe presentation |
Product-specific manufacturing and device claims may create incremental barriers |
| Manufacturing process |
Know-how, cell-culture controls, purification and release specifications remain commercially relevant |
| Pediatric and orphan exclusivity |
Historical periods have expired for the original U.S. approvals |
A biosimilar sponsor would still need to demonstrate analytical similarity, establish an adequate clinical development package and address immunogenicity, device presentation, stability and interchangeability requirements. Patent expiry alone does not guarantee immediate market entry.
Are there Kineret biosimilars or Paragraph IV challenges?
As a biologic, Kineret is not subject to a traditional Paragraph IV abbreviated new drug application challenge. A competing product would generally be developed under the 351(k) biosimilar pathway.
The United States has had limited biosimilar competition for anakinra compared with products such as filgrastim, pegfilgrastim, trastuzumab and adalimumab. The reasons include the modest size of the RA market, daily injection requirements, low-dose product economics, complex sterile manufacturing and the relatively small rare-disease population.
A competing anakinra product may target:
- Hospital formularies using anakinra for acute inflammatory syndromes.
- RA patients facing payer-driven substitution.
- European markets with tender-based procurement.
- Pediatric and rare-disease centers.
- Pre-filled syringe and autoinjector convenience segments.
No broad U.S. Kineret Paragraph IV litigation pathway is expected to be the principal competitive mechanism.
How strong is the Kineret patent estate?
Kineret’s patent estate is weak as a molecule-blocking estate and stronger as a commercial execution platform.
Patent strength by category
| Category |
Relative strength |
Assessment |
| Core molecule |
Low |
Foundational rights are expired |
| Broad therapeutic use |
Low to moderate |
Historical use claims do not prevent general follow-on development |
| Rare-disease positioning |
Moderate |
Clinical evidence and physician concentration create practical barriers |
| Formulation and device |
Moderate |
Presentation, stability and injection usability may support differentiation |
| Manufacturing |
Moderate to high |
Process reproducibility and quality controls can delay or increase biosimilar costs |
| Regulatory know-how |
Moderate |
Rare-disease submissions and pediatric evidence are difficult to replicate quickly |
Kineret’s principal defense is therefore not a single blocking patent. It is the accumulated regulatory, manufacturing and clinical infrastructure surrounding a mature biologic.
What patent litigation affects Kineret?
Kineret has not generated the level of high-value, multi-defendant patent litigation associated with biologics such as Humira, Enbrel or Stelara. The absence of a major active U.S. patent campaign reflects the age of the molecule and the limited number of direct biosimilar entrants.
Potential disputes would more likely involve:
- Biosimilar patent dance and information-exchange procedures.
- Manufacturing-process claims.
- Device or prefilled-syringe patents.
- Interchangeability or substitution issues.
- Contractual supply and distribution arrangements.
- Trade-secret allegations involving production methods.
No major current U.S. settlement agreement is publicly associated with a broad anakinra generic-entry delay comparable to major anti-TNF settlements.
Who owns and markets Kineret?
Sobi is the principal global commercial owner of Kineret. The product originated with Amgen, which transferred global commercial rights to Sobi in a 2018 transaction covering Kineret and certain other products. Sobi has described Kineret as part of its Immunology portfolio and has expanded its commercial presence in rare inflammatory disease [7].
Amgen’s historical role remains relevant because it developed and commercialized the product before the Sobi transaction. Sobi controls current commercial strategy in the territories covered by its rights.
What licensing deals affect Kineret?
The major strategic transaction was Sobi’s acquisition of global rights to Kineret from Amgen. The deal gave Sobi control of a mature IL-1 product with established regulatory approvals and a rare-disease franchise.
Kineret’s value is linked to the broader Sobi immunology portfolio, including treatments for rare inflammatory diseases and complement-mediated disorders. The product also provides commercial relationships with specialty pharmacies, hospital systems and pediatric centers.
How large is the Kineret market and what is the revenue outlook?
Kineret generates hundreds of millions of dollars annually for Sobi and remains a material product despite its age. Sobi reports product-level sales in Swedish kronor, and Kineret has continued to benefit from rare-disease demand and expansion in inflammatory indications. Annual sales have fluctuated with exchange rates, geography, COVID-19-related demand and inventory timing [7, 8].
Kineret market drivers
The main growth factors are:
- Rising diagnosis of rare autoinflammatory syndromes.
- Continued use in NOMID, CAPS and DIRA.
- Hospital use in selected cytokine-driven inflammatory conditions.
- Physician familiarity with anakinra’s short half-life.
- Demand for a readily titratable IL-1 blocker.
Kineret market constraints
The principal constraints are:
- Daily subcutaneous administration.
- Injection-site reactions.
- Competition from canakinumab, rilonacept and other targeted immunotherapies.
- Biosimilar or follow-on entry.
- Price controls and hospital tenders in Europe.
- Limited evidence for broad use in COVID-19.
- Mature RA demand and biologic substitution.
Kineret revenue projection
A reasonable base-case outlook is for largely stable to modestly declining global revenue over the medium term, with rare-disease growth offsetting erosion in mature RA use. The downside case involves an approved follow-on anakinra product entering major European markets or the United States and triggering payer substitution. The upside case depends on sustained hospital adoption in biomarker-selected inflammatory syndromes and continued expansion of rare-disease diagnosis.
| Scenario |
2025-2027 commercial direction |
Principal assumption |
| Base case |
Flat to low-single-digit decline |
Rare-disease growth offsets mature-market erosion |
| Upside case |
Low-single-digit growth |
Hospital and specialty inflammatory use expands |
| Downside case |
Mid- to high-single-digit decline |
Follow-on competition and payer substitution accelerate |
These projections are directional rather than company guidance. Sobi’s reported financial results remain the controlling source for actual revenue performance [8].
How does Kineret compare with Ilaris and Arcalyst?
| Product |
Active ingredient |
Target |
Administration |
Commercial position |
| Kineret |
Anakinra |
IL-1 receptor |
Generally daily subcutaneous dosing |
Broadest practical experience and rapid reversibility |
| Ilaris |
Canakinumab |
IL-1 beta |
Infrequent subcutaneous dosing |
Strong convenience and rare-disease positioning |
| Arcalyst |
Rilonacept |
IL-1 trap |
Weekly subcutaneous dosing |
Chronic IL-1 blockade in selected diseases |
Kineret is more flexible for acute treatment because of its short half-life. Ilaris and Arcalyst have stronger convenience profiles for chronic therapy. Kineret remains attractive when clinicians need rapid dose adjustment, inpatient use or treatment of conditions in which prolonged IL-1 blockade creates safety concerns.
What generic launch risks exist for Kineret?
The most credible launch scenario is a staged biosimilar entry rather than an immediate broad substitution event.
United States
A U.S. entrant would need a 351(k) application, analytical comparability, immunogenicity data and a commercial strategy for specialty pharmacy and hospital distribution. Interchangeability could become an important differentiator if FDA standards and commercial economics support a designation.
Europe
European entry could occur through national tender systems, hospital procurement and country-specific reimbursement negotiations. Price erosion may be faster in tender markets than in U.S. specialty channels.
Japan and other markets
Regulatory requirements differ by jurisdiction. Local biosimilar standards, reimbursement rules and physician familiarity will determine the speed of uptake.
Manufacturing is a meaningful barrier. Anakinra is a protein product requiring controlled fermentation, purification, sterile filling, cold-chain distribution and validated device presentation. These requirements are less demanding than for many monoclonal antibodies but remain materially more complex than for a conventional tablet.
Key Takeaways
- Kineret is anakinra, a recombinant IL-1 receptor antagonist marketed primarily by Sobi.
- FDA-approved uses include RA, NOMID/CAPS and DIRA.
- COVID-19 evidence is mixed. SAVE-MORE supported selected biomarker-guided use in Europe, while COV-AID did not show broad benefit.
- Kineret is a biologic and is analyzed through the Purple Book, not a traditional Orange Book Paragraph IV framework.
- Core molecule exclusivity has expired, but manufacturing, formulation, device and regulatory know-how remain practical barriers.
- No major active U.S. patent litigation campaign currently defines Kineret’s market.
- Revenue is likely to remain stable to modestly lower, with rare-disease demand offsetting mature RA erosion.
- The main long-term risk is biosimilar or follow-on anakinra competition combined with payer substitution.
FAQs about Kineret clinical trials, patents and market competition
Is Kineret FDA-approved for COVID-19?
No. Kineret is not FDA-approved for COVID-19. European regulators authorized anakinra for selected hospitalized adults at risk of severe respiratory failure based largely on biomarker-guided evidence.
Does Kineret have orphan-drug exclusivity today?
The historical orphan-exclusivity periods associated with its U.S. rare-disease approvals have expired. Rare-disease clinical expertise and limited patient populations remain commercial barriers.
Can an anakinra biosimilar be automatically substituted for Kineret?
Not automatically in every jurisdiction. In the United States, automatic pharmacy substitution depends on FDA interchangeability status and state law. A biosimilar without interchangeability may still be used under physician direction.
Which drug competes most directly with Kineret?
Ilaris, or canakinumab, is the most direct branded competitor because it targets the IL-1 pathway and is used in related autoinflammatory diseases. Its longer dosing interval gives it a convenience advantage.
Why might hospitals continue using Kineret after biosimilar entry?
Hospitals may retain Kineret because of established dosing protocols, short half-life, pediatric experience, supply reliability and familiarity in cytokine-driven inflammatory syndromes.
References
- U.S. Food and Drug Administration. (2024). Kineret (anakinra) prescribing information.
- European Medicines Agency. (2024). Kineret: EPAR product information.
- Kyriazopoulou, E., et al. (2021). Early treatment of COVID-19 with anakinra guided by soluble urokinase plasminogen activator receptor plasma levels: A double-blind, randomized controlled phase 3 trial. Nature Medicine, 27, 1752-1760.
- European Medicines Agency. (2021). Kineret: Extension of indication for treatment of COVID-19.
- REMAP-CAP Investigators. (2021). Effect of interleukin-6 receptor blockade and other immunomodulatory treatments in critically ill patients with COVID-19. New England Journal of Medicine, 384, 1491-1502.
- U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products.
- Swedish Orphan Biovitrum AB. (2018). Sobi acquires global rights to Kineret and Orencia from Amgen.
- Swedish Orphan Biovitrum AB. (2024). Annual report 2023.
