TheraRadar
Data updated: May 26, 2026

LEFLUNOMIDE

Immunology Approved 2005-09-13

LEFLUNOMIDE is indicated for the treatment of Active rheumatoid arthritis.

Source: FDA Label • Teva • Antirheumatic Agent

How LEFLUNOMIDE Works

Leflunomide acts as a pyrimidine synthesis inhibitor by inhibiting dihydroorotate dehydrogenase (DHODH), a mitochondrial enzyme essential for *de novo* pyrimidine synthesis. By blocking this pathway, the drug exerts antiproliferative effects, particularly on activated T-lymphocytes, which are highly dependent on *de novo* synthesis for expansion. This results in a reduction of the inflammatory response associated with rheumatoid arthritis.

Source: FDA Label
7
Indications
--
Phase 3 Trials
20
Years on Market

Details

Status
Discontinued
First Approved
2005-09-13
Routes
ORAL
Dosage Forms
TABLET

LEFLUNOMIDE Approval History

2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
Original
New Indication
New Form
Label Update
102 FDA actions from 2005 to 2025
Oct 2025 SUPPL
Label · Labeling
Dec 2024 SUPPL
Label · Labeling
Sep 2024 SUPPL
Label · Labeling

What LEFLUNOMIDE Treats

1 indications

LEFLUNOMIDE is approved for 1 conditions since its original approval in 2005. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Active rheumatoid arthritis
Source: FDA Label

LEFLUNOMIDE Boxed Warning

EMBRYO-FETAL TOXICITY and HEPATOTOXICITY Embryo-Fetal Toxicity Leflunomide is contraindicated for use in pregnant women because of the potential for fetal harm. Teratogenicity and embryo-lethality occurred in animals administered leflunomide at doses lower than the human exposure level. Exclude pregnancy before the start of treatment with leflunomide in females of reproductive potential. Advise females of reproductive potential to use effective contraception during leflunomide treatment and duri...

LEFLUNOMIDE Competitive Set

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Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

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Clinical Trial Registry

34 trials
Trial Sponsor ID Phase Status Title
NCT04508790 19418 NCI-2020-01962, 19418 Ph 2 recruiting Leflunomide, Pomalidomide, and Dexamethasone for the Treatment of Relapsed or Refractory Multiple Myeloma
NCT05014646 21049 NCI-2021-07263, 21049 Ph 2 active not recruiting Leflunomide for the Treatment of High-Risk Smoldering Multiple Myeloma in African-American and European-American Patients
NCT06454383 23540 NCI-2024-04359, 23540 Ph 1 recruiting Gemcitabine and Leflunomide in Patients With Advanced Unresectable Pancreatic Cancer
NCT03709446 GCO 18-1832 Ph 1, Ph 2 completed Leflunomide in Previously Treated Metastatic Triple Negative Cancers
NCT03739853 SPEED results posted 18/SC/0107 Ph 4 completed Severe Psoriatic Arthritis - Early intervEntion to Control Disease: the SPEED Trial
NCT07138898 25-00380 Ph 2 not yet recruiting Immunosuppressant Management in Rheumatology Patients Undergoing Elective Total Shoulder Arthroplasty
NCT05443425 22026 NCI-2022-05061, 22026 Ph 1 recruiting Leflunomide in Combination With Steroids for the Treatment of Acute Graft-versus-Host Disease After Donor Stem Cell Transplant for Hematologic Malignancies
NCT04212416 19202 NCI-2019-04532, 19202 Ph 1 active not recruiting Leflunomide in Treating Patients With Steroid Dependent Chronic Graft Versus Host Disease
NCT04997993 GCO 20-2528 Ph 1 recruiting Leflunomide in Patients With PTEN-Altered Advanced Solid Malignancies and HER2 Negative Breast Cancer
NCT02451748 results posted 2015-0117 Ph 4 completed IL-7 and IL-7R Expression in RA Patients With Active vs. Inactive Disease Treated With DMARD or CIMZIA
NCT04532372 results posted 20291 NCI-2020-05746, 20291 Ph 1, Ph 2 completed Leflunomide for the Treatment of Severe COVID-19 in Patients With a Concurrent Malignancy
NCT04361214 IRB20-0622 Ph 1 terminated Leflunomide in Mild COVID-19 Patients
NCT06229340 NТО-RAS LS01 Ph 2 recruiting Leflunomide or Combination of MEK Inhibitor and Hydroxychloroquine for Refractory Patients With RAS Mutations
NCT04463615 results posted 19606 NCI-2020-02973, 19606 Ph 2 completed Leflunomide for the Treatment of Relapsed or Refractory CD30+ Lymphoproliferative Disorders
NCT02509052 results posted 15140 NCI-2015-01181, 15140 Ph 1, Ph 2 completed Leflunomide in Treating Patients With Relapsed or Refractory Multiple Myeloma
NCT05937191 Lef for IPH 2021-KY-001 Ph 1, Ph 2 recruiting Leflunomide for Idiopathic Pulmonary Hemosiderosis in Children
NCT05007678 DEFEAT-COVID 2020ZC01 Ph 3 completed Targeting de Novo Pyrimidine Biosynthesis by Leflunomide for the Treatment of COVID-19 Virus Disease
NCT05626348 Response of DMARDs in RA QiluH Ph 4 recruiting The Clinical Efficacy of Immunomodulators in RA Patients
NCT03449758 SariPRO results posted SARILL08755 U1111-1197-7699, 2017-002951-27 Ph 4 completed Effect of Sarilumab on Patient-reported Outcomes in Patients With Active Rheumatoid Arthritis
NCT01727193 ZS-LEF Ph 3 completed The Efficacy and Safety of Leflunomide or Azathioprine Therapy in Myasthenia Gravis Patients After Expand Thymectomy
NCT02930343 results posted JIP/IEC/2016/27/893 Ph 3 terminated Comparison of Disease Modifying Antirheumatic Drugs Therapy in Patients With RA Failing Methotrexate Monotherapy
NCT03797872 POISE results posted 18/SC/0261 Ph 4 completed Psoriatic Oligoarthritis Intervention With Symptomatic thErapy
NCT03952832 18458 NCI-2019-00247, 18458 Ph 2 withdrawn Leflunomide in Treating Patients With High-Risk Smoldering Multiple Myeloma
NCT02644499 JIP/IEC/SC/2013/5/433 Ph 4 completed Comparison of Combination Disease Modifying Antirheumatic Drugs With Methotrexate Therapy in Early Rheumatoid Arthritis
NCT02703194 ChinaPLAGH-IgG4 Ph 4 completed Leflunomide for Maintenance of Remission in IgG4 Related Disease
NCT01172639 results posted CareRA 2008-007225-39 Ph 4 completed Effectiveness in Daily Practice of Different Treatment Strategies for Early Rheumatoid Arthritis.
NCT01941095 results posted ML28695 2013-000359-42 Ph 3 completed A Study of Subcutaneous Tocilizumab as Monotherapy and/or in Combination With Non-Biologic Disease Modifying Anti-Rheumatic Drugs (DMARDs) in Participants With Rheumatoid Arthritis
NCT02373202 results posted LTS13618 U1111-1160-6525 Ph 3 completed A Study Assessing the Safety and Efficacy of Sarilumab Added to Non-MTX DMARDs or as Monotherapy in Japanese Patients With Active Rheumatoid Arthritis (SARIL-RA-HARUKA)
NCT01709578 results posted EFC10832 U1111-1115-8466, 2011-003538-16 Ph 3 completed To Evaluate The Effect Of SAR153191 (REGN88) Added To Other RA Drugs In Patients With RA Who Are Not Responding To Or Intolerant Of Anti-TNF Therapy (SARIL-RA-TARGET)
NCT01768572 results posted SFY13370 2012-003536-23, U1111-1133-7839 Ph 3 completed To Evaluate The Safety of SAR153191 (REGN88) and Tocilizumab Added to Other RA Drugs in Patients With RA Who Are Not Responding to or Intolerant of Anti-TNF Therapy (SARIL-RA-ASCERTAIN)
NCT02057250 SARIL-RA-EASY results posted MSC12665 2012-004339-21, U1111-1130-9931 Ph 3 completed To Evaluate Sarilumab - SAR153191 (REGN88) - Auto-injector Device In Patients With Rheumatoid Arthritis
NCT01611675 12-088 Ph 1 terminated Leflunomide+Vemurafenib in V600 Mutant Met. Melanoma
NCT01225393 ALT4864g GA00932 Ph 2 completed A Study to Evaluate the Efficacy and Safety of MLTA3698A in Combination With a Disease-Modifying Anti-Rheumatic Drug (DMARD) Compared With Adalimumab in Combination With a DMARD in Patients With Active Rheumatoid Arthritis
NCT01659242 YK 01-2012 Ph 4 terminated Leflunomide Versus Sulfasalazine/Methotrexate in Rheumatoid Arthritis:an Ultrasound/Magnetic Resonance Imaging Study
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Active Pipeline

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

LEFLUNOMIDE FDA Label Details

Indications & Usage

LEFLUNOMIDE is indicated for the treatment of Active rheumatoid arthritis.

⚠️ BOXED WARNING

WARNING: EMBRYO-FETAL TOXICITY and HEPATOTOXICITY Embryo-Fetal Toxicity Leflunomide is contraindicated for use in pregnant women because of the potential for fetal harm. Teratogenicity and embryo-lethality occurred in animals administered leflunomide at doses lower than the human exposure level. Exc...

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Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.