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Drug

Leflunomide

Established medicine
ClassDihydroorotate dehydrogenase inhibitorResearchOngoing clinical research
Also known as 4-ISOXAZOLECARBOXAMIDE, 5-METHYL-N-(4-(TRIFLUOROMETHYL)PHENYL)-, 5-Methyl-N-(4-(trifluoromethyl)phenyl)-4-isoxazolecarboxamide, 5-Methylisoxazole-4-carboxylic acid (4-trifluoromethyl)anilide, Arava+4 more

4-ISOXAZOLECARBOXAMIDE, 5-METHYL-N-(4-(TRIFLUOROMETHYL)PHENYL)-, 5-Methyl-N-(4-(trifluoromethyl)phenyl)-4-isoxazolecarboxamide, 5-Methylisoxazole-4-carboxylic acid (4-trifluoromethyl)anilide, Arava, N-(4-(TRIFLUOROMETHYL)PHENYL) 5 METHYLISOXAZOLE-4-CARBOXAMIDE, Leflunomida, Leflunomidum, alpha,alpha,alpha-Trifluoro-5-methyl-4-isoxazolecarboxy-p-toluidide.

14
Active clinical trials
DHODH
Primary target
4
Regulatory events
Latest activity
beta

Recent clinical, regulatory, research and industry developments relating to this drug.

Immunosuppressant Management in Rheumatology Patients Undergoing Elective Total Shoulder Arthroplasty

Clinical trial2026-07-09Results expected Q1 2028 · ClinicalTrials.gov

A Phase 2 Trial of Leflunomide, Pomalidomide, and Dexamethasone for Relapsed/Refractory Multiple Myeloma

Clinical trial2026-05-29Results expected Q1 2027 · ClinicalTrials.gov

Approval: Leflunomide medac (EMA)

Regulatory2010-07-27EMA

Approval: Arava (EMA)

Regulatory1999-09-02EMA

Profile

Identifiers & mechanism

Canonical identifiers, marketed brand names and mechanism, resolved across RxNorm, ChEMBL and ATC.

Canonical name
Leflunomide
Aliases & brands
4-ISOXAZOLECARBOXAMIDE, 5-METHYL-N-(4-(TRIFLUOROMETHYL)PHENYL)-5-Methyl-N-(4-(trifluoromethyl)phenyl)-4-isoxazolecarboxamide5-Methylisoxazole-4-carboxylic acid (4-trifluoromethyl)anilideAravaN-(4-(TRIFLUOROMETHYL)PHENYL) 5 METHYLISOXAZOLE-4-CARBOXAMIDELeflunomidaLeflunomidumalpha,alpha,alpha-Trifluoro-5-methyl-4-isoxazolecarboxy-p-toluidide
RxNorm CUI
27169
ChEMBL ID
CHEMBL960
ATC codes
L04AK01
UNII
G162GK9U4W
Primary mechanism
Dihydroorotate dehydrogenase inhibitor
Regulatory jurisdictions
ema

Pharmacology & targets

1 target

Known molecular targets and mechanisms supported by curated pharmacology databases.

INHIBITORDihydroorotate dehydrogenase inhibitor

Regulatory timeline

4 events

The complete regulatory record, grouped by authority — approvals, safety advisories and label changes. Each authority shows its most recent events; expand one to read its full history.

Earliest approval
1999-09-02
Latest approval
2010-11-28
Authorities
EMA
Total events
4
emaEuropean Medicines Agency· 4 events
2010-11-28Approval
Approval: Leflunomide ratiopharm (EMA)
Indication: Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD); active psoriatic arthritis.Show full indication

Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD); active psoriatic arthritis. Recent or concurrent treatment with hepatotoxic or haematotoxic DMARDs (e.g. methotrexate) may result in an increased risk of serious adverse reactions; therefore, the initiation of leflunomide treatment has to be carefully considered regarding these benefit / risk aspects. Moreover, switching from leflunomide to another DMARD without following the washout procedure may also increase the risk of serious adverse reactions even for a long time after the switching.

Evidence ↗
2010-07-27Approval
Approval: Leflunomide medac (EMA)
Indication: Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD). Recent or concurrentShow full indication

Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD). Recent or concurrent treatment with hepatotoxic or haematotoxic DMARDs (e.g. methotrexate) may result in an increased risk of serious adverse reactions, therefore, the initiation of leflunomide treatment has to be carefully considered regarding these benefit / risk aspects. Moreover, switching from leflunomide to another DMARD without following the washout procedure may also increase the risk of serious adverse reactions even for a long time after the switching.

Evidence ↗
2010-01-08Approval
Approval: Leflunomide Zentiva (previously Leflunomide Winthrop) (EMA)
Indication: Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD); active psoriatic arthritis.Show full indication

Leflunomide is indicated for the treatment of adult patients with: active rheumatoid arthritis as a 'disease-modifying antirheumatic drug' (DMARD); active psoriatic arthritis. Recent or concurrent treatment with hepatotoxic or haematotoxic DMARDs (e.g. methotrexate) may result in an increased risk of serious adverse reactions; therefore, the initiation of leflunomide treatment has to be carefully considered regarding these benefit / risk aspects. Moreover, switching from leflunomide to another DMARD without following the washout procedure may also increase the risk of serious adverse reactions even for a long time after the switching.

Evidence ↗

Contains information from the European Medicines Agency (European Medicines Agency), © EMA, reused under CC BY 4.0.

Clinical trials

74 trials

The current development programme across all trial phases — status mix, phase distribution and the late-stage studies shaping the evidence base.

Development programme
CLINICALTRIALS.GOV · LIVE REGISTRY
74
registered trials across all phases
LATEST COMPLETION 2025
14
Active studies
11
Recruiting
42
Late-stage (III+)
38
Completed
22
Discontinued
PHASE DISTRIBUTIONn = 74
Early Phase 11Phase 112Phase 1 / 25Phase 214Phase 2 / 31Phase 316Phase 415Phase N / A10

Late-stage studies

Phase III+ trials still open or recently active — where late-stage evidence is being generated.

Recent completions

Trials that read out recently, adding to the completed evidence base.

References & data sources
  • RxNorm (U.S. National Library of Medicine) — drug identity
  • ChEMBL (EMBL-EBI) & UniProt — pharmacology and targets
  • ClinicalTrials.gov — clinical trials
  • Regulatory event sources are credited in the Regulatory Timeline above.