Baricitinib in patients with rheumatoid arthritis with inadequate response to methotrexate: results from a phase 3 study

Clin Exp Rheumatol. 2020 Jul-Aug;38(4):732-741. Epub 2020 May 20.


Objectives: This study evaluated the efficacy and safety of baricitinib, an oral Janus kinase (JAK)1/JAK2 inhibitor, in patients with moderately to severely active rheumatoid arthritis (RA) and inadequate response to methotrexate (MTX) therapy.

Methods: In this phase 3, double-blind, 52-week, placebo-controlled study, 290 patients with moderately to severely active RA and inadequate response to MTX were randomly assigned 1:1 to placebo or baricitinib 4-mg once daily, stratified by country (China, Brazil, Argentina) and presence of joint erosions. Primary endpoint measures included American College of Rheumatology 20% response (ACR20) at week 12. Secondary endpoints included changes in Health Assessment Questionnaire-Disability Index (HAQ-DI) and Disease Activity Score for 28-joint counts (DAS28)-high-sensitivity C-reactive protein (hsCRP), Simplified Disease Activity Index (SDAI) score ≤3.3, mean duration of morning joint stiffness, severity of morning joint stiffness numeric rating scale (NRS 0-10), worst tiredness NRS, and worst joint pain NRS at week 12.

Results: Most patients (approximately 80%) were from China. More patients achieved ACR20 response at week 12 with baricitinib than with placebo (58.6% vs. 28.3%; p<0.001). Statistically significant improvements were also seen in HAQ-DI, DAS28-hsCRP, morning joint stiffness, worst tiredness, and worst joint pain in the baricitinib group compared to placebo at week 12. Through week 24, rates of treatment-emergent adverse events, including infections, were higher for baricitinib compared to placebo, while serious adverse event rates were similar between baricitinib and placebo.

Conclusions: In patients with RA who had an inadequate response to MTX, baricitinib was associated with significant clinical improvements as compared with placebo.

Publication types

  • Clinical Trial, Phase III
  • Randomized Controlled Trial

MeSH terms

  • Antirheumatic Agents / therapeutic use*
  • Argentina
  • Arthritis, Rheumatoid / drug therapy*
  • Azetidines
  • Brazil
  • China
  • Double-Blind Method
  • Drug Therapy, Combination
  • Humans
  • Methotrexate / therapeutic use
  • Purines
  • Pyrazoles
  • Sulfonamides
  • Treatment Outcome


  • Antirheumatic Agents
  • Azetidines
  • Purines
  • Pyrazoles
  • Sulfonamides
  • baricitinib
  • Methotrexate