Baricitinib in Patients with Refractory Rheumatoid Arthritis

N Engl J Med. 2016 Mar 31;374(13):1243-52. doi: 10.1056/NEJMoa1507247.

Abstract

Background: In phase 2 studies, baricitinib, an oral Janus kinase 1 and 2 inhibitor, reduced disease activity in patients with rheumatoid arthritis who had not previously received treatment with biologic disease-modifying antirheumatic drugs (DMARDs).

Methods: In this phase 3 study involving 527 patients with an inadequate response to or unacceptable side effects associated with one or more tumor necrosis factor inhibitors, other biologic DMARDs, or both, we randomly assigned the patients in a 1:1:1 ratio to baricitinib at a dose of 2 or 4 mg daily or placebo for 24 weeks. End points, tested hierarchically at week 12 to control type 1 error, were the American College of Rheumatology 20% (ACR20) response (primary end point), the Health Assessment Questionnaire-Disability Index (HAQ-DI) score, the 28-joint Disease Activity Score based on C-reactive protein level (DAS28-CRP), and a Simplified Disease Activity Index (SDAI) score of 3.3 or less (on a scale of 0.1 to 86.0, with a score of 3.3 or less indicating remission). Comparisons with placebo were made first with the 4-mg dose of baricitinib and then with the 2-mg dose.

Results: Significantly more patients receiving baricitinib at the 4-mg dose than those receiving placebo had an ACR20 response at week 12 (55% vs. 27%, P<0.001). Differences between the higher-dose baricitinib group and the placebo group were also significant for the HAQ-DI score and the DAS28-CRP but not for an SDAI score of 3.3 or less. Adverse-event rates through 24 weeks were higher for patients receiving the 2-mg dose of baricitinib and those receiving the 4-mg dose than for patients receiving placebo (71% and 77%, respectively, vs. 64%), including infections (44% and 40%, vs. 31%). The rates of serious adverse events were 4%, 10%, and 7% in the three groups, respectively. Two nonmelanoma skin cancers and two major adverse cardiovascular events, including a fatal stroke, occurred in the higher-dose group. Baricitinib was associated with a small reduction in neutrophil levels and increases in serum creatinine and low-density lipoprotein cholesterol levels.

Conclusions: In patients with rheumatoid arthritis and an inadequate response to biologic DMARDs, baricitinib at a daily dose of 4 mg was associated with clinical improvement at 12 weeks. (Funded by Eli Lilly and Incyte; ClinicalTrials.gov number, NCT01721044.).

Publication types

  • Clinical Trial, Phase III
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antirheumatic Agents / adverse effects
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Rheumatoid / drug therapy*
  • Azetidines / adverse effects
  • Azetidines / therapeutic use*
  • Female
  • Humans
  • Janus Kinase 1 / antagonists & inhibitors
  • Janus Kinase 2 / antagonists & inhibitors
  • Logistic Models
  • Male
  • Middle Aged
  • Protein Kinase Inhibitors / adverse effects
  • Protein Kinase Inhibitors / therapeutic use*
  • Severity of Illness Index
  • Sulfonamides / adverse effects
  • Sulfonamides / therapeutic use*

Substances

  • Antirheumatic Agents
  • Azetidines
  • Protein Kinase Inhibitors
  • Sulfonamides
  • Janus Kinase 1
  • Janus Kinase 2
  • baricitinib

Associated data

  • ClinicalTrials.gov/NCT01721044