Efficacy, Safety, and Pharmacodynamic Effects of the Bruton's Tyrosine Kinase Inhibitor Fenebrutinib (GDC-0853) in Systemic Lupus Erythematosus: Results of a Phase II, Randomized, Double-Blind, Placebo-Controlled Trial

Arthritis Rheumatol. 2021 Oct;73(10):1835-1846. doi: 10.1002/art.41811. Epub 2021 Aug 24.


Objective: Fenebrutinib (GDC-0853) is a noncovalent, oral, and highly selective inhibitor of Bruton's tyrosine kinase (BTK). The efficacy, safety, and pharmacodynamics of fenebrutinib in systemic lupus erythematosus (SLE) were assessed in this phase II, multicenter, randomized, placebo-controlled study.

Methods: Patients who had moderately to severely active SLE while receiving background standard therapy were randomized to receive placebo, fenebrutinib 150 mg once daily, or fenebrutinib 200 mg twice daily. Glucocorticoid taper was recommended from weeks 0 to 12 and from weeks 24 to 36. The primary end point was the SLE Responder Index 4 (SRI-4) response at week 48.

Results: Patients (n = 260) were enrolled from 44 sites in 12 countries, with the majority from Latin America, the US, and Western Europe. The SRI-4 response rates at week 48 were 51% for fenebrutinib 150 mg once daily (P = 0.37 versus placebo), 52% for fenebrutinib 200 mg twice daily (P = 0.34 versus placebo), and 44% for placebo. British Isles Lupus Assessment Group-based Combined Lupus Assessment response rates at week 48 were 53% for fenebrutinib 150 mg once daily (P = 0.086 versus placebo), 42% for fenebrutinib 200 mg twice daily (P = 0.879 versus placebo), and 41% for placebo. Safety results were similar across all arms, although serious adverse events were more frequent with fenebrutinib 200 mg twice daily. By week 48, patients treated with fenebrutinib had reduced levels of a BTK-dependent plasmablast RNA signature, anti-double-stranded DNA autoantibodies, total IgG, and IgM, as well as increased complement C4 levels, all relative to placebo.

Conclusion: While fenebrutinib had an acceptable safety profile, the primary end point, SRI-4 response, was not met despite evidence of strong pathway inhibition.

Trial registration: ClinicalTrials.gov NCT02908100.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antirheumatic Agents / adverse effects
  • Antirheumatic Agents / pharmacology
  • Antirheumatic Agents / therapeutic use*
  • Autoantibodies / blood*
  • Complement C3 / metabolism
  • Complement C4 / metabolism
  • Double-Blind Method
  • Female
  • Humans
  • Lupus Erythematosus, Systemic / blood
  • Lupus Erythematosus, Systemic / drug therapy*
  • Male
  • Middle Aged
  • Piperazines / adverse effects
  • Piperazines / pharmacology
  • Piperazines / therapeutic use*
  • Pyridones / adverse effects
  • Pyridones / pharmacology
  • Pyridones / therapeutic use*
  • Treatment Outcome
  • Young Adult


  • Antirheumatic Agents
  • Autoantibodies
  • Complement C3
  • Complement C4
  • Piperazines
  • Pyridones
  • fenebrutinib

Associated data

  • ClinicalTrials.gov/NCT02908100
  • EudraCT/2016-001039-11