Ofatumumab, a human anti-CD20 monoclonal antibody, for treatment of rheumatoid arthritis with an inadequate response to one or more disease-modifying antirheumatic drugs: results of a randomized, double-blind, placebo-controlled, phase I/II study

Arthritis Rheum. 2010 Aug;62(8):2227-38. doi: 10.1002/art.27524.


Objective: To investigate the safety and efficacy of ofatumumab, a novel human anti-CD20 monoclonal antibody (mAb), in patients with active rheumatoid arthritis (RA) whose disease did not respond to > or = 1 disease-modifying antirheumatic drug.

Methods: This combined phase I/II study investigated the safety and efficacy of 3 doses of ofatumumab. In part A (phase I), 39 patients received 2 intravenous (i.v.) infusions of ofatumumab (300 mg, 700 mg, or 1,000 mg) or placebo in a 4:1 ratio 2 weeks apart, using a specified premedication and infusion regimen. In part B (phase II), 225 patients received study treatment as per phase I in a 1:1:1:1 ratio. Safety was assessed by adverse events (AEs) and laboratory parameters. Efficacy was assessed by the American College of Rheumatology 20% criteria for improvement (ACR20), the Disease Activity Score in 28 joints, and the European League Against Rheumatism (EULAR) response criteria. B cell pharmacodynamics were also investigated.

Results: AEs were predominantly reported at the first infusion and were mostly mild to moderate in intensity. Rapid and sustained peripheral B cell depletion was observed in all dose groups. In phase II, patients in all ofatumumab dose groups had significantly higher ACR20 response rates (40%, 49%, and 44% for the 300 mg, 700 mg, and 1,000 mg doses, respectively) than did patients receiving placebo (11%) at week 24 (P < 0.001). Overall, 70% of patients receiving ofatumumab had a moderate or good response according to the EULAR criteria at week 24.

Conclusion: Our findings indicate that ofatumumab, administered as 2 i.v. infusions of doses up to 1,000 mg, is clinically effective in patients with active RA.

Trial registration: ClinicalTrials.gov NCT00291928.

Publication types

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

MeSH terms

  • Antibodies, Monoclonal / administration & dosage
  • Antibodies, Monoclonal / adverse effects
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents / administration & dosage
  • Antirheumatic Agents / adverse effects
  • Antirheumatic Agents / therapeutic use
  • Arthritis, Rheumatoid / therapy*
  • Double-Blind Method
  • Drug Administration Schedule
  • Female
  • Humans
  • Male
  • Middle Aged
  • Patient Selection
  • Severity of Illness Index
  • Treatment Outcome


  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents
  • ofatumumab

Associated data

  • ClinicalTrials.gov/NCT00291928