a proof-of-concept study of the human anti-IL-6
monoclonal antibody sirukumab failed to
demonstrate superiority of the drug to placebo in
patients with active nephritis. 73 A Phase I trial of
the IL-6 receptor antagonist tocilizumab showed
improved SLE disease activity and decreased
autoantibody production, but the observed
dose-related decreases in absolute neutrophil
counts raised concerns. 74
The importance of the type I IFN pathway
in the pathogenesis of SLE has prompted the
investigation of anti-IFN antibodies as potential
drugs. 75 The first data supporting the efficacy of
IFN-α inhibition came from a Phase IIb trial of
sifalimumab; 76 the results were modest but in
favour of sifalimumab. However, another phase II
study of the