Incidence, characterization, and clinical impact analysis of peginterferon beta1a immunogenicity in patients with multiple sclerosis in the ADVANCE trial

Background:Efficacy of interferon beta in multiple sclerosis (MS) can be dampened in patients who develop neutralizing antidrug antibodies (NAbs). Peginterferon beta1a is an interferon conjugated with a polyethylene glycol (PEG) moiety. Pegylation increases a drug’s half life and exposure, and may also reduce immunogenicity.Objective:The objective of this study was to characterize the incidence and impact of immunogenicity to peginterferon beta1a over 2 years in patients with MS.Methods:Patients with relapsing–remitting MS (N = 1512) were randomized to subcutaneous peginterferon beta1a 125 μg every 2 or 4 weeks, or placebo, for 1 year; patients in the placebo group were rerandomized to active treatment in year 2. The incidence and titers of binding antibodies (BAbs) and NAbs to interferon and antibodies to PEG (anti-PEG) were assessed in analytically validated assays. The clinical impact of immunogenicity on relapse and magnetic resonance imaging endpoints was evaluated.Results:Over 2 years, 6%, less than...