Table 3.
Year 1 |
Over 2 years |
||||
---|---|---|---|---|---|
Placebo (n = 489) | Peginterferon beta1a | Peginterferon beta1a | Peginterferon beta1a | Peginterferon beta1a | |
every 2 weeks (n = 491) | every 4 weeks (n = 492) | every 2 weeks (n = 715) | every 4 weeks (n = 716) | ||
Patients with ⩾1 positive antipeginterferon beta1a NAbs result, n (%)b | 2 (<1) | 4 (<1) | 2 (<1) | 7 (<1) | 6 (<1) |
Transient positive, n (%)c | 1 (<1) | 2 (<1) | 2 (<1) | 2 (<1) | 5 (<1) |
Persistent positive, n (%)c | 1 (<1) | 2 (<1) | 0 | 5 (<1) | 1 (<1) |
Low titer, n (%) | 1 (<1) | 3 (<1) | 1 (<1) | 2 (<1) | 3 (<1) |
Medium titer, n (%) | 1 (<1) | 1 (<1) | 1 (<1) | 3 (<1) | 3 (<1) |
High titer, n (%) | 0 | 0 | 0 | 1 (<1) | 0 |
All patients who received peginterferon beta1a at any point during the study.
NAb assay was performed only in anti-IFN BAb-positive samples, per tiered assay design; percentages are given as a proportion of the total number of patients at risk (the number of patients whose baseline antibody was not positive and who had at least one post-baseline immunogenicity assessment).
Transient positive defined as a single positive evaluation, or more than one positive evaluation occurring less than 74 days apart; persistent positive defined as at least two consecutive positive evaluations that occurred at least 74 days apart or a positive evaluation at the final assessment. Results reported as ‘positive titer not determinable’ were considered titer missing. Antipeginterferon NAbs titer levels: low (⩽50), medium (>50 and ⩽700), or high (>700).
BAb, binding antibody; IFN, interferon; NAb, neutralizing antibody.