High-dose intravenous interferon beta in patients with neutralizing antibodies (HINABS): a pilot study

BackgroundNeutralizing antibodies (NABs) against interferon beta (IFNβ) are associated with a loss of IFNβ bioactivity and clinical effectiveness. To date, there are no anti-NAB strategies available. The primary objective of this trial was to investigate whether intravenous IFNβ-1b can restore bioactivity in NAB-positive patients with MS.MethodsNAB-positive patients with MS were treated with 8 MIU IFNβ-1b s.c., 8 MIU i.v., and 16 MIU i.v. Each application was preceded by a wash-out period of 1 week. Blood samples were collected before, 3, 12, and 24 h after each administration. Myxovirus protein A (MxA) RNA and protein levels were determined. The study has been approved by the local ethics committee.ResultsFive patients completed the study. NAB titers ranged from 42 to 4482 neutralizing units. Median MxA protein (1821, range 12–3234) and RNA (2186, range 114–7525) area under the curve levels for the four measurements at each IFNβ injection were significantly higher after i.v. application of 16 MIU as comp...