Horizon Therapeutics plc announced new findings from a post hoc analysis of the N-MOmentum Phase 3 pivotal trial of UPLIZNA supporting the medicine's efficacy in Europeans living with NMOSD. These data are being presented during the 8thCongress of the European Academy of Neurology (EAN),June 25-28 in Vienna. UPLIZNA received marketing authorization from the European Commission (EC) on April 25, 2022 and is the first and only targeted CD19+ B-cell-depleting monotherapy proven to reduce attacks in adult patients with NMOSD who are anti-aquaporin-4 immunoglobulin G seropositive (AQP4-IgG+).

This post hoc analysis compared attack rates, disability-related outcomes and safety among 50 trial participants from the European Union (EU) (including participants from Bulgaria, Czech Republic, Estonia, Germany, Hungary and Poland) versus 163 non-EU participants. Participants in the EU who were treated with UPLIZNA experienced fewer attacks (12.5%) compared to those treated with placebo (30%), sharing similar results with non-EU participants receiving UPLIZNA (10.7%) or placebo (45.2%). No significant differences in Expanded Disability Status Scale (EDSS) worsening were found between participants in the EU (15%) versus non-EU participants (14.9%).

Fewer NMOSD-related hospitalisations were reported among those receiving UPLIZNA compared to those treated with placebo (mean, EU: 1.0 vs 2.0; non-EU: 1.0 vs 1.33). NMOSD is a unifying term for neuromyelitis optica (NMO) and related syndromes. NMOSD is a rare, severe, relapsing, neuroinflammatory autoimmune disease that attacks the optic nerve, spinal cord, brain and brain stem.

Approximately 80% of all patients with NMOSD test positive for anti-AQP4 antibodies. AQP4-IgG binds primarily to astrocytes in the central nervous system and triggers an escalating immune response that results in lesion formation and astrocyte death.