Long-term efficacy, tolerability and retention rate of azathioprine in 103 aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder patients: a multicentre retrospective observational study from the UK.

Journal article

BACKGROUND: Azathioprine (AZA) is a common immunosuppressive drug used for relapse prevention in neuromyelitis optica (NMO). OBJECTIVES: The objective of this paper is to assess efficacy, tolerability and retention of AZA in a large NMO cohort. METHODS: We conducted a retrospective review of medical records of 103 aquaporin-4 antibody-positive NMO and NMO spectrum disorder (NMOSD) patients treated with AZA. RESULTS: This is the largest reported cohort of AQP4-Ab positive patients treated with AZA. Eighty-nine per cent (n = 92) had reduction in median annualised relapse rates from 1.5 (IQR 0.6-4.0) to 0 (IQR 0-0.27, p < 0.00005) with treatment. Sixty-one per cent (n = 63) remained relapse free at a median follow-up of 18 months. Neurological function improved or stabilised in 78%. At last follow-up, treatment was discontinued in 46% (n = 47). Of these, 62% (n = 29) were because of side effects, 19% (n = 9) because of death, 15% (n = 7) because of ongoing disease activity, and 2% (n = 1) because of pregnancy. Using Kaplan-Meyer curves, we estimate that 73%, 58%, 47% and 33% of patients will remain on AZA for longer than one, three, five and 10 years, respectively, after initiation of treatment. CONCLUSIONS: AZA is a modestly effective treatment for NMO. However, many patients discontinue AZA over time and this seems to reflect poor tolerability more than lack of efficacy.

Authors: Elsone, L; Kitley, J; Luppe, S; Lythgoe, D; Mutch, K

• Publication status: Published
• Publisher: SAGE Publications
• Journal: Multiple sclerosis (Houndmills, Basingstoke, England)
• Volume: 20
• Issue: 11
• Pages: 1533-1540
• Publication date: 2014-10-01
• DOI: 10.1177/1352458514525870
• EISSN: 1477-0970
• ISSN: 1352-4585
• Language: English
• Keywords: NMO; azathioprine; aquaporin-4; tolerability; Neuromyelitis optica; retention