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119  Long-term effectiveness of natalizumab for RRMS: UK and global interim results from TYSABRI observational program
  1. Richard Nicholas1,
  2. Timothy Harrower2,
  3. Shirley Liao3,
  4. Jean Vonsy4
  1. 1Imperial College Healthcare
  2. 2Royal Devon and Exeter NHS Trust
  3. 3Biogen, Cambridge, USA
  4. 4Biogen, UK


Introduction The TYSABRI Observational Program (TOP) is an ongoing observational study of natalizumab treatment in relapsing-remitting multiple sclerosis (RRMS) patients. Country-specific data on relapse and disability outcomes, alongside global data, can provide information on natalizumab’s effectiveness in local practice.

Methods Annualised relapse rate (ARR) was analysed in TOP UK (n=134) and global (N=6320) cohorts using data from July 2007 to November 2020. A subgroup analysis assessed ARR in patients with one prior disease modifying therapy (DMT) in the UK (n=64) and global (n=2795) cohorts. Cumulative probabilities of 24-week confirmed disability worsening and improvement will be presented.

Results ARR decreased in UK patients from 2.21 in the year before initiation to 0.16 on natalizumab (P<0.0001), consistent with a global decrease from 2.00 to 0.18 (P<0.0001). In patients with one prior DMT, ARR decreased in UK patients from 2.13 in the year before initiation to 0.15 on natalizumab (P<0.0001), similar to the global decrease from 2.03 to 0.16 (P<0.0001).

Conclusions The reduction in ARR on natalizumab was similar in the TOP UK and global cohorts, including in the subset of patients with one prior DMT. These findings support the real-world effectiveness of natalizumab.

Support.Biogen. Disclosures: Included on the poster.

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