Natalizumab Improves Disability in Relapsing-Remitting Multiple Sclerosis

Heinz Wiendle, MD

Data from the Tyasbri Observational Program (TOP) demonstrated that treatment with natalizumab (Tyasbri; Biogen) showed disability score improvement, including confirmed functional system (FS) improvement in all measures, in patients with relapsing-remitting multiple sclerosis (RRMS).¹

Conducted by Heinz Wiendl, MD, professor and chair, department of neurology, University Hospital of Muenster, and colleagues, the results showed that 1287 of the 5384 patients (23.9%) included in the study had confirmed disability improvement (CDI). Among those, 51.8% experienced CDI in the first treatment year.

CDI was defined as a decrease ≥1.0 confirmed 24 weeks later from a baseline Expanded Disability Status Scale (EDSS) score ≥2.0. Patients with CDI ≥1.5 points accounted for 56.6% of the total subset that showed improvement, while 34.4% had CDI ≥2.0 points. Researchers noted that the cumulative probability of maintaining improvement 8 years after the CDI event was 52.6%.

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EDSS scores were significantly lower after 3 years of natalizumab treatment than at baseline in the patient group with ≤1 year since MS symptom onset at treatment initiation but not in the groups with longer disease duration at treatment initiation (mean change from baseline in EDSS score [SEM], —0.78; P <.0001).

When mentioning the impact that the results can have on clinical care, Wiendl and colleagues concluded, “The potential for substantial, long-lasting disability improvement with natalizumab treatment should be considered when evaluating treatment choices for RRMS.”

They also noted that the findings “extend previous disability improvement analyses from the AFFIRM randomized controlled trial, to show that improvement can occur during long-term treatment in real-world settings.”

Furthermore, the cumulative probability of CDI in previously treatment-naïve patients at 3 years ranged from 28.8% for patients with >5 years since symptom onset to 47.9% for patients with ≤1 year since MS symptom onset at natalizumab initiation. Those with 1—5 years since MS symptom onset saw a 37.1% cumulative probability of achieving CDI since time from first natalizumab dose.

Patients with ≤1 year since MS symptom were 1.4 times more likely to experience CDI than those with 1—5 years since onset (hazard ratio [HR] for 1–5 years vs ≤1 year, 0.69; P = .0426) and were twice as likely to experience CDI as those with ≥5 years since symptom onset (HR for ≥5 years vs ≤1 year, 0.50; P = .0019).

At 8 years, treatment with natalizumab showed an 88.8% cumulative probability of confirmed improvement in any FS. Notably, the cumulative probability of maintaining confirmed improvement in individual FS scores was ≥98.9% over 1 year, ≥58.6% over 3 years, and ≥33.6% over 8 years. The statistically significant improvement comes after 5363 (85.2%) patients had impairment in ≥1 FS at treatment initiation.

Those who were treatment-naïve at natalizumab initiation were more likely to have confirmed improvement in any FS score than those who had used prior disease-modifying therapies (DMTs). For patients with 1 prior DMT versus treatment-naïve patients, confirmed improvement was 0.81 (range, 0.72—0.91; P = .0006) and 0.72 (0.64—0.82; P <.0001) for those with ≥2 prior DMTs versus treatment-naïve patients.

The FDA approved natalizumab in November 2004 as a treatment for relapsing forms of MS to reduce the frequency of clinical relapses. The therapy was also granted accelerated approval following priority review designation based on 1-year data from 2 phase 3 studies.²

Recent data presented at the 2020 Annual Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) suggested that treatment with natalizumab was associated with a greater “feel-good” experience compared with other DMTs for patients with RRMS.³

REFERENCES

Wiendl H, Spelman T, Butzkueven H, et al. Real-world disability improvement in patients with relapsing-remitting multiple sclerosis treated with natalizumab in the Tysabri observational program. J Mult Scler. Published online June 24, 2020. doi: 10.1177/1352458520926869.