While Tysabri (natalizumab) failed to slow worsening disability in people with secondary progressive multiple sclerosis (SPMS) in a Phase 3 trial, researchers now suggest that the treatment did improve walking and arm function in people with advanced disability.
Gavin Giovannoni of England’s Barts and the London School of Medicine and Dentistry presented the study, “Natalizumab improves walking and upper-limb disability compared with placebo in patients with secondary progressive multiple sclerosis: an integrated, post hoc area under the outcome-time curve analysis from the ASCEND trial.”
Biogen’s Tysabri failed to show effectiveness in the ASCEND trial back in 2015. But researchers didn’t give up on the idea that Tysabri might benefit people with SPMS. Earlier this year, researchers showed that Tysabri improved the mental health-related quality of life in patients treated in the ASCEND study.
Giovannoni’s data suggests the drug can also improve disability in patients.
He said the way data from the ASCEND trial was initially analyzed “was not sensitive enough.” Giovannoni believes the method his team used is more sensitive, as it takes into account both improvement and worsening in disability, assessed through several parameters.
“This post-hoc analysis has very important implications for how we conduct trials,” he said.
The trial included 887 SPMS patients who had not experienced relapses in the past year. Participants were randomly assigned treatment with Tysabri or a placebo for two years. None had received Tysabri before.
Using a specific type of statistical analysis, the research team analyzed how patients changed in their disability levels, measured by the expanded disability status scale (EDSS), timed 25-foot walk — a mobility and leg function performance test — and the 9-Hole Peg Test, which measures arm function.
Data indicated that Tysabri-treated patients experienced less disability worsening on mobility and arm function tests than placebo-treated patients.
In contrast, there was no difference in EDSS changes between the groups. Neither saw average change in scores over the two-year period.
Taken together, these results show that Tysabri “significantly improved the overall disability experience for walking and upper-limb function compared with placebo in mostly non-relapsing SPMS patients with advanced disability,” said Giovannoni, adding that “consistent with the primary results from ASCEND, treatment effects were greatest for upper-limb function.”