Impaired walking is a prominent symptom of MS. Mobility problems are reported in up to 58 per cent of patients in the first year after diagnosis and in up to 93 per cent within 10 years. This loss of mobility leads to increased use of healthcare resources and reduced quality of life.
Establishing if drugs are able to improve mobility is difficult, and several scales have been developed by physicians to objectively describe walking.
Two common ways of measuring walking and lower extremity function are the timed 25-foot walk (T25FW) and the timed 100-metre walk (T100MW). These tests are used in clinical trials worldwide to assess the effectiveness of drugs for walking and disability.
A study in December’s European Journal of Neurology looked at whether natalizumab is effective in improving walking performance in patients with relapsing-remitting MS (RRMS). Natalizumab is used in many countries to treat RRMS patients who do not respond to the first-line disease-modifying drugs.
The authors published a report of walking scores in 842 patients from two multi-centre clinical trials on natalizumab, called TIMER and AFFIRM.
Natalizumab was associated with clinically meaningful improvements in walking speeds in the TIMER study after one year and in the AFFIRM study after two years.
The results of TIMER also suggest that T100MW may be a more sensitive test of walking capacity than T25FW. However, both tests may be able to detect clinically meaningful improvements in functioning not reflected by changes in EDSS score (EDSS is a scale used by neurologists to assess disability in MS).