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DALLAS -- Extended-release dalfampridine (Ampyra) is approved for boosting walking speed in multiple sclerosis patients, but its benefits extend to other aspects of physical function, according to a small study reported here.

Both digital dexterity and coarse hand-arm function improved significantly from baseline, on average, in patients who completed 14 weeks of treatment at standard doses of dalfampridine, reported , of Mount Sinai Rehabilitation Hospital in Hartford, Conn.

Improvements from baseline were also seen in walking endurance, lower-extremity control, and patients' subjective impressions of their walking ability, Lo told attendees at the joint meeting of the Consortium of Multiple Sclerosis Centers and the Americas Committee for Treatment and Research in Multiple Sclerosis (CMSC-ACTRIMS).

For some of these measures, improvements occurred even in patients whose walking speed failed to improve with treatment, he noted.

The findings bolster those from a placebo-controlled trial reported last month at the American Academy of Neurology's annual meeting, which indicated that the drug led to better scores for balance and other lower-body functions.

Dalfampridine was approved in 2010 on the basis of trial results indicating faster completion of a 25-foot walk test in mildly to moderately disabled MS patients.

Although the drug's indication is restricted to improving walking speed, Lo said, patients have reported anecdotally that they find improvements in other types of physical activity such as hand function.

Consequently, he approached the drug's manufacturer, Acorda Therapeutics, to support an uncontrolled observational study to explore such effects.

Lo and colleagues enrolled 45 patients who started on the drug for the projected 14-week trial. Of those, 39 completed the study and were included in the statistical analyses. (The other six withdrew for reasons not related to the drug, Lo said.)

Sample characteristics were typical of MS patients with mild to moderate disability: mean age was 54, about three-quarters were women, and mean disease duration was 13 years (SD 9) with mean Expanded Disability Status Scale scores of 5.1 (SD 1.6). Only patients not taking dalfampridine at recruitment were included.

At baseline and at four visits while on treatment, patients were evaluated with six different physical function measures:

• Timed 25-foot walk test
• 6-minute walk test
• six-spot step test, dominant and nondominant leg
• 12-item MS Walking Scale (patient self-assessment)
• nine-hole peg test, dominant and nondominant hand
• Box-and-blocks test, dominant and nondominant hand

Lo presented results for the entire 39-patient group and also for subgroups defined by whether or not their walking speed improved in the 25-foot walk test. Those with faster speeds than at baseline in at least three of the four on-treatment evaluations were considered responders (N=20); patients with no improvement in any follow-up visit were considered nonresponders.

In the overall group, statistically significant average improvements were seen in all six measures, Lo reported. This was true as well for those classed as walking speed responders.

Among walking speed nonresponders, there was also no significant improvement in a few measures: the 6-minute walk test, the 6-spot step test for the dominant leg, and the box-and-block test for the nondominant hand.

But for all other measures, the walking speed nonresponders did show statistically significant improvements from baseline, Lo said.

In some cases, the absolute changes were relatively small. For example, mean time to complete the 9-hole peg test with the nondominant hand in walking speed nonresponders improved by only about 2 seconds from a baseline of 28 seconds.

But the patients' self-assessments of walking ability improved dramatically -- by about 15 points in all groups on the 60-point scale. Lo noted that this was especially remarkable considering that those classed as nonresponders had shown little or no objective improvement.

He concluded that the six-spot step test "may be a more sensitive measure" of walking ability than either the 25-foot or 6-minute walk tests.

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