Acorda Therapeutics will press ahead with development of its multiple sclerosis (MS) therapy Ampyra in patients with stroke-related disability following encouraging data from mid-stage trials.

Ampyra (dalfampridine) is a potassium channel blocker approved in the US in 2010 as a treatment for improving walking in patients with MS.

Laboratory studies have previously shown the drug can improve impulse conduction in nerve fibers in which the insulating layer, or myelin, has been damaged, leading to its approval in MS.

Now, a Phase II trial involving 83 patients - who had experienced an ischaemic stroke at least six months prior to enrollment and had chronic motor deficits - indicate that Ampyra may also be of benefit in treating stroke-related disabilities.

Patients receiving the drug showed a significant improvement in walking speed compared to those in the control group, as well as a positive change on the Functional Independence Measurement (FIM) scale, which assesses an individual’s ability to perform daily tasks such as bathing, grooming, eating, and walking independently.

"There were clear efficacy signals in the dalfampridine-ER post-stroke deficits trial and we therefore plan to proceed with a clinical development program for this indication," commented Ron Cohen, Acorda’s president and chief executive.

'Desperate' need

Highlighting the opportunities in the field, he also noted that while there are more than seven million stroke survivors in the US, around half of whom have some lasting mobility impairment, there are no medications currently available for these patients, "so new therapies are desperately needed”. 

On the safety side, Acorda said findings were consistent with previous clinical and post-marketing trials of Ampyra in patients with MS, the most common adverse events being: dizziness (10.4% dalfampridine-ER versus 2.5% placebo); nausea (3.9% vs 6.2%); fatigue (5.2% vs 3.7%); insomnia (5.2% vs 2.5%); and arthralgia (2.6% vs 3.7%).

Findings of a separate proof-of-concept trial in 24 participants with cerebral palsy are still being assessed.

Ampyra is being developed and commercialised by Biogen Idec under the trade name Fampyra in markets outside of the US.