Phase 2 Study of Treatment for ALS-Induced Cramps, FLX-787, Underway in Australia

Margarida Azevedo, MSc avatar

by Margarida Azevedo, MSc |

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ALS research

Flex Pharma has begun a Phase 2 clinical trial assessing FLX-787 in patients with amyotrophic lateral sclerosis (ALS). The aim of the study, taking place in Australia, is to evaluate the safety and efficacy of FLX-787 in treating ALS-related leg cramps and/or spasticity.

Patients with ALS — a disorder that involves the death of neurons that control voluntary muscles —  frequently experience fasciculations, or persistent muscle twitches that can interfere with sleep, and more than half of all patients with ALS also experience painful muscle cramps that affect their quality of life.

“We have initiated three human efficacy studies this year – in nocturnal leg cramps, multiple sclerosis, and now ALS – with our single agent candidate, FLX-787,” Thomas Wessel, MD, PhD, Flex Pharma’s chief medical officer, said in a press release. “We are hopeful that our efforts will ultimately help the many patients with severe neuromuscular diseases who suffer from these painful conditions.”

FLX-787 is a single molecule, chemically synthesized, transient receptor potential (TRP) ion channel activator.

The drug is thought to be capable of interfering with the TRPV1 and TRPA1 receptors involved in pain and neurogenic inflammation, the company said in an October 2015 presentation to the Society for Neuroscience. In that presentation, researchers said that FLX-787 had demonstrated an ability to significantly reduce human muscle cramp intensity in a dose-response way, with higher concentrations showing better inhibitory effect.

“Topical Chemical Neuro Stimulation is a process whereby small molecules activate TRP ion channels on sensory nerves in the oral mucosa, which we hypothesize signal through neural circuits to inhibit the hyperexcitable motor neurons in the spinal cord that can cause muscle cramps,” said Dr. Rod MacKinnon, a Nobel laureate and Flex Pharma’s Scientific co-founder, Board Member, and Scientific Advisory Board co-chair. “We hypothesize that this approach may be generally applicable as a treatment for cramps and spasms in a spectrum of neuromuscular conditions.”

In addition to this randomized, controlled, blinded, cross-over study, the safety and efficacy of FLX-787 is also being assessed in a Phase 2 clinical trial in multiple sclerosis (MS) patients who suffer from cramps, spasms, and/or spasticity as a result of the disease.