Flex Pharma’s MS Treatment Candidate FLX-787 Improves Cramps, Stiffness, Phase 2 Trial Shows

Topline results of an exploratory Phase 2 clinical trial revealed that Flex Pharma‘s treatment candidate FLX-787 improves muscle cramps, spasms and muscle stiffness in patients with multiple sclerosis (MS).

The double-blinded trial, conducted in Australia, evaluated an oral dose of 19 mg FLX-787, taken twice daily in liquid form, in 57 MS patients.

Results showed that, in comparison with placebo treatment, FLX-787 led to a 27.3 percent decrease in the frequency of cramps/spasms, and a 1.4 day increase in days without these MS symptoms (cramp/spasm-free days) per 14-day period.

Also, treatment with FLX-787 resulted in a clinician-rated improvement in muscle spasticity. Physicians reported that seven of 28 patients taking FLX-787 had “much improved” or “very much improved” spasticity, whereas none of the patients in the placebo group experienced such level of improvement.

Subsequent analysis including all enrolled patients confirmed the improvements in muscle spasticity, but did not find benefits in cramp/spasm frequency, or in other clinical muscle spasticity scales.

“MS patients frequently complain of cramps, spasms, and spasticity which can dramatically affect their quality of life,” Anneke van der Walt, PhD, the study’s lead investigator, said in a press release. “These new data suggest that FLX-787 may have the potential to address this important unmet medical need.”

Data also demonstrated that FLX-787 was generally well-tolerated and did not induce drug-related serious adverse events. Participants occasionally reported diarrhea and nausea.

Flex Pharma plans to present these results at future medical meetings.

“We see in these data the clear potential of FLX-787 to improve cramps and spasticity in patients with MS,” said William McVicar, PhD, president and CEO at Flex Pharma. “Based upon these strong data and the learnings from this study, we look forward to the development and execution of a refined Phase 2b study as part of our full FLX-787 clinical development program.”

FLX-787 activates two proteins, the TRPA1 and TRPV1 ion channels, which are involved in nervous system pain and inflammation. FLX-787 intends to suppress the excessive excitability of spinal cord circuits regulating cramps, spasms and muscle spasticity.

Besides MS, Flex Pharma also is developing FLX-787 for neuromuscular disorders such as amyotrophic lateral sclerosis (ALS) and Charcot-Marie-Tooth disease. In July 2017, the U.S. Food and Drug Administration granted FLX-787 fast track status to expedite its development as a treatment for severe muscle cramps in ALS.

“Late last year, FLX-787 demonstrated a similar efficacy profile in a small exploratory study of ALS patients,” said Thomas Wessel, MD, PhD, Flex Pharma’s chief medical officer.

“Our MS trial results provide a second set of clinical evidence that FLX-787 may provide beneficial activity in patients with underlying neurological disease and demonstrates the potential of chemical neurostimulation in treating symptoms arising from motor neuron and reflex hyperexcitability,” Wessel concluded.