Flex Pharma Inc announced today that its extract formulation demonstrated efficacy in treating nocturnal leg cramps (NLC) in a randomized, controlled, blinded study. Flex Pharma is a biotechnology company developing treatments for NLC, spasms associated with severe neuromuscular conditions, and exercise-associated muscle cramps.

Statistically significant effects (p<0.05) were demonstrated on key endpoints: muscle cramp frequency; the physician-rated Clinical Global Impression of Change (CGI-C); specific sleep disturbance measures; and specific pain measures. Additionally, the product appeared to be safe and well-tolerated and there were no serious adverse events reported. The magnitude of efficacy in this study on reduction in muscle cramps appears similar to published quinine efficacy studies. Quinine, the only therapeutic intervention for leg cramps with randomized, controlled, blinded study support for efficacy, is associated with serious adverse events and was banned for the treatment of leg cramps by the FDA. Flex Pharma expects to present detailed results of this study at a future medical meeting.

The company estimates that NLC affects four million Americans nightly; there is no approved therapeutic in the United States to treat this condition. The randomized, blinded, controlled, crossover study evaluated 50 healthy subjects (50-77 years of age) who experienced nocturnal leg cramps at least four nights per week. After an initial placebo run-in period, the subjects were randomized to either control or study product for two weeks. Subjects were then crossed over to the other treatment for another two-week period so that each subject acted as his or her own control.

“Based upon these results, we plan to initiate our next study in nocturnal leg cramps later this year with a single molecule, selective and specific transient receptor potential (TRP) ion channel agonist,” says Flex Pharma chief medical officer Thomas Wessel, MD, PhD, in a release. “Additionally, our studies in MS and ALS with our drug candidate, FLX-787, are expected to initiate outside the US this year.”

John Winkelman, MD, PhD, chief of the Sleep Disorders Clinical Research Program at Massachusetts General Hospital and Flex Pharma Scientific Advisory Board member, says, “Flex Pharma is at the forefront of clinical development in nocturnal leg cramps, and the statistically significant human efficacy data generated in this study may provide a promising new treatment in the future for the millions of patients who currently have no safe and effective therapeutic options.”

Rod MacKinnon, MD, Nobel laureate and Flex Pharma Scientific co-founder, board member, and Scientific Advisory Board co-chair, says, “As a medical scientist, it is fulfilling to confirm the potential positive impact of chemical neuro stimulation-the process by which a small molecule chemical signal, acting topically, is translated into an electrical signal for the benefit of patients. Based upon the results from this nocturnal leg cramp study, it appears that chemical neuro stimulation may prove to be helpful to the millions afflicted with nocturnal leg cramps, to those suffering from exercise-associated muscle cramps, and hopefully also to those with severe neuromuscular disorders such as MS and amyotrophic lateral sclerosis.”