FLX-787, Which Treats ALS-Associated Muscle Cramps, Wins FDA Fast Track Status

The U.S. Food and Drug Administration has granted fast track status to FLX-787, Flex Pharma‘s treatment for severe muscle cramps in amyotrophic lateral sclerosis.

Flex designed FLX-787 to interfere with transient receptor potential ion channels that are believed to play a role in nervous system pain and inflammation. FLX-787 inhibits channels known as vanilloid 1 and ankyrin 1.

Flex has reported in conference presentations that FLX-787 significantly reduced muscle cramps, with the higher the dose, the better the result.

A Phase 2 clinical trial of FLX-787 has begun in the United States, which has yet to approve a treatments for ALS-associated severe muscle cramps.

The FDA created fast track to accelerate the approval of drugs that are urgently needed to treat serious, unmet medical needs. Among other things, the designation opens the door to priority review of new drug applications.

The COMMEND trial (NCT03196375) will evaluate FLX-787 in patients with ALS and other neurodegenerative diseases who experience cramps. The study will include a run-up period to establish a cramp frequency level before treatment starts.

Patients will be randomized to receive either 30 mg of FLX-787 three times a day or a placebo for 28 days. The primary objective is to see whether FLX-787 reduces the frequency of cramps.

Flex Pharma began assessing FLX-787 in Australian ALS patients in September 2016. The goal was to evaluate its safety and ability to treat ALS-associated leg cramps and spasticity, or shaking.

“Our COMMEND trial, which is a Phase 2 study of primarily ALS patients in the U.S., has certain advantages to our ongoing ALS study in Australia, including longer run-in and treatment periods, increased dosing, a parallel design, and of course a much larger population from which patients can be recruited,” Dr. Thomas Wessel, Flex’s chief medical officer, said in a press release.

“As a result, we have elected to prioritize and focus our efforts on the COMMEND study, and will end the exploratory Australian ALS study early, with roughly a dozen patients. The data from the Australian study will inform our larger COMMEND clinical trial, particularly regarding baseline cramp frequency and intra-subject variability, which could influence sample size calculation and other aspects of trial conduct for this important U.S. study.”