Flex Pharma Stops Phase 2 Trial of FLX-787 to Ease Muscle Cramps in ALS Patients

Flex Pharma announced that it is stopping Phase 2 clinical trials of its investigational compound to ease muscle cramps, FLX-787, in patients with amyotrophic lateral sclerosis (ALS) and Charcot-Marie-Tooth disease (CMT).

The company’s decision was based on tolerability concerns in each study with the oral disintegrating tablet formulation at 30 mg, which was being taken three times daily.

“In the past few months we have reported positive efficacy data in two serious and distinctly different neurological diseases: multiple sclerosis (MS) and ALS … showing the clear potential of FLX-787 … to reduce painful cramps and spasms in these patient populations,” Bill McVicar, PhD, president and CEO at Flex Pharma, said in a press release.

“However, recent observations of oral intolerability at the current dose and formulation, in a subset of patients, in both studies, indicate that more formulation and dose-ranging studies are required,” McVicar said. These additional studies, however, will be challenging given the company’s current resources, he added.

Flex reported positive topline results from an exploratory Phase 2 trial in Australia that tested FLX-787 in ALS patients with frequent muscle cramps in November 2017. Benefits reported included reduced intensity of cramp-associated pain and stiffness compared to placebo.

The company followed by opening a larger Phase 2 trial (NCT03196375), called COMMEND, in the U.S. The study was evaluating FLX-787’s effectiveness, at 30mg three times a day, compared to placebo in easing muscle cramps in people with ALS and other motor neuron diseases. The study was expected to conclude this month.

It also launched the Phase 2 COMMIT study (NCT03254199) to evaluate FLX-787 as a treatment candidate for muscle cramps in CMT patients.

Flex announced that it will continue to assess FLX-787 as a possible treatment for dysphagia (difficulty swallowing).

However, the company is restructuring to lower costs, including cutting its workforce by nearly 60 percent. A sale or merger is possible, it announced in the release.

The U.S. Food and Drug Administration granted FLX-787 fast track status as a potential therapy for severe muscle cramps in ALS in 2017.