Flex Pharma Halts Phase 2 FLX-787 Trial in CMT Patients Due to Tolerability Concerns

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by Alice Melao |

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Flex Pharma is terminating a Phase 2 clinical trial that was assessing FLX-787 as a potential treatment for muscle cramps in Charcot-Marie-Tooth disease (CMT) patients due to concerns about the oral tolerability of the investigational therapy.

The randomized, double-blind COMMIT trial (NCT03254199) was being conducted at 20 centers in the United States, and enrolled about 120 patients with confirmed CMT who had frequent, painful muscle cramping.

The trial was designed to determine the safety and effectiveness of 30 mg of FLX-787 taken orally three times a day in a disintegrating tablet formulation.

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

“However, recent observations of oral intolerability at the current dose and formulation, in a subset of patients indicate that more formulation and dose-ranging studies are required, which is challenging for the Company based upon our current resources,” he said.

The trial was initiated after the U.S. Food and Drug Administration granted FLX-787 investigational new drug status as a potential treatment for CMT patients. It was also endorsed by the Inherited Neuropathies Consortium.

FLX-787 is a small molecule designed to activate two proteins, TRPA1 and TRPV1, which trigger mechanisms that indirectly regulate the hyperactive signals of nerve cells in the spinal cord that cause muscle cramping.

Previous studies showed that the therapy could successfully stop muscle cramps induced by electrical stimulation in humans. FLX-787 also reduced the frequency of cramps and severity of pain in people who experience nighttime leg cramps.

The investigational therapy was given fast track designation by the FDA for the treatment of severe muscle cramps associated with ALS, and was also being evaluated in a Phase 2 trial for this indication. Like the COMMIT study, the COMMEND study (NCT03196375) in ALS patients will also be stopped for tolerability concerns.

Despite this disappointing result, the company announced it is going to further explore FLX-787’s potential as a possible treatment for dysphagia, or difficulty swallowing.

Following these decisions, the company is looking to reduce costs by restructuring its organization, which includes reducing its workforce by about 60 percent. Most of these changes are expected to be completed by the end of June.