The US Food and Drug Administration (FDA) granted orphan drug designation to NMD670, a skeletal muscle-specific chloride ion channel (ClC-1) inhibitor designed to treat myasthenia gravis (MG), according to a recently published press release.

Evidence collected from several animal models suggests that ClC-1 inhibition can increase the function of the neuromuscular union, thus improving muscle function in patients with neuromuscular disorders such as MG.

The phase 1/2a clinical trial meant to assess safety, tolerability, and efficacy, as well as its pharmacokinetics and pharmacodynamics in the clinical setting, was recently finished. Results from the trial are expected to be published soon.

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This initial randomized, double-blind, placebo-controlled, single and multiple dose escalation study clinical trial included approximately 80 patients, including healthy control patients and patients with MG.

Furthermore, the primary outcomes of the study evaluated mainly tolerability and safety indicators, such as the presence of serious adverse effects or adverse effects, changes from baseline in clinical laboratory studies (hematology, chemistry, coagulation), changes in systolic and diastolic blood pressure, changes in respiratory rate, and changes in both electrocardiography and 24-hour Holter reading.

Secondary endpoints were mostly pharmacokinetic, with a collection of blood and urine samples for assay of NMD670 and its metabolite. Pharmacokinetic variables, such as Tmax, the area under the curve, and Cmax, were also taken into consideration.

“Myasthenia gravis is a rare neuromuscular disease with a high unmet medical need for innovative new treatments to address the debilitating symptoms of muscle weakness and fatigue,” said Thomas Holm Pedersen, chief executive officer of NMD Pharma. “Receiving orphan drug designation for our lead product candidate, NMD670, is a significant milestone for NMD Pharma as it further strengthens our belief in this novel treatment approach and helps to progress our investigational drug to patients.”

The orphan drug denomination is given to drugs intended to treat diseases that affect fewer than 200,000 persons in the United States of America.


FDA grants orphan drug designation for NMD670 for the treatment of myasthenia gravis. NMD Pharma A/S; News release. September 27, 2022.

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