The ClC-1 chloride channel inhibitor NMD670 improves skeletal muscle function in rat models and patients with myasthenia gravis.

Myasthenia gravis (MG) is a neuromuscular disease that results in compromised transmission of electrical signals at the neuromuscular junction (NMJ) from motor neurons to skeletal muscle fibers. As a result, patients with MG have reduced skeletal muscle function and present with symptoms of severe muscle weakness and fatigue. ClC-1 is a skeletal muscle specific chloride (Cl-) ion channel that plays important roles in regulating neuromuscular transmission and muscle fiber excitability during intense exercise. Here, we show that partial inhibition of ClC-1 with an orally bioavailable small molecule (NMD670) can restore muscle function in rat models of MG and in patients with MG. In severely affected MG rats, ClC-1 inhibition enhanced neuromuscular transmission, restored muscle function, and improved mobility after both single and prolonged administrations of NMD670. On this basis, NMD670 was progressed through nonclinical safety pharmacology and toxicology studies, leading to approval for testing in clinical studies. After successfully completing phase 1 single ascending dose in healthy volunteers, NMD670 was tested in patients with MG in a randomized, placebo-controlled, single-dose, three-way crossover clinical trial. The clinical trial evaluated safety, pharmacokinetics, and pharmacodynamics of NMD670 in 12 patients with mild MG. NMD670 had a favorable safety profile and led to clinically relevant improvements in the quantitative myasthenia gravis (QMG) total score. This translational study spanning from single muscle fiber recordings to patients provides proof of mechanism for ClC-1 inhibition as a potential therapeutic approach in MG and supports further development of NMD670.

Antagonists of the human adenosine A2A receptor. Part 1: Discovery and synthesis of thieno[3,2-d]pyrimidine-4-methanone derivatives.

The (-)-(11R,2'S)-enantiomer of the antimalarial drug mefloquine has been found to be a reasonably potent and moderately selective adenosine A(2A) receptor antagonist. Further investigation of this compound has led to the discovery of a series of keto-aryl thieno[3,2-d]pyrimidine derivatives, which are potent and selective antagonists of the adenosine A(2A) receptor. These derivatives show selectivity against the A(1) receptor. Furthermore, some of these compounds have been shown to have in vivo activity in a commonly used model, suggesting the potential for the treatment of Parkinson's disease.

Synthesis and SAR of novel 2-arylthiazolidinones as selective analgesic N-type calcium channel blockers.

A series of new N-type (Ca(v)2.2) calcium channel blockers derived from the 'hit' structures 2-(3-bromo-4-fluorophenyl)-3-(2-pyridin-2-ylethyl)thiazolidin-4-one 9 and its 2-[4-(4-bromophenyl)pyridin-3-yl]-3-isobutyl analogue 10 is described. Extensive SAR studies using a range of synthetic approaches resulted in novel, patented compounds with IC50 values of up to 0.2 microM in an in vitro IMR32 assay, and selectivities for N/L of up to 30-fold. The new compounds described have potential in treatment of neuropathic pain.