Discovery and SAR of 2-arylbenzotriazoles and 2-arylindazoles as potential treatments for Duchenne muscular dystrophy.

Families of 2-arylbenzotriazoles and 2-arylindazoles that show positive effects in screens predictive of endogenous utrophin upregulation have been identified. Synthesis and structure-activity relationships are described leading to compounds with attractive in vitro profiles.

Daily treatment with SMTC1100, a novel small molecule utrophin upregulator, dramatically reduces the dystrophic symptoms in the mdx mouse.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a lethal, progressive muscle wasting disease caused by a loss of sarcolemmal bound dystrophin, which results in the death of the muscle fibers leading to the gradual depletion of skeletal muscle. There is significant evidence demonstrating that increasing levels of the dystrophin-related protein, utrophin, in mouse models results in sarcolemmal bound utrophin and prevents the muscular dystrophy pathology. The aim of this work was to develop a small molecule which increases the levels of utrophin in muscle and thus has therapeutic potential. METHODOLOGY AND PRINCIPAL FINDINGS: We describe the in vivo activity of SMT C1100; the first orally bioavailable small molecule utrophin upregulator. Once-a-day daily-dosing with SMT C1100 reduces a number of the pathological effects of dystrophin deficiency. Treatment results in reduced pathology, better muscle physiology leading to an increase in overall strength, and an ability to resist fatigue after forced exercise; a surrogate for the six minute walk test currently recommended as the pivotal outcome measure in human trials for DMD. CONCLUSIONS AND SIGNIFICANCE: This study demonstrates proof-of-principle for the use of in vitro screening methods in allowing identification of pharmacological agents for utrophin transcriptional upregulation. The best compound identified, SMT C1100, demonstrated significant disease modifying effects in DMD models. Our data warrant the full evaluation of this compound in clinical trials in DMD patients.

Discovery of 2-arylbenzoxazoles as upregulators of utrophin production for the treatment of Duchenne muscular dystrophy.

A series of novel 2-arylbenzoxazoles that upregulate the production of utrophin in murine H2K cells, as assessed using a luciferase reporter linked assay, have been identified. This compound class appears to hold considerable promise as a potential treatment for Duchenne muscular dystrophy. Following the delineation of structure-activity relationships in the series, a number of potent upregulators were identified, and preliminary ADME evaluation is described. These studies have resulted in the identification of 1, a compound that has been progressed to clinical trials.

Transduction patterns of pseudotyped lentiviral vectors in the nervous system.

We have developed a non-primate-based lentiviral vector based on the equine infectious anemia virus (EIAV) for efficient gene transfer to the central and peripheral nervous systems. Previously we have demonstrated that pseudotyping lentiviral vectors with the rabies virus glycoprotein confers retrograde axonal transport to these vectors. In the present study we have successfully produced high-titer EIAV vectors pseudotyped with envelope glycoproteins from Rhabdovirus vesicular stomatitis virus (VSV) serotypes (Indiana and Chandipura strains); rabies virus [various Evelyn-Rokitnicki-Abelseth ERA strains and challenge virus standard (CVS)]; Lyssavirus Mokola virus, a rabies-related virus; and Arenavirus lymphocytic choriomeningitis virus (LCMV). These vectors were delivered to the striatum or spinal cord of adult rats or muscle of neonatal mice by direct injection. We report that the lentiviral vectors pseudotyped with envelopes from the VSV Indiana strain, wild-type ERA, and CVS strains resulted in strong transduction in the striatum, while Mokola- and LCMV-pseudotyped vectors exhibited moderate and weak transduction, respectively. Furthermore ERA- and CVS-pseudotyped lentiviral vectors demonstrated retrograde transport and expression in distal neurons after injection in brain, spinal cord, and muscle. The differences in transduction efficiencies and retrograde transport conferred by these envelope glycoproteins present novel opportunities in designing therapeutic strategies for different neurological diseases.