Discovery of novel oxazepine and diazepine carboxamides as two new classes of heat shock protein 90 inhibitors.

Two novel series of oxazepine and diazepine based HSP90 inhibitors are reported. This effort relied on structure based design and isothermal calorimetry to identify small drug like macrocycles. Computational modelling was used to build into a solvent exposed pocket near the opening of the ATP binding site, which led to potent inhibitors of HSP90 (25-30).

In utero and postnatal VX-770 administration rescues multiorgan disease in a ferret model of cystic fibrosis.

Cystic fibrosis (CF) is a multiorgan disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). In patients with CF, abnormalities initiate in several organs before birth. However, the long-term impact of these in utero pathologies on disease pathophysiology is unclear. To address this issue, we generated ferrets harboring a VX-770 (ivacaftor)-responsive CFTR G551D mutation. In utero VX-770 administration provided partial protection from developmental pathologies in the pancreas, intestine, and male reproductive tract. Homozygous CFTR G551D/G551D animals showed the greatest VX-770-mediated protection from these pathologies. Sustained postnatal VX-770 administration led to improved pancreatic exocrine function, glucose tolerance, growth and survival, and to reduced mucus accumulation and bacterial infections in the lung. VX-770 withdrawal at any age reestablished disease, with the most rapid onset of morbidity occurring when withdrawal was initiated during the first 2 weeks after birth. The results suggest that CFTR is important for establishing organ function early in life. Moreover, this ferret model provides proof of concept for in utero pharmacologic correction of genetic disease and offers opportunities for understanding CF pathogenesis and improving treatment.

Identification of novel HSP90α/ß isoform selective inhibitors using structure-based drug design. demonstration of potential utility in treating CNS disorders such as Huntington's disease.

A structure-based drug design strategy was used to optimize a novel benzolactam series of HSP90α/ß inhibitors to achieve >1000-fold selectivity versus the HSP90 endoplasmic reticulum and mitochondrial isoforms (GRP94 and TRAP1, respectively). Selective HSP90α/ß inhibitors were found to be equipotent to pan-HSP90 inhibitors in promoting the clearance of mutant huntingtin protein (mHtt) in vitro, however with less cellular toxicity. Improved tolerability profiles may enable the use of HSP90α/ß selective inhibitors in treating chronic neurodegenerative indications such as Huntington's disease (HD). A potent, selective, orally available HSP90α/ß inhibitor was identified (compound 31) that crosses the blood-brain barrier. Compound 31 demonstrated proof of concept by successfully reducing brain Htt levels following oral dosing in rats.