Pharmaceuticals & Vitamin D : Orphan diseases


Gene Correction of Pompe Disease and Other Autosomal Recessive Disorders via CRISPR and other RNA-Guided Nucleases

UW–Madison researchers have developed a complexed CRISPR-Cas system (S1mplex; P170309US01) for treating patients with inherited autosomal recessive conditions. The work focuses on Pompe disease. The inventors identified new guide RNA target sites and repair templates that could be used for gene therapy strategies and cell therapeutic strategies.

The inventors demonstrated successful editing of fibroblast and induced pluripotent stem cells from three Pompe patients at UW Hospital having heterozygous mutations (each allele containing a different mutation, both leading to loss of function of the enzyme). Using their complexed CRISPR-Cas technology markedly increased editing precision (18.4-fold) in two different cell lines (HEK and hPSC), easing concerns about off-target effects. Importantly, rapid glycogen processing improvements were observed after gene correction – 24 hours and 96 hours, respectively.

Compounds and Methods for Modulating Frataxin Expression in Friedreich’s Ataxia

UW–Madison researchers have generated new chimeric complexes that selectively increase FXN mRNA production to eliminate the physiological cause of Friedrich’s Ataxia. The synthetic transcription elongation factors (Syn-TEFs) of the present invention comprise a bromodomain inhibitor (such as Brd4), bound to a linker (such as PEG), which is further bound to a polyamide designed to target a gene sequence of interest near the repeats (see image below). Mechanistically, the complex binds selectively to the DNA near the triplet repeats in FRDA patients, and then the linked bromodomain inhibitor binds BRD4 and thereby recruits the elongation machinery to restart the paused transcription complex.

The inventors observed a 4.3-fold improvement at 500 nM after 1 day, which should be sufficient for real improvement, since FRDA carriers only have 40% of normal expression and show no symptoms. Increasing the dose to 1 μM increased FXN mRNA 8.5-fold after 1 day, with 3-fold improvement after only 6 hours.