02 December 2013
ByAppeared in BioNews 733
A biotech start-up that will develop genome-editing therapies has received US $43 million investment from three venture capital firms.
Editas Medicine, based in Massachusetts, plans to develop a new class of drugs that can precisely correct disease-causing mutations in DNA, using a technology called CRISPR/Cas9.
CRISPR can be used to edit single base pairs and larger stretches of DNA, leading researchers to believe its versatility can be used to target any mutation.
'The way to think about it is molecular surgery… you can go in and make changes to the DNA', Dr J Keith Joung, co-founder of Editas Medicine, told the Boston Globe. 'If there's a defect, you can fix it; if there's a missing piece, you can put the missing piece in'.
CRISPR/Cas9 is a gene-editing system initially identified in bacteria, where it protects against viruses (see BioNews 730). A guide RNA molecule brings the Cas9 protein to a specific stretch of DNA, which it then cuts in a precise way. Unwanted DNA can therefore be 'deleted' and replaced with versions of DNA to correct the faulty gene.
Dr Douglas Cole is a general partner at Flagship Ventures, one of the venture capital firms alongside Polaris Partners and Third Rock Ventures that have invested in Editas. He said: 'The gene editing approaches on which Editas is based represent some of the most exciting and promising scientific breakthroughs in recent years, making it possible, for the first time, to correct the genomic defects responsible for a broad range of diseases'.
Editas Medicine has not announced the conditions they will be aiming to treat. But their focus will be on diseases that are proving especially hard to treat with traditional gene therapy or gene knock-down efforts that do not actually remove the faulty gene from cells. These traditional efforts have associated safety concerns and cannot correct diseases that arise from faulty genes producing toxic proteins; such is the case in Huntington's Disease.
Therapies based on CRISPR could overcome these problems by precisely and accurately replacing the faulty gene in its normal chromosomal region.
However, there are technological and ethical barriers still to overcome, in addition to the normal clinical trials, so it is likely to be years before a precise genome-editing therapy will be available on the market.