Ionis» trial, led in partnership with Prof Sarah Tabrizi of University College London, was the first time
a targeted huntingtin - lowering drug had been tested in humans.
The Swiss team's cool idea was to make a CRISPR / Cas machine that
targets the huntingtin gene — but with an extra CRISPR sequence that also makes the Cas nuclease target its own DNA.
Ionis pharmaceuticals are currently nearing the end of an exciting clinical trial using an ASO that
targets the huntingtin RNA.
Not exact matches
Being able to detect and measure the amount of mutant
huntingtin present in the nervous system will be a valuable way of seeing whether the gene - silencing drug is hitting its
target and has the intended effect, lowering the amount of disease causing mHTT protein.
The zinc finger protein works by
targeting the mutant copies of the
Huntingtin gene, repressing its ability to express and create harmful proteins.
«We don't know exactly how the mutant
Huntingtin gene causes the disease, so the idea is that
targeting the gene expression cuts off the problem at its source — preventing it from ever having the potential to act,» said Dr Isalan.
Zeitlin says the study may also help researchers find new
targets for drugs against Huntington's — such as compounds that block the clumping of abnormal
huntingtin.
An approach to treating HD that uses
targeted molecules to tell cells not to produce the harmful
huntingtin protein
A quirk of the
huntingtin gene might be helpful when it comes to avoiding these «off -
target effects».
Since RNA - based gene silencing drugs have been successful so far, why bother with the greater challenge of
targeting the DNA of the
huntingtin gene itself, especially if it means dealing with virus particles and big, fragile drugs made of protein?
Another option may be the pursuit of «allele - specific» therapies, those that specifically
target mutant
huntingtin while leaving the normal form intact.
Huntingtin, the protein that causes Huntington's disease, has been an elusive
target.
Rigorous experiments in animals have given way to clinical trials of drugs that
target the HD gene in people, and there are more techniques for decreasing or eliminating
huntingtin on the horizon.
It's the world's first trial in patients to slow, stop, prevent or reverse HD, using a method that
targets the root cause of the disease, a gene producing a protein called
huntingtin.