A trial done by Intellia Therapeutics demonstrated that CRISPR (Cas9) can be administered into the body and target the liver to treat a disease called transthyretin amyloidosis. This would be done by Cas9 editing the gene that expresses the mutated protein (ATTR). This gene is the mutated form of the normal gene that expresses TTR. The mutated protein builds up in the heart and kidneys. A patient with this disease has the inability to control basic body functions.
Some drugs that were utilized were small interfering RNAs and antisense oligonucleotides. Small interfering RNAs are RNAs that affect the transcription of a certain gene. This would prevent the gene from being transcribed and then translated into a mutated protein. Antisense oligonucleotides are small pieces of RNA or DNA that bind to a specific mRNA, which would block it from being translated. These drugs had to be administered monthly which also had side effects. Cas9 provides a safer alternative by splicing the genome and preventing the expression from happening.
In Phase I of the trials, 3 out of the 6 patients with transthyretin amyloidosis look a low dose of Cas9 (drug name NTLA-2001), and the other half took a higher dose. The results showed that TTR levels dropped by 50% and 96% for the higher dose group. If these trials continue, then this can be used in 2 hours in the nearest outpatient clinic.