Patients will develop abnormal extra movements they can’t control. They can develop trouble walking. They can have difficulty with coordination, especially of their hands and their mouth, and tongue and throat muscles, so swallowing can be impaired. Patients frequently develop cognitive impairment and that can progress even to dementia. Psychiatric symptoms can mean depression, psychosis and hallucinations. It can include apathy. Some of our patients with Huntington’s disease really lack motivation to do much at all. Over time, parts of the brain degenerate and it leads to death, usually within 15 to 20 years after symptom onset.
Q. Can you describe the new treatment?
A. It involves a neurosurgical procedure. It inserts small pieces of RNA into specific parts of the brain. Those little pieces of RNA will bind to the Huntington’s RNA and prevent abnormal protein from being produced. Because we’re pretty sure the abnormal protein is what leads to all the damage that happens, by preventing it from being produced, we can hopefully reduce a lot of the damage or prevent a lot of damage from taking place.
Q. How was the study conducted?
A. This study enrolled a fairly small number of people, 17, and had two different doses, so a low dose injection of this study drug and then a higher dose injection to the study drug. And they compared it to historical control. What it seemed to show was after getting this treatment over about three years, patients who had received the high dose treatment had lower progression of their disease.
Q. What is your opinion of the study findings?
A. This is really the area that I want to emphasize here: I think we probably need to be pretty cautious about interpreting this. This study was only a phase 1/2 trial. And usually phase 1 trials assess, “Is this a safe thing to do to people?” Phase 2 trials usually assess, “Is this intervention doing what we think it will do?” Most drugs are not approved by the FDA until they have a big phase 3 trial that shows that not only is it safe, not only does it do what we think it does, but by doing what we think it does, that it improves people's lives.
Q. Is there room for optimism?
A. I think cautious optimism is probably my feeling right now. It’s clearly really exciting. And I think there’s a good chance that the full results (not yet released) will bear it out. But I don't know that we’re ready to completely flip Huntington’s on its head and say “This is now treatable.”
If, for whatever reason, the full results of this trial are revealed or a bigger phase 3 trial takes place and it turns out that all of this hype was for nothing, there are still somewhere around eight or 10 other potentially disease-modifying treatments that are in trials in humans going on right now or that are gearing up to start. I’m extremely confident that at some point in the relatively near future, one of these things will be successful and we will have a true treatment for Huntington’s disease before I retire. I’m 37 years old. Hopefully (a treatment will come) in the next five or 10 years, but almost certainly before I retire.
