Is it possible to stop the progression of the terrible amyotrophic lateral sclerosis, ALS, a serious fatal neurodegenerative disease, also called Lou Gehrig’s disease, for which there is currently no effective treatment? A team of researchers at the University Hospital of Montreal (CHUM) believes it can do so with a drug that has been used for about fifty years to treat schizophrenia and sells at a very low price.
A text by Normand Grondin
His name: the pimozide. And for now, the first results of a clinical trial in humans seem to prove them right.
“One of the big problems with ALS is that we now know most of the genes involved in the disease, but we still have almost nothing to offer patients to relieve them,” says researcher Pierre Drapeau in neuroscience at the CHUM research center.
Pierre Drapeau and his colleague Alex Parker, also a researcher in neuroscience at the CHUM, began in 2012 to approach this difficulty from a different angle.
They first genetically modified two species commonly used in the laboratory to present the human form of ALS: the zebrafish and the tiny worm C. elegans.
“Because they are animals with a relatively simple nervous system, you can do a lot of lab manipulations in a short time and in a very economical way,” says Parker.
And manipulations, they will do a lot. For five years, they test on their guinea pigs the effectiveness of more than 3800 known and approved drugs!
“We have tested drugs already known, says Pierre Drapeau, with the idea that if we found a molecule with an effect on ALS, it would then be much easier to use in patients.”
Finally, they discover the best candidate: pimozide, an antipsychotic.
Potential of pimozide
Exposed to pimozide, guinea pigs whose muscles are paralyzed by the human version of ALS begin to move more normally. “The product works particularly well to prevent paralysis in fish,” says Pierre Drapeau. In the worm C. elegans, the same result: the product restores the bridge between the brain, the nervous system and the muscles. The product is then tested in the mouse successfully.
Then, in 2015, it’s the first clinical trial in humans with a small group of 25 people. A test of just six weeks, but which shows that pimozide has potential. This opens the door to a second, larger clinical trial that begins this fall with about 100 volunteers in nine Canadian hospitals.
Daniel Rompré, who has had ALS for 18 months, hopes to be part of this group. “I have been told that it is a product that does not cure the disease, but that could possibly slow or stop it. ”
For this man who, until recently, had a busy and very active life, a hope of healing, even the thinnest, is worth grasping.
In the circumstances like that, when we know the outcome, we are ready to try anything.
Daniel Rompré, affected by amyotrophic lateral sclerosis
Alex Parker, who, like his colleague, is a professor at the University of Montreal in neuroscience, however, recalls that pimozide is a powerful drug, with side effects sometimes very serious, and that only a clinical trial can assess whether the weight benefits of the drug weighs heavier than that of the disadvantages.
“We are testing several thousand derivatives of the same molecule (pimozide) to find one that would potentially have the same positive effect, but without the negative effects.”
Finally, pimozide has another major advantage: it’s extremely low cost: 10 cents a pill, $ 100 for an annual treatment.
When compared to edaravone, one of the only other treatments available in the world (but not in Canada), with reduced efficacy and costing more than $15,000 a year, this is an argument that has weight.