Last November, the United Kingdom became the first country in the world to approve a therapy based on Crispr genome editing, in this case a treatment for sickle cell anemia and beta thalassemia called Casgevy. The British regulator, which wishes to position the country as a pioneer in terms of authorization of gene editing therapies, is ahead of its American and European counterparts.
These two genetic diseases affect hemoglobin, a protein present inside red blood cells. The deformation of red blood cells leads to blockage of small blood vessels and causes anemia and severe pain. Until now, bone marrow transplantation, which had to come from a closely matched donor and carries a risk of rejection, was the only feasible treatment option.
On the verge of a revolution
This approval of Crispr technology, only eleven years after the scientific discovery by researchers Jennifer Doudna and Emmanuelle Charpentier, a discovery celebrated by a Nobel Prize in 2020, is proof of the revolution that is coming. Gene therapy, which involves introducing genetic material into cells to treat a disease, is not new. Its first applications date back to the early 2000s. The initial strategy aimed to replace a diseased gene by importing a copy of a functional gene into a target cell, either in vivo, directly into the patient’s body via a viral vector, or ex vivo, by modifying stem cells collected in the laboratory before reinjecting them. The imported gene does not modify the diseased gene, it simply adds to the genetic heritage of the cells. The first ex vivo gene therapy drug, Strimvelis, hit the market in 2016.
Crispr allows us to go much further by repairing the altered gene directly in the cell, while being much simpler than pre-existing genome editing tools based on nucleases, zinc fingers or Talen. Casgevy remains a difficult drug to administer. Patients must have their stem cells extracted from their bone marrow so that their genes can be edited in the laboratory. Once the modified cells are reintroduced into their bodies, they must spend at least a month in the hospital before they start producing normal red blood cells. If blood disorders were targeted as a priority, it is because the cells concerned are the easiest to extract.
The island of stings
This advance in gene therapies will increase the number of unregulated initiatives. Particularly for meliorative medicine. One million tourists visit Roatan every year. But this paradise island off the coast of Honduras is about to become famous other than for its beaches, thanks to the gene therapy offered there by Minicircle, an American biotech. The therapy would stimulate the body’s production of follistatin, a protein naturally found in mammals that helps increase muscle mass and bone density. Follistatin can be injected, but its half-life of less than an hour and a half means that several injections are needed per day to maintain the effect. Minicircle injects intravenously plasmids, pieces of DNA, which will reprogram the fat cells of the abdomen over a long period, until they are renewed.
Minicircle’s capital includes the usual Silicon Valley champions, from Peter Thiel to Sam Altman. If the company’s headquarters is in Austin (Texas), the injection is carried out in Honduras, because the legal framework there is very flexible and the treatment is not approved by the American drug agency, the FDA . Despite their lack of diplomas, the two co-founders have become stars among biohackers, these enthusiasts wishing to improve the performance of the human body. The company has already convinced dozens of people to take its therapy, which costs $25,000. She recently created a buzz by bringing the pope of the fight against aging, Bryan Johnson, to Roatan. This multi-millionaire gives of himself: he has embarked on an extreme process of rejuvenation, with the help of dietary supplements, experimental drugs and carefully planned sports sessions.
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