Washington (AFP)
Last summer in Nashville, an American mother had the genome changed and stopped suffering.
"Since I was 11, I was hoping for a cure," writes Victoria Gray, 34, to AFP. "Since receiving the new cells, I have found the pleasure of spending time with my family without living in fear of pain or urgency."
Victoria has a genetic disease of the blood, sickle cell disease, which causes atrocious attacks. She participated in an experimental treatment. Over several weeks, her blood was taken, before extracting the cells at the origin of her disease: the stem cells that lodge in the bone marrow and make red blood cells - globules that are deformed at Victoria , causing seizures.
These stem cells were shipped to a Scottish laboratory, where their DNA was modified using a new tool called Crispr / Cas9, dubbed molecular scissors (pronounced "crisper"). Then, he was retransfused genetically modified cells ... who returned to the fold, in the bone marrow. "Miracle," says Victoria: after a month, she produced normal blood cells.
It is not known if the repair will last. But in theory, she is healed for life.
"It's a single patient, it's still early," says her doctor, Haydar Frangoul, of the Sarah Cannon Cancer Center in Nashville. "But these results are great."
In Germany, a 19-year-old woman was treated with the same method for another blood disorder, beta-thalassemia. She previously needed 16 annual blood transfusions. Nine months later she was released.
The DNA of living things has been changed for decades, as is the case with corn or GM salmon. Including for humans in therapeutic trials for these same blood diseases and others, with older techniques.
But Crispr, invented in 2012, has democratized the practice because it is simpler than previous technologies, cheaper, and usable in small laboratories. And it is because it is easy to use that he has revived fantasies about the manipulation of life.
"Everything is going very quickly," says AFP the co-discoverer of Crispr, the French geneticist Emmanuelle Charpentier, co-founder of Crispr Therapeutics, the company that carries out this first clinical trial.
- 2019, year of breakthroughs -
Crispr is a revolution, but still experimental.
It should not hide that the year 2019 marked a historic turning point in an adventure begun three decades ago: gene therapy is becoming a reality.
For the first time, gene therapies have been granted marketing approval for a neuromuscular disease (in the United States) and for a blood disease (in the European Union). In total, there are now eight gene therapies on the market in the world, mostly against cancers and especially against a form of blindness.
Gene therapy involves inserting a normal gene into cells that have a defective gene, such as a Trojan horse, to do the work that this bad gene does not do: make Victoria's red blood cells, for example, or in the case of cancer, make super-white blood cells that kill tumors.
Crispr goes further: instead of adding a new gene, the tool modifies an existing gene.
The French may remember the first telethon, in December 1987, for the benefit of children with myopathies, muscular diseases. Many of the gene drugs that are maturing today, after years of clinical trials, are the result of research launched by Telethon and its laboratory, Genethon.
In Paris, Telethon's scientific director, Serge Braun, sees 2019 as a pivotal year, a prelude to a medical revolution.
"Twenty-five, 30 years is the time," he told AFP. "It always takes a generation, gene therapy has not escaped, now it's going to crescendo."
Near Washington, at the American Institutes of Health, there is also a "period of breakthroughs".
"We have reached a point of inflection," says Secretary General Carrie Wolinetz.
The problem is that these new therapies are expensive: up to one or even two million dollars, forcing painful negotiations with insurers. They are also heavy, so restricted to rich countries.
Victoria Gray spent months in the hospital, between blood tests, chemotherapy to clean the bone marrow, perfusion graft, and a final hospital stay of a month ... not to mention sepsis, an infection.
"We can not do that in the local hospital," his doctor said.
Still, the number of authorized gene therapies will increase to 40 by 2022, according to MIT researchers, for cancers and diseases of the muscles, the nervous system, the eye ... China, in particular, has many trials in progress.
- Sorcerer Apprentices -
The simplicity of Crispr has stimulated the imagination of sorcerer's apprentices.
In China last year, a scientist, He Jiankui, modified with Crispr embryos that became binoculars Lulu and Nana, causing its banishment from the international scientific community.
He wanted to create an immunizing mutation against the AIDS virus (with no apparent need), but caused other inadvertent mutations ... that will be passed on to their descendants.
"The technology is not yet safe," says Kiran Musunuru, a professor of genetics at the University of Pennsylvania. Crispr scissors often cut next to the targeted gene. "It's easy to use if you do not care about the consequences."
But ethical self-discipline seems to prevail. Even if a Russian, Denis Rebrikov, plans to use Crispr to help deaf parents to have children without the handicap.
For animals, the temptation is to modify the genome of whole species: the mosquitoes of malaria to decimate them (Burkina Faso); or host mice of Lyme disease ticks (USA). Their designers are advancing cautiously, aware of the unpredictability of the chain reactions on the ecosystem.
Emmanuelle Charpentier does not believe in the darkest predictions.
American "biohackers" who inject Crispr bought on the internet? "Not everyone is biologist or scientist," she sweeps.
And a military diversion to create virus killing soldiers or bacteria that would ravage the agriculture of the enemy?
"I'm a bacteriologist, we've been talking about bioterrorism for years," she says. "Nevertheless, it never happened."
She remains convinced that technology tends to be used for the better and that, in essence, the future will bring more Victoria than Lulu and Nana.
© 2019 AFP