I watched scientists, ethicists, patient advocacy groups and others wrestle with these topics at the Third International Human Genome Editing Summit in London earlier this week.
There’s a lot to be excited about when it comes to gene editing. In the decade since scientists discovered they could use CRISPR to edit cell genomes, numerous clinical trials have been conducted to test the technology’s use for serious diseases. CRISPR has already been used to save some lives and transform others.
But not everything goes smoothly. Not all trials went as planned and some volunteers died. Successful treatments are likely to be expensive and therefore limited to the wealthy few. And while those attempts tend to involve changes to genes in adult body cells, some hope to use CRISPR and other tools to edit genes in eggs, sperm and embryos. The specter of designer babies continues to loom over the field.
At the most recent summit held in Hong Kong in 2018, He Jiankui, then based at the Southern University of Science and Technology in Shenzhen, China, announced that he had used CRISPR on human embryos. The news of the first “CRISPR babies,” as they’ve come to be known, caused quite a stir, as you can imagine. “We will never forget the shock,” Victor Dzau, president of the US National Academy of Medicine, told us.
He Jiankui went to prison and was released only last year. And while hereditary genome editing was already banned in China at the time—it had been banned since 2003—the country has since passed a series of additional laws designed to prevent such a thing from happening again. Today, hereditary genome editing is prohibited by criminal law, Yaojin Peng of the Beijing Institute of Stem Cell and Regenerative Medicine told the audience.
There was much less drama at this year’s summit. But there were many emotions. In a session on how gene editing could be used to treat sickle cell disease, Victoria Gray, a 37-year-old survivor of the disease, took the stage. She told the audience how her severe symptoms disrupted her childhood and adolescence and thwarted her dreams of training to be a doctor. She described episodes of severe pain that kept her hospitalized for months at a time. Her children were worried that she might die.
But then she underwent a treatment involving gene editing in cells from her bone marrow. Her new “super cells,” as she calls them, transformed her life. Within minutes of receiving a transfusion of edited cells, she felt reborn and shed tears of joy, she told us. It took her seven to eight months to feel better, but after that point, “I really started to enjoy the life that I once felt was just passing me by,” she said. I could see the typical stoic scholars around me wiping tears from their eyes.
Victoria is one of more than 200 people who have been treated with CRISPR-based therapies in clinical trials, said David Liu of the Broad Institute at MIT and Harvard, who is leading the development of new and improved forms of CRISPR. Trials are also underway for a number of other diseases, including cancer, genetic vision loss and amyloidosis.