More than 200 people have been treated with experimental CRISPR treatments

At the Third International Human Genome Editing Summit in London earlier this week, I watched as scientists, ethicists, patient advocates and others grappled with these topics.

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 a cell’s genome, several clinical trials have been created to test the technology’s use in serious diseases. CRISPR has already been used to save some lives and change others.

But all was not smooth sailing. Not all experiments went to plan, and some volunteers died. Effective treatments can be expensive, and therefore only a few are wealthy. And while these experiments involve changes to genes in adult body cells, some hope to use CRISPR and other gene-editing tools in eggs, sperm and embryos. The look of designer babies continues to be seen on the field.

In the year It was at the last summit held in Hong Kong in 2018 that He Jianku, then based at the Southern University of Science and Technology in Shenzhen, China, announced the use of CRISPR in human embryos. As you can imagine, the news of the first “CRISPR babies,” as they are known, caused quite a stir. “We will never forget the shock,” said Victor Zaw, president of the US National Academy of Medicine.

He Jianku was in prison and was released only last year. And while genetic genome editing was banned in China at the time — it’s been illegal since 2003 — the country has since passed a series of additional laws designed to prevent it from happening again. Today, genetic 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 he had a lot of feeling. During a session on how gene editing can be used to treat sickle-cell disease, 37-year-old survivor Victoria Gray took to the stage. She told the audience how her severe symptoms disrupted her childhood and teenage years and ruined her dreams of becoming a doctor. She described a severe illness that kept her hospitalized for months at a time. Her children were worried that she might die.

But then she underwent a treatment that involved editing the genes in the cells in her bone marrow. Her new “super cells,” as she calls them, changed her life. Within minutes of receiving the transplanted cells, she told us she felt reborn and shed tears of joy. It took her seven to eight months to feel better, but after that time, she says, “I began to enjoy the life that I once felt had passed me by.” I saw the normally stoic scientists around me wipe tears from their eyes.

Victoria is one of more than 200 people who have been treated with CRISPR-based therapy in clinical trials.David Liu of the Broad Institute of MIT and Harvard, who led the development of new and improved types of CRISPR, said. Trials are underway for a variety of other diseases, including cancer, genetic vision loss and amyloidosis.