HONG KONG — A major international conference on human genome editing that starts here on Tuesday is sponsored by the Academy of Sciences of Hong Kong, Britain’s Royal Society, and the U.S. National Academies — but not the host nation’s leading scientific body.

The Chinese Academy of Sciences (CAS), which co-sponsored the first such summit in 2015 in Washington with its British and American counterparts, pulled out this time.

A year ago, after months of planning leading up to the Second International Summit on Human Genome Editing, China quietly bowed out, David Baltimore of the California Institute of Technology, chairman of the meeting’s organizing committee, told STAT. The development has not previously been reported and was not announced by the organizers, who were hesitant to discuss the reasons.

advertisement

“CAS did not want to have a 500-person meeting in [mainland] China and we needed that to accommodate the expected number of attendees,” Baltimore said. “So they dropped out.” At that point the Hong Kong Academy of Sciences offered a venue and sponsorship.

Other scientists involved in the months of planning believe more was at issue than Beijing’s supposed inability to find an auditorium. “Originally we had co-sponsorship from the Chinese Academy of Sciences and the summit was to be in Beijing,” said a scientist familiar with the planning. “But there was clearly reluctance on the part of the [Chinese] government to host it at the scale and transparency we wanted.”

The Chinese Academy did not reply to requests for comment.

Its absence, and that of officials from China’s science ministry, means a key player in genome editing will not be officially represented. Science in China and how quickly its researchers are moving to correct inherited diseases by editing human embryos —  is nevertheless expected to be a star attraction.

On the eve of the summit, news broke about a Chinese scientist’s stunning claim that for the first time, babies — twin girls — had been born in recent weeks with genes that had been edited as embryos. The DNA changes, which the girls could pass on to their offspring, were intended to make them resistant to infection with HIV. Other scientists said the work was premature and unsafe, and denounced it as human experimentation.

Besides the absence of the Chinese Academy, this summit differs from 2015’s in name. Rather than “gene editing,” this is a summit on “genome editing”: That change reflects the power of technologies such as CRISPR, which in lab animals and human cells alter not only individual genes but multiple ones simultaneously, treating the entire genome like a bad manuscript awaiting the ministrations of a red-pencil-wielding editor. Summit sessions will showcase advances in CRISPR science, describe regulation and public attitudes about it around the world, and air the ethical issues it raises.

At the 2015 summit, a science ministry official raised eyebrows when he said that although China has strict regulations on the use of genome editing in human embryos, he could not guarantee that rogue labs and clinics were not conducting experiments they shouldn’t.

There have been rumors for years that researchers in China are speeding ahead with experiments using genome editing to alter the DNA of human embryos in ways that scientists in the West are reluctant, or forbidden, to attempt. Laws in some countries, including the U.S., prohibit using public funds to alter the DNA of human embryos, even those that are non-viable, the size of only a few cells, and not destined to start a pregnancy. Such “germline editing” would be inherited by descendants.

Scientists in China, in contrast, are marching ahead. In 2015, biologists at Sun Yat-sen University in Guangzhou carried out the first experiment altering the DNA of human embryos, describing their work in an obscure online journal after better-known ones rejected the paper for ethics reasons. It spurred an immediate outcry. Many scientists and others argued against altering the human genome in a way that could last for generations.

Since then, influential groups like the U.S. National Academies and Britain’s Nuffield Council on Bioethics have endorsed research on germline editing, which has the potential to prevent inherited diseases such as Huntington’s, sickle cell, Tay-Sachs, and more before a child is even born. But even proponents of eventual human use call for much more research on whether germline editing can be done safely before it’s attempted on an IVF embryo intended for a pregnancy.

Leading CRISPR scientists say they’re largely in the dark about what evidence of safety that labs in China think is necessary before using CRISPR in IVF clinics. This summer, researchers led by Xingxu Huang of ShanghaiTech University reported using a new form of CRISPR called base editing to correct the mutation that causes Marfan syndrome in IVF embryos. No pregnancies were attempted. Huang, whose research is supported by the Chinese government, is scheduled to speak at the summit.

A key reason why summit organizers wanted to meet in China “is that we think this is the area of the world most likely to move forward without in-depth oversight of the kind we have in the U.S. and U.K.,” said the scientist who discussed the Chinese Academy’s pullout.

“We’ll be hearing from a number of scientists from Asia working on human embryo editing,” said University of California, Berkeley, biochemist Jennifer Doudna, a CRISPR pioneer and a member of the organizing committee. “I’m personally very interested to hear what they’re doing and what they’re thinking about. What degree of safety do they think is necessary before going into the clinic? Is this something the general public understands and wants? Do people see it as positive or negative?”

Few people understand that embryo editing is even a possibility, Doudna said. “My perception is that there are quite a large proportion of people who don’t know about this at all,” she said. “I worry that people outside the scientific community will be caught off guard.”

Nor do most people understand what a momentous step embryo editing would be. As Baltimore said, no medical intervention has ever had “effects that will go on through the generations.”

Ready or not, it is probably unstoppable. “There has been an evolving consensus that genome editing will be safe enough in IVF embryos to eradicate a disease,” said Dr. George Daley, dean of Harvard Medical School. “I still think it’s premature to use the technology in assisted reproduction” to change inherited, disease-causing genes. “But that will be actively discussed at the summit — what additional scientific advances do you need before that can be tried? My guess is that we’ll hear that the science has evolved enough in the last three years that we can think about the clinical translational pathway.”

Even Doudna, whose concerns about germline editing led her to organize a private meeting about it in early 2015, now believes that “we are moving toward a time when people will start using genome editing in human embryos,” making guidelines all the more urgent.

U.S. regulations say any use of CRISPR on a patient is cell therapy. All cell therapies, regardless of who’s paying for them, must be approved by the Food and Drug Administration. Congress made it illegal for the FDA to review proposed uses of CRISPR in human embryos.

Although China is sometimes portrayed as using CRISPR in ways that scientists elsewhere wouldn’t consider, “there are incentives for people to behave in ways that are accepted internationally,” Baltimore said. CRISPR’ing an IVF embryo and allowing it to gestate for nine months would violate the international scientific consensus that it’s premature to do that, given the uncertainties about safety. “If something is not consistent with [research] guidelines, they would meet with opprobrium from the rest of the world,” he said. “The Chinese are very sensitive to that. They don’t want to be considered a rogue nation.”

Doudna will chair the session on public engagement efforts, where experts from three countries will describe how they’re trying to educate the public about genome editing. In another session, representatives of seven countries ranging from Tasmania and Singapore to China and the U.S. will explain their government’s policies on human genome editing, both germline editing (of embryos) and the less controversial kind that’s carried out in a child or adult to treat an existing disorder. Such “somatic editing” would not be inherited by future generations.

Many of the scientific presentations will address what’s needed to make CRISPR a tool of medicine and not only research. Since the 2015 summit, “a lot has changed” in what’s known about the safety, precision, and efficacy of CRISPR, said Daley. “For somatic indications, at least 12 clinical trials using CRISPR-Cas9 are underway.”

They include one for the blood disease beta thalassemia, by Vertex Pharmaceuticals and CRISPR Therapeutics, that removes blood-making cells from patients, uses CRISPR to correct the disease-causing mutation, and returns the edited cells. Many of the rest are for cancer, using CRISPR to alter immune cells so they attack tumors. Summit sessions will describe progress on using CRISPR on additional blood disorders, as well as muscular dystrophy.

Law professor and bioethicist R. Alta Charo of the University of Wisconsin, Madison, a member of the summit organizing committee, thinks that’s the right emphasis. “We continue to have a public fascination with the least likely applications” of CRISPR, she said: “Germline editing, which will be the most complicated use to evaluate in terms of its risks and benefits, and enhancement” — using CRISPR not to treat a disease but to improve someone’s appearance, strength, or other traits. People, she added, put these applications together — germline editing for enhancement, a.k.a. “designer babies” — “and we’re off to the races.”

Leave a Comment

Please enter your name.
Please enter a comment.

Sign up for our Daily Recap newsletter

A roundup of STAT’s top stories of the day in science and medicine

Privacy Policy