By Allison DeAngelis
Massachusetts biotech executives and scientists expressed concern Monday following reports that a Chinese scientist has used gene-editing technology to alter the DNA of human embryos, leading to the birth of twin girls — a practice that is banned in the United States.
According to media reports and a filing with Chinese regulators, researcher He Jiankui used the gene-editing technology CRISPR/Cas9 to alter the embryos of seven couples during fertility treatments in the hopes of making them immune to HIV infection. The experiment led to the birth of two healthy twin girls a few weeks ago, The Associated Press reported.
The researcher's claims, which have not yet been published in a scientific paper, prompted a swift outcry among Boston-area life sciences officials Monday, given that such genetic changes can be passed on to future generations. Several Cambridge-based biotechs are developing drugs using CRISPR/Cas9, but they have balked at pursuing this kind of "germline" editing for regulatory and ethical reasons.
Noted MIT researcher and CRISPR/Cas9 pioneer Feng Zheng is among those calling for a moratorium on genome editing in embryos.
"Given the current state of the technology, I’m in favor of a moratorium on implantation of edited embryo," Zheng said in a statement Monday. "Not only do I see this as risky, but I am also deeply concerned about the lack of transparency surrounding this trial."
Execs speak out
Several local companies are hoping to use gene editing tools to address diseases ranging from a rare blood disorder to Duchenne muscular dystrophy. CRISPR Therapeutics (Nasdaq: CRSP) and Vertex Pharmaceuticals (NASDAP: VRTX) launched the first company-backed trials using CRISPR/Cas9 in the U.S. and Europe earlier this year.
Spokespeople for Cambridge biotechs Intellia Therapeutics (Nasdaq: NTLA), Editas Medicine (Nasdaq: EDIT) and Casebia Therapeutics told the Business Journal that the companies do not plan to test CRISPR/Cas9 in embryos.
"This is something we’ve talked about as an industry, a scientific community," said Casebia CEO Jim Burns. "We concur, we feel like this is not the right time... We just don't know about the safety — we hope to someday, but we're just not there yet."
A spokesperson for CRISPR Therapeutics did not immediately respond to a request for comment.
Science under the microscope
Scientists, meanwhile, continue to theorize how CRISPR/Cas9 will work in humans, with some medical journals reporting that cutting into the human genome could cause dangerous off-target effects.
Congress has forbidden the FDA from using federal funds to accept or evaluate clinical applications using genetically-modified human embryos, essentially prohibiting the practice in the U.S. But the National Academy of Sciences has remained open to the concept as long as trials are conducted safely and with strict oversight, according to guidelines published last year.
Records show He started the clinical trial last year,though a 2014 article in the medical journal Reproductive Biology and Endocrinology states that manipulating genes in embryos used for reproduction is prohibited in China. (Chinese researchers have previously tried to genetically modify embryos, but have never before used them to produce a baby).
He has been suspended without pay from the Southern University of Science and Technology in Shenzhen following the news, according to the MIT Technology Review.
Burns, the Casebia CEO, said he would like to see if and how He's work was regulated.
"I'd like to know that this wasn't done under a veil of secrecy," Burns said.
In a video posted to the website for his lab, He states, "I understand my work will be controversial, but I believe families need this technology, and I'm willing to take the criticism for them."