A team of researchers from Philadelphia-based University of Pennsylvania expect to receive FDA clearance to conduct the first CRISPR trial treating human patients in the U.S., according to The Wall Street Journal.
However, due to a less stringent regulatory process, physicians in China have been running human trials with the gene-editing tool since as early as 2015. There are nine human CRISPR trials from China listed in a U.S. National Library of Medicine database.
Here are six things to know about human trials using CRISPR in the U.S. and China.
1. CRISPR, which stands for Clustered Regularly Interspaced Short Palindromic Repeats, is a gene-editing technology that enables scientists to edit an organism's DNA. Many scientists consider the CRISPR-Cas9 system — which creates modified RNA segments that bind to the CRISPR-associated protein 9 enzyme — to be one of the most precise and least expensive gene-editing techniques currently in use.
2. Scientists in the U.S. helped develop CRISPR-Cas9, which researches have successfully used to edit genomes in animals, such as mice suffering from hereditary deafness, and even in human cells in laboratory environments. However, physicians in the U.S. have not been cleared by regulatory agencies to use the technology in human trials.
3. The researchers at UPenn have been working toward their human CRISPR trial — which would edit DNA from cancer patients to improve their ability to fight the disease — for almost two years to meet various federal requirements to ensure patient safety. The researchers completed the study's ethics review in late 2017 and are awaiting final FDA clearance, which they expect as early as this month.
4. Dr. Wu Shixiu, an oncologist and president of Hangzhou Cancer Hospital in China, has been using CRISPR-Cas9 to treat cancer patients by deleting a gene that may inhibit the immune system's ability to fight the disease since March. Dr. Wu did not need approval from national regulators for the trial, and his hospital review board reportedly took one afternoon to OK the trial.
"China shouldn't have been the first one to do it," Dr. Wu told The Wall Street Journal. "But there are fewer restrictions."
5. While China's regulatory process has fewer roadblocks, many researchers in the U.S. emphasized ethical considerations regarding gene editing, given CRISPR makes irreversible changes in the human genome. While Dr. Wu agrees there are risks to the technology, he noted the cancer patients he sees are facing terminal diseases. "If we don't try, we will never know," he told The Wall Street Journal.
6. The Wall Street Journal noted the U.S. researchers it spoke with didn't suggest America relax its regulatory requirements. Instead, they tended to advocate for an "international consensus" on ethical issues related to these emerging technologies that change human DNA, particularly as researchers are still studying potential unintended consequences.
"How do we make sure everyone is under the same tent?" said Jeffrey Kahn, PhD, director of the Berman Institute of Bioethics at Baltimore-based Johns Hopkins University. "We need to be talking to each other internationally."