A new technology called Crispr-Cas9 has allowed Chinese scientists to edit the DNA of dozens of cancer patients. The country has raced ahead over the last couple of years in experimenting with gene editing.

However, the Wall Street Journal recently published an article stating that one such gene editing trial has lost touch with its patients. This set off alarm bells with western scientists who believe that these patients should be monitored for years after their trials. Additionally, the same article notes concerns about an Indian man whose cancer improved as a result of gene editing, but who later suffered a heart attack and brain stroke. According to the man’s family, Chinese doctors didn’t investigate his cause of his death.

Naturally, this is placing these types of trials under scrutiny from authorities in Beijing and scientists worldwide. The scrutiny has recently intensified, especially after news broke last month that a doctor had edited the genes of twin babies. This doctor is now reportedly on house arrest. 

Unlike the United States, there’s no governing body that oversees rules and regulations for these types of trials in China. Understandably, doctors in the United States have been troubled by this – they fear that mistakes in early trials could wind up ultimately setting back the development of the technology.

Among other things, American scientists are concerned with the types of consequences that could occur far into the future with these types of patients. 

Jennifer Doudna, a biochemistry professor at the University of California, Berkeley and one of the inventors of the Crispr technology, stated: “Since we do not fully understand the human genome and are still developing knowledge of Crispr-Cas technology, we need to monitor the intended and unintended consequences over the lifespan of patients.” 

Feng Zhang, another inventor and molecular biologist at MIT and Harvard called the Wall Street Journal's findings "surprising", noting that trial designs for this type of new technology should be rigorous.

After a Shenzhen-based scientist came out last month and said he had used the tool to modify the genes of embryos, the spotlight got even brighter on the new technology. Editing embryos can have far-reaching consequences, as future generations can continue to bear the effects. Beijing officials claim that they’re investigating the scientist and say that implanting gene-edited embryos into a human is illegal.

While modifying the DNA of adults isn’t technically illegal in China or the United States, American scientists have been extremely cautious with it. Despite the technology being invented as early as 2012, US regulators only approved its first trial this year. It took the University of Pennsylvania nearly 2 years to receive clearance from regulatory bodies for such a trial. Additional consent letters and lab tests, both of which were scrutinized closely, were necessary before allowing people to enroll. Even after that, the University had a hard time recruiting patients because of the strict requirements. Patients are going to be followed for 15 years after the trial takes place.

For trials in China, however, doctors just need to get approval from their hospital's ethics committee. A dozen of these trials have been listed publicly in China and at least 86 cancer patients have had their genes edited so far. Anhui Kedgene Biotechnology Co. is a private start-up company that has treated most of these people.

But one of Anhui Kedgene's projects has lost touch with its patients, according to a person familiar with the matter. The founder of the company, Mandy Zhou, said one trial did not complete its research as planned, and that it lost touch with its patients as a result.

Another trial that treated 18 patients saw many of its participants die as their cancer grew. Despite the trial beginning more than a year ago, scientists and regulators in Beijing waited until this month to seek out information about the deaths. Another Anhui Kedgene trial that started this year has seen at least 19 of its 21 patients die. The doctor who led the trial has stated that the deaths were not related to the use of the gene editor.

Finally, an Indian government official, Sanjit Kumar Samal, who flew to China to try and contain his esophageal cancer, began improving after getting his first dose of modified blood infusions, according to his brother. After his second infusion, his results showed that “90% of his tumor had gone; hardly anything was left”.

But six weeks later, Samal died in India. Doctors in India said that he had a heart attack and a brain stroke. He didn’t have a prior heart condition and was still due to head back to China for a third blood infusion. The doctor who was administering his blood infusions reportedly did not ask for his medical results after he passed away.

While the family of Samal doesn’t blame the gene editing therapy – in fact, they said they would recommend it for other cancer sufferers – Doudna still believes that follow-up with patients needs to be more in depth.

She said: “Any death in any clinical trial must be fully investigated. [She is concerned] about reckless applications of genome editing that put the safety of patients at risk, damages the public’s acceptance of Crispr technology, and could trigger a range of negative but permanent unintended consequences.”