CRISPR gene editing heads to human trial as cancer treatment

Approval in the U.S. of a human trial using the gene-editing technique called CRISPR to target certain cancers could open the door to dozens of trials using the promising new technology.

A National Institutes of Health advisory panel earlier this week approved a University of Pennsylvania trial of CRISPR in treatment of myeloma, melanoma and sarcoma.

The experiment still must be approved by the Food and Drug Administration, which regulates clinical trials, as well as regulators at the institutions where the work is being done.

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What researchers, led by Dr. Carl June, hope to do is use T cells, the body’s natural system that repels viruses and other invaders, to attack the tumours. 

To make the T cells effective on these cancers, the researchers must snip out pieces of three genes using CRISPR/Cas9 technology, according to the journal Nature. The T cells are isolated from the patient’s blood, the edit is performed on the T cells, then the cells are injected back into the patient.

CRISPR/Cas9 is not the first gene-editing technique medical researchers have worked with, but so far, it is the cheapest and most accurate.

There is research in Canada on using the technique to target a rare form of blindness, but also ovarian, brain, retinal and colorectal cancers.

Researchers will be looking for ‘unintended consequences’ from editing genes in human trials. (Shutterstock)

Last year researchers at the Hospital for Sick Children in Toronto used this technology to edit cells obtained from a patient with Duchenne muscular dystrophy, pointing to the potential for therapeutic uses to treat the disease.

CRISPR/Cas9 technology is also being researched in the U.S. as treatment for HIV. 

Human trials using CRISPR/Cas9 technology in Canada can’t be far off, according to Udo Schuklenk, Professor and Ontario Research Chair in Bioethics at Queens University.

“I do believe that the promise of this technology is really amazing. It can be done quickly and it doesn’t cost a lot of money,” he told CBC News.

Schuklenk says Health Canada already has guidelines in place for researchers wanting to edit human genes. An ethics board would have to approve such research and researchers would have to prove informed consent by any patients involved.

Concern over gene editing

Much of the concern over editing of genes has been centred around changes to sperm, eggs and embryos.

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“The ethical issues people have been concerned about only apply to human genome modification and… the concern basically is if you change it in embryos, will it pass on to other generations. None of that is applicable to this particular research,” he said.

The University of Pennysylvania researchers plan a trial of about 18 patients — a small number — which will help determine whether there are unintended consequences of the gene-editing process, as well as whether it is safe for humans.  

The research is being funded by billionaire tech entrepreneur Sean Parker’s cancer foundation. Although British researchers used another gene-editing technique called TALEN to treat a child with leukemia last year, this is the first human trial with CRISPR/Cas9 to treat cancer.

NIH oversight

The NIH group that granted the approval was the Recombinant DNA Advisory Committee, which was established to weigh the risks of studies involving gene therapy and also investigate reports of deaths and side effects.

“While the application of new gene editing technologies in this field has great potential to improve human health, it is not without concerns,” Carrie Wolinetz, associate director of science policy at the NIH, said in a blog post.

She said the special NIH committee devoted to DNA research filled an important role in creating a public debate around gene editing.

“As science continues to evolve, we will strive for parallel evolution in our policies to make oversight of research commensurate with the risks involved,” she wrote.