First CRISPR medicine now in the US

On December 8, The US Food and Drug Administration approved a first-of-its-kind treatment that involves CRISPR gene editing. Casgevy therapy treats patients with sickle cell disease, which is an inherited blood disorder. Vence Bonham, acting deputy director of the National Human Genome Research Institute, said, “This is a major milestone.”

Many have been skeptical about CRISPR gene editing due to its potential unknown consequences. Fortunately, Crispr Therapeutics of Switzerland and Vertex Pharmaceuticals of Boston proved its life-saving benefits with Casgevy. The United States recently approved it, so we are more likely to see more gene-editing treatments in the future.

This article will elaborate on the first CRISPR medicine approved in the US. Later, I will explain CRISPR and its potential benefits and risks.

How does the CRISPR medicine work?

Casgevy uses CRISPR gene editing technology to modify a patient’s cells so that they provide healthy hemoglobin. Wired said the latter is the protein that carries oxygen through the body.

This system has two parts: a protein that cuts genetic material and a molecule that guides the former where to cut. Experts start by extracting stem cells from a patient’s bone marrow.

They edit the cells and make a single cut in the  BCL11A gene to trigger the production of the hemoglobin fetal form. It compensates for the abnormal adult hemoglobin.

Then, the experts return the edited cells into the patient’s bloodstream. Wired said 45 patients received Casgevy in a clinical trial, and then the researchers followed 31 for two years.

They discovered that 29 had been free of pain crises for a year after the CRISPR medicine. Previously, the only cure for sickle cell disease was a stem cell transplant from a closely related donor.

It was only available to a few people. Also, transplants may pose lethal risks and don’t always work. However, the first commercial Casgevy patients likely won’t get treatment until early 2024. 

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It takes weeks to collect patient cells, edit them, and conduct quality controls before the cells are ready for infusion. Samarth Kulkarni, president and CEO of CRISPR Therapeutics, said:

“It takes a little bit of time to treat the patients. But we don’t want to waste any time—and patients don’t want to waste any time because they’ve been waiting for this for a while.”

Alexis Thompson, chief of the division of hematology at Children’s Hospital of Philadelphia, says these new gene therapies will significantly help patients. “I can now talk to parents about the possibility of their child perhaps being cured of sickle cell,” she said.

What is CRISPR?

Genetics education website Your Genome said it “is a unique technology that enables geneticists and medical researchers to edit parts of the genome by removing, adding, or altering sections of the DNA sequence.” Here’s how it works:

1. The Cas9 enzyme follows a guide RNA molecule to a cell’s specific DNA sequence.
2. Then, it makes a cut across both DNA strands.
3. In response, the cell tries to repair the DNA.
4. Scientists use that repair machinery to introduce changes to one or more genes of a specific cell.

Integrated DNA Technologies said CRISPR has a fast, flexible design that is more cost-effective than other gene-editing techniques. It can target multiple genes simultaneously and has numerous applications, such as agriculture and medicine.

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On the other hand, Automata research labs said targeting a specific gene is still challenging with modern methods. Otherwise, CRISPR may cause unintended changes.

Some crops and gene targets may show none of their desired genetic changes. Moreover, others believe it may cause fewer genetic variations in plants and animals.

As a result, they could become more susceptible to pests and diseases. Regulations may also hamper gene editing research and its applications.

Conclusion

The United States recently approved a one-of-a-kind CRISPR medicine for sickle cell disease. It activates the production of hemoglobin to replace abnormal ones. 

Casgevy therapy might become a safer alternative to existing treatments. However, we must wait until the beginning of 2024 to see its real-life impacts.

Healthcare innovation has been steadily advancing lately, especially due to artificial intelligence. Learn more about those breakthroughs and other digital trends at Inquirer Tech.