Will CRISPR make sickle cell disease a thing of the past?

On Friday, the US Food and Drug Administration approved a sickle cell disease drug called  Casgevy, co-developed by Vertex Pharmaceuticals and CRISPR Therapeutics.

It’s the first gene editing treatment to be approved in the US. CRISPR (which stands for Clustered Regularly Interspaced Short Palindromic Repeats) technology has been in development for cancer and sickle cell treatment for years. But it wasn’t long ago that gene editing seemed like science fiction.

Concerns of designer babies and “fixing” people deemed genetically inferior are not unfounded — if humans are good at one thing, it’s abusing technology — but the reality of the research has been that it focuses on curing conditions that cause pain, suffering and early death.

Sickle cell disease is one of those conditions. The inherited blood disorder is most common among people descended from Southern Hemisphere countries; in the US, most people with the disease or who carry the trait are Black.

Reaching the right populations

Dr. Eric Kmiec, director of ChristianaCare’s Gene Editing Institute in Wilmington, Delaware, is one of the scientists across the country working on a cure for sickle cell, a disease that has been historically deprioritized.

Back in 2021, Kmiec launched a program called “CRISPR in a Box” that aimed to bring CRISPR education to communities where sickle cell disease had the greatest impact: Black, underresourced neighborhoods and schools. The program delivered boxes of CRISPR experiments to science labs in places like public and technical high schools and community colleges. It partnered with the Black-owned local television network to educate communities about the technology and its potential to cure sickle cell disease. The aim was that as CRISPR became more inclusive on the medical side, community trust in their work would build.

“The program not only talks about gene editing using CRISPR in a Box to demonstrate, but also — why has sickle cell disease remained uncured?” Kmiec told Technical.ly at the time. “Why is there discrimination against underserved populations? Is it because these diseases don’t affect the mainstream culture? We’re going to engage in those kinds of conversations.”

For Kmiec, there was no doubt that the technology could cure the condition. But it has to be used the right way.

“It must reach minority groups,” he said. “Most breakthrough technology developed rarely reaches minority communities. We are going to break that. We are dedicated to moving CRISPR so that everyone who needs treatment with CRISPR or education with CRISPR will have that afforded to them.”

How does CRISPR work?

It can be hard to wrap one’s mind around a process that actually edits DNA, so a visual like the one below might help:

But what happens to the patients when they get the treatment?

Here’s a simple explanation: It starts with collecting a patient’s blood. The blood is sent to a lab where Casgevy is used to edit the genes in the blood, while the patient takes a chemotherapy drug to prepare the bone marrow for the treated cells. The treated cells are then injected into the patient. While the treatment is not very invasive, it requires a hospital stay due to the chemo drug’s side effects and sterility requirements for the procedure.

In the hospital where it is administered, it will look and feel like a typical medical procedure rather than something out of a science fiction movie.

Now that CRISPR has gotten its first approval in the US, gene editing cancer treatment could be next. Kmiec founded oncology-based CRISPR startup CorriXR in 2022, with a medical trial launching in 2024 or early 2025.