The U.S. is on the brink of authorizing the first gene-editing therapy for sickle cell patients, marking a groundbreaking advancement.

• The FDA is predicted to sanction exa-cel gene modification remedy for sickle cell anemia.
• The first approved medicine in the U.S. to use CRISPR gene-editing technology would be Exa-cel.
• The treatment, developed by Vertex Pharmaceuticals and CRISPR Therapeutics, could cost approximately $2 million per patient.

In his 30s, Joe Tsogbe had more than a dozen hospitalizations a year.

The genetic mutation in sickle cell disease results in abnormally shaped red blood cells that get stuck in blood vessels, restricting blood flow and causing intense pain.

In the U.S., approximately 100,000 people are affected by the disease, with a disproportionate number of Black individuals being affected. Currently, there are limited treatment options available, and the only cure is a bone marrow transplant that involves receiving healthy blood stem cells from a donor. New genetic treatments are being developed to provide relief and eliminate the need to track down donors.

In 2021, Tsogbe, now 37, was given one of the options known as exa-cel, which was co-developed by and via a clinical trial. This treatment utilizes Nobel Prize-winning technology called CRISPR to edit a person's DNA and relieve the symptoms of sickle cell disease.

The U.S. is predicted to sanction exa-cel for sickle cell patients by the week's conclusion, as the U.K. already approved it under the name Casgevy in the previous month.

Another gene therapy, lovo-cel, is being reviewed by U.S. regulators. Unlike exa-cel, it works differently but is administered similarly and aims to eliminate pain crises. It is expected to receive approval later this month.

The approval of exa-cel by the U.S. Food and Drug Administration would represent a significant scientific achievement a decade after the discovery of CRISPR and a major breakthrough for patients in need of a better treatment option.

The potential cost of the new treatment could be a significant challenge for the American healthcare system, with Wall Street estimating a price tag of approximately $2 million per patient. With tens of thousands of people potentially eligible, this could present a major test for the healthcare system.

First-of-its-kind treatment

In 2012, Jennifer Doudna and Emmanuelle Charpentier published a paper on a gene editing system using CRISPR-Cas9, which ignited a wave of companies looking to apply this knowledge to treat diseases.

Sickle cell emerged as a prime target.

In 1949, scientist Linus Pauling identified sickle cell as the first molecular disease. Although the disorder is most prevalent in Africa, where it was advantageous due to the sickle cell gene's protection against malaria, individuals with one copy of the mutation typically exhibit no symptoms. However, those inheriting two copies, one from each parent, may develop severe complications.

Editing a patient's genes using CRISPR technology could activate fetal hemoglobin, a protein that typically turns off after birth, to maintain the shape of red blood cells. This procedure can be performed in a lab by extracting, editing, and infusing blood stem cells back into the patient's bloodstream.

Dr. Markus Mapara, director of blood and marrow transplantation at NewYork-Presbyterian/Columbia University Irving Medical Center, who treated patients in the exa-cel trials, stated that they are essentially training cells to produce more fetal hemoglobin.

The process of administering the treatment takes months, even though it is only given once.

Vertex's lab genetically modifies blood stem cells that are extracted and isolated before being sent to the lab. After chemotherapy, patients receive the new cells, which they spend weeks in the hospital recovering.

In 2015, Vertex and CRISPR agreed to collaborate on creating gene-editing therapies for genetic disorders, including sickle cell. Under the agreement, Vertex will spearhead the launch of exa-cel, pending regulatory clearance.

The company views exa-cel as a multibillion-dollar opportunity and intends to concentrate on the approximately 32,000 individuals in the U.S. and Europe who suffer from the most severe forms of the disease, such as Tsogbe.

The FDA is set to decide on Vertex's request to use exa-cel for beta thalassemia treatment in March.

Despite Wall Street's doubts, analysts predict that Vertex will generate $1.2 billion in exa-cel sales by 2028, which is a small fraction of the $14 billion in revenue they expect for the entire company that year, according to FactSet.

The cost of a possible cure

Mapara stated that it is premature to label exa-cel a cure, but he presented charts from clinical trials showing the reduction in pain crises experienced by participants after treatment. For the majority of participants, the number of pain crises was significantly reduced or eliminated.

Mapara, a paid consultant for Vertex and CRISPR, exclaimed, 'It’s mind-blowing! You really see how effective this treatment has really been.'

The long treatment timeline, potential infertility from chemotherapy, limited availability at specialized healthcare facilities, and high cost make exa-cel a challenging option for some patients.

Vertex is predicted to charge approximately $2 million per patient for the treatment, making it less expensive than recently approved gene therapies that cost over $3 million per person. However, its availability to a larger number of patients could make insurers less likely to broadly cover it.

For Tsogbe, any price is worth it.

In Togo, a baby named Tsogbe cried with swollen fingers, toes, knees, and joints. His mother visited numerous doctors until a specialist diagnosed him with sickle cell disease. At that time, there were limited treatment options available.

Tsogbe vowed to his mother that he would journey to the United States and discover a cure for sickle cell, thus ending his own suffering. At the age of 16, he relocated to the U.S. and eventually participated in the exa-cel trial.

Although the treatment he received two years ago has not completely eliminated his aches and pains, it has kept him out of the hospital and allowed him to become busier than ever. He now runs two entertainment companies and teaches dance, activities he loves but that previously left him drained.

Since he left Togo in 2003, he hadn't visited his mother until last year, when he returned to the country and realized how much he had changed.

“In a way I kept my promise,” Tsogbe said.

— CNBC’s Patrick Manning contributed to this report.