FDA Approves Sickle Cell Treatments, Including One Using CRISPR

People with the genetic disease have new opportunities to eliminate their symptoms, but treatments have obstacles that limit their reach.

On Friday, the Food and Drug Administration approved the first gene-editing therapy ever used in humans, for sickle cell disease, a debilitating blood disorder caused by a single mutated gene. /p>

The agency also approved a second treatment using conventional gene therapy for sickle cell disease, which does not use gene editing.

For the 100,000 Americans with sickle cell disease. Suffering from the disease, most of them black, the approvals offer hope of finally living free from an affliction that causes excruciating pain, organ damage and strokes.

While patients, their families, and their doctors welcome FDA approvals, obtaining either therapy will be difficult and expensive.

“It’s practically a miracle that this is possible,” Dr. Stephan said. Grupp, chief of the cell therapy and transplantation section at Children's Hospital of Philadelphia. Dr. Grupp, who consults for Vertex, said his medical center hopes to begin treating sickle cell patients next year.

But, he added , "I'm very realistic about how difficult it is."

The obstacles to treatment are innumerable: an extremely limited number of medical centers authorized to provide it; l requirement that each patient's cells be edited or a gene added individually; procedures so cumbersome that not everyone can tolerate them; and a multimillion-dollar price tag and potential insurance hurdles.

As a result, according to sickle cell experts, only a small fraction of patients in the United States are expected to receive the new treatment (not to mention the millions of sickle cell patients worldwide). abroad, particularly in Africa, for whom it is perhaps completely out of reach for the moment). The FDA. estimates that approximately 20,000 patients, aged 12 and older and who have had episodes of debilitating pain, will be eligible for the therapies.

Gene editing treatment, called Exa-cel and using the brand name Casgevy, was jointly developed by Vertex Pharmaceuticals of Boston and CRISPR Therapeutics of Switzerland. It uses CRISPR, the Nobel Prize-winning gene editing tool, to cut patients’ DNA. For a small number of subjects in clinical trials, it corrected the effects of the mutation, which result in sickle- or crescent-shaped red blood cells that get stuck in blood vessels, blocking them.

< p class=" css-at9mc1 evys1bk0">Casgevy is the first approved treatment using CRISPR. Patients will also need expensive, intensive medical care and lengthy hospitalization.

The other treatment, called Lyfgenia and made by Bluebird Bio of Somerville, Mass., uses a common gene. therapeutic method for adding a good hemoglobin gene to patients' DNA.

Vertex says its price for modifying a patient's genes will be 2.2 millions of dollars ; for Bluebird, it will cost $3.1 million.

But living with the disease is also extremely expensive: on average, $1.7 million for those who benefit commercial insurance for the life of a patient. Patients themselves may pay about $44,000 out of pocket on average over their lifetime.

For patients and the doctors who care for them, it is tempting to think about free. complications of sickle cell disease. So contempt...