First gene therapies to treat sickle cell disease get FDA approval

An estimated 14,000 Georgians are living with the inherited blood disease that can result in a lifetime of hospital visits and medical treatment

Sickle cell disease is a group of inherited red blood cell disorders.According to the Centers for Disease Control and Prevention, it affects about 100,000 people in the United States alone.It is caused by a mutation that makes red blood cells become rigid, sticky and misshapen.Sickle cell disease can cause delayed growth, as in the case of Sawyer Guillory, standing next to his twin, Saxton.Sickle cell caused Lawrencevill teen Joshua Biyoyouwei to have a stroke when he was just 18 months old

The Food and Drug Administration approved two gene therapies for the treatment of sickle cell disease Friday, including a CRISPR gene-editing therapy to treat the disease, the first treatment approved in the U.S. using CRISPR technology.

Casgevy and Lyfgenia, the gene therapy treatments, will be available for patients 12 and older for treatment of the disease that affects 100,000 people in the United States — 14,000 of them in Georgia — a majority of whom are Black.

“Sickle cell disease is a rare, debilitating and life-threatening blood disorder with significant unmet need, and we are excited to advance the field especially for individuals whose lives have been severely disrupted by the disease by approving two cell-based gene therapies today,” said Dr. Nicole Verdun, director of the Office of Therapeutic Products within the FDA’s Center for Biologics Evaluation and Research.

“Gene therapy holds the promise of delivering more targeted and effective treatments, especially for individuals with rare diseases where the current treatment options are limited.”

The newly approved CRISPR gene therapy is known as Casgevy, developed by Vertex Pharmaceuticals Inc. CRISPR is an abbreviation for a family of gene sequences. The new technology allows doctors to edit a patient’s genes to eliminate a faulty genetic code that causes normally round, smooth blood cells to be shaped like a crescent or sickle. The malformed cells clot and clump inside blood vessels causing extreme pain and sometimes damaging organs.

Trials for both treatments showed a majority of patients who received the therapy went for an extended length of time without suffering a medical crisis caused by clogged blood vessels.

With an estimated cost of about $2 million, the CRISPR treatment isn’t cheap, but is the first to offer a potential cure to those who would otherwise spend a lifetime suffering from the disease. It isn’t clear if insurance companies will cover the treatment cost.

The second new treatment for sickle cell approved by the FDA is Lyfgenia, a product of Bluebird Bio Inc., which uses a deactivated virus as a gene delivery vehicle. The patient’s blood stem cells are genetically modified to lower the risk of blood cells being misshapen and promote better blood flow.

According to the FDA’s report, blood cancer has occurred in patients treated with Lyfgenia so a “black box” warning of the risk is included in the drug’s label. Patients receiving Lyfgenia should have lifelong monitoring for these malignancies.

Both treatments require doctors to take bone marrow and stem cells out and treat them in a laboratory setting before returning them to the patients.

Severe pain riddles the lives of those living with sickle cell, often leading to repeated emergency room or hospital visits to manage the pain. Many are unable to work, exercise or otherwise lead a normal life.

According to the American Society of Hematology, the median life expectancy for people with the disease is 42 to 47 years, compared to 76 years overall in the United States.

Prior to Friday’s approval, questions were raised about the high cost making the new treatments unavailable for those who have the disease.

Tabatha McGee, executive director of the Sickle Cell Foundation of Georgia, said many sickle cell patients are uninsured. She estimates that it costs Georgia $16.8 billion a year to treat people living with sickle cell in the state.

“These approvals represent an important medical advance with the use of innovative cell-based gene therapies to target potentially devastating diseases and improve public health,” said Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research.

“Today’s actions follow rigorous evaluations of the scientific and clinical data needed to support approval, reflecting the FDA’s commitment to facilitating development of safe and effective treatments for conditions with severe impacts on human health.”

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