On Wednesday, Kendric Cromer, a 12-year-old boy from a Washington suburb, became the first person in the world with sickle cell anemia to begin a commercially approved gene therapy that could cure the disease.
For the approximately 20,000 people with sickle cell disease in the United States who qualify for the treatment, the start of Kendric’s months-long medical journey may offer hope. But it also speaks to the challenges patients face when seeking two new treatments for sickle cell disease.
For a lucky few, like Kendric, treatment could allow them to live the life they aspire to. As a solemn and shy teenager, he had learned that ordinary activities—riding a bike, going out on a cold day, playing soccer—could cause episodes of burning pain.
“Sickle cell still steals my dreams and interrupts all the things I want to do,” he said. Today, he feels like he has a chance at leading a normal life.
Late last year, the Food and Drug Administration approved two companies to sell a gene therapy to people with sickle cell disease — a genetic disease of red blood cells that causes debilitating pain and other medical problems. In the United States, an estimated 100,000 people have sickle cell disease, most of them black. People are born with the disease when they inherit the mutated gene corresponding to the disease from each parent.
The treatment has helped patients in clinical trials, but Kendric is the first commercial patient for Bluebird Bio, a Somerville, Massachusetts, company. Another company, Vertex Therapeutics of Boston, declined to say whether it had started treatment for patients with its approved cure based on CRISPR gene editing.
Kendric — whose family health insurance agreed to cover the procedure — began treatment at Children’s National Hospital in Washington. Wednesday’s treatment was just the first step. Doctors took bone marrow stem cells from him, which Bluebird will then genetically modify in a specialized laboratory for his treatment.
It will take months. But before it begins, Bluebird needs hundreds of millions of stem cells from Kendric, and if the first collection — which takes six to eight hours — isn’t enough, the company will try one or two more times.
If he still doesn’t have enough, Kendric will have to spend another month preparing for another stem cell extraction.
The entire process is so complex and time-consuming that Bluebird estimates it can process cells from only 85 to 105 patients each year – and that includes not only sickle cell patients, but also patients with a much rarer disease – beta thalassemia – who can receive similar gene therapy.
Medical centers also have the capacity to care for a limited number of patients treated with gene therapy. Every person needs expert, intensive care. After the stem cells are processed, the patient must stay in the hospital for a month. Most of the time, patients become seriously ill from powerful chemotherapy.
Children’s National can only accept about 10 genes…
