
Little Evie’s life Already defined by pain. He was born with sickle cell disease, which causes red blood cells to be sticky, C-shaped, and not smooth or round. These cells should move freely in the blood vessels that carry oxygen to the body. But in people with this inherited form of anemia, they clump together and impede blood flow. This triggers excruciating episodes known as pain crises, which can occur anywhere in the body and last for hours or even weeks. Over time, the disease damages organs and can lead to stroke and early death.
People with sickle cell often feel fatigued because their red blood cells die rapidly, cutting off the body’s supply of oxygen. Strenuous exercise, sudden temperature changes, and dehydration can also trigger a pain crisis. Growing up in the Bronx in New York City, Junior recalls being easily out of breath and having to be careful when exercising or swimming. The pain was so severe that he was often absent from school.
As an adult, it doesn’t get any easier. Sometimes he can take ibuprofen for pain relief and be able to go back to work the next day. But every few months, a severe crisis landed him in the hospital. Things got so bad that in 2019, he joined a UCLA clinical trial that had been testing a gene therapy for sickle cell disease. It involves genetically modifying a patient’s blood stem cells in the laboratory so that they can produce healthy red blood cells. This process is experimental. Junior knew it might not work. “I think it’s time for a Hail Mary,” he said. “Before that, I’d been sick my whole life.”
In July 2020, he received a one-time infusion of his engineered stem cells. Three months into treatment, tests showed expected changes in 70 percent of his blood cells—well above the threshold needed to clear symptoms. Since then, he has not experienced a pain crisis again. He can do more outdoor activities without worrying about missing work. He plans to go skydiving soon – something he’d never dreamed of doing before. “My quality of life is much better now,” he said.
Junior, 30, is one of dozens of patients with sickle cell disease receiving gene therapy in clinical trials in the U.S. and Europe, some led by universities and others by biotech companies. Two such therapies are closest to hitting the market, one from Bluebird Bio and another from Crispr Therapeutics and Vertex Pharmaceuticals. The companies are now seeking regulatory approval in the US and Europe. If successful, many more patients will soon benefit from these therapies, although access and affordability may limit who gets them.
“I’m optimistic that this will be a game-changer for these patients,” said Cheryl Mensah, a hematologist at Weill Cornell Medicine and New York-Presbyterian Hospital who treats adults with sickle cell disease. “If more patients were treated, especially younger patients, fewer adults would suffer from chronic pain and fatigue.”
sickle cell anemia Affects approximately 100,000 people in the United States and millions more worldwide. The vast majority are of African ancestry, but the disease also affects Hispanics from Central and South America, as well as people of Middle Eastern, Asian, Indian, and Mediterranean ancestry.