For most of his 12 years, Kendric Cromer believed he would live with sickle cell disease (SCD) forever. The genetic disorder, caused by a mutation in hemoglobin genes, had robbed him of his childhood. Activities like playing basketball or riding a bike triggered excruciating pain crises, often landing him in the hospital. But Cromer’s life changed earlier this year when he became the first patient to receive a newly approved gene therapy for SCD—a groundbreaking development in the fight against the disease.
SCD appears in the human body in the form of misshapen blood cells. Instead of round discs, people with SCD will have crescent-like cells, which cannot hold up to the task of transporting oxygen through the body efficiently. Sickle cell disease affects about 100,000 people in the United States, with 20,000 experiencing severe symptoms. These crescent-shaped red blood cells block blood vessels, causing intense pain, organ damage, and even strokes.
For years, treatment options were limited to pain management, blood transfusions, and in rare cases, risky bone marrow transplants. But in December 2023, the FDA approved two gene therapies—Bluebird Bio’s $3.1 million treatment and Vertex Pharmaceuticals’ $2.2 million option—offering patients like Cromer a new path to freedom from SCD.
Cromer’s journey to recovery began on May 1st of this year, when he had stem cells extracted and sent for processing to a lab in New Jersey. There, technicians inserted new, healthy hemoglobin genes into the sickle cells. In September, only two months ago, Kendric was admitted to the Children’s National Hospital in order to begin the final stage of his treatment, which involved grueling procedures with terrifying side effects.
Cromer underwent intense chemotherapy and radiation treatment to clear his bone marrow and make space for the modified stem cells. The evidence was severe, and ranged from mucositis, organ damage, a shortened life expectancy, and skin burning, however Cromer and his family believed in the outcome. Unable to eat, Kendric relied on IV nutrition, and communicating became so difficult that he tied bells around a stuffed animal to alert his parents or medical staff when he needed something.
Yet, despite these challenges, the treatment offered hope. A week and a half after he was admitted in Washington, Kendric’s doctors infused the modified stem cells back into his body. Over time, the new cells began to produce healthy hemoglobin, gradually replacing the defective ones. Kendric’s recovery is ongoing. Excess iron from transfusions must be removed to prevent damage to his organs, and his weakened immune system requires careful monitoring and re-immunization. Still his case represents a monumental step forward.
Gene therapy holds promise for 20000 American teens diagnosed with SCD who, until now, had no hope for a cure. But accessibility remains a challenge. High costs and limited patient education about the risks mean only a handful of patients—just 10 for Bluebird and 20 for Vertex as of late 2024—have received the treatment.