Kendric Cromer, a 12-year-old boy, left Children’s National Hospital on Wednesday after becoming the first patient to receive gene therapy for sickle cell disease since its approval.
After 44 days in the hospital, Kendric felt overwhelmed. “I thought I would have sickle cell for the rest of my life,” he stated. The disease deprived him of a typical childhood, preventing him from engaging in activities such as basketball or bicycling because of the risk of intense pain and frequent hospitalizations.
Despite the moment of joy, Kendric and his parents are still grappling with the difficulties of his hospital stay. Neither conversations with doctors nor reading the 13-page consent form, which described risks such as organ damage and death, had fully prepared them for the challenges they would face.
Specifically, sickle cell disease affects approximately 100,000 people in the United States, and for the 20,000 with the most severe cases, gene therapy offers hope for a normal life. The disease, caused by a mutation in hemoglobin genes, leads to crescent-shaped red blood cells that block blood vessels, triggering painful episodes and potentially damaging organs. For many, there has been no solution, until now.
In December, the Food and Drug Administration (FDA) approved two innovative gene therapies for sickle cell disease: a $3.1 million therapy from Bluebird Bio of Somerville, Massachusetts, and a $2.2 million therapy from Vertex Pharmaceuticals of Boston. These therapies offer patients like Kendric the possibility of a life free from the debilitating effects of the disease, if their insurance covers the cost. However, so far only a small number of people have benefited. As of Sept. 24, Bluebird reported that 10 patients had started treatment after FDA approval, while Vertex reported 20 in July.
Kendric’s treatment began on May 1, when doctors extracted stem cells from his bone marrow and sent them to a facility in New Jersey. There, technicians modified the cells by adding healthy hemoglobin genes. A few months later, Bluebird returned the treated cells.
On September 3, Kendric was admitted to Children’s National Hospital for the final stage of his therapy. Two days later, he underwent intensive chemotherapy to clear his bone marrow, allowing the modified cells to take hold. On September 11, doctors infused the treated stem cells back into his body. His medical team informed Kendric and his parents that he would need to stay in the hospital for about a month.
The side effects of Kendric’s chemotherapy began quickly. On September 15, he developed mucositis, a painful inflammation that caused sores in his mouth and intestines. The following day, his tongue swelled so much that he could barely talk, and the pain spread to his stomach.
Gradually, Kendric began to recover. His tongue’s swelling reduced, and he was able to talk again. However, his treatment is not yet complete. Blood transfusions left him with excess iron, requiring regular bloodletting to prevent organ damage. Additionally, because his immune system was weakened by chemotherapy, he will need to be re-immunized with childhood vaccines and avoid crowds while he recovers.
