NJ Man Pain-Free After FDA-Approved CRISPR Therapy at CHOP

Austin Louis, a 20-year-old from New Jersey, spent most of his life coping with sickle cell disease, a genetic blood disorder that causes severe vaso-occlusive crises and disproportionately affects people of color. Exposure to cold temperatures could trigger intense pain episodes, limiting routine activities. Nearly a year after undergoing a one-time gene-editing procedure at the Children’s Hospital of Philadelphia (CHOP), he says that pattern has ended.

“It totally worked, I feel amazing,” Louis said. “I feel totally different. It’s a brand new body. I feel like a new human.” Following the infusion, he added, “I totally feel relieved.”

Louis received the treatment last March when he returned to CHOP for infusion of his own genetically modified stem cells. Hospital officials confirmed he was the first patient there to receive the newly FDA-approved therapy outside of a clinical trial. Since the procedure, he has not experienced the severe vaso-occlusive crises that once dominated his life, according to CBS Philadelphia, and he can now spend time outdoors in cold weather without triggering pain.

The therapy administered to Louis is CASGEVY, also known as exagamglogene autotemcel or exa-cel. It is an individualized, non-viral cell therapy that uses CRISPR/Cas9 gene-editing technology to modify a patient’s own CD34+ hematopoietic stem cells. The process involves collecting stem cells from the patient, editing them to reactivate fetal hemoglobin production, and then reinfusing the corrected cells. Once engrafted, these cells produce red blood cells capable of carrying oxygen without sickling. Vertex Pharmaceuticals and its partners describe the approach as editing and reinfusing a person’s own stem cells so red blood cells no longer sickle.

Clinical findings published in the New England Journal of Medicine reported that most evaluable patients in the pivotal trial remained free from severe vaso-occlusive crises for at least 12 consecutive months following infusion. The therapy is authorized for individuals 12 years of age and older who experience recurrent vaso-occlusive crises.

Before receiving the edited cells, patients must undergo myeloablative conditioning, a preparative regimen that suppresses bone marrow function so the modified cells can engraft. The CLIMB study and subsequent reporting in the New England Journal of Medicine identified the most serious short-term risks as those associated with conditioning and transplant-style care, including low blood counts and increased infection risk. Patients require months of monitoring after infusion. Clinicians describe the potential outcome for many as a durable reduction or elimination of hospitalizations and pain episodes, though the treatment pathway is intensive and resource-heavy.

CHOP participated as a key site in the multi-center CLIMB studies evaluating exa-cel and now processes edited stem cells in its Cell and Gene Therapy Laboratory. The manufacturer and its partners are introducing the therapy through a network of authorized treatment centers, and CRISPR Therapeutics has reported a growing number of activated centers and patients completing stem cell collections. This expansion enabled CHOP to provide the FDA-authorized therapy outside the original research setting.

Dr. Alexis Thompson, attending hematologist and chief of hematology at CHOP, described the therapy as “extraordinary.” “You don’t get these very often in your career. So for me, wow, this is a big one,” she said. “To be able to imagine something that is as extraordinary as gene therapy affecting a population that so often feels overlooked and is underserved by our health care system, it’s just so rewarding.”

Louis’ parents relocated their family from New York to South Jersey to remain close to CHOP for his follow-up care, CBS Philadelphia reported. Because sickle cell disease primarily affects people of color, this Black History Month carries particular meaning for them. “This is history in the making,” said his mother, Jennifer Louis. “I think it’s pretty amazing.”

An increasing number of patients have undergone the gene-editing therapy, and CHOP officials state they will continue tracking long-term outcomes while expanding capacity through authorized centers as more individuals complete the treatment process. As gene editing moves from clinical trials into standard medical care, questions remain regarding access, long-term follow-up, and cost.

“I’m paving the way for others,” Louis said. “So I feel great about that.”