Groundbreaking Gene Therapy: A Gamechanger in Sickle Cell Disease in the Capital of the World

Background: In December 2023, the FDA approved two cell-based gene therapies, Casgevy from CRISPR/Vertex and Lyfgenia from bluebird bio available to individuals with sickle cell disease 12 years or older with recurrent vaso-occlusive crises in the United States. The goal of this groundbreaking gene therapy is to edit certain cells which decrease pain caused by vaso-occlusive crises and ultimately decrease hospital admissions for people living with sickle cell disease. Prior to this discovery, bone marrow transplants were the only long-lasting treatments available. Bone marrow transplants require patients to take immunosuppressive therapy post-transplant, with acknowledging the risk that donated cells can be rejected or attack the patient’s organs. However, we now see that the gene therapies we have available are made from the patients’ own blood stem cells which are then modified and given back to the patient as a one-time, single-dose induction as part of a hematopoietic stem cell transplant. This study is the first to analyze how NYC has been a leader in gene-therapy and the process of learning a new way of life.

Methods: In this cross-sectional study, we examined how receptive families were to have gene-therapy as a treatment option. Gene-therapy is not a well-recognized concept and that raises the question if patients truly understand the risks and benefits of gene therapy for sickle cell disease. Educating the patient and their families of the mechanism of gene-therapy, whether they’ll be eligible based on demographics, the course of treatment and ultimately the ability to improve quality of life and reducing hospitalizations for vaso-occlusive crises.

Results: Gene therapy is a multi-stage process as the patient’s own cells must be collected and treated before bringing that back into their own body. Clinical trials have shown increases in fetal hemoglobin at six months. In over a two-year period, little to no severe vaso-occlusive crises were seen in patients who received Casgevy. Gene therapy offers a high chance of eliminating sickle cell disease symptoms. The data supports good prognosis, improved quality of life, and longer life expectancy. Further long-term clinical efficacy is underway.

Conclusions: For decades, researchers have combined gene-addition strategies and gene-editing approaches to develop lifechanging transformative care for sickle cell disease. As of now, NYC has three hospitals offering gene therapy as an option of care for patients with sickle cell disease. Gene-therapy has shown to improve social determinants of health. Further studies would be beneficial to evaluate the efficacy and long-term safety of gene therapy. Prospective studies on patients who received the treatment would also be instrumental. Future research is needed to improve access to care and make gene therapy more accessible especially in low-socioeconomic communities.