Gene therapy is a revolutionary medical approach that aims to treat or prevent diseases by modifying the genes inside our cells. Genes are like instruction manuals that guide the workings of our bodies, and when there are errors or missing parts in these instructions, it can lead to various health issues.
The main idea behind gene therapy is to fix these genetic instructions. One powerful tool in gene therapy is CRISPR technology. It’s like a pair of molecular scissors that can precisely cut the DNA at specific locations.It is utilized to remove or replace the problematic parts of the gene, fixing the instructions to make them accurate.
The U.S. Food and Drug Administration approved two Genetherapy treatments, Casgevy and Lyfgenia, representing the first cell-based treatment for sickle cell disease (SCD) in patients 12 years and older.
Gene Therapy for Sickle Cell Disease: Casgevy vs Lyfgenia
| Casgevy | Lyfgenia | |
|---|---|---|
| Type of Genome Editing Technology | CRISPR/Cas9 | Lentiviral Vector |
| Targeted Gene Modification | Fetal Hemoglobin (HbF) production | HbAT87Q production |
| Mechanism of Action | Increases HbF levels to prevent sickling | Produces HbAT87Q to reduce sickling risk |
Casgevy employs CRISPR/Cas9 to increase fetal hemoglobin HbF levels, preventing sickling, while Lyfgenia uses a lentiviral vector to produce HbA (T87Q), reducing the risk of sickling and occlusion.
Both treatments utilize the patient’s own blood stem cells, which are modified and administered back to patient as a one-time, single-dose infusion during a hematopoietic (blood) stem cell transplant. Before the therapy, the patient’s own stem cells are collected. Subsequently, the patient undergoes myeloablative conditioning with high-dose chemotherapy. This process essentially eliminates abnormal cells from the bone marrow along with the others, paving the way for the replacement with the new modified cells in both Casgevy and Lyfgenia. Long-term studies are planned for both therapies to assess their safety and effectiveness in patients.
