CRISPR was first described ten years ago as a viral mechanism for defense, taken from bacteria, which could be transformed into genetic scissors and accurately alter DNA.
CRISPR Therapeutics joined with Vertex Pharmaceuticals in developing the newly approved medicine called Casgevy. It has been developed for people twelve years and older who have painful sickle cell disease but are not eligible to receive stem cell transplants.
Casgevy is also designed to treat beta-thalassemia disorder when it requires continuous blood transfusions.
About the Paradigm
Casgevy is created from the patient’s stem cells.
The cells are:
- Edited with CRISPR in the lab, and then
The end result is the production of hemoglobin, which is the vital protein that carries oxygen to tissues in the body but is damaged by sickle cell and beta-thalassemia.
Clinical studies have shown that the treatment is twofold. It eliminates the pain that often accompanies sickle cell disease and mitigates the need for continuous blood transfusions in beta-thalassemia.
As a bonus, CRISPR’s editing of stem cells’ DNA offers the potential to last for a lifetime.
Potential Trouble Ahead
Being approved does not necessarily mean clear sailing. This is especially true concerning the drug’s price, as a very conservative estimate would be a cost of over one million dollars. The companies have not yet announced the price of the medicine.
Another hurdle is a “preconditioning” regimen of chemotherapy that patients must undergo to create space in the marrow for new stem cells.
A variety of side effects may occur, such as oral sores and possible infertility. Vertex assured fertility preservation for the clinical trial patients but has not stated whether that procedure will proceed for the commercial market.
There is also the concern that older patients with a higher amount of damage from either disease may not be able to tolerate the preconditioning.
The process of administering Casgevy plus the preconditioning may take a few months. The UK Regulatory Agency suggests that patients may be required to spend additional weeks in the hospital for safety measures.
Vertex is expected to face tough marketing competition, especially in Europe. The product is currently under review by the US Food and Drug Administration with the decision to be announced before December 8, 2023.
CEO Samarth Kulkarni, CEO of CRISPR Therapeutics, believes that this is only the first application to be followed by many more to benefit patients with serious diseases.