Future Prospects of a New Casgevy Therapy for Sickle Cell Diseases: Crispr Therapeutics and its FDA Final Decision
There are episodes of excruciating pain associated with sickle cell disease that can be prevented with the help of a new vaccine called Casgevy. The patient’s cells are edited outside the body and then infused back into them. Some people may benefit from the therapy.
Crispr therapies are just beginning. There are a lot more to come,” says Samarth Kulkarni, chairman and CEO of Crispr Therapeutics. Crispr has been found to be a way to treat a range of other genetic conditions as well as certain types of cancer and HIV. It works by cutting out bits of DNA.
The Crispr therapy is expected to be approved soon by Europe and the United States. The US Food and Drug Administration has until December 8 to make a decision. On October 31, an advisory committee to the FDA concluded that the treatment was safe for patients.
The CRISPR Trial for Sickle-cell Disease: What you need to know (Invited talk at the Collider, Nature, 28 September 2001, Volterra, Italy)
Errors in the DNA sequence of genes that help red blood cells carry oxygen around the body can cause diseases like Sickle-cell disease.
29, out of 45 participants, have been in the trial for more than a year and draw interim results. Casgevy completely relieved 28 of those people of debilitating episodes of pain for at least one year after treatment.
A severe form of the disease is conventionally treated with blood transfusions about once a month. The trial has resulted in interim results for 42 patients and 54 participants. For at least one year after treatment, 39 participants, or 93% of those treated, did not need a red-blood-cell transfusion. The remaining three people had their need for blood transfusions reduced by more than a 70%.
In sickle-cell disease, abnormal haemoglobin makes blood cells misshapen and sticky, causing them to form clumps that can clog blood vessels. Pain crises are caused by the reduction of oxygen supplies to tissues, which can cause periods of severe pain.
Beta-thalassaemia occurs when mutations in the haemoglobin gene lead to deficient or absent levels of the oxygen-carrying molecule in red blood cells, low numbers of red blood cells and symptoms such as fatigue, shortness of breath and irregular heartbeats.
Source: UK first to approve CRISPR treatments for diseases: what you need to know
The cost of gene therapy in the developed countries with the best health systems: The case of blood stem cell-transplantation for the treatment of malignancies
The therapy is likely to remain in the developed nations with the best health-care systems. “This treatment may not easily scale up to be able to provide treatments in low- and middle-income countries, since it requires the technology to obtain a patient’s blood stem cells, deliver the genetic editor to these stem cells, and then reinjection of these cells,” geneticist Simon Waddington at University College London told the SMC. “It is not an ‘off the shelf’ medicine that can be readily injected or taken in pill form,” he says.
The trials participants experienced side effects include nausea, fatigue, fever and an increased risk of infection, but there were no safety concerns. The MHRA and manufacturer are monitoring the safety of the technology and will release further results.
The treatment’s price has not yet been settled in the United Kingdom, but estimates suggest that it could cost roughly US$2 million per patient, in line with the pricing of other gene therapies.
“We have not established a list price for the UK at this time and are focused on working with the health authorities to secure reimbursement and access for eligible patients as quickly as possible,” a Vertex spokesperson told Nature.