“Historic day in science and medicine”
Britain Approves World’s First Genetic Scissor Therapy
Today, November 17, 2023 | 08:47
In Britain, a drug based on Crispr genetic scissor technology was approved for the first time in the world. The announcement was made by the Medicines and Healthcare products Regulatory Agency (MHRA) on Thursday.
The drug called “Casgevy” has been approved for the treatment of sickle cell disease and beta-thalassemia in patients aged 12 years and older. Both genetic blood disorders are caused by errors in the hemoglobin gene. This is an iron-containing protein complex found in red blood cells and used to transport oxygen.
The discoverer of CRISPR received the Nobel Prize in 2020
So-called Crispr/Cas genetic scissors can be specifically targeted at individual genes. The method’s developers, Emmanuelle Charpentier and Jennifer A. Doudna, received the Nobel Prize for this in 2020. “Casgevy” is used to alter defective genes in patients’ bone marrow stem cells so that they can produce functional hemoglobin, the MHRA said in a statement. To do this, stem cells are removed from the bone marrow, processed in the laboratory and then reinserted into the patient.
A hospital stay of several weeks is required for therapy. But the result has the potential to last a lifetime, she said.
Therapy can cure beta thalassemia
Both sickle cell disease and beta-thalassemia are painful, lifelong conditions that, in some cases, can be fatal, said Julian Beach, acting executive director of the MHRA’s Department of Healthcare Quality and Access. He added: “Until now, a bone marrow transplant – which must come from a compatible donor and carries a risk of rejection – has been the only permanent treatment option.”
Sickle cell disease can cause severe pain attacks, serious and potentially fatal infections, and anemia, a lack of oxygen in the blood, also known as anemia. Patients with beta thalassemia also suffer from anemia and often require blood transfusions at intervals of three to five weeks.
97 percent of those treated were pain free for at least a year
Of the 28 patients with sickle cell disease who were treated with the drug in a clinical trial, 97 percent were free from severe pain attacks for at least a year.
In the clinical study of beta thalassemia patients who depend on blood transfusions, 93 percent (39 of 42 patients) did not require a red blood cell transfusion for at least twelve months. In the remaining three patients, a reduction of at least 70% in blood transfusions was possible.
Kewalramani: “Historic day in science and medicine”
The drug is manufactured in collaboration between Vertex and CRISPR Therapeutics, based in the US and Switzerland. According to a statement from the two companies, around 2,000 people in Britain are currently eligible for treatment with “Casgevy”.
Vertex managing director Reshma Kewalramani spoke of a “historic day in science and medicine”. CRISPR Therapeutics head Samarth Kulkarni said he hopes this is just the first of many applications of the method that could benefit people with serious illnesses, according to the statement.
Selim Corbacioglu from the University Hospital Regensburg, who has personally tested the Crispr therapy, mentions some concerns. “We cannot be 100 percent sure that genetic scissors will not alter other sections of DNA as well,” he said. “Crispr therapy cannot be done ‘now’.” There are significant side effects and the therapy is also very expensive.
According to Joachim Kunz from Heidelberg University Hospital, the therapy is “extremely complex, requires complex logistics and is unlikely to be infinitely scalable due to the resources required, but will only be available to a limited number of patients per year.” Current clinical studies on Crispr therapy are promising, but even patients initially treated have only been followed for about four years. “Even though there is no evidence of this yet, it could be that the effect of gene therapy diminishes over the years because, for example, the lifespan of engineered blood stem cells is shortened.”