According to the Charité, for the first time in Germany a patient has been successfully treated with a drug based on the Crispr genetic scissors technology.
The developers of the method, Emmanuelle Charpentier and Jennifer Doudna, received the Nobel Prize for this in 2020. The 19-year-old patient Mohammad has the genetic blood disorder beta thalassemia and, according to the Berlin Charité, is no longer dependent on blood transfusions thanks to the treatment. “Mohammad’s immune system has also regenerated and he is currently doing really well,” said the university hospital.
The drug, called “Casgevy,” has been approved in the European Union since 2024 for the treatment of sickle cell disease and beta-thalassemia for certain patients aged 12 and over. So far, the preparation has only been used in clinical studies in Germany. With the treatment of the 19-year-old, gene scissors therapy was used in regular care for the first time. “This means that basic research has become medical care,” said Charité senior physician Lena Oevermann.
Both genetic blood diseases are caused by errors in the gene for hemoglobin. This is an iron-containing protein complex that is found in red blood cells and is used to transport oxygen. Beta thalassemia is life-threatening when severe. Symptoms include severe fatigue, pain, impaired physical and cognitive development, and iron overload, which can damage organs. According to the Charité, around 60,000 children worldwide are born with severe beta thalassemia every year.
According to the Charité, affected children need blood transfusions every three weeks to survive, but in the long term these sometimes have serious side effects. The disease can be cured with a stem cell transplant, but the patient must not be older than around 14 years. Mohammad was already too old for the procedure.
As an alternative, the 19-year-old was given the drug with the active ingredient Exagamglogene Autotemcel for the first time at the Charité in May 2026. Charpentier visited the patient himself, it was said. The treatment lasts about twelve months.
“Casgevy” is used to change genes in patients’ bone marrow stem cells so that they produce functioning hemoglobin again. To do this, stem cells are taken from the bone marrow, processed in the laboratory and then reinserted into the patient.
In May, the 19-year-old had 900 million of his genetically modified stem cells returned to his blood via infusion, explained Charité doctor Lena Oevermann, who heads the hemoglobinopathies program.
After the infusion, the patient's body began to produce the previously missing hemoglobin within about 40 days, the Charité said. The value is now within the normal range, so transfusions are no longer necessary. The 19-year-old can now lead a normal everyday life.
The therapy also has side effects and risks. To create space in the bone marrow, patients must undergo chemotherapy. According to Oevermann, this can lead to painful inflammation of the mucous membranes and liver damage and is likely to make you infertile. “We also don’t yet have any data on the long-term safety and effects of gene therapy.”
The drug is therefore only approved under certain conditions. This includes, among other things, follow-up of the patient over a period of 15 years. In Germany, health insurance companies cover the costs of the treatment, but the clinic must submit a special application, as the Charité explains.
Some experts have concerns about the method. Joachim Kunz from Heidelberg University Hospital once explained that the therapy is extremely complex, requires complex logistics and will probably not be infinitely scalable due to the resources required, but will only be available to a limited number of patients per year.
