UK Becomes the First Country To Authorise Gene Therapy for Sickle Cell Anemia Treatment

People suffering from sickle cell anaemia in Britain are set to get relief as the UK government approved gene therapy for its treatment.

On November 16, the Medicines and Healthcare Products Regulatory Agency (MHRA) authorised the use of Vertex Pharmaceuticals (Europe) Ltd and CRISPR Therapeutics created gene therapy for sickle cell anaemia and transfusion-dependent β-thalassemia treatment.

The new intervention Casgevy (exagamglogene autotemcel) is based on the CRISPR gene editing tool, an invention that bagged the 2020 Chemistry Nobel Prize.

This is the first time gene therapy has been approved for the treatment of sickle cell anemia which is crucial for the UK as 15,000 people suffer from this disorder.

The MHRA has said that the gene therapy is approved for patients over 12 years of age after rigorous quality and safety assessment which also checked the effectiveness of it.

With this authorisation, Casgevy has become the first medicine developed by the CRISPR gene editing tool to be licensed.

The two diseases – sickle cell disease and β-thalassemia are genetic conditions arising from errors in the haemoglobin genes. Haemoglobin is used by the red blood cells in our body to carry oxygen. An impaired haemoglobin prevents oxygen exchange in the blood.

While sickle cell anaemia is prevalent in African Caribbean origin people, South Asian, Southeast Asian, Mediterranean and Middle Eastern people suffer from β-thalassemia.

The sickle cell disease causes severe pain and life-threatening infections in certain cases. In both sickle cell anaemia and β-thalassaemia, patients require blood transfusions every month due to severe anaemia. They remain heavily dependent on injections and medicines throughout their life.

The Casgevy gene therapy medicine with edit the faulty haemoglobin gene in the patient's bone marrow stem cells which will result in functional haemoglobin production.

Casgevy Gene therapy shows near 100 per cent effectiveness in trials

Speaking about the authorisation, the Interim Executive Director of Healthcare Quality and Access at the MHRA, Julian Beach, highlighted how a bone marrow transplant from a closely matched door was the only treatment for these two lifelong fatal diseases.

Beach said he was pleased to announce that "an innovative and first-of-its-kind gene-editing treatment called Casgevy, has been found to restore healthy haemoglobin production in the majority of participants with sickle-cell disease and transfusion-dependent β-thalassaemia, relieving the symptoms of disease".

"The MHRA will continue to closely monitor the safety and effectiveness of Casgevy, through real-world safety data and post-authorisation safety studies being carried out by the manufacturer", Beach added.

The MHRA trial results showed that 97 per cent of patients reported they were free from severe pain crises for at least 12 months after receiving Casgevy. A reported 28 of the 29 patients who could be analysed said this.

In the case of transfusion-dependent β-thalassemia trials, Casgevy could reduce the need for blood transfusion in 93 percent of people, 12 months after the treatment. A recorded 39 out of 42 patients reported this success. In the remaining three patients there was a 70 percent reduction in blood transfusions.

There are no severe side effects of this newly approved treatment. Casgevy has similar side effects to those seen in stem cell transplants which include fever, fatigue, nausea and an increased risk of infection.

So far the MHRA hasn't reported any safety concerns in the trials and the results of the trials will be disclosed soon.

The treatment procedure involves taking out stem cells from the bone marrow of patients, editing them in the laboratory and inserting them in the patient to make a lifelong cure for the disease.

Patients treated through this gene therapy have to spend a month in the hospital so that the treated cells develop in their bone marrow and start making red blood cells with functional haemoglobin.

The Chief Executive of Sickle Cell Society, John James OBE welcomed the authorisation saying: "There are limited medicines currently available to patients, so I welcome today's news that a new treatment has been judged safe and effective, which has the potential to significantly improve the quality of life for so many."