In November 2023, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) was the first in the world to approve gene-editing therapy for sickle cell disease (SCD) as well as transfusion-dependent beta-thalassaemia: painful, lifelong conditions which can cause organ damage.[1] Both conditions are caused by errors in the genes that encode haemoglobin.[2]

The new therapy involves taking stem cells out of the patient’s bone marrow and editing a gene in the cells in a lab. Patients then undergo chemotherapy to clear unedited cells before the modified cells are returned to the patient.[3]

SCD affects approximately 17,500 people in the UK, predominantly people with African and Caribbean heritage due to the gene’s role in malaria resistance.[4] Beta-thalassaemia mainly affects people of Mediterranean, south and southeast Asian, and Middle Eastern heritage.[5] There are around 1,000 people living with beta-thalassaemia in the UK.[6]

1. Patient perspectives

The Times interviewed Victoria Gray, a participant in US-based SCD clinical trials. After years of intense pain, Ms Gray recounted having to be reassured she was still alive when she woke up with an unfamiliar sensation—being pain free.[7] Ms Gray also highlighted challenges of the treatment, including side effects of chemotherapy and withdrawal from the high-dose painkillers she had previously used for pain management.

A study in the journal Blood Advances aimed to assess what level of risk patients would accept from novel gene-editing treatments for the possibility of recovery.[8] 174 adult patients and 109 parents of children with SCD were presented with hypothetical treatment and risk scenarios. The study found that respondents would accept gene therapy in most scenarios, even with increased risk of mortality or side effects. The more recent and severe the symptoms from SCD, the more likely the patient or parent was to accept higher levels of risk.

Conversely, Dr Jeffrey Glassberg, the director of the Mount Sinai Center for SCD in New York, told NBC News he thought less than 10% of his patients would opt for gene therapy.[9] He cited risks associated with the chemotherapy stage of treatment, as well as distrust of medicine among some Black patients.

The Royal College of Nursing magazine published a history of SCD in the UK by historian Dr Grace Redhead, detailing that in the mid-twentieth century, Black patients were “routinely dismissed, abused, or ignored by white health care professionals who didn’t understand the disease”.[10] Training and the development of specialist centres saw some improvement, but Dr Redhead holds that patients continue to suffer from being disbelieved about their pain in generalist departments.

The MIT Technology Review also published an account from clinical trial participant Jimi Olaghere. Mr Olaghere said he now feels confident that he will live to see his children grow up, but cautioned about the “intense” process:

I spent a total of 17 weeks in the hospital. Not everyone will want to subject themselves to such a gruelling process or be able to take time away from family obligations or work.[11]

Mr Olaghere was also concerned the therapy would be unaffordable for the majority of people with SCD who live in Sub-Saharan Africa.

2. Global access

One of the challenges of therapies based on gene editing is how to make them accessible and affordable to the global market. The New York Times reported that therapies “will be out of reach where they are needed most” with treatments “far too expensive for governments that struggle to pay for basic health services” and lack medical infrastructure. For example, few African countries have routine screening of newborns, and estimates indicate up to half of Nigerian children with SCD die before their fifth birthday.[12]

Writing for anthropology magazine Sapiens, medical anthropologist Morenike Samuel argues that gene therapies will be unattainable for most families in Nigeria.[13] Therefore, social solutions should be prioritised, with a focus on “inclusion, empathy and a web of support”, in addition to accessible care.

Nature similarly reported that “the therapy is likely to remain the reserve of rich nations with developed healthcare systems”.[14] Dr Simon Waddington, a geneticist at University College London, explained that the treatment is difficult to scale up and requires high-tech equipment, and that “it is not an ‘off the shelf’ medicine that can be readily injected or taken in pill form”.

The Independent has reported that pharmaceutical companies are working on treatments which do not require chemotherapy, as well as developing a pill that would change the body’s haemoglobin production without gene editing.[15] Harvard Medical School paediatrics professor Dr Stuart Orkin is unsure these next generation treatments will be more affordable. He said that “someone’s going to want to be compensated for the development of that pill”.

In the journal Nature Biotechnology, Anne W T Muigai, professor of genetics at the National Defence University in Kenya, argued for a rethink of pricing practices.[16] Professor Muigai stated that a key factor driving up costs of genetic therapies is the small patient numbers for most genetic diseases. However, in cases where there are large global patient populations (an estimated 270 million for beta thalassemia and 20 million with SCD,[17] companies could price therapies affordably for the mass market.

3. In the UK

Whether the treatment will become widely accessible in the UK is undecided at time of writing. The government has pledged to advance genomic medicine, but the National Institute for Health and Care Excellence (NICE) must decide if specific treatments represent value for money.

The UK government has committed to creating “the most advanced genomic healthcare system in the world”[18] and has invested in genomic research.[19] The NHS also has experience introducing new gene therapies and negotiating on price, announcing in 2022 that it had secured “a significant confidential discount” from the £2.8mn list price of gene therapy for metachromatic leukodystrophy, a disease which causes severe damage to a child’s nervous system and organs.[20]

The MHRA-approved treatment for SCD and beta-thalassaemia would need to be deemed value for money by NICE before NHS implementation.[21] US body the Institute for Clinical and Economic Review assessed that the treatment would be value for money in the American market if priced between $1.35mn (£1.06mn) and $2.05mn (£1.61mn) per patient and encouraged providers to set prices at the lower end for “access and affordability across all insurance systems”.[22]

Dr Padraig Dixon, senior researcher in health economics from the Centre for Evidence-Based Medicine at the University of Oxford, said an estimated cost of £1.5mn per patient in the UK could be value for money because of savings from the likely future costs of treating severe illness across a patient’s life.[23] He also highlighted inherent value in improvements to quality of life.

Cover image by Braňo on Unsplash.


  1. Medicines and Healthcare products Regulatory Agency, ‘MHRA authorises world-first gene therapy that aims to cure sickle-cell disease and transfusion-dependent beta-thalassemia’, 16 November 2023. Return to text
  2. Carissa Wong, ‘UK first to approve CRISPR treatment for diseases: What you need to know’, Nature (£), 16 November 2023. Return to text
  3. Medicines and Healthcare products Regulatory Agency, ‘MHRA authorises world-first gene therapy that aims to cure sickle-cell disease and transfusion-dependent beta-thalassemia’, 16 November 2023. Return to text
  4. Sickle Cell Society, ‘About sickle cell’, accessed 5 March 2024. Return to text
  5. NHS, ‘Thalassaemia’, accessed 6 March 2024. Return to text
  6. BBC News, ‘Casgevy: UK approves gene-editing drug for sickle cell’, 16 November 2023. Return to text
  7. Rhys Blakely, ‘Sickle-cell hope: ‘I woke with no pain, I had to check I wasn’t dead’’, Times (£), 9 December 2023. Return to text
  8. Juan Marcos Gonzalez Sepulveda et al, ‘Preferences for potential benefits and risks for gene therapy in the treatment of sickle cell disease’, Blood Advances, 2023, vol 7, issue 23, pp 7371–81. Return to text
  9. Claretta Bellamy, ‘New sickle cell treatment sparks feelings of hope and some hesitancy among Black patients’, NBC News, 7 December 2023. Return to text
  10. Grace Redhead, ‘Empire, racism and the NHS: The history of sickle cell disorder’, RCN Magazine, 3 November 2022. Return to text
  11. Jimi Olaghere, ‘I received the new gene-editing drug for sickle cell disease. It changed my life’, MIT Technology Review, 4 December 2023. Return to text
  12. Rebecca Robbins and Stephanie Nolen, ‘New sickle cell therapies will be out of reach where they are needed most’, New York Times (£), 11 January 2024. Return to text
  13. Morenike Samuel, ‘Gene therapy’s promise meets Nigeria’s sickle cell reality’, Sapiens, 25 January 2024. Return to text
  14. Carissa Wong, ‘UK first to approve CRISPR treatment for diseases: What you need to know’, Nature (£), 16 November 2023. Return to text
  15. Laura Ungar, ‘Promising new gene therapies for sickle cell are out of reach in countries where they’re needed most’, Independent, 14 December 2023. Return to text
  16. Anne W T Muigai, ‘Expanding global access to genetic therapies’, Nature Biotechnology, 2022, vol 40. Return to text
  17. National Heart, Lung and Blood Institute, ‘What is sickle cell disease?’, accessed 6 March 2024. Return to text
  18. Office for Life Sciences et al, ‘Genome UK: The future of healthcare’, 26 September 2020. Return to text
  19. Genomics England, ‘About Genomics England’, 2022. Return to text
  20. NHS England, ‘NHS to roll out life-saving gene therapy for rare disease affecting babies’, 4 February 2022. Return to text
  21. Stephanie Vine, ‘Reactions to the UK’s approval of a CRISPR medicine’, Medicine Maker, 24 November 2023. Return to text
  22. Institute for Clinical and Economic Review, ‘ICER publishes final evidence report on gene therapies for sickle cell disease’, 21 August 2023. Return to text
  23. Padraig Dixon, ‘Can high-cost drugs be good value? The case of Casgevy for sickle-cell disease and beta-thalassemia’, Centre for Evidence-Based Medicine, 12 February 2024. Return to text