Ahead of Rare Disease Day 2026, Dr Jacqueline Barry, Chief Clinical Officer at the Cell and Gene Therapy Catapult discusses how system-wide collaboration is key to ensuring the life-changing benefits of advanced therapies reach as many patients with rare diseases as possible.
There are 3.5 million people in the UK and 300 million people around the world living with a rare disease. While the number of people with each specific condition is small, when added together this group of diseases affects many people. 1 in 17 people are affected by a rare condition at some point in their lives, so this means about 6 out of 100 people could be affected.
In addition, many patients face long diagnostic journeys, waiting extended periods for a diagnosis, and seeing multiple clinicians. Far too often, once diagnosed there is then no treatment available. 95% of rare diseases lack an approved treatment.
There is strong collaboration between academics, charities, therapy developers, regulators and the NHS to develop new medicines for rare diseases. Some of these treatments already exist, for example, there are cell and gene therapies approved and reimbursed in the UK for conditions such as spinal muscular atrophy, metachromatic leukodystrophy and sickle cell disease. Building on this progress, the UK is well placed to be a global leader in tackling rare disease.
Rare diseases bring several challenges. Because each condition affects only a small number of people, diagnosis can be difficult and there is often limited information about how the disease develops over time. This makes it harder to create predictive preclinical models for testing new treatments. Clinical trials are also more complex, as the small number of eligible patients means that traditional approaches, such as large double-blind studies, are not possible. As a result, it can be difficult for regulators to assess these treatments, and alternative approval pathways are often needed to account for the limited data available.
With few patients receiving a potential treatment, but high development costs, therapy developers may shy away from this area preferring instead to focus on higher-prevalence conditions with larger patient populations and so more opportunities to have their therapy reimbursed by healthcare systems.
Although rare diseases can make the development, testing and funding of new treatments more complicated, these challenges can be overcome. A key part of this is making sure that treatments for rare diseases keep pace with wider advances in approvals and healthcare, which requires strong collaboration across the whole system.
This means bringing together everyone involved, from academics who turn early research into new ideas and companies, to regulators who decide which treatments can be approved and funded, to the healthcare services that will eventually deliver these therapies to patients. It also includes all the other partners who help move a treatment from first discovery to everyday care.
The UK has a strong academic clinical science base, with world‑leading universities producing research that is shaping the future of rare disease treatments. One example is Orchard Therapeutics, which began as a spin out from University College London. The company has since grown internationally and recently announced an £11 million investment in the UK to support the continued development of gene therapies for rare diseases.
UK clinical scientists are also playing an important role in major international initiatives. Professor Claire Booth, Consultant Immunologist at Great Ormond Street Hospital, co-founded the AGORA initiative, established in 2022 and bringing together around fifty academics, physicians and patient organisations across Europe. This network aims to address the regulatory and economic barriers that prevent life-saving gene therapies from reaching patients.
LifeArc plays an important role in developing new treatments for rare diseases by funding research and supporting the translation of early discoveries into therapies, including major national centres for rare disease research. Charities such as Genetic Alliance UK, Beacon for Rare Diseases and Kidney Research UK support research networks to produce products, faster diagnosis and better access to care for the rare disease community.
The Medicines and Healthcare products Regulatory Agency (MHRA) is committed to improving outcomes for rare disease patients. It is introducing a more flexible approach to approving clinical trials and licensing treatments, aiming to balance the limited evidence available for rare diseases with the need to ensure that patients have access to promising new therapies in a safe and timely way. The Agency is working with NICE, the devolved equivalents and the NHS. Together, these organisations have potential to help therapies reach patients more quickly.
In addition, the NHS is improving its ability to deliver these therapies. We have a wealth of healthcare data that can be used to identify patients and improve understanding of disease. Genomics England is a world leader in using whole genome sequencing to improve the diagnosis and treatment of rare diseases. Its landmark 100,000 Genomes Project delivered new genetic diagnoses for around one quarter of participating rare disease patients, helping to shorten the diagnostic journey and guide more personalised treatment options. Today, Genomics England continues to expand this work through new initiatives that will strengthen the UK’s position at the forefront of rare disease genomics and ensure that more families receive faster, more accurate answers. There are dedicated Rare Diseases policy teams advising the health services in all four UK nations. While the Advanced Therapy Treatment Centre (ATTC) network, funded by NIHR, works with therapy developers and healthcare providers to develop the specialist services needed to deliver advanced therapies to patients.
Importantly, there is willingness across players in the sector to collaborate. For example, there has been a call for the appointment of a National Clinical Director (NCD) for Rare Diseases. Such a role could help update the strategy for rare diseases in the UK and work with the rare disease community to translate this into action. By coordinating various parts of the sector, they could ensure that efforts from discrete parts of the sector can be applied by other parts, and ultimately, benefit patients.
With the strengths already in place across the UK, the country is well positioned to bring partners together and make real progress for people with rare diseases, offering a great opportunity to ensure that patients receive the right product, at the right time, at the right cost.
Dr Jacqueline Barry, Chief Clinical Officer, CGT Catapult