Haemophilia affects around 10,000 people in the UK — 7,000 with haemophilia A and 2,000 with haemophilia B, plus several hundred with other bleeding disorders. After decades of incremental improvements in factor replacement therapy, the field is now experiencing a transformative wave of gene therapy approvals, non-factor therapeutics, and extended half-life products. Here is what is actively recruiting.
The UK Haemophilia Centre Doctors' Organisation (UKHCDO) coordinates a network of 28 comprehensive care centres across the country, providing the infrastructure for some of the world's most advanced haemophilia clinical trials. British centres have been pivotal in gene therapy development — the first ever haemophilia B gene therapy approval (Hemgenix) relied heavily on UK trial data.
There are currently over 40 actively recruiting haemophilia trials in the UK, spanning gene therapy, non-factor therapeutics, extended half-life products, and novel inhibitor management strategies.
Types of Haemophilia Trials
Gene Therapy
AAV-vectored gene transfer delivering functional factor VIII or IX genes, aiming for one-time treatment with sustained endogenous factor production.
Non-Factor Therapies
Emicizumab (bispecific antibody), fitusiran (antithrombin siRNA), and anti-TFPI agents rebalancing haemostasis without factor replacement.
EHL Factors
Extended half-life factor VIII and IX products with Fc fusion, PEGylation, and albumin fusion technologies reducing infusion frequency to once-weekly or beyond.
Inhibitor Management
Immune tolerance induction (ITI) optimisation, bypassing agents, and novel agents for patients who develop inhibitory antibodies against factor concentrates.
Gene Therapy
Gene therapy represents the biggest therapeutic advance in haemophilia since the development of factor concentrates in the 1970s:
Haemophilia A gene therapy — Roctavian (valoctocogene roxaparvovec) and next-generation AAV5 vectors delivering the B-domain-deleted factor VIII gene, with UK post-marketing long-term follow-up studies now running at major centres
Haemophilia B gene therapy — Hemgenix (etranacogene dezaparvovec) and newer AAV vectors with enhanced factor IX expression, including studies of lower-dose approaches
Next-generation capsid design — novel AAV capsids with reduced immunogenicity, higher liver tropism, and potential for re-dosing (overcoming a key limitation of current vectors)
Liver-directed vs. alternative targets — exploring extra-hepatic targeting (haematopoietic stem cells, platelet-directed) to avoid liver toxicity and immune clearance
Corticosteroid optimisation — trials exploring the optimal corticosteroid regimens to manage post-gene-therapy transaminitis without blunting factor expression
Non-Factor Therapies
Non-factor therapies are transforming haemophilia by bypassing the coagulation cascade entirely. These treatments can be given subcutaneously and work regardless of inhibitor status:
Emicizumab — the bispecific monoclonal antibody mimicking factor VIII, now standard for haemophilia A with inhibitors. UK trials are exploring: once-monthly dosing, use in haemophilia A without inhibitors, and paediatric approval for younger age groups
Fitusiran — an RNA interference therapeutic targeting antithrombin, rebalancing haemostasis regardless of haemophilia type or inhibitor status. Now in Phase 3 UK trials with subcutaneous monthly dosing
Anti-TFPI: concizumab and marstacimab — monoclonal antibodies blocking tissue factor pathway inhibitor, with Phase 3 UK trials for both haemophilia A and B, with and without inhibitors
SerpinPC — an activated protein C inhibitor under development for both haemophilia A and B, in early UK trials
Extended Half-Life Products
EHL factors have already reduced infusion burden significantly, and newer products offer even longer intervals:
Fc fusion factors — Elocta (efmoroctocog alfa) for haemophilia A and Alprolix (eftrenonacog alfa) for haemophilia B, with half-lives approximately 1.5-2× standard
PEGylated factors — Esperoct (turoctocog alfa pegol), Jivi (damoctocog alfa pegol), and Refixia (nonacog beta pegol) providing sustained factor levels with reduced dosing frequency
Albumin fusion — IDELVION (albutrepenonacog alfa) offering once-weekly or even less frequent dosing for haemophilia B
Super-enhanced half-life products — next-generation products combining multiple half-life extension technologies for once-every-14-days or once-monthly prophylactic potential
Prophylaxis-by-gesture vs. continuous prophylaxis — UK trials comparing high-trough, low-frequency prophylaxis (aiming for >15% trough levels) with standard prophylaxis on bleeding rates
Inhibitor Management
Inhibitory antibodies to factor VIII are one of the most challenging complications in haemophilia care:
Immune tolerance induction (ITI) optimisation — UK trials refining ITI protocols with novel immunomodulatory agents (rituximab, mycophenolate) to improve inhibitor eradication rates
Emicizumab prophylaxis for inhibitor patients — long-term follow-up studies establishing emicizumab's durability and safety in inhibitor patients on prophylaxis
Bypassing agent optimisation — trials comparing recombinant factor VIIa with activated prothrombin complex concentrates (aPCC) for breakthrough bleeds in inhibitor patients
Prediction and prevention of inhibitors — studies using genetic profiling (HLA type, F8 mutation) and immune biomarkers to predict which patients will develop inhibitors
Paediatric Haemophilia Research
Treating children with haemophilia requires distinct considerations, and UK paediatric haemophilia centres are active in dedicated trials:
Early prophylaxis initiation — trials comparing early (age <1 year) versus standard prophylaxis on long-term joint outcomes
Emicizumab in children — paediatric extension studies of emicizumab, including once-monthly subcutaneous dosing for school-age children
Competitive sports and haemophilia — prospective studies on sports participation guidelines and bleeding risk in children on modern prophylaxis
Gene therapy in paediatric patients — early-phase trials exploring whether gene therapy before age 12 offers better outcomes (before joint damage accumulates)
Transition to adult care — research on maintaining prophylaxis adherence during transition from paediatric to adult comprehensive care centres
Who Can Participate?
Eligibility depends on haemophilia type, severity, inhibitor status, and prior treatment:
Gene therapy trials — typically require severe haemophilia A (FVIII <1%) or B (FIX <2%), age 18–65 no pre-existing antibodies to the AAV vector capsid, stable liver function, no active inhibitors, and no significant liver fibrosis
Non-factor trials — may accept both moderate and severe haemophilia, with or without inhibitors. Fitusiran and anti-TFPI trials include both haemophilia A and B
EHL factor trials — often require established prophylaxis with standard half-life products, with documented bleeding rate data for comparison
Inhibitor trials — require confirmed high-responding inhibitors (>5 Bethesda Units) for ITI trials, or inhibitor history for emicizumab studies
General exclusions — active hepatitis B or C (some allow), HIV with CD4 <200, significant cardiovascular disease, and current participation in other interventional haemophilia trials
💡 Tip: Gather Your Bleeding History
Trial teams will want detailed records: your factor VIII or IX baseline level, annualised bleeding rate (ABR), joint status and history of target joints, inhibitor history (peak titre, treatments), current prophylaxis regimen (product, dose, frequency), and any allergic or thrombotic complications. Your comprehensive care centre can provide a summary pack.
UK Haemophilia Trial Locations
Major UK centres running haemophilia trials include:
London — Royal Free Hospital (Katharine Dormandy Haemophilia and Thrombosis Centre), St Thomas' Hospital, Great Ormond Street Hospital (paediatric), Barts Health
Oxford — Oxford Haemophilia and Thrombosis Centre, Churchill Hospital
Manchester — Manchester Royal Infirmary, University of Manchester Haemophilia Centre
Bristol — Bristol Royal Infirmary Haemophilia Centre, University Hospitals Bristol
Cardiff — University Hospital of Wales Haemophilia Centre
Glasgow — Glasgow Royal Infirmary Haemophilia Centre
Edinburgh — Royal Infirmary of Edinburgh Haemophilia Centre
Sheffield — Royal Hallamshire Hospital Haemophilia Centre
How to Find Your Match
Use our Smart Matcher to find haemophilia trials tailored to your type (A or B), severity, inhibitor status, and treatment goals. Whether you are exploring gene therapy as a one-time cure, interested in non-factor prophylaxis to reduce infusion burden, or managing inhibitors, we can match you to actively recruiting studies.