Macrophage Therapy for Acute Liver Injury (MAIL): a study protocol for a phase 1 randomised, open-label, dose-escalation study to evaluate safety, tolerability and activity of allogeneic alternatively activated macrophages in patients with paracetamol-induced acute liver injury in the UK

Introduction Acute liver failure (ALF) has no effective treatment other than liver transplantation and is commonly caused by paracetamol overdose. New treatments are needed to treat and prevent ALF. Alternatively-activated macrophages (AAMs) can promote resolution of liver necrosis and stimulate hepatocyte proliferation. Using AAMs in unscheduled care requires the use of an allogeneic product. A clinical trial is needed to determine the safety and tolerability of allogeneic AAMs.Methods and analysis A single-centre, open-label, dose-escalation, phase 1 randomised trial to determine whether there is dose-limiting toxicity of AAMs in patients with paracetamol-induced acute liver injury. Randomisation will occur at higher doses. Between 17 and 30 patients will receive treatment, subject to dose-limiting toxicity and an adaptive trial design which aims to reduce the risk of allocation bias through blinding and randomisation.Ethics and dissemination The trial will be conducted according to the ethical principles of the Declaration of Helsinki 2013 and has been approved by North East-York Research Ethics Committee (reference 23/NE/0019), National Health Service Lothian Research and Development department, and the UK Medicines and Healthcare products Regulatory Agency. When the trial concludes, results will be shared by presentation and publication.Trial registration number ISRCTN12637839.