Randomised Treatment of Acute Pancreatitis With Infliximab: Double-blind, Placebo-controlled, Multi-centre Trial (RAPID-I)

Inclusion Criteria: * Adult patients attending Accident and Emergency (A\&E) at or admitted to recruiting hospitals via a GP with a new diagnosis of AP established by two of the following three criteria: (1) typical continuous upper abdominal pain; (2) amylase and/or lipase three or more times the upper limit of normal; (3) characteristic findings on abdominal imaging (if undertaken urgently by CT or MRI) * Patients in whom trial treatment can be started within 36 hours of admission to hospital with a new diagnosis of acute pancreatitis allowing 120 min for preparation of trial medication * Patients from whom appropriate consent is obtained (from the patient or their legal representative). Exclusion Criteria: * Age \<18 or \>85 * Patients with a bodyweight over 200 kg * Known previous AP within the last 30 days or chronic pancreatitis * Multiple sclerosis, systemic vasculitis, Guillain-Barré syndrome or other demyelinating disorder * Known epilepsy * Moderate to severe heart failure and/or coronary disease (NYHA III/IV) * Severe respiratory conditions including cystic fibrosis, severe asthma and severe chronic obstructive pulmonary disease (COPD) * On home oxygen or home mechanical ventilation * Jaundice (serum bilirubin \>50 µmol/L), and/or known advanced liver disease, on waiting list for liver transplantation or considered unsuitable for transplantation * Known cancer for which chemotherapy and/or radiotherapy ongoing/completed in last 6 months * Known haematological malignancy * Known end-stage cancer requiring palliative care * Known established infection prior to or suspected infection, including COVID-19, at the time of AP onset * Known history of tuberculosis, or household contact with those with tuberculosis or opportunistic infection * Known history of infective hepatitis * Rare diseases or inborn errors of metabolism that significantly increase the risk of infections, including severe combined immunodeficiency (SCID) and homozygous sickle cell disease * Known live vaccine or infectious agent within one month of admission * Known immunosuppressive or biologic therapy within one month of admission * Known hypersensitivity to infliximab or to inactive components of REMICADE® or to any murine proteins * Known pregnancy or lactation at admission * Females of childbearing potential who do not agree to use adequate contraception up to 6 months after infliximab infusion * Known participation in investigational medicinal product study within last three months.