Randomised Evaluation of COVID-19 Therapy (RECOVERY)

The RECOVERY trial has already shown that:

• Dexamethasone (a type of steroid) & tocilizumab reduce the risk of dying for patients hospitalised with COVID-19 receiving oxygen,
• Regeneron's monoclonal antibody combination reduces deaths for hospitalised COVID-19 patients who have not mounted their own immune response,
• Baricitinib reduces the risk of death when given to hospitalised patients with severe COVID-19.

The trial also concluded that there is no beneficial effect of hydroxychloroquine, lopinavir-ritonavir, azithromycin, convalescent plasma, colchicine or aspirin in patients hospitalised with COVID-19, and these arms have been closed to recruitment.

BACKGROUND: In early 2020, as this protocol was being developed, there were no approved treatments for COVID-19, a disease induced by the novel coronavirus SARSCoV-2 that emerged in China in late 2019. The UK New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG) advised that several possible treatments should be evaluated, including Lopinavir-Ritonavir, low-dose corticosteroids, and Hydroxychloroquine (which has now been done). A World Health Organization (WHO) expert group issued broadly similar advice. These groups also advised that other treatments will soon emerge that require evaluation.

ELIGIBILITY AND RANDOMISATION: This protocol describes a randomised trial among patients hospitalised for COVID-19. All eligible patients are randomly allocated between several treatment arms, each to be given in addition to the usual standard of care in the participating hospital. The study is subdivided into several parts, according to whether participants are children or adults, and by geographic area. The study is dynamic, and treatments are added and removed as results and suitable treatments become available. The parts in the current version of the protocol are as follows:

Part A: discontinued in Protocol v19.0, (children's recruitment to Part A discontinued in Protocol v17.1)

Part B: discontinued in Protocol v16.0.

Part C: discontinued in Protocol v15.0.

Part D: discontinued in Protocol v20.0

Part E (adults ≥18 years old with hypoxia only): In a factorial design, high-dose corticosteroids vs no additional treatment.

Part F (adults ≥18 years): In a factorial design, empagliflozin vs no additional treatment.

Part J (UK patients ≥12 years old): In a factorial design, sotrovimab vs no additional treatment.

Park K (patients ≥18 years old): In a factorial design, molnupiravir vs no additional treatment.

Park L (UK patients ≥18 years old): In a factorial design, paxlovid vs no additional treatment.

Children with PIMS-TS: Tocilizumab vs anakinra vs no additional treatment (UK only) (discontinued in Protocol v23.1).

For patients for whom not all the trial arms are appropriate or at locations where not all are available, randomisation will be between fewer arms.

ADAPTIVE DESIGN: The interim trial results will be monitored by an independent Data Monitoring Committee (DMC). The most important task for the DMC will be to assess whether the randomised comparisons in the study have provided evidence on mortality that is strong enough (with a range of uncertainty around the results that is narrow enough) to affect national and global treatment strategies. In such a circumstance, the DMC will inform the Trial Steering Committee who will make the results available to the public and amend the trial arms accordingly. New trial arms can be added as evidence emerges that other candidate therapeutics should be evaluated.

OUTCOMES: The main outcomes will be death, discharge, need for ventilation and need for renal replacement therapy. For the main analyses, follow-up will be censored at 28 days after randomisation. Additional information on longer term outcomes may be collected through review of medical records or linkage to medical databases where available (such as those managed by NHS Digital and equivalent organisations in the devolved nations).

SIMPLICITY OF PROCEDURES: To facilitate collaboration, even in hospitals that suddenly become overloaded, patient enrolment (via the internet) and all other trial procedures are greatly streamlined. Informed consent is simple and data entry is minimal. Randomisation via the internet is simple and quick, at the end of which the allocated treatment is displayed on the screen and can be printed or downloaded. Key follow-up information is recorded at a single timepoint and may be ascertained by contacting participants in person, by phone or electronically, or by review of medical records and databases.

DATA TO BE RECORDED: At randomisation, information will be collected on the identity of the randomising clinician and of the patient, age, sex, major co-morbidity, pregnancy, COVID-19 onset date and severity, and any contraindications to the study treatments. The main outcomes will be death (with date and probable cause), discharge (with date), need for ventilation (with number of days recorded) and need for renal replacement therapy. Reminders will be sent if outcome data have not been recorded by 28 days after randomisation. Suspected Unexpected Serious Adverse Reactions (SUSARs) to one of the study medication (eg, Stevens-Johnson syndrome, anaphylaxis, aplastic anaemia) will be collected and reported in an expedited fashion. Other adverse events will not be recorded but may be available through linkage to medical databases.

NUMBERS TO BE RANDOMISED: The larger the number randomised the more accurate the results will be, but the numbers that can be randomised will depend critically on how large the epidemic becomes. If substantial numbers are hospitalised in the participating centres then it may be possible to randomise several thousand with mild disease and a few thousand with severe disease, but realistic, appropriate sample sizes could not be estimated at the start of the trial.

HETEROGENEITY BETWEEN POPULATIONS: If sufficient numbers are studied, it may be possible to generate reliable evidence in certain patient groups (e.g. those with major comorbidity or who are older). To this end, data from this study may be combined with data from other trials of treatments for COVID-19, such as those being planned by the WHO.

ADD-ON STUDIES: Particular countries or groups of hospitals, may well want to collaborate in adding further measurements or observations, such as serial virology, serial blood gases or chemistry, serial lung imaging, or serial documentation of other aspects of disease status. While well-organised additional research studies of the natural history of the disease or of the effects of the trial treatments could well be valuable (although the lack of placebo control may bias the assessment of subjective side-effects, such as gastrointestinal problems), they are not core requirements.