NCT03852537.

Methods	Trial design: double‐blinded RCT Sample size: 44 Setting: inpatient Language: English Number of centres: 1 Type of intervention (treatment/prevention): treatment
Participants	Inclusion criteria Patients admitted to hospital with COVID‐19 pneumonia (high suspicion or confirmed by positive SARS CoV‐2 testing).  Acute respiratory failure SpO2/FiO2 < 315 (SpO2 < 90% on room air or < 97% on 2L NC) Exclusion criteria Contraindications or unwilling to use steroids by patient or provider Refractory septic shock defined as a requirement of norepinephrine dose or equivalent above > 0.1 microgram/kg/min or 2 or more vasopressors Pre‐admission chronic use of steroids or other immunosuppressive medications Adrenal insufficiency Comfort care Leukopenia < 1000/mm or neutropenia < 500/mm (except if attributable to pneumonia) HIV positive with a CD4 count < 100 Recent or past history of bone marrow or solid organ transplantation Suspected flare of interstitial lung disease (infectious and non‐infectious) Positive influenza testing or high suspicion for influenza
Interventions	Details of intervention Dose: methylprednisolone will be administered based on CRP‐guided protocol outlined under 'Biomarker‐adjusted steroid dosing' Route of administration: no information Treatment details of control group (e.g dose, route of administration):  usual care as determined by the patients treatment team. Concomitant therapy: no information
Outcomes	Primary study outcome: fasibility of the timely initiation of corticosteroids and implementation of biomarker‐titrated corticosteroid dosing: percentage of eligible patients adhered to the timely initiation (time frame: within 30 days of enrolment in study)
Notes	Recruitment status: completed Prospective completion date: 15 March 2021 Date last update was posted:  13 April 2021 Sponsor/funding: Mayo Clinic