NCT04435795.

Methods	Trial design: randomised controlled, triple‐blind trial Sample size: 215 Setting: outpatient Language: English Number of centres: 1 Type of intervention: treatment
Participants	Inclusion criteria: symptomatic adults positive by PCR for COVID‐19 within 5 days of enrolment with fever, cough, or shortness of breath provision of informed consent at day 0, patients should be at home Exclusion criteria: already receiving inhaled corticosteroid medication currently using systemic corticosteroids (oral or intravenous or intramuscular such as prednisone) or use of steroids 7 days prior to enrolment severely ill at enrolment (i.e. admitted to ICU at admission) unable to self‐administer the inhaler known or suspected pregnancy and breastfeeding known allergy to study medication or its components (non‐medicinal ingredients; including lactose allergy (type I)) with untreated fungal, bacterial, or tubercular infections of the respiratory tract current hospitalisation current use of oxygen at home or in the hospital
Interventions	Intervention group: intranasal ciclesonide 50 μg twice daily to each nostril and inhaled ciclesonide 600 μg twice daily for 14 days Control group: intranasal normal saline twice daily and inhaled placebo 3 puffs by MDI twice daily Concomitant therapy: no
Outcomes	Primary outcome: proportion of participants with no symptoms of cough, fever, or dyspnoea at day 7 Secondary outcomes: proportion of participants with no symptoms of cough, fever, or dyspnoea at day 14; overall feeling – proportion who reporting they are "very much improved" or "much improved" at day 7; overall feeling – proportion who reporting they are "very much improved" or "much improved" at day 14; improvement in dyspnoea at days 7 and 14 (dyspnoea defined as reporting "shortness of breath" or "chest congestion" or "chest tightness". In those who reported dyspnoea at baseline, resolution will be defined as having no symptoms in these 3 areas); Visual Analog scale for Cough – wet or dry cough at days 7 and 14; hospitalisation for SARS‐CoV‐2 and hospitalisation for SARS‐CoV‐2‐related illness at day 14; 2‐point change in PROMIS Dyspnoea Severity Scale at days 7 and 14; 2‐point changes in PROMIS Dyspnoea Severity Scale at days 7 and 14; incidence of new oxygen use during the trial (defined as oxygen use not present at randomisation) at day 14; all‐cause mortality at days 14 and 29; PROMIS Anxiety 7a scale 1–5 (1 = never had symptoms and 5 = always had symptoms) at days 7 and 14; PROMIS Sleep Disturbance 4a scale from 1 to 5 (1 = very good and 5 = very poor) at days 7 and 14
Notes	Recruitment status: terminated (could not meet target enrolment) Prospective completion date: 8 June 2021 Date last update was posted: 30 July 2021 Sponsor/funding: McGill University Health Centre/Research Institute of the McGill University Health Centre