Randomized open label clinical trial carried out at study centers in Sweden, including Karolinska University Hospital, S:t Göran Hospital, Danderyd Hospital and Västmanlands Hospital. Patients with COVID-19 who are hospitalized with oxygen therapy are eligible for inclusion. Subjects are randomized to 14 days of inhalation with ciclesonide 360 µg twice daily or to standard of care. Primary outcome is duration of received supplemental oxygen therapy. Key secondary outcome is a composite outcome of death and received invasive mechanical ventilation within 30 days.

Inclusion criteria:

• Patients 18 years of age or older who have given their written consent to participate in the study.
• Hospitalized and treated with oxygen for a maximum of 48 hours.
• Verified Covid-19: Positive sample for Sars-Cov2 RNA or a positive Sars-Cov2 antigen test from the upper respiratory tract
• Receives oxygen treatment.
• Negative pregnancy test (women of childbearing potential)
• Willing to exercise contraception categorized as "very effective" according to the Clinical Trial Facilitation Group during ongoing study treatment + 7 days (Appendix 2). (female research participant of childbearing potential)

Exclusion criteria:

• Pregnancy, breast-feeding or planned pregnancy.
• Hypersensitivity to ciclesonide or to any of the excipients.
• Concomitant medication with cortisone, ketoconazole, itraconazole, ritonavir or nelfinavir.
• Treatment with> 8 l oxygen / min or supply of > 50% oxygen with nasal high-flow cannula
• Ongoing palliative care or expected survival of less than 72 hours.
• Expected admission to the intensive care unit within 48 hours.
• Active or inactive pulmonary tuberculosis.
• Severe Liver Failure (Child-Pugh C)
• Diagnosed with pulmonary arterial hypertension (PAH) or fibrosis.
• Mental inability, reluctance or language difficulties that make it difficult to understand the meaning of participating in the study.
• Participates in or has recently participated in a clinical trial in the last 30 days. Previous participation in this study.