Chloroquine, Hydroxychloroquine or Only Supportive Care in Patients AdmItted With Moderate to Severe COVID-19

Rationale: Currently there are no approved treatments for COVID-19. In the Dutch treatment protocol guideline (SWAB) designated treatment is supportive care with the option to add chloroquine base (CQ) or hydroxychloroquine (HCQ). CQ and HCQ are implemented because of their in vitro activity, results from small animal studies, and anecdotal patient's data. There are no published randomized studies with these medications in patients with disease caused by any coronavirus. Objective: To evaluate if treatment with only supportive care or addition of one of two anti-COVID\_19 agents (chloroquine or hydroxychloroquine) results in less disease progression in patients with moderate to severe COVID-19 who require hospital admission. Study design: Multicentre, cluster randomized cross-over, open label trial. Hospitals will be randomly allocated to one of 3 treatment arms in sequential periods of one week: chloroquine base versus hydroxychloroquine versus supportive care without any drug presumed active against SARS-COV-2. Patients will be treated based on the date of inclusion. Study population: Adults aged of 18 years and older with moderate to severe, with a NEWS-2 score ≤ 5, laboratory confirmed COVID-19, who require hospital admission in a ward outside the Medium Care or Intensive Care. Intervention (if applicable): Depending on the treatment arm, the study subject will receive only supportive care or an addition with one of the two agents active against SARS-CoV-2 (chloroquine or hydroxychloroquine). Main study parameters/endpoints: Disease progression defined as a NEWS-2 score ≥ 7 within 14 days, or admission to Medium Care or Intensive Care Unit, or death.