Impact of the use of oral corticoids in organizing pneumonia post COVID-19 (the NORCOVID clinical trial)

<bold>Introduction:</bold> Organizing pneumonia (OP) is one of the most frequent sequelae of Sars-Cov-2 pneumonia. The aim of this study is to establish the optimal dose of oral corticosteroids for the treatment of this complication. <bold>Methods:</bold> Randomized, open, parallel, single-center, non-inferiority clinical trial with an active control group comparing two oral prednisone regimens. The control group received prednisone 0.75 mg/Kg/day 4 weeks; 0.5mg/Kg/day 4 weeks; 20mg/day 4 weeks; 10mg/day 6 weeks; 5 mg/day 6 weeks (6 months) and the experimental group prednisone 0.5 mg/Kg/d 3 weeks, 20 mg/day 3 weeks; 15mg/day 2 weeks; 10mg/day 2 weeks, 5mg/day 2 weeks (3 months). Visits were carried out at baseline and at 3, 6 and 12 months with clinical history, physical examination, functional tests and chest CT. The primary outcome was non-inferiority with a margin of 10% in CO transfer (DLCO) at 6 months. <bold>Results:</bold> Seventy-nine patients were randomized, 40 in the experimental group and 39 in the control group. Mean baseline DLCO was 59.3% (SD 16.7) in the experimental group and 55.5% (SD 16.5) in the control group, with mean improvements at 6 months of 11.7% (95%CI 7.18 -16.17) and 12.8% (95%CI 8.57-17.11) respectively. The difference between groups at 6 months was 1.23% [(95%CI -5.13-7.59], the experimental regimen being non-inferior to the control group with the margin of 10%. Patients in the experimental group had less than half as many adverse effects as controls: 9 (23%) vs 22 (56%) (p=0.0027). <bold>Conclusions:</bold> Treatment with oral corticosteroids lasting three months (initial dose of prednisone 0.5 mg/Kg/d) may be recommended in patients with post-COVID OP. <bold>Funded by:</bold> Instituto de Salud Carlos III(PI21/01046)