Evaluation of the initial response in clinical trial efforts for COVID-19 in Brazil.

Abstract

To describe the methodological characteristics and good research practices of COVID-19 interventional studies developed in Brazil in the first months of the pandemic. We reviewed the bulletin of the National Research Ethics Committee - Coronavirus Special Edition (Comissão Nacional de Ética em Pesquisa - CONEP-COVID) (May 28, 2020) and the databases of the International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, and Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clínicos - ReBEC) to identify interventional studies registered in Brazil that assessed drug type, biological therapy, or vaccines. We described their methodological characteristics and calculated their power for different effect magnitudes. A total of 62 studies were included, 55 retrieved from the CONEP website, and 7 from registry databases. The most tested pharmacological interventions in these studies were: chloroquine/hydroxychloroquine, azithromycin, convalescent plasma, tocilizumab, sarilumab, eculizumab, vaccine, corticosteroids, anticoagulants, n-acetylcysteine, nitazoxanide, ivermectin, and lopinavir/ritonavir. Out of 22 protocols published on registry databases until May 2020, 18 (82%) were randomized clinical trials, and 13 (59%) had an appropriate control group. However, 9 (41%) of them were masked, and only 5 (24%) included patients diagnosed with a specific laboratory test (for example, reverse transcription polymerase chain reaction - RT-PCR). Most of these studies had power > 80% only to identify large effect sizes. In the prospective follow-up, 60% of the studies available at CONEP until May 2020 had not been published on any registry platform (ICTRP/ReBEC/ClinicalTrials) by July 21, 2020. The interventions evaluated during the Brazilian research response reflect those of international initiatives, but with a different distribution and a large number of studies assessing hydroxychloroquine/chloroquine. Limitations in methodological design and sample planning represent challenges that could affect the research outreach.