Study Design Characteristics and Pharmacological Mechanisms in International Clinical Trials Registry Platform: Registered Clinical Trials on Antiviral Drugs for COVID-19

OBJECTIVE: This study aimed to evaluate the pharmacological mechanisms of antiviral drugs against the novel coronavirus disease (COVID-19) and the study designs in clinical trials registered with the International Clinical Trials Registry Platform (ICTRP). METHODS: Clinical trials involving antiviral drugs for treating COVID-19 were retrieved from the ICTRP database. For each trial, the study design, number of participants, primary endpoints, source register, antiviral mechanism, and results were evaluated. RESULTS: On June 10, 2020, 145 eligible clinical trials were retrieved from the ICTRP, of which 99 (68.3%) were randomized trials, 109 (75.2%) were parallel assignment trials, 38 (26.2%) were double or single blinded, 130 (89.7%) involved two groups, and 75 (51.6%) included more than 100 participants; and clinical improvement or recovery and virus-negative conversion were the two most common endpoints, accounting for 40.7% and 18.6%, respectively. The drugs were divided according to the antiviral mechanism into HIV reverse transcriptase inhibitors, RNA-dependent RNA polymerase inhibitors, HIV protease inhibitors (PIs), hepatitis C virus NS3 PIs, and anti-influenza drugs. CONCLUSION: The design characteristics of clinical trials of antiviral drugs for treating COVID-19 as well as the mechanism of action and antiviral efficacy of the drugs were evaluated in this study. The results of these trials could constitute a reference for future clinical trials to be executed on COVID-19 treatment and prevention.