Efficacy and safety of Lianhua Qingwen capsules combined with standard of care in the treatment of adult patients with mild to moderate COVID-19 (FLOSAN): protocol for a randomized, double-blind, international multicenter clinical trial.

Background: Effective anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) drugs are not only the next defense after vaccines but also the key part of establishing a multi-tiered coronavirus disease 2019 (COVID-19) prevention and control system. Previous studies had indicated that Lianhua Qingwen (LHQW) capsules could be an efficacious Chinese patent drug for treating mild to moderate COVID-19. However, pharmacoeconomic evaluations are lacking, and few trials have been conducted in other countries or regions to evaluate the efficacy and safety of LHQW treatment. So, this study aims to explore the clinical efficacy, safety, and economy of LHQW for treating adult patients with mild to moderate COVID-19. Methods: This is a randomized, double-blind, placebo-controlled, international multicenter clinical trial protocol. A total of 860 eligible subjects are randomized at a 1:1 ratio into the LHQW or placebo group to receive two-week treatment and follow-up visits on days 0, 3, 7, 10, and 14. Clinical symptoms, patient compliance, adverse effects, cost scale, and other indicators are recorded. The primary outcomes will be the measured median time to sustained improvement or resolution of the nine major symptoms during the 14-day observation period. Secondary outcomes regarding clinical efficacy will be evaluated in detail on the basis of clinical symptoms (especially body temperature, gastrointestinal symptoms, smell loss, and taste loss), viral nucleic acid, imaging (CT/chest X-ray), the incidence of severe/critical illness, mortality, and inflammatory factors. Moreover, we will assess health care cost, health utility, and incremental cost-effectiveness ratio (ICER) for economic evaluation. Discussion: This is the first international multicenter randomized controlled trial (RCT) of Chinese patent medicine for the treatment of early COVID-19 in accordance with WHO guidelines on COVID-19 management. This study will help clarify the potential efficacy and cost-effectiveness of LHQW in the treatment of mild to moderate COVID-19, facilitating decision-making by healthcare workers. Registration: This study is registered at the Chinese Clinical Trial Registry, with registration number: ChiCTR2200056727 (date of first registration: 11/02/2022).