ICON (Ivermectin in COvid Nineteen) Study: Use of Ivermectin Is Associated with Lower Mortality in Hospitalized Patients with COVID-19

Background: No therapy to date has been shown to improve survival for patients infected with SARS-CoV-2. Ivermectin has been shown to inhibit replication of SARS-CoV-2 in-vitro, which has led to off-label use, but clinical in-vivo efficacy has not been previously described. Methods: This is a retrospective cohort study of consecutive patients hospitalized at four Broward Health hospitals in South Florida with confirmed SARS-CoV-2 between March 15, 2020 through May 11, 2020. 280 patients with confirmed SARS-CoV-2 infection, of whom 173 were treated with ivermectin and 107 with usual care, were reviewed. Treatment decisions were at the discretion of the treating physicians. Severe pulmonary involvement at baseline was defined as need for either FiO2 ≥50%, noninvasive ventilation, or invasive mechanical ventilation. The primary outcome was all-cause in-hospital mortality. Secondary outcomes included subgroup mortality in patients with severe pulmonary involvement, extubation rates for patients requiring invasive ventilation, and length of hospital stay. Logistic regression and propensity score matching were used to adjust for confounders. Findings: Univariate analysis showed lower mortality in the ivermectin group (15·0% versus 25·2%, OR 0·52, CI 0·29-0·96, P=0·03). Mortality was also lower among patients with severe pulmonary involvement treated with ivermectin (38·8% vs 80·7%, OR 0·15, CI 0·05-0·47, p=0·001), but there were no significant differences in successful extubation rates (36·1% vs 15·4%, OR 3·11 (0·88-11·00), p=0·07) or length of stay. After multivariate adjustment for confounders and mortality risks, the mortality difference remained significant (OR 0·27, CI 0·09-0·85, p=0·03). 194 patients were included in the propensity-matched cohort; mortality was again significantly lower in the ivermectin group (12.4% vs 25.8%, OR 0·41, CI 0·19-0·87, p=0·02). Interpretation: Ivermectin treatment was associated with lower mortality during treatment of COVID-19, especially in patients who required higher inspired oxygen or ventilatory support. These findings should be further evaluated with randomized controlled trials. Funding: NoneDeclaration of Interests: All authors declare none.Ethics Approval Statement: The protocol was approved by the institutional review board for the Broward Health hospital system.