key: cord-0709225-9de3kcjp
authors: Mohan, Anant; Tiwari, Pawan; Suri, Tejas Menon; Mittal, Saurabh; Patel, Ankit; Jain, Avinash; Thirumurthy, Velpandian; Das, Ujjalkumar Subhash; Boppana, Tarun Krishna; Pandey, Ravindra Mohan; Shelke, Sushil Suresh; Singh, Angel Rajan; Bhatnagar, Sushma; Masih, Shet; Mahajan, Shelly; Dwivedi, Tanima; Sahoo, Biswajeet; Pandit, Anuja; Bhopale, Shweta; Vig, Saurabh; Gupta, Ritu; Madan, Karan; Hadda, Vijay; Gupta, Nishkarsh; Garg, Rakesh; Meena, Ved Prakash; Guleria, Randeep
title: Single-dose oral ivermectin in mild and moderate COVID-19 (RIVET-COV): a single-centre randomized, placebo-controlled trial
date: 2021-08-25
journal: J Infect Chemother
DOI: 10.1016/j.jiac.2021.08.021
sha: 55133430b1eb98322c8f41196a74475cd97b2a05
doc_id: 709225
cord_uid: 9de3kcjp

Introduction Ivermectin is an antiparasitic drug which has in-vitro efficacy in reducing severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) viral load. Hence, Ivermectin is under investigation as a repurposed agent for treating COVID-19. Methods In this pilot, double blind, randomized controlled trial, hospitalized patients with mild-to-moderate COVID-19 were assigned to a single oral administration of an elixir formulation of Ivermectin at either 24 mg or 12 mg dose, or placebo in a 1:1:1 ratio. The co-primary outcomes were conversion of RT-PCR to negative result and the decline of viral load at day 5 of enrolment. Safety outcomes included total and serious adverse events. The primary outcomes were assessed in patients who had positive RT-PCR at enrolment (modified intention-to-treat population). Safety outcomes were assessed in all patients who received the intervention (intention-to-treat population). Results Among the 157 patients randomized, 125 were included in modified intention-to-treat analysis. 40 patients each were assigned to Ivermectin 24 mg and 12 mg, and 45 patients to placebo. The RT-PCR negativity at day 5 was higher in the two Ivermectin arms but failed to attain statistical significance (Ivermectin 24 mg, 47.5%; 12 mg arm, 35.0%; and placebo arm, 31.1%; p-value = 0.30). The decline of viral load at day 5 was similar in each arm. No serious adverse events occurred. Conclusions In patients with mild and moderate COVID-19, a single oral administration of Ivermectin did not significantly increase either the negativity of RT-PCR or decline in viral load at day 5 of enrolment compared with placebo.

The COVID-19 pandemic has become a major public health challenge, affecting over 175 million people globally and causing more than 3 million deaths (1) . Although most patients have a mild illness, the contagiousness of the causative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contributes to rapid spread of infection. To date, no antiviral agent has been shown to be conclusively beneficial in non-severe COVID-19.

New and repurposed drugs are being trialled in mild-to-moderate COVID-19 to help suppress viral transmission and prevent disease progression. Ivermectin is one such repurposed drug which has an established safety record with over 2.5 billion doses dispensed over the past three decades (2) .

Originally introduced as an anthelminthic agent, it has recently been found to possess antiviral, antiinflammatory and anti-cancer actions as well (2) . A broad-spectrum antiviral effect against single stranded RNA viruses such as HIV-1, dengue, yellow fever, West Nile virus and others has been observed in preclinical studies (3) (4) (5) . This is attributed to a host directed action against the importin α/β protein which is used by the viral nucleocapsid to enter the host nucleus (5) .

Recently, an in-vitro study by Caly et al demonstrated that micromolar concentrations (2-2.5 µg/mL) of Ivermectin can reduce viral load by 5000-fold at 48 hours in VERO/hSLAM cells (6) . Although equivalent plasma concentrations are difficult to achieve with routine antiparasitic doses of Ivermectin (150-400 µg/kg), there are inherent differences in the in-vivo and in-vitro responses to drugs.

Ivermectin may act through its metabolites, get concentrated three-fold in lung tissue and have additional immunomodulatory actions at routine doses (7, 8) . Till date, only a few small trials of ivermectin in COVID-19 patients have used routine clinical doses in tablet form and have shown conflicting results (9) (10) (11) (12) . Single dose of Ivermectin was found to hasten viral load decline in the study by Samaha et al (using 150 µg/kg) (10) but not in the study by Chaccour et al (using 400 µg/kg) (12) . Doses higher than those approved for clinical indications (1-2 g/kg) have been shown to be well tolerated (13, 14) . Hence this pilot study was designed to determine the efficacy and safety of a novel elixir formulation of ivermectin aimed to maximize oral bioavailability of ivermectin in COVID-19. 

Consecutive patients aged above 18 years admitted at the trial site were considered eligible for inclusion if they were diagnosed with non-severe COVID-19, i.e., room air saturation (SpO2) >90%, and with no hypotension or requirement of mechanical ventilation. Diagnosis of COVID-19 was based on a positive result on either SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) or a rapid antigen test. Patients were excluded if they did not give informed consent. Other exclusion criteria included: pregnancy or lactation, known hypersensitivity to ivermectin, chronic kidney disease with creatinine clearance <30 mL/min, elevated transaminase levels (>5X upper limit of normal), myocardial infarction or heart failure within 90 days prior to enrolment, prolonged corrected QT interval (>450 ms), any other severe comorbidity as per investigator's assessment, or enrolment in another clinical trial.

All included subjects underwent a detailed clinical evaluation. Comorbidities including diabetes mellitus, systemic hypertension, coronary artery disease, chronic obstructive pulmonary disease, and tuberculosis were recorded. The baseline chest radiograph was graded using the Brixia score (15) .

Baseline laboratory investigations were performed, and patients were managed according to the institutional management protocol by the clinical team. The patients were followed up for a minimum J o u r n a l P r e -p r o o f of 14 days or till hospital discharge, whichever was later. All treatments administered during hospital stay were recorded.

In preparation for the trial, our group performed a pharmacokinetic simulation study of the dosing requirements for achieving an Ivermectin lung concentration of 2-2.5 µg/mL (unpublished work). The details of the same are provided in the Supplementary Appendix. Accordingly, we found that an alcohol-based elixir formulation of Ivermectin at a dose of 400 µg/kg administered after a meal may achieve a plasma Ivermectin concentration >150 ng/mL. A 20 mL dose of elixir formulation consisted of accurately weighted ivermectin (12 or 24 mg) in ethanol (40%v/v) with syrup base which was suitability flavoured and coloured. Representative samples were subjected for the quality control to ensure the drug content and batch uniformity. It was compounded and dispensed from the in-house pharmacy by a qualified pharmacist. Similar placebos were also prepared without ivermectin and formulations were coded before delivery to the trial site. After baseline evaluation, eligible patients were randomized in a 1:1:1 ratio to receive a single dose of Ivermectin 12 mg or 24 mg elixir, or identical placebo. A variable block randomization stratified based on disease severity (mild or moderate illness) was done using a centralized telephone-based system and the patients, investigators, caregivers, and statisticians were blinded to the allocation. The intervention was given two hours after breakfast on the day of randomization.

All randomized patients underwent a baseline oropharyngeal and nasopharyngeal swab for COVID-19

RT-PCR. Samples were transported in a standardized viral transport medium at 2-8 degrees Celsius and were processed within 24 hours. RNA was extracted using an FDA-approved automated magnetic bead-based extraction system (Genolution, South Korea). For real time RT-PCR, Quantstudio™ (Thermofisher Scientific, Waltham, MA USA) was used. To determine sample adequacy and ascertain adequate extraction of RNA, an endogenous control was used for each sample as part of the assay. A reference control was run in 8 serial dilutions to make a standard curve based on cycle J o u r n a l P r e -p r o o f threshold (CT) values at each dilution. Furthermore, with each set of samples one reference each with high and low CT value was run, hence a semiquantitative estimate of viral load (expressed as log10 viral copies/mL) was provided. In patients with positive baseline RT-PCR report, follow up RT-PCR was performed on days 3, 5 and 7 of enrolment to estimate the change in viral load.

The primary outcomes were to evaluate the efficacy of the two different doses of oral ivermectin Table 1 ) (17) . The frequency of total and serious adverse events was documented.

As this was a pilot trial of a repurposed drug in a pandemic setting, a sample size of convenience was chosen. All randomized patients who received a study medication were included in the intention-totreat (ITT) analysis. Among these, patients with a positive nasopharyngeal/oropharyngeal SARS-CoV-2 RT-PCR on the day of enrolment were included in the modified intention-to-treat (mITT) analysis. The primary outcomes (viral load decline and conversion to negative RT-PCR at day 5) were assessed in the mITT population. Clinical outcomes were assessed in the mITT population, whereas the adverse effects were evaluated in the ITT population. Statistical analysis was performed using STATA (version 14). Inter-group comparisons of categorical outcome variables were performed using Fisher's exact test. Inter-group comparisons of continuous outcome variables were performed using analysis of variance (ANOVA) or Kruskal-Wallis test. The comparisons of decline of log10 viral copies/mL between individual study groups were performed using t-test and were expressed as mean difference with 95% confidence intervals (CI). In the presence of a negative RT-PCR test on a follow-J o u r n a l P r e -p r o o f up sample, the viral load was imputed to 0 on the log scale. A p-value of less than 0.05 denoted statistical significance.

Between 28 July, 2020 and 29 September, 2020, a total of 278 patients with mild or moderate COVID-19 were screened, out of which 157 eligible patients were randomized. Among these, 5 patients subsequently withdrew consent. The ITT population (n=152) included 51 patients assigned to ivermectin 24 mg, 49 patients assigned to ivermectin 12 mg, and 52 patients assigned to placebo. Baseline clinical severity by WHO ordinal scale was 3 (i.e., hospitalized, not requiring supplemental oxygen) in the majority (92%) of patients, and was 4 (i.e., hospitalized, requiring supplemental oxygen) in the remaining patients. The median duration of symptoms at the time of enrolment was 5 days (interquartile range, 3 to 7 days) and was similar in the three arms. There were no significant differences in the comorbidities, presenting symptoms or baseline laboratory parameters in the three arms (Table 1 and Supplementary Table 2) . A minority (10%) of patients received concurrent antiviral therapies including remdesivir, favipiravir or hydroxychloroquine as decided by site physicians without any difference in the three arms (Supplementary Table 3 ).

The proportion of subjects who became RT-PCR negative on day 5 of enrolment was numerically higher with ivermectin 24 mg arm (47.5%) compared with ivermectin 12 mg arm (35.0%) and placebo arm (31.1%) ( Table 2) ; however, the difference was not statistically significant (p-value = J o u r n a l P r e -p r o o f 0.30) (Figure 2a) . In subjects who received intervention early in the course of illness (within 4 days of symptom onset), Ivermectin 24 mg arm had numerically higher negativity of RT-PCR at day 5 compared with placebo arm (47.0% vs 28.6%, p-value = 0.38). The viral load at enrolment or baseline disease severity did not impact the efficacy of the therapies to achieve negative RT-PCR at day 5.

There was no significant difference in the viral load (expressed as log10 viral copies/mL) in the three arms, either at baseline or at day 5 of enrolment, or in the decline of viral load between the ivermectin arms and placebo at day 5 ( Figure 2b ). Baseline disease severity did not affect the efficacy of ivermectin in achieving viral load decline (Supplementary tables 5-8).

There was no significant difference in the three arms in terms of conversion to negative RT-PCR (table 2) , or in the decline of viral load at either day 3 or day 7 of enrolment (Table 3) . Secondary clinical outcomes were also similar in the three arms (Supplementary Table 9 ). There was no difference in the mean (SD) duration of symptom resolution in the three groups and placebo, 86.7%; p-value = 0.42). The proportion of patients with clinical worsening (defined as an increase in the WHO ordinal score during treatment) was similar in the three groups (ivermectin 24 mg, 7.5%; ivermectin 12 mg, 5.0%; and placebo, 11.1%; p-value = 0.65).

There were no serious adverse events reported during the study (Supplementary Table 10 ). The frequency of all adverse events in the ITT population was similar in the three arms (ivermectin 24 mg, 11.8%; ivermectin 12 mg, 16.3%; and placebo, 11.5%; p-value = 0.76). The most frequent adverse event was epigastric burning sensation, which occurred in 17 (11.2%) patients. (18) . Ivermectin bioavailability increases 2.5fold when given alongwith a fat-rich meal or in an alcohol-based formulation (14, 19) , and it preferentially distribute into the lung tissue (16) . Hence, we administered a higher dose (400 µg/kg) of Ivermectin in an alcohol-based elixir after breakfast. However, even higher doses (up to 1-2 g/kg) may be required to achieve optimal therapeutic doses against SARS-CoV-2 (13, 14) . Furthermore, Ivermectin may have immunomodulatory actions at nanomolar doses by inhibiting the nicotinic acetylcholine receptor (nAChR), which may act as a receptor for SARS-CoV-2 and drive dysregulated cytokine release from macrophages (20, 21) .

In our study, Ivermectin did not improve the time to symptom recovery or clinical status at day 14 after drug administration. Similar results were observed in the other randomized trials of Ivermectin (11, 22) . López-Medina et al showed that a five-day course of ivermectin (300 μg/kg) failed to hasten symptom resolution in mild COVID-19 compared with placebo (11) . In contrast, Samaha et al demonstrated that a single administration of Ivermectin can hasten viral load decline at day 3 (10) . We performed RT-PCR at days 3, 5 and 7 to serially evaluate decline in viral load with ivermectin compared with placebo. Our rationale was that faster viral load decline may enable non-severe J o u r n a l P r e -p r o o f COVID-19 patients to become non-infectious sooner, thereby limiting the contagion (23) . Hence, the trend towards increased viral negativity at day 5 with ivermectin 24 mg in our trial, particularly among mildly ill patients, encourages further exploration in this regard.

In a retrospective study of hospitalized patients in Florida, patients who received Ivermectin were found to have a significantly lower mortality that those who did not (15% versus 25%) (24). The mortality benefit remained significant after propensity-matched analysis and adjusting for confounders. However, they included patients with greater illness severity than our study population, illustrated by lack of mortality in our trial. Furthermore, the greater use of concurrent therapies and retrospective design preclude drawing definitive conclusions from their data. The immunomodulatory rather than antiviral effect of Ivermectin may be hypothetically more important in moderate and severe COVID-19 (25).

There were no serious adverse events in our trial. Since we have used a novel elixir-based formulation with an aim to maximize plasma bioavailability of Ivermectin, this reassures us regarding its safety for further study. The frequency of mild adverse events was similar with ivermectin at either dose or placebo. Other studies of Ivermectin in COVID-19 have also found a low rate of adverse events (22, 26) . The predominant adverse event in our study was transient burning sensation in the epigastrium which could be attributed to the alcohol-based elixir preparation.

The major limitation of our study was that it was conducted at a single centre with a relatively small sample size. Most of our patient population was male and relatively young (mean age, 35. design, data collection, data analysis or writing of the report. The corresponding author had full access to the study data and had the final responsibility for the decision to submit for publication. 

None

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