Antivirals for COVID-19 Posted May 7, 2020
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COVID-19 CURBSIDE CONSULTS Pavithra Srinivas, PharmD Gretchen Sacha, PharmD Christine Koval, MD Inpatient Pharmacy, Cleveland Clinic Inpatient Pharmacy, Cleveland Clinic Infectious Disease, Respiratory Institute, Cleveland Clinic Antivirals for COVID-19 Posted May 7, 2020 ■ ABSTRACT that antiviral drug development against other RNA Drugs targeting RNA respiratory viruses has resulted respiratory viruses has resulted in very few effective in few effective therapies, highlighting challenges for therapies. This is primarily due to poorly character- antivirals to treat COVID-19. Several antivirals are being ized RNA polymerases and weak clinical activity of investigated for symptomatic COVID-19 but no defi nitive nucleoside analogs (ribavirin for respiratory syncytial data support their clinical use. Remdesivir, with good virus [RSV] and parainfl uenza). For the developed in vitro activity against SARS-CoV2, appeared to result non-nucleoside drugs (neuraminidase inhibitors in favorable outcomes for hospitalized patients in a and adamantanes for infl uenza) clinical challenges compassionate use series with shortened time to recovery include short therapeutic windows, limited effects on and a modest decrease in mortality. Currently, remdesivir the severely ill, and drug resistance. While the fol- is available in phase III clinical trials, the compassionate lowing antivirals are of interest for treating symptom- use program, and eventually through the emergency use atic COVID-19, they may suffer the same challenges. authorization. A randomized controlled trial of lopinavir/ Those drugs with evidence of clinical activity may ritonavir demonstrated no apparent clinical or virologic also warrant investigation as prevention in high risk benefi t and drug-drug interactions and side effects further populations. limit its utility. Antivirals to treat infl uenza (oseltamivir) have limited activity against SARS-CoV-2, but favipiravir ■ REMDESIVIR and umifenovir, infl uenza antivirals available interna- Remdesivir (GS-5734) is an adenosine analog anti- tionally, have distinct viral targets and require further viral drug that inhibits viral RNA polymerase and investigation. Antivirals with evidence of clinical activity has demonstrated in vitro activity against various must be studied as treatment and prophylaxis for those at viruses including Ebola, SARS-CoV, and Middle high risk for severe COVID-19. Eastern respiratory syndrome (MERS-CoV). More recently, remdesivir has demonstrated potent activ- ■ INTRODUCTION ity against SARS-CoV-2 in in vitro and animal Since COVID-19 emerged in Wuhan, China, over 3 model studies, and holds some promise for treat- million cases have been confi rmed worldwide with a ment of COVID-19.2,3 A recent case series describ- mortality of 7%.1 The majority of infected individuals ing the compassionate use of remdesivir in 61 adult achieve full recovery, many with few symptoms. For hospitalized patients with COVID-19 demonstrated those with more severe illness or high risk for mortal- that 68% of patients experienced an improvement ity or both, therapeutic strategies have emerged to in the need for oxygen support over a median 18 combat severe acute respiratory syndrome coronavi- day follow-up period, while 15% of patients clini- rus (SARS-CoV-2) directly with antivirals and indi- cally worsened. Clinical improvement was observed rectly with immune modulation. In this discussion in 84% of patients, but was less frequent among of proposed antiviral therapies that may hold some older patients (70 or older vs less than 50), and in promise against SARS-CoV-2, it should be recognized patients who were on invasive ventilation compared with patients on noninvasive ventilator support. The statements and opinions expressed in COVID-19 Curbside Consults are Mortality occurred in 13% of patients, with older based on experience and the available literature as of the date posted. While patients (70 or older) and patients with higher base- we try to regularly update this content, any offered recommendations can- not be substituted for the clinical judgment of clinicians caring for individual line serum creatinine demonstrating a higher risk. patients. Adverse events were reported by 60% of patients, doi:10.3949/ccjm.87a.ccc030 most commonly increased hepatic transaminases CLEVELAND CLINIC JOURNAL OF MEDICINE 1 Downloaded from www.ccjm.org on September 29, 2021. For personal use only. All other uses require permission. (23%), diarrhea (9%), rash (8%), renal impairment use program reserved for pediatric and pregnant hos- (8%) and hypotension (8%).4 The lack of a com- pitalized patients, and eventually through the EUA. parator control arm is a signifi cant limitation to the ■ interpretation of the data presented in this compas- LOPINAVIR/RITONAVIR (KALETRA) sionate use experience. Lopinavir/ritonavir is a combination antiretroviral On April 29, 2020, the National Institutes of drug comprising 2 protease inhibitors. Lopinavir, the Health released a statement regarding promising primary agent, acts through viral protease inhibition preliminary data from the ongoing randomized and ritonavir inhibits CYP3A4-mediated metabolism Adaptive COVID-19 Treatment Trial involving of lopinavir thus increasing its plasma concentrations. 1,063 patients. According to the interim analysis, Currently approved by the FDA for the treatment preliminary data suggest that remdesivir conferred of HIV, lopinavir/ritonavir was studied as an anti- a 31% faster median time to recovery compared viral agent in both the SARS and MERS outbreaks with placebo of 11 days in the remdesivir group due to demonstrable in vitro activity against both vs 15 days in the placebo group (P < 0.001) and coronaviruses.8,9 In SARS, patients who received mortality of 8% in the remdesivir group vs 11.6% lopinavir/ritonavir (often in combination with riba- in the placebo group (P = 0.059).5 On the same day, virin and corticosteroids) compared with historical the maker of remdesivir (Gilead Sciences, Inc.) controls had lower mortality rates, lower mechanical also released a statement regarding their open-label ventilation requirements, required less rescue corti- phase III SIMPLE trial that demonstrated similar costeroid treatment, and had lower viral loads after rates of clinical improvement with a 5-day treat- treatment.9,10 ment course of remdesivir therapy compared with a In light of these fi ndings in SARS, lopinavir/rito- 10-day treatment course.6 Both studies are pending navir was evaluated in patients with COVID-19. Of complete data analysis and peer review. Finally, a note, there are no in vitro studies of lopinavir/ritona- randomized placebo-controlled trial of 236 adult vir against SARS-CoV-2. In March 2020, a random- hospitalized patients with COVID-19 in Wuhan, ized, controlled, open-label trial comparing lopinavir/ China, was also published on April 29, 2020. Con- ritonavir (400 mg and 100 mg, respectively) twice trary to the press releases for the aforementioned daily for 14 days vs standard care in 199 hospitalized studies, this study demonstrated no signifi cant dif- patients with COVID-19 at a single hospital in China ference in time to clinical improvement (21 days demonstrated no statistically signifi cant difference for remdesivir vs 23 days for placebo) or 28-day in the primary outcome of time to clinical improve- mortality (14% for remdesivir vs 13% for placebo). ment (hazard ration [HR] 1.39; 95% confi dence In a subgroup of patients initiated on treatment interval [CI] 1.00 to 1.91).11 Furthermore, mortality early (ie, within 10 days of symptom onset), time rates were not signifi cantly different in the cohort of to clinical improvement was 18 days for remdesivir patients who received lopinavir/ritonavir (19.2% vs vs 23 days for placebo and 28-day mortality was 25.0%; 95% CI –17.3 to 5.7). There was no differ- 11% for remdesivir vs 15% for placebo, although ence between groups for detection of viral RNA over the differences were not statistically signifi cant. Of time. Based on these fi ndings, the authors concluded note, enrollment in this trial was terminated early that no benefi t was observed with lopinavir/ritonavir due to achievement of infection control in China, treatment in COVID-19 beyond standard care. thus the sample size may represent a limitation of Moreover, lopinavir/ritonavir is associated with this study.7 many adverse reactions (Table 1) and drug interac- Remdesivir is currently still undergoing rigorous tions due to the strong inhibition of CYP3A4. In evaluation in multiple phase III randomized clinical fact, 48% of patients who received lopinavir/rito- trials as a possible treatment option for COVID-19. navir for COVID-19 experienced adverse reactions, On May 1, 2020, the US Food & Drug Administra- most commonly gastrointestinal effects. Of these, 19 tion (FDA) issued an emergency use authorization events were noted to be serious, and 13 patients dis- (EUA) for remdesivir for the treatment of patients continued the drug due to adverse reactions.11 Over- hospitalized with COVID-19. Logistics on medica- all, based on the lack of supportive data for its use in tion access through the EUA are still in process COVID-19, its adverse effect profi le and signifi cant between Gilead and the United States government. drug interactions, lopinavir/ritonavir for COVID-19 Currently, remdesivir is only available in the US should be reserved for use only in the context of a through one of the clinical trials, a compassionate clinical trial.12 2 CLEVELAND