Opinion Article
Therapeutic strategies in an outbreak scenario to treat the novel coronavirus originating in Wuhan, China [version 1; peer review: awaiting peer review]
Robert L. Kruse https://orcid.org/0000-0002-8669-6242
Author details
This article is included in the Disease Outbreaks gateway.
Abstract
A novel coronavirus (2019-nCoV) originating in Wuhan, China presents a potential respiratory viral pandemic to the world population. Current efforts are focused on containment and quarantine of infected individuals. Ultimately, the outbreak could be controlled with a protective vaccine to prevent 2019 -nCoV infection. While vaccine research should be pursued intensely, there exists today no therapy to treat 2019-nCoV upon infection, despite an urgent need to find options to help these patients and preclude potential death. Herein, I review the potential options to treat 2019-nCoV in patients, with an emphasis on the necessity for speed and timeliness in developing new and effective therapies in this outbreak. I consider the options of drug repurposing, developing neutralizing monoclonal antibody therapy, and an oligonucleotide strategy targeting the viral RNA genome, emphasizing the promise and pitfalls of these approaches. Finally, I advocate for the fastest strategy to develop a treat ment now, which could be resistant to any mutations the virus may have in the future. The proposal is a biologic that blocks 2019-nCoV entry using a soluble version of the viral receptor, angiotensin-converting enzyme 2 (ACE2), fused to an immunoglobulin Fc domain, providing a neutralizing antibody with maximal breath to avoid any viral escape, while also helping to recruit the immune system to build lasting immunity. The sequence of the ACE2-Fc protein is provided to investigators, allowing its possible use in recombinant protein expression systems to start producing drug today to treat patients under compassionate use, while formal clinical trials are later undertaken. Such a treatment could help infected patients before a protective vaccine is developed and widely available in the coming months to year (s).
Keywords
Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro
Dear Editor,
In December 2019, a novel pneumonia caused by a previously unknown pathogen emerged in Wuhan, a city of 11 million people in central China. The initial cases were linked to exposures in a seafood market in Wuhan.1 As of January 27, 2020, the Chinese authorities reported 2835 confirmed cases in mainland China, including 81 deaths. Additionally, 19 confirmed cases were identified in Hong Kong, Macao and Taiwan, and 39 imported cases were identified in Thailand, Japan, South Korea, United States, Vietnam, Singapore, Nepal, France, Australia and Canada. The pathogen was soon identified as a novel coronavirus (2019-nCoV), which is closely related to sever acute respiratory syndrome CoV (SARS-CoV).2 Currently, there is no specific treatment against the new virus. Therefore, identifying effective antiviral agents to combat the disease is urgently needed.
An efficient approach to drug discovery is to test whether the existing antiviral drugs are effective in treating related viral infections. The 2019-nCoV belongs to Betacoronavirus which also contains SARS-CoV and Middle East respiratory syndrome CoV (MERS-CoV). Several drugs, such as ribavirin, interferon, lopinavir-ritonavir, corticosteroids, have been used in patients with SARS or MERS, although the efficacy of some drugs remains controversial.3 In this study, we evaluated the antiviral efficiency of five FAD-approved drugs including ribavirin, penciclovir, nitazoxanide, nafamostat, chloroquine and two well-known broad-spectrum antiviral drugs remdesivir (GS-5734) and favipiravir (T-705) against a clinical isolate of 2019-nCoV in vitro.
Standard assays were carried out to measure the effects of these compounds on the cytotoxicity, virus yield and infection rates of 2019-nCoVs. Firstly, the cytotoxicity of the candidate compounds in Vero E6 cells (ATCC-1586) was determined by the CCK8 assay. Then, Vero E6 cells were infected with nCoV-2019BetaCoV/Wuhan/WIV04/20192 at a multiplicity of infection (MOI) of 0.05 in the presence of varying concentrations of the test drugs. DMSO was used in the controls. Efficacies were evaluated by quantification of viral copy numbers in the cell supernatant via quantitative real-time RT-PCR (qRT-PCR) and confirmed with visualization of virus nucleoprotein (NP) expression through immunofluorescence microscopy at 48 h post infection (p.i.) (cytopathic effect was not obvious at this time point of infection). Among the seven tested drugs, high concentrations of three nucleoside analogs including ribavirin (half-maximal effective concentration (EC50) = 109.50 μM, half-cytotoxic concentration (CC50) > 400 μM, selectivity index (SI) > 3.65), penciclovir (EC50 = 95.96 μM, CC50 > 400 μM, SI > 4.17) and favipiravir (EC50 = 61.88 μM, CC50 > 400 μM, SI > 6.46) were required to reduce the viral infection (Fig. 1a and Supplementary information, Fig. S1). However, favipiravir has been shown to be 100% effective in protecting mice against Ebola virus challenge, although its EC50 value in Vero E6 cells was as high as 67 μM,4 suggesting further in vivo studies are recommended to evaluate this antiviral nucleoside. Nafamostat, a potent inhibitor of MERS-CoV, which prevents membrane fusion, was inhibitive against the 2019-nCoV infection (EC50 = 22.50 μM, CC50 > 100 μM, SI > 4.44). Nitazoxanide, a commercial antiprotozoal agent with an antiviral potential against a broad range of viruses including human and animal coronaviruses, inhibited the 2019-nCoV at a low-micromolar concentration (EC50 = 2.12 μM; CC50 > 35.53 μM; SI > 16.76). Further in vivo evaluation of this drug against 2019-nCoV infection is recommended. Notably, two compounds remdesivir (EC50 = 0.77 μM; CC50 > 100 μM; SI > 129.87) and chloroquine (EC50 = 1.13 μM; CC50 > 100 μM, SI > 88.50) potently blocked virus infection at low-micromolar concentration and showed high SI (Fig. 1a, b).
Remdesivir has been recently recognized as a promising antiviral drug against a wide array of RNA viruses (including SARS/MERS-CoV5) infection in cultured cells, mice and nonhuman primate (NHP) models. It is currently under clinical development for the treatment of Ebola virus infection.6 Remdesivir is an adenosine analogue, which incorporates into nascent viral RNA chains and results in pre-mature termination.7 Our time-of-addition assay showed remdesivir functioned at a stage post virus entry (Fig. 1c, d), which is in agreement with its putative anti-viral mechanism as a nucleotide analogue. Warren et al. showed that in NHP model, intravenous administration of 10 mg/kg dose of remdesivir resulted in concomitant persistent levels of its active form in the blood (10 μM) and conferred 100% protection against Ebola virus infection.7 Our data showed that EC90 value of remdesivir against 2019-nCoV in Vero E6 cells was 1.76 μM, suggesting its working concentration is likely to be achieved in NHP. Our preliminary data (Supplementary information, Fig. S2) showed that remdesivir also inhibited virus infection efficiently in a human cell line (human liver cancer Huh-7 cells), which is sensitive to 2019-nCoV.2
Chloroquine, a widely-used anti-malarial and autoimmune disease drug, has recently been reported as a potential broad-spectrum antiviral drug.8,9 Chloroquine is known to block virus infection by increasing endosomal pH required for virus/cell fusion, as well as interfering with the glycosylation of cellular receptors of SARS-CoV.10 Our time-of-addition assay demonstrated that chloroquine functioned at both entry, and at post-entry stages of the 2019-nCoV infection in Vero E6 cells (Fig. 1c, d). Besides its antiviral activity, chloroquine has an immune-modulating activity, which may synergistically enhance its antiviral effect in vivo. Chloroquine is widely distributed in the whole body, including lung, after oral administration. The EC90 value of chloroquine against the 2019-nCoV in Vero E6 cells was 6.90 μM, which can be clinically achievable as demonstrated in the plasma of rheumatoid arthritis patients who received 500 mg administration.11 Chloroquine is a cheap and a safe drug that has been used for more than 70 years and, therefore, it is potentially clinically applicable against the 2019-nCoV.
Our findings reveal that remdesivir and chloroquine are highly effective in the control of 2019-nCoV infection in vitro. Since these compounds have been used in human patients with a safety track record and shown to be effective against various ailments, we suggest that they should be assessed in human patients suffering from the novel coronavirus disease.
Gilead Sciences Statement on the Company’s Ongoing Response to the 2019 Novel Coronavirus (2019-nCoV)
Foster City, Calif., January 31, 2020 — Gilead Sciences today issued the following statement from Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences:
"Gilead is working closely with global health authorities to respond to the novel coronavirus (2019-nCoV) outbreak through the appropriate experimental use of our investigational compound remdesivir. Together with the U.S. Food and Drug Administration (FDA), the U.S. Centers for Disease Control and Prevention (CDC), the U.S. Department of Health and Human Services (DHHS), the China CDC and National Medical Product Administration (NMPA), the World Health Organization (WHO), and the U.S. National Institute of Allergies and Infectious Diseases (NIAID), and along with individual researchers and clinicians, Gilead is focused on contributing our antiviral expertise and resources to help patients and communities fighting 2019-nCoV.
Remdesivir is not yet licensed or approved anywhere globally and has not been demonstrated to be safe or effective for any use. At the request of treating physicians, and with the support of local regulatory agencies, who have weighed the risks and benefits of providing an experimental drug with no data in 2019-nCoV, Gilead has provided remdesivir for use in a small number of patients with 2019-nCoV for emergency treatment in the absence of any approved treatment options.
Gilead is working with health authorities in China to establish a randomized, controlled trial to determine whether remdesivir can safely and effectively be used to treat 2019-nCoV. We are also expediting appropriate laboratory testing of remdesivir against 2019-nCoV samples.
While there are no antiviral data for remdesivir that show activity against 2019-nCoV at this time, available data in other coronaviruses give us hope. Remdesivir has demonstrated in vitro and in vivo activity in animal models against the viral pathogens MERS and SARS, which are coronaviruses that are structurally similar to 2019-nCoV. There are also limited clinical data available from the emergency use of remdesivir in the treatment of patients with Ebola virus infection.
Gilead is committed to supporting the global health community to quickly and effectively respond to serious and life-threatening viral outbreaks worldwide."
.作者: StephenW 时间: 2020-2-5 09:11
Coronavirus: Gilead’s Remdesivir Begins Trials as Researchers Publish Positive In Vitro Results
By
Alex Philippidis
-
February 5, 2020
Clinical trials of Gilead Sciences’ remdesivir have begun in Wuhan, China, the center of the novel coronavirus outbreak, a day after Chinese researchers recommended that the antiviral drug candidate remdesivir be assessed in humans as a potential treatment for 2019-nCoV
Clinical trials of Gilead Sciences’ remdesivir have begun in Wuhan, China, the center of the novel coronavirus outbreak, a day after Chinese researchers recommended that the antiviral drug candidate remdesivir be assessed in humans as a potential treatment for 2019-nCoV.
China’s National Medical Products Administration has approved applications by the China-Japan Friendship Hospital and the Chinese Academy of Medical Sciences to conduct trials evaluating remdesivir.
Today, China’s state-owned Xinhua news agency reported that Friendship Hospital plans to study a total of 761 patients in two trials—one trial to assess 308 with mild or moderate infection, the other 453 severely infected patients—at Jinyintan Hospital in Wuhan, under Phase III studies that have been officially launched.
“We hope good results will be achieved in the trials,” said , deputy director of the science and technology ministry’s China Biotechnology Development Center, at a press conference held by the National Health Commission.
According to updated coronavirus figures reported today by the National Health Commission, 65 people died and 3,887 more people were confirmed to be infected on Tuesday. To date, 24,324 people have been confirmed as infected with 2019-nCoV, and 490 people have died—more than the 349 who died in the SARS outbreak of 2002–03—with 892 patients cured and discharged from hospitals.
China has launched numerous initiatives in recent days aimed at controlling the outbreak, with Xinhua reporting today that President Xi Jinping said “the infection prevention and control is at a critical moment and stressed the utmost importance of carrying out the work in a law-based, scientific and orderly manner,” during the third meeting of the Commission for Overall Law-based Governance of the Communist Party of China Central Committee, headed by Xi.
Xi also signaled that China may hold some officials accountable for the nation’s initial slow response to containing 2019-nCoV: “Xi spoke of the need to improve legislation related to epidemic prevention and control, strengthen the building of supporting institutions and improve punishment procedures.” He has previously characterized China’s initial response as marked by “shortcomings and deficiencies.”
Remdesivir, chloroquine “highly effective”
The trials were announced as having begun a day after the experimental drug and a marketed anti-malarial, chloroquine, showed promising preclinical results.
“Our findings reveal that remdesivir and chloroquine are highly effective in the control of 2019-nCoV infection in vitro,” the researchers reported in “Remdesivir and chloroquine effectively inhibit the recently emerged novel coronavirus (2019-nCoV) in vitro,” a study published as a letter to the editor of the Nature-owned journal Cell Research.
“Since these compounds have been used in human patients with a safety track record and shown to be effective against various ailments, we suggest that they should be assessed in human patients suffering from the novel coronavirus disease,” the researchers added.
The research team consisted of investigators from the Wuhan Institute of Virology, Chinese Academy of Sciences / National Center for Biosafety and the National Academy of Military Medical Research Institute of Emergency Medicine for Prevention and Control of Drugs.
The researchers published their recommendation Tuesday, the same day that China’s Ministry of Science and Technology first said it would launch human clinical trials of remdesivir after a batch of the drug arrived in the country, the state-run Xinhua news agency reported.
In their study, the researchers assessed remdesivir and chloroquine and five other drugs against a clinical isolate of 2019-nCoV in vitro. The five were: ribavirin, penciclovir, nitazoxanide, nafamostat, and favipiravir (T-705 or Avigan).
“Notably, Remdesivir (EC50 = 0.77 μM; CC50 > 100 μM; SI > 129.87) and chloroquine (EC50 = 1.13 μM; CC50 > 100 μM, SI > 88.50) potently blocked virus infection at low-micromolar concentration and showed high SI [selectivity index],” the researchers reported.
A time-of-addition assay showed remdesivir to function at a stage post virus entry, which according to the scientists appeared to reflect its putative anti-viral mechanism as a nucleotide analogue.
“Our data showed that EC90 value of remdesivir against 2019-nCoV in Vero E6 cells was 1.76 μM, suggesting its working concentration is likely to be achieved in NHP,” the researchers added. “Our preliminary data showed that remdesivir also inhibited virus infection efficiently in a human cell line (human liver cancer Huh-7 cells), which is sensitive to 2019-nCoV.”
Pursuing remdesivir patent
Remdesivir proved sufficient effective, the institutions added in a statement issued by the Wuhan Institute of Virology, that they have applied for Chinese invention patents on January 21 “in accordance with international practice and from the perspective of protecting national interests (Resistance to new coronaviruses in 2019).”
The institutions stated that they also plan to pursue multiple patents worldwide as allowed under the global Patent Cooperation Treaty.
However, the institutions added that should Gilead “intend to contribute to China’s epidemic prevention and control, we both agree that if the state needs it, we will not require the implementation of the rights claimed by the patent for the time being.”
The institutions have opted not to pursue patents for chloroquine, which is already marketed in China, also with the aim of encouraging partners to join them in efforts to prevent and control the spread of coronavirus.
Gilead said on January 31 that it will partner with officials to carry out clinical trials of remdesivir, and has offered the Nuc inhibitor for use in a “small number” of patients with 2019-nCoV for emergency treatment in the absence of any approved treatment options. The company added that it is also expediting “appropriate” laboratory testing of remdesivir against 2019-nCoV samples.
Gilead chief medical officer Merdad Parsey, MD, PhD, has cited positive in vitro and in vivo activity shown by remdesivir in animal models against MERS and SARS, coronaviruses that are structurally similar to 2019-nCoV.
Remdesivir also showed “no adverse events” after it was administered as a treatment to the first American confirmed to be infected with 2019-nCoV, according to “First Case of 2019 Novel Coronavirus in the United States,” a case study published Friday in The New England Journal of Medicine by members of the Washington State 2019-nCoV Case Investigation Team.
Rating unchanged despite potential
“This case-report suggests that remdesivir could be an effective treatment for 2019-nCoV and should be formally investigated as a therapeutic agent for the treatment of 2019-nCoV pneumonia, and we are encouraged by Gilead’s efforts to further investigate remdesivir, through the recently initiated trial in collaboration with Chinese health authorities,” SVB Leerink director of therapeutics research and senior research analyst, Geoffrey C. Porges, MBBS, wrote Monday in an investor note along with colleagues Neil Puri, MD, Ke (Andrew) Yuan, CFA, CPA, and Bradley Canino, CPA.
They added, however, that they would not change SVB Leerink’s “Market Perform” rating of Gilead stock as a result of remdesivir’s potential in treating coronavirus.
“From a societal perspective, we are unequivocally supportive of Gilead’s (and other company’s) efforts to develop an effective treatment for this rapidly spreading, and potentially fatal, infection; however these activities do not alter our fundamental assessment and outlook for GILD’s stock, as therapies of this nature are likely to provide a short-term financial boost, but unlikely to yield a significant impact on long-term shareholder value,” Porges and colleagues wrote.
Atazanavir, an antiretroviral medication used to treat and prevent HIV, was the most promising chemical compound to emerge from an artificial intelligence-based prediction model for antiviral drugs that may be effective on 2019-nCoV, according to an article posted Sunday on the bioRxiv preprint server by researchers at Deargen and Dankook University in South Korea, and Emory University in Atlanta—the latest report in GEN’s ongoing coverage of the 2019-nCoV novel coronavirus outbreak.作者: StephenW 时间: 2020-2-6 15:52