Remdesivir is an experimental antiviral drug that was originally developed by Gilead Sciences to treat Ebola virus disease. Test-tube studies have shown that remdesivir is effective against MERS and SARS coronaviruses. Studies are currently underway to determine if remdesivir can treat COVID-19 as well. In early February, the National Institutes of Health in the United States started clinical trials involving remdesivir for the treatment of COVID-19. The trials aim to determine if remdesivir is safe and effective for treating COVID-19. Data from these clinical trials are expected in the coming months and will help determine if remdesivir should be used more widely to treat COVID-19.
Chloroquine and Hydroxychloroquine
Chloroquine and its analogue hydroxychloroquine are Coronavirus Treatment Drugs that have been used for many years to treat malaria and certain autoimmune diseases like lupus and rheumatoid arthritis. Some small studies of chloroquine for COVID-19 patients have indicated potential benefit against the infection, making the drug a promising candidate. However, large clinical trials are still needed to confirm if chloroquine or hydroxychloroquine actually help treat COVID-19 or reduce severity of symptoms. Both drugs have potential side effects like eye problems, heart rhythm issues, and hypoglycemia so they should only be used under proper medical supervision and after evaluating risks versus benefits in patients. More data is awaited before they can be recommended widely for COVID-19 treatment.
Lopinavir/Ritonavir
Lopinavir and ritonavir are used together as a fixed dose combination under the trade name Kaletra for treating human immunodeficiency virus (HIV). The combination works by blocking proteases needed for HIV replication. Since coronaviruses also encode proteases essential for their replication cycle, researchers thought these drugs could potentially work for COVID-19 as well. Clinical trials in China involving over 200 COVID-19 patients treated with lopinavir-ritonavir found no statistically significant difference in time to clinical improvement, mortality rate at 28 days or detectability of virus in throat swabs when compared to standard care alone. Thus, although theoretically these HIV drugs may work against COVID-19, available data so far does not support their use for treating COVID-19.
Umifenovir
This is an antiviral drug approved for use against influenza viruses in Russia and China. Umifenovir was included in the recommendations made by China’s National Health Commission for the treatment of COVID-19 infection. However, there is currently no published evidence to demonstrate the efficacy of umifenovir for COVID-19 treatment. Further studies would be needed to determine if umifenovir can be beneficial for COVID-19 patients.
Favipiravir
Favipiravir is an antiviral drug approved for treatment of novel or re-emerging influenza virus infections in some countries. Favipiravir works by inhibiting a viral enzyme (RNA polymerase) necessary for viral replication inside the infected host cell. A few small clinical studies from China showed faster viral clearance and clinical improvement in patients treated with favipiravir compared to patients not given the drug. However, no large randomized clinical trials have been done yet. Favipiravir is being evaluated in multiple ongoing clinical trials worldwide for safety and efficacy against COVID-19. Early results are keenly awaited to see if it can potentially be useful for treating COVID-19.
Interferons
Interferons are proteins released by host cells in response to viral infections. They activate the immune system and inhibit viral replication. Two types of interferons, interferon alpha and beta, have been studied for treatment of viral respiratory infections like influenza and MERS. Some in-vitro studies have found that interferons are effective against Coronavirus Treatment Drugs like COVID-19 as well. However, larger clinical studies are still needed to prove if interferon treatment can reduce severity or duration of COVID-19 disease. Interferon treatment comes with potential adverse effects so more long term safety data is needed.
Convalescent Plasma Therapy
In convalescent plasma therapy, plasma (the liquid part of blood) from patients who have recovered from COVID-19 infection is transferred to those still battling the infection. The plasma contains antibodies against COVID-19 that may help fight the active infection. This approach has been used before to treat infections like Ebola and SARS. Initial studies from China found that giving COVID-19 patients convalescent plasma therapy helped some severely ill patients recover faster. Larger randomized controlled trials have now begun in several countries to better evaluate efficacy and safety of convalescent plasma therapy for COVID-19 treatment. If found consistently beneficial, this could be a potential short-term measure to help severe COVID-19 patients as vaccine development may take longer.
Antibody Treatment
Monoclonal antibodies are artificially created antibodies that can be targeted specifically against a pathogen like COVID-19. If monoclonal antibodies that effectively neutralize COVID-19 are developed, they may be administered to infected patients to help them fight off the virus. Experimental treatments involving monoclonal antibodies are now being explored by several biotechnology and pharmaceutical companies. The potential advantages of monoclonal antibodies as compared to convalescent plasma include better quality control, lack of infectious agents and higher concentrations of antibodies. However, successfully creating and testing monoclonal antibody treatments typically takes many months. Multiple research candidates are now in early stages of development and testing to evaluate their efficacy against COVID-19.
Cytokine Inhibitors
Since severe COVID-19 disease involves an overactive immune response, drugs that dampen this immune overdrive, known as cytokine storm, are also being studied. Cytokine inhibitors like anakinra (anti-IL1), tocilizumab (anti-IL6), and sarilumab (anti-IL6) are approved to treat certain autoimmune conditions like arthritis by inhibiting specific cytokines implicated in driving inflammation. Early experiences of using these cytokine inhibitors in COVID-19 patients showing cytokine release syndrome report faster recovery times and reduced need for mechanical ventilation in some patients. However, more randomized clinical trials are needed before their efficacy in COVID-19 can be fully determined and appropriate use guidelines formulated.
In summary, while no approved drugs have been proven definitively effective against COVID-19 yet, multiple treatment options are under investigation. Remdesivir, chloroquine/hydroxychloroquine, favipiravir, and monoclonal antibodies seem most promising based on preliminary studies. However, large clinical trials are still ongoing to establish clear evidence on safety and efficacy of these potential treatment approaches. The global scientific community continues efforts on a war footing to develop effective drugs against this pandemic coronavirus.
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1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it