Among the many drugs that the Drug Controller General of India has been approving for the treatment of Covid-19, two anti-viral drugs Favipiravir for those with mild to moderate symptoms of coronavirus in Covid-19 patients and Remdesivir for Covid-19 patients on oxygen support have been at the forefront.
Favipiravir was launched recently by Glenmark Pharmaceuticals, Cipla and Hetero introduced Remdesivir. Many experts, however, have raised concerns on its efficacy. For instance, both these drugs were originally designed to treat other diseases such as any skin disease or arthritis.
Similarly, Remdesivir is an experimental anti-viral drug, which is being studied for Ebola. Now, though, the companies have introduced the drugs’ generic version to treat coronavirus patients, especially Remdesivir being used on compassionate grounds to counter Covid-19.
Dr Reddy’s Laboratories Ltd. (DRL), a global pharmaceutical company headquartered in India, is scaling up antimalarial drug hydroxychloroquine, which is now being used as a prophylactic drug for Covid-19.
The company had already launched hydroxychloroquine sulfate tablets in the US in 2018. Moreover, FUJIFILM Corporation has partnered with DRL and Global Response Aid for the development, manufacture and sales of Avigan Tablets for Covid-19.
Dr Viswesvaran Balasubramanian, Senior Interventional Pulmonologist & Sleep Medicine Specialist, Yashoda Hospitals
Manufacturers claim that the drug administration in 88% of patients (across age groups 20 to 90 years) with mild to moderate cases resulted in a clinical improvement and that the drug can be used in mild to moderate Covid-19 patients with comorbidities such as diabetes and heart disease.
However, the positive results from the study should be interpreted with caution as other therapies were administered in this non-randomised, open-label study, which could have confused the results. “Though a multinational, randomised placebo-controlled trial observed reduced time to recovery from severe Covid-19 with use of Remdesivir, another study conducted in China reported conflicting results. The drug shouldn’t be used in patients having hypersensitivity to any ingredients of the formulation, patients with gross liver enzyme and renal function abnormalities.
K.I. Varaprasad Reddy, (founder of vaccine manufacturing company Shantha Biotechnics)
The new norm now is to have drugs repurposed. These drugs were not designed for coronavirus. And they were already in existence for different purposes. ‘Repurposed drugs’ are those that are not actually meant for a certain disease but might be used to fight it in the absence of anything else.
With this drug-repurposing, we get accustomed to thinking that such drugs are all antiviral, which may not be the case. Favipiravir, for instance, was made in Japan about 13 years ago for influenza. Doctors using Favipiravir in the trials for Covid-19 observed that the drug suppressed the symptoms in people suffering from mild attacks of corona. However, the drug does not offer total safety and the disease may recur in the patient. There can be grave side effects too some people die with these drugs! ”
Dr Nageshwar Reddy, MD of Asian Institute of Gastroenterology
There have been no randomised studies in which both the drugs have shown to decrease the number of days of illness. Let us not forget that its use has been recommended only in the case of a mild to moderate attack of the disease in patients, most of whom recover normally. So, to do a randomised control trial (RCT), it would take not only large numbers of patients but also a long time. The Drug Controller General of India (DGCI) has granted permissions for using these drugs only in view of the pandemic. Otherwise, the rules are very stringent, and it takes very long to get the permissions. However, these are a part of the armamentarium against Covid-19, but we still don’t have a magic bullet like, say, antibiotics against bacterial infections.”
G.V. Prasad, co-chairman and managing director of DRL
These drugs have not undergone full controlled trials yet. There are three stages in a Covid-19 attack Asymptomatic is when one needs to merely fortify the patient with vitamins and zinc supplement. The second stage is when a patient exhibits mild symptoms.
In most cases around the world, people are trying various approaches to combat the mild symptoms, and Favipiravir has been approved in China and Russia for this indication. Remdesivir has been showing some benefit for Covid-19 patients on oxygen and ventilator.
All these drugs, however, exist for other problems and indications, and are being ‘repurposed’ for Covid-19. Many countries have been conducting human trials as we speak.
How close are we to manufacturing the vaccine?
Quite like the opinions by experts all around the world, Varaprasad Reddy shares that we will not come out with a vaccine at least until next year May or June. “To escalate the production itself takes three to four months. Some companies in India have already started boasting that they have come up with a vaccine. We do not have the money to develop anything here. Recently, there was news that a vaccine is out and that it is in Phase-One trial, and that it will then have Phases Two and Three after which the company hopes to get a license and start production. Then, they would need to escalate the production of the vaccine. And when a few millions samples of the vaccine are available, only then can people start getting it,” he explains.
To illustrate the logistics and money involved in the production and testing of vaccines, Varaprasad shares the example of the Gates Foundation. “Gavi and Gates Foundation realised that they require at least 1. 5 billion doses of vaccine a day at six centres across the globe, which would entail untold logistics to be able to manufacture and supply it to all these six centres throughout the globe. It would take billions in,” states Varaprasad.
“No one has developed any vaccine here. People are only doing clinical trials yet. This is what was done for Remdesivir, too in small trials for 100 or 200 people. When everything seemed okay, these companies were given license to sell Remdesivir for Covid-19,” elaborates Varaprasad Reddy.