Oral pill. Anti-virals, a shot of optimism to Covid treatments

There is no silver-bullet yet to treat SARS-CoV-2, the virus that causes Covid-19. But there is much optimism presently over two anti-viral pills showing promising results in treating Covid-19, that are in various stages of regulatory reviews and approvals across the world. Significantly, this comes at a time coronavirus cases surge in different regions.

The oral pill makes it easy to give, unlike injectables like anti-viral remdesivir, extensively used at one point of time. Some doctors still see benefits in remdesivir, though the World Health Organization has since dropped it from its recommendations.

Present treatment options include steroids like dexamethasone; a class of drugs called IL6 inhibitors that help suppress overreaction of the immune system -tocilizumab and sarilumab; and more recently, antibody cocktails.

Antiviral molnupiravir is from Ridgeback Biotherapeutics and Merck Sharp & Dohme (MSD) and was given the go-ahead in the UK, earlier this November.The European regulator has also given a recommendation on this pill on Friday, allowing member countries to use the drug.

Molnupiravir awaits similar approvals in other regions, including India.

The other investigational anti-viral is from Pfizer –Paxlovid (PF-07321332, to be administered along with ritonavir, a known drug used in treating HIV).

Merck and Pfizer’s antivirals are expected to go in for review in the US, later this month, so the drug could be globally available by the year end. Meanwhile, the UK and US governments have already committed to buying these pills from both companies.

Yes. Merck has voluntary licensing agreements with a host of major Indian drug companies, including Dr Reddy’s Laboratories, Cipla, Sun Pharma, Hetero, Emcure, Aurobind, Torrent etc.

When the drug is approved by the Indian regulator, these companies would make and supply it in India and other low and middle income countries, at prices that will be less than the original drug’s price.

Pfizer has no such direct agreements, but it recently tied-up with UN-backed Medicines Patent Pool, that would grant sub-licenses to generic companies to make their versions of this antiviral at lower prices for certain markets. Indian companies like Cipla, DRL and Sun Pharma have told Business Line, they would be open to making this anti-viral as well.

A date on when these medicines would be available locally, is unclear. Though Molnupiravir looks likely to be available sooner.

The UK regulator that approved Molnupiravir explains, the anti-viral pill works byinterfering with the virus’ replication.This prevents it from multiplying, keeping virus levels low in the body and therefore reducing the severity of the disease. Based on clinical trial data, it is most effective when given during the early stages of infection - as soon as possible, following a positive Covid-19 test and within five days of symptoms onset, the regulator says.

Molnupiravir claims to halve hospitalisation risk in mild to moderate patients, while Pfizer’s antiviral claims to cut it by 89 percent in high-risk adults.

In the UK, molnupiravir has been authorised for use in people who have mild to moderate Covid-19 and at least one risk factor for developing severe illness. Such risk factors include obesity, older age (>60 years), diabetes mellitus, or heart disease. And the European regulator suggested themedicine, capsules in this case, be taken twice a day for 5 days.

According to Pfizer, its oral therapy would be prescribed “atthe first sign of infection or at first awareness of an exposure”, to prevent a deterioration of the condition into severe illness which can lead to hospitalisation and death.

No. Vaccination continues to remain a staple, as it’s a preventive (except in people who cannot take the vaccine). Most therapies available now are to treat the infection at different stages – and do not target prevention.

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