First clinical trials showing that a pill can be taken at-home has been welcomed as a game changer that could help protect those most in need from the devastating effects of Covid-19. Molnupiravir is now part of a growing number of promising medicines. These are the major developments in treatment so far.
Favipiravir
This antiviral drug is designed to prevent virus replication in the early stages of illness. It is licensed in Japan to treat flu since 2014. This antiviral drug was also the first to be tested in the UK's Principle trial in residential or peoples homes. Phase 3 results are expected in the next few weeks.
Antiviral Pfizers PF-07321332
Pfizer is currently testing an antiviral competitor pill on up to 2,660 healthy adults. This includes a cohort of people living in the same household with someone with confirmed Covid-19 infection, and another group of non-hospitalised, symptomatic adults. The goal of this study is to find out if treatment can be used to prevent infection. The medicine blocks the activity of Covid protease which is an enzyme that the virus uses to multiply in the body. The trial results will be available before the end the year.
Antiviral inhaler Synairgens
Synairgen reported promising early results for a drug originally developed to treat chronic obstructive lung disease (COPD). The drug is administered via a battery-operated, hand-held nebuliser. It is based upon interferon beta, which is a naturally occurring molecule that stimulates immune defenses in the lungs. The drug is currently in phase 3 trials and has been shown to have broad-spectrum antiviral properties.
Budesonide Inhaler
Budesonide, a common corticosteroid that is used to treat COPD and asthma, has been also tested in the Principle trial. Recent research has shown that the drug can reduce recovery time by up to three days for patients who are not admitted to hospital. Budesonide is currently not recommended for standard treatment. However, it can be used off-label in patients with additional risk factors such as those over 65 and with co-morbidities.
Roche, a Swiss pharmaceutical company, is working with Atea Pharmaceuticals in Europe to develop an oral antiviral. It believes it has the potential to both treat Covid-19-positive people and prevent disease from people who have been exposed. The company stated that initial results from patients admitted to hospital with moderate Covid-19 were positive and showed a sustained antiviral response against Sars-CoV-2. There was no unexpected safety issues and the patient had no other complications.
Dexamethasone
This inexpensive steroid is approximately 60 years old and was a success story in the pandemic. The Oxford-led Recovery trial discovered that it saved the lives of 1 in 8 people with Covid who were on ventilators in hospitals. For seriously ill patients admitted to hospital, a low dose of the drug has become the norm. It acts as an anti-inflammatory and can reduce the immune system's overreaction to coronavirus in severe cases.
Remdesivir
The US-based Gilead Sciences has approved this antiviral for emergency use in the US and India. It is also approved for use in Australia, Japan, and Australia for severe symptoms. It is intravenously administered and can be expensive. The benefits of the drug for patients are disputed. A large World Health Organization study found that it has little impact on mortality and does not require ventilation.
Convalescent blood plasma
As convalescent plasma has been used successfully to treat other diseases, it was hoped that blood containing antibodies from patients who had recovered from Covid-19 would have a protective impact. It was granted emergency authorization by the USA, but the largest clinical trial to date, which involved 500,000 Americans hospitalised for Covid-19, showed no overall benefit. Patients who received convalescent blood experienced more adverse events than those who received regular care.
