The latest news on the fight against coronavirus is encouraging. Two new antiviral drugs have been found to be so effective that clinical trials have ended ahead of schedule. The data from these trials have not yet been published. However, the regulators are keen to consider the widespread use of these drugs. They will fill a big gap in the toolkit the doctors are using to combat covid and may well help end the global pandemic. This is stated in the editorial of magazine The Economist, published on November 13.
The new drugs are:
- molnupiravir (Lagevrio), developed by the pharmaceutical company Merck working with the biotech firm Ridgeback Biotherapeutics;
- Paxlovid, developed by Pfizer.
All three developers are American companies.
It is noted that those infected with the coronavirus are much less likely to be hospitalized or die if they take any of these drugs within five days of the onset of symptoms.
In October, Merck reported that molnupiravir reduced the risk of hospitalization or death by about half when given to patients with risk factors such as obesity or heart disease. Regulatory authorities in the United States and Europe, as well as the World Health Organization (WHO) are assessing the drug. The UK has already approved it and will begin using it for treatment in December.
Pfizer stated on November 5 that its drug reduced the risk of hospitalization or death by 89% when taken for three days. During the trials, none of the patients died while taking Paxlovid within five days of the symptom onset.
Molnupiravir is a so-called prodrug. It turns into its active form when it gets inside the cells. Once there, it is embedded in the virus genetic material and disrupts its ability to replicate (multiply). The errors accumulate in the genetic material of the virus and a process known as the "error catastrophe" occurs.
Paxlovid is a combination of two drugs: an existing one called Ritonavir that is given alongside a new protease inhibitor known as aspf-07321332. The protease inhibitor was developed to bind and block protease enzymes that the SARS-COV-2 coronavirus uses to replicate. Ritonavir prevents the body from breaking down the protease inhibitor too quickly.
Molnupiravir and Paxlovid are low molecular weight drugs, so they are easy to manufacture.
Merck and Pfizer state that the price of the drugs will vary depending on the wealth of the country that buys them. This would likely mean that rich countries would pay $700 for a five-day course of pills, while poorer countries could pay about $20 or less, as production costs quickly decrease.
Merck has already issued licenses that allow other companies to manufacture its drug and has reserved 3 million doses for low- and middle-income countries. This is to prevent rich countries from monopolizing the supply of new drugs, as they did with the vaccines. Merck expects to produce 10 million doses this year and 20 million next year. Generic manufacturers will do a lot more.
Pfizer, which has yet to receive any regulatory approvals, expects 180,000 pill packs to be produced by the end of this year, and 21 million in the first half of 2022.
These drugs mark the second turning point in the pandemic (the first one was the vaccine), The Economist notes.