Anti-Covid pill, what is molnupiravir and how it works

In an interview with Cnn Anthony Fauci, the famous US immunologist advisor to the White House, defined the results of the anti-Covid pill “impressive“. The molnupiravir it’s a antiviral drug developed by Msd, that is the colossus Merck & Co. (known with this acronym only in the USA and Canada) which during the emergency supported some competing groups in the production of vaccines, and Ridgeback Biotherapeutics. The product is in the phase 3 clinical trial dubbed “MOVe-OUT” on 775 patients in 170 international centers and the results are remarkable: he has shown of reduce the risk of hospitalization and death by 50% in unvaccinated adult patients with mild or moderate Covid-19 and yet at risk of developing a serious disease due to some risk factor (obesity, old age, diabetes or cardiovascular disease among others).

Among other things, in 80% of the cases evaluated it was Delta variants, Gamma e Mu del virus Sars-Cov-2.

The two companies announced the results in a statement a few days ago – they are expected to be published in a peer-reviewed study – and announced their intention to ask the FDA, the US Food and Drug Administration, toauthorization for emergency use. The drug was discovered at Emory University in Atlanta, where the active ingredient had been working since 2013: the pandemic has recalibrated the studies, restarted by the ferrets (where it blocked the transmission of the virus in 24 hours) and progressively reached humans. The mechanism is different from vaccines: the drug does not stimulate the production of the Spike protein in order to trigger the antibody response but intervenes on viral polymerase, an enzyme that the coronavirus uses to replicate in the host. It therefore drives the replication mechanism crazy, introducing errors in the genetic code of the virus whose multiplication therefore ends up on a dead end. In fact, the immune system is not significantly stressed.

Incidentally, the recruitment of volunteers for the phase 3 study was suspended for shows superiority of the drug over placebo: the benefit of the drug was so high that it was no longer ethically sustainable not to administer it to the other at-risk patients in the control group. Specifically, in the placebo group, 53 patients, or 14.1%, were hospitalized or died. For those who received the drug, 28 patients, or 7.3%, were hospitalized or died.

The drug – which is part of the class of ribonucleosidicysis analogues – assumes in this way: two pills a day for five days and must be used in early stages of infection, essentially within five days of the onset of symptoms, somewhat at the same timing as monoclonal antibodies (which instead cost a lot and need hospital care). The importance of undergo a tampon it will therefore remain central also in the future: the effectiveness of the drug will largely depend on the precocity of the diagnosis. Molnupiravir will cost about $ 700 per cycle, so for 10 pills, although it should be manufactured in voluntary non-exclusive license with established manufacturers of generic drugs to accelerate their availability in more than 100 low- or middle-income countries, where therefore the price should be reshaped. The US government has already purchased 1.7 million treatments pledging $ 1.2 billion.

The side effects? At the moment the drug seems safe with comparable events between the two groups involved in the study, i.e. who took molnupiravir and who took a pill without an active ingredient. An adverse event, or a negative outcome, occurred in 35% of those who received the new drug and 40% of those who received the placebo. Only 1.3% of molnupiravir-treated subjects discontinued the drug due to an adverse event, compared with 3.4% who discontinued placebo. At the moment vaccines seem the best solution in any case, to continue to follow: not only because they reduce hospitalization and death by 90% but also because they cost less, they can be administered at any time (net of individual factors) and we now have a considerable amount of data on them. However, more complete data on side effects and dosages are needed for different populations.

Apparently, molnupiravir could be part of therapeutic cocktails along with other direct-acting agents, according to what is being done for viral diseases such as HIV and hepatitis C. Merck has already put the drug into production with the aim of already producing 10 million doses by the end of ‘year.