Last updated on October 12th, 2021 at 12:41 pm
Pharmaceutical giant Merck announced a new drug to treat COVID-19, called molnupiravir, which appeared to cut the risk of hospitalization and death by nearly half for at-risk patients. Furthermore, Merck will be seeking an emergency use authorization for it immediately.
Although this may sound like good news, and if you are reading the news about this drug, you’d think it was a miracle, I want to make sure that everyone understands several important factors about this drug’s safety and effectiveness profile. It is not a miracle, but it may be an important addition to the treatment protocols for COVID-19 patients, especially those at the highest risk of hospitalization or death.
This is not a worthless drug, at least for COVID-19, such as the horse dewormer, ivermectin, that has become popular with the pseudoscience crowd. Molnupiravir was designed from the beginning as an anti-viral drug.
All about molnupiravir
Molnupiravir is an experimental antiviral drug that is orally active and was developed for the treatment of influenza. It exerts its antiviral action through the introduction of copying errors during viral RNA replication of the virus. In other words, as opposed to the aforementioned horse dewormer, this drug was designed from the bottom up to actually stop viral replication.
I’m going to review the data from Merck with the caution that it is from a press release, not from a peer-reviewed publication. And press releases are near the bottom of the hierarchy of published scientific research – its sole purpose is to promote Merck and its new drug, but it is all we have for the time being.
The interim analysis announced by Merck was taken from the phase III MOVe-OUT trial that included 775 higher-risk non hospitalized COVID-19 patients. Here are the results of that study:
- 7.3% of those taking molnupiravir were hospitalized or died through day 29 from randomization, as compared to 14.1% of those receiving placebo (P=0.0012). This is approximately a 48.2% reduction in hospitalization or death in the molnupiravir group.
- There were no deaths in the molnupiravir group versus eight in the placebo group.
- Based on viral sequencing data from about 40% of participants, the drug appeared to be effective against the Gamma, Mu, and Delta variants of SARS-CoV-2.
- 35% of patients experience an adverse event in the molnupiravir group versus 40% in the placebo group.
- 12% of the molnupiravir group experienced drug-related adverse events versus 11% in the placebo group.
- Interestingly, more participants in the placebo group discontinued the drug (3.4%) compared to the monupiravir group (1.3%).
Merck didn’t give any details about the adverse events, so we would need to understand them more completely, but with the data that was presented, it does not appear that, at a general level, there are any differences in adverse events between the two groups. But I don’t think we should draw any conclusions until we see more detail.
Merck intends to have a total of 1550 participants enrolled as it moves to file documents with the FDA for an Emergency Use Authorization (EUA). In fact, the data monitoring committee has recommended stopping the trial, although the final decision also rests with the FDA.
Caution about this new drug
Peter Hotez, MD, Ph.D., of the Baylor College of Medicine, posted this on Twitter:
1/5 Many thanks @JohnBerman @brikeilarcnn for hosting me @NewDay on breaking news that the Merck & co drug molnupiravir looking promising as a small molecule antiviral drug for Rx of COVID19 to reduce hospitalizations and deaths. Merck applying for EUA. Exciting but some caveats
2/5 first good news that drug was developed as a ribonucleoside inhibitor @EmoryUniversity @GeorgiaStateU for influenza to interfere with virus replication, unlike ivermectin or hydroxychloroquine this one actually makes sense that it could work vs COVID19
3/5 one concern that it introduces virus mutations or potential mutagenic probably means it won’t be recommended in pregnancy. I seem to remember my good colleague @RickABright had a concern about this drug when he was at BARDA so maybe he can comment. Also important to remember
4/5 this is no substitute for vaccination. It’s not a miracle cure but a companion tool. So get vaccinated. Another issue is emerging drug resistance. If this is used indiscriminately this can be a problem with antiviral drugs
5/5 Finally there’s access. Unlike mRNA vaccines which can take years to learn how to produce at scale under a quality umbrella, like ARTs this one is far more straightforward. Likely Cipla or equivalent can make it now. I believe Merck & Co discussing tiered pricing.
6/5 But because of resistance issue I worry about making this available OTC, also counterfeits. I understand that Pfizer and Roche also developing similar antiviral drugs for COVID19. Anyway those are my first impressions on breaking news
Dr. Hotez is essentially cautioning overreaction because of indiscriminate use which can lead to drug resistance. Then we’re back to square one.
He also warned that this drug probably will not be approved for pregnant women.
And, as Dr. Hotez said, this drug is not an alternative to vaccines. Anti-virals tend to have more severe adverse events than vaccines, and it should be considered the last resort not the first tier plan to deal with COVID-19. Also, since COVID-19 vaccines are free in most countries, the eventual cost of molnupiravir will probably be higher than that. This will not be an inexpensive drug.
Molnupiravir is not a miracle. It does not cure 100% of COVID-19 cases, although there appeared to be a statistically significant reduction in hospitalization and death. But it did not reduce those outcomes to zero. Again, vaccines do a much better job in reducing hospitalization and death than this drug because it prevents the infection in the first place.
Importantly, we don’t have a good handle on the adverse events of the drug. I’m sure that the benefits of the drug will outweigh the risks, but those risks for this drug could be more serious and frequent than is observed with the various COVID-19 vaccines.
An independent committee of scientists, clinicians, and statisticians will review Merck’s submission for the drug before recommending (or rejecting) an emergency use authorization to the FDA. Merck will be required to file a complete data dump to the committee, which will be public, and we can further analyze the good and the bad about this new drug.
I am cautiously optimistic that molnupiravir will be an important tool to save lives. And there are other similar drugs coming from other companies in the next few months, so that might mean better or safer drugs than this one.
However, this is not a miracle drug. And in no way should anyone consider this a replacement for vaccination. Don’t go there.
Emergency use authorization application
On 11 October 2021, Merck filed for an Emergency Use Authorization (EUA) for molnupiravir with the US FDA. Like with the EUAs for COVID-19 vaccines, an expert committee will probably meet to review the clinical trial data, along with any safety and effectiveness issues, before sending a recommendation to the FDA Commissioner. The Commissioner may accept or reject their recommendations.
There will probably be a quick turnaround on this application, such as what was done with the COVID-19 vaccines, since molnupiravir can reduce hospitalization and death with COVID-19 patients.
As I wrote above, because the results were so clearly favorable that an independent drug monitoring committee recommend that the Phase 3 trials end early.
Furthermore, the studies showed that molnupiravir appeared effective against variants of concern, including Gamma, Delta, and Mu. This could help reduce the impact of these new variants on the pandemic landscape.
As I wrote above, this drug is not a panacea – it will not end the pandemic, it will not mean the end of vaccinations, and it will not be a miracle. But it could be an important tool in treating the disease, unlike the horse dewormer.
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