Pfizer’s Covid Pill Might Not be as Great as They’re Saying
Merck’s Covid-19 pill (50% reduction in hospitalization with possibly mutagenic side-effects) was an obvious cash grab. Their sales team was scrambling to dump the product and sign deals before better oral treatments were announced. And they would have gotten away with it to, if it wasn’t for that meddling Pfizer. Atea/Roche’s drug flopped in trials, and Pfizer said their data would be delayed by months. This would have given Merck a tiny window to unload their drug. Just yesterday the UK approved molnupiravir, although they’re now probably regretting it.
89% vs 50% sounds like it’s a lot better, right? But here’s the thing. Merck’s trial was a lot different. Pfizer had 45% US patients. Merck only 7%. (We can expect the healthcare given to US patients in a big pharma study to be better than the healthcare given in India.) While not a deal-breaker, this next bit of data is.
Every double-blinded randomly controlled study has a control group. This control group is given a placebo (a pill that does nothing) or the standard of care. When looking for efficacy in a new drug you compare the group that got the new drug to the group that got the placebo or standard of care.
Covid-19 disproportionately affects certain groups. Like people with diabetes, hypertension, asthma, chronic lung disease, severe heart conditions, chronic kidney disease, the obese, or people with weak immune system.
The patients in the Merck study and the patients in Pfizer study were drastically different. Merck gave the drug to people who were more than twice as likely to end up in the hospital. Pfizer gave their drug to a healthier population of patients, and, spoiler alert, saw less of them be hospitalized.
Merck’s control arm was hospitalized at 14.1%
Pfizer’s control arm was hospitalized at 7%.
What this means is the real-world efficacy for the Merck drug and the Pfizer drug could be quite similar. In the real world you can’t cherry pick your patients. Covid-19 rips through everyone.
Also: Merck gave their drug to unvaccinated people, while Pfizer hasn’t said whether their participants were vaccinated or not.
All the headlines are saying “Game changer” or “The beginning of the end of the pandemic.” The reality is, there is still quite a bit of room for improvement. Pfizer’s results might have been near the same, or even worse than Merck’s had they run their trial on actual high-risk patients. If both drugs are approved, a study will be run comparing them against each other. It might even show the Merck drug to be superior.
If Pfizer’s drug trial was run with “high-risk patients” then Merck’s drug trial was run with “extreme risk” patients. Their results shouldn’t be compared as simply as 89% vs 50%. You wouldn’t compare the effectiveness of cancer drugs in patients with stage 2 against a trial run on stage 3 patients, would you?
Of course not.
Gilead still has a chance to redeem themselves here. If you ignore the ease of use (oral vs IV) for a moment and just look at the data, early use of IV remdesivir is similar to the Pfizer pill. Early use of remdesivir reduced hospitalization by 87%.
Pfizer’s 89% comes from patients who were diagnosed within three days.
Gilead’s study allowed for up to seven days. (Antivirals are more effective when given early.)
This means there is still room for improvement in the oral Covid-19 treatment space. Pfizer might have shot themselves in the foot by running a trial against a relatively healthier population. This is bad science and gives vulnerable people false hope.
If you’re at extreme risk of being hospitalized by Covid-19 then it’s unlikely that if you take the Pfizer pill your chance of ending up in the hospital is reduced by 89%. It’s probably a lot lower. Maybe as low as 40-50%. But we won’t know until the drug is out in circulation.
If the Pfizer drug is quickly approved it will set a bad precedent for therapeutics for Covid-19. It will open the floodgates to low-grade trials and outright scams. Companies might even run trials on supremely healthy people. While this won’t fool the FDA, it will lead to pump-and-dump scams.
“Hey, look at our new covid drug, we gave it to 25 Olympic athletes between the ages of 19-23. None of them ended up in the hospital. Efficacy 100%!”
If you’re an investor in a company developing an oral covid-19 treatment, the game isn’t over. Pfizer claims a slam dunk but it appears the net was lowered to seven feet.
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Disclaimer: This post does not constitute financial advice.
