On Tuesday, Pfizer announced additional results from a Phase 2/3 study of it’s COVID-19 treatment, Paxlovid. And those results are good.
For high-risk adults—either older adults or those with secondary conditions such as obesity or high blood pressure—Paxlovid cut rates of hospitalization or death by 88% if administered within five days of the beginning of symptoms. A smaller trial of low-risk adults—who have a lesser chance of going to the hospital in the first place—showed the treatment still reduced hospitalizations by 70%. The treatment is a mix of two antiviral drugs which can be offered to patients and which can be administered at home, as a pill, rather than requiring injection or an IV by medical personnel.
Perhaps best of all, Pfizer expects these results to be much the same against the fast-spreading omicron variant. That’s because the antibodies created either by past infection or vaccines tend to focus on the spike protein by which the virus is attached to receptor sites on human cells, but that’s not how Paxlovid works. This is a protease inhibitor, which directly attacks the ability of viruses to replicate inside the cell. Changes to the spike protein should not affect that process. According to Pfizer, nirmatrelvir (one of the two ingredients in Paxlovid) has shown consistent antiviral activity against alpha, beta, delta, gamma, lambda, and mu variants. They don’t expect that to change with omicron.
Should Paxlovid become widely available, it could be a game changer for how people deal with COVID-19, particularly for those who are fully vaccinated. Hospitalization rates are currently 17 times lower for fully vaccinated adults. Pair that with the ability to treat almost 90% of cases when symptoms appear, and the basis for seeing an end, but too-high death rates and an overstrained health care system, could be in sight.
Pfizer sought Emergency Use Authorization for Paxlovid in November and expects the FDA to make the drug available soon. It has also licensed the drug to the international public health group Medicines Patent Pool, which will make it available as a low-cost generic in 95 countries.
Shortly before Pfizer announced the first results on its pill-based treatment for COVID-19, Merck introduced a pill called molnupiravir, also an antiviral, whose early results suggested that it could cut hospitalization by 50%. An FDA advisory panel gave molnupiravir a tentative approval for Emergency Use Authorization in November in a tight 13-10 vote based on that early data. However, the full trial data cut the efficiency of molnupiravir to just a 30% reduction in hospitalization rates. Molnupiravir works in a similar, though slightly different, route from either of the drugs in Paxlovid. Rather than directly inhibiting replication, it induces large errors in the transcription of RNA, resulting in “bad copies” of the original virus.
Costs below are for a projected “course of treatment,” which can range from one or more IV sessions to several days of pills. In some cases, such as with Paxlovid, the federal government has already agreed to cover the cost of the drug in the short term and has pre-purchased millions of doses.
Treatment Form Class At Home Use Efficacy Cost
Paxlovid*
Molnupiravir**
Monoclonal Antibodies***
Remdesivir****
*The U.S. government has already purchased 10 million doses of Paxlovid, however, it will not be available until the FDA provides an Emergency Use Authorization, which is likely in the next few weeks.
** The U.S. government has already negotiated the price and availability of molnupiravir. However, Merck has indicated that the price could drop, should the company obtain the approvals and patents it is seeking.
*** There are at least two different monoclonal antibody treatments currently available. A recent study of one of these, sotrovimab, developed by GlaxoSmithKline and Vir Biotechnology, tested whether it could be provided as a single intramuscular injection, rather than an IV drip. However, the study indicated a significant decline in efficacy, making it unclear if this method will be made widely available. Some states, such as Texas and Florida, have set up clinics to provide antibodies to COVID-19 patients. However, there is limited availability of the treatment. Early tests on both monoclonal antibodies from Eli Lily and Regeneron indicate that they are likely to be significantly less effective against omicron.
****Remdesivir was the first treatment for COVID-19 to become widely available and is still in frequent use. While trials suggest it does not reduce the rate of hospitalization or death in the first two weeks, it does significantly improve rates of recovery after 14 days. So it may be effective both at helping patients get home from hospitalization with fewer symptoms as well as possibly reducing the rates of “long COVID.” The price varies from $2,300 to $3,120 depending on insurance.
For high-risk adults—either older adults or those with secondary conditions such as obesity or high blood pressure—Paxlovid cut rates of hospitalization or death by 88% if administered within five days of the beginning of symptoms. A smaller trial of low-risk adults—who have a lesser chance of going to the hospital in the first place—showed the treatment still reduced hospitalizations by 70%. The treatment is a mix of two antiviral drugs which can be offered to patients and which can be administered at home, as a pill, rather than requiring injection or an IV by medical personnel.
Perhaps best of all, Pfizer expects these results to be much the same against the fast-spreading omicron variant. That’s because the antibodies created either by past infection or vaccines tend to focus on the spike protein by which the virus is attached to receptor sites on human cells, but that’s not how Paxlovid works. This is a protease inhibitor, which directly attacks the ability of viruses to replicate inside the cell. Changes to the spike protein should not affect that process. According to Pfizer, nirmatrelvir (one of the two ingredients in Paxlovid) has shown consistent antiviral activity against alpha, beta, delta, gamma, lambda, and mu variants. They don’t expect that to change with omicron.
Should Paxlovid become widely available, it could be a game changer for how people deal with COVID-19, particularly for those who are fully vaccinated. Hospitalization rates are currently 17 times lower for fully vaccinated adults. Pair that with the ability to treat almost 90% of cases when symptoms appear, and the basis for seeing an end, but too-high death rates and an overstrained health care system, could be in sight.
Pfizer sought Emergency Use Authorization for Paxlovid in November and expects the FDA to make the drug available soon. It has also licensed the drug to the international public health group Medicines Patent Pool, which will make it available as a low-cost generic in 95 countries.
Shortly before Pfizer announced the first results on its pill-based treatment for COVID-19, Merck introduced a pill called molnupiravir, also an antiviral, whose early results suggested that it could cut hospitalization by 50%. An FDA advisory panel gave molnupiravir a tentative approval for Emergency Use Authorization in November in a tight 13-10 vote based on that early data. However, the full trial data cut the efficiency of molnupiravir to just a 30% reduction in hospitalization rates. Molnupiravir works in a similar, though slightly different, route from either of the drugs in Paxlovid. Rather than directly inhibiting replication, it induces large errors in the transcription of RNA, resulting in “bad copies” of the original virus.
Costs below are for a projected “course of treatment,” which can range from one or more IV sessions to several days of pills. In some cases, such as with Paxlovid, the federal government has already agreed to cover the cost of the drug in the short term and has pre-purchased millions of doses.
| Pill | Antiviral | Yes | 70-89% | $530 |
| Pill | Antiviral | Yes | 30% | $700 |
| IV | COVID-19 Specific Antibodies | No | 65-85% | $1,800 |
| IV | No | 0% | $3,000 |
Treatment Form Class At Home Use Efficacy Cost
Paxlovid*
Molnupiravir**
Monoclonal Antibodies***
Remdesivir****
*The U.S. government has already purchased 10 million doses of Paxlovid, however, it will not be available until the FDA provides an Emergency Use Authorization, which is likely in the next few weeks.
** The U.S. government has already negotiated the price and availability of molnupiravir. However, Merck has indicated that the price could drop, should the company obtain the approvals and patents it is seeking.
*** There are at least two different monoclonal antibody treatments currently available. A recent study of one of these, sotrovimab, developed by GlaxoSmithKline and Vir Biotechnology, tested whether it could be provided as a single intramuscular injection, rather than an IV drip. However, the study indicated a significant decline in efficacy, making it unclear if this method will be made widely available. Some states, such as Texas and Florida, have set up clinics to provide antibodies to COVID-19 patients. However, there is limited availability of the treatment. Early tests on both monoclonal antibodies from Eli Lily and Regeneron indicate that they are likely to be significantly less effective against omicron.
****Remdesivir was the first treatment for COVID-19 to become widely available and is still in frequent use. While trials suggest it does not reduce the rate of hospitalization or death in the first two weeks, it does significantly improve rates of recovery after 14 days. So it may be effective both at helping patients get home from hospitalization with fewer symptoms as well as possibly reducing the rates of “long COVID.” The price varies from $2,300 to $3,120 depending on insurance.