Pfizer COVID Pill Stops Hospitalization, Not Milder Symptoms

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Data from a new study showed that Pfizer Inc.’s experimental COVID-19 pill was highly effective at keeping patients out of the hospital, but less adept at erasing the milder symptoms often associated with breakthrough infections.

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Pfizer disclosed the findings of two studies in a statement Tuesday. In one, their treatment, Paxlovid, failed to achieve the primary goal of reducing self-reported symptoms in 673 adults at standard risk of developing complications from COVID-19. However, the drug showed a tendency to reduce hospitalizations in the group by 70%.

In the other study, the treatment remained 89% effective in preventing hospitalizations in high-risk unvaccinated people when used within 3 days of symptoms onset. That confirmed Pfizer’s earlier analysis of results from fewer patients.

The complicated results suggest that the pill is likely to become a standard treatment for COVID patients at risk of developing serious illness. But the mixed reading in healthier patients shows that more studies are likely needed before it becomes an option for vaccinated people who develop frustrating but not life-threatening infections.

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The high-risk finding “underscores the potential of the treatment candidate to save the lives of patients around the world,” Pfizer CEO Albert Bourla said in the statement. “If authorized or approved, this potential treatment could be a critical tool to help quell the pandemic.”

The stock rose 0.3% at 9:44 am in New York. Another study by South African researchers found that a cycle of two injections of the COVID vaccine from Pfizer and BioNTech SE prevented 70% of hospitalizations and one-third of infections caused by the omicron variant. The findings from Discovery Ltd., South Africa’s largest health insurer, were based on some 78,000 Covid test results.

Omicron Shield

Pfizer said laboratory tests indicate that Paxlovid will also maintain its activity against omicron, as expected. The drug targets an internal protein, called a protease, which is not believed to mutate much between variants. Rather, the vaccines target the so-called spike protein, which is heavily mutated in omicron and could change further in future variants.

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The data in high-risk unvaccinated people seem clear. If confirmed by regulators, the results could pave the way for an emergency authorization and widespread use in these patients as soon as Pfizer can produce it in large quantities.

In an interview, Pfizer Senior Vice President Annaliesa Anderson said the company began submitting the data necessary to obtain a US emergency clearance in high-risk patients “a while ago” and that it would provide the new data. updated to US regulators shortly.

What Bloomberg Intelligence says:

Pfizer’s updated final data for its COVID-19 antiviral, Paxlovid, is even better than its provisional reading and has been submitted to the FDA, increasing the likelihood that it will become the pill of choice and potentially question the use of the molnupiravir from Merck.

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– Bloomberg Intelligence analyst Sam Fazeli.

The other stretch of data from the study suggests a more complicated way to use the drugs in patients at lower risk of complications from the virus.

The standard risk trial included vaccinated patients who had at least one risk factor for severe disease and low-risk unvaccinated people. Pfizer did not release additional details on the primary endpoint for self-reported symptoms. He said in his statement that an independent data monitoring committee had recommended that the trial continue.

Adverse events were similar between the drug and placebo groups in both trials, Pfizer said, suggesting that there are no major side effect problems so far.

Important goal

In the standard-risk trial, the apparent decrease in hospitalizations was not statistically significant because of the small number of patients involved, said Anderson, who heads Pfizer’s hospital unit, which includes antiviral research.

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Anderson said the company had focused on symptom reduction as the main goal of the standard risk study, not hospitalization, as it had calculated that a reduction in hospitalizations would be difficult to achieve in lower-risk people.

“We are working on what our way forward will be in this patient population,” Anderson said, adding that the company should have full results from the standard-risk trial “soon.”

From a public health perspective, a drug that can reduce deaths among the unvaccinated and reduce pressure on the health care system is critical.

But in the long term, it is also important to show that the drug can also help those vaccinated. Over time, unvaccinated adults are becoming a smaller and smaller minority. And if the immune-evading omicron variant replaces delta, or at least becomes a major player in the future, less severe COVID cases among vaccinated people may become even more common.

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