On August 24, the “New England Journal of Medicine” published a real-world data of Pfizer’s new crown oral drug Paxlovid (nirmatrelvir + ritonavir) against Omicron variant B.1.1.529. The results showed that Paxlovid significantly reduced the risk of hospitalization and death in patients 65 years of age and older, but no evidence of benefit was found in those 40-64 years old.
The trial is based primarily on data from the electronic medical records of members of Clalit Health Services (CHS). CHS is Israel’s largest organization of medical services, covering approximately 52% of the total population and almost two-thirds of the elderly. The start date of the study is January 9, 2022, and the end date is March 31, 2022.
Of the 109,254 high-risk COVID-19 patients included in the analysis, 3,902 (4%) received nirmatrelvir at least once during the study period, including 1,418 patients aged 40-64 years and 2,484 patients aged 65 years.
The results showed that compared with patients of the same age group who did not receive Paxlovid, the risk of death was significantly lower in patients 65 years and older who received the treatment. Specifically, the number of hospitalizations per 100,000 patients was 14.7 per 100,000 patients treated with Paxlovid, compared with 58.9 per 100,000 patients who did not receive the drug, with an adjusted hazard ratio of 0.27 (95% CI, 0.15-0.49) .
However, among young adults aged 40-64, the risk of hospitalization and death did not differ significantly with or without Paxlovid. The number of hospitalizations in patients receiving Paxlovid was 15.2 per 100,000 people compared with 15.8 per 100,000 in patients not receiving the drug, with an adjusted hazard ratio of 0.74 (95% CI, 0.35-1.58).
In addition, among patients 65 years and older, 2 of 2,484 treated patients died of COVID-19 and 158 of 40,337 untreated patients died of COVID-19, an adjusted hazard ratio of 0.21 (95% Cl, 0.05-0.82). Among patients aged 40-64, 1 in 1,418 treated patients died of Covid-19 and 16 of 65,015 untreated patients died of Covid-19, with an adjusted hazard ratio of 1.32 (95% Cl, 0.16-10.75).
From this, the researchers concluded that there is no evidence that Paxlovid is beneficial in people aged 40-64.
It is worth noting that the study was not conducted on the currently prevalent Omicron variants, and only compiled data from the Israeli health service organization.