As China continues to battle the COVID-19 pandemic, it is crucial to initiate early small-molecule antiviral treatments upon diagnosis in high-risk populations. Recent findings from the EPIC-SR (Phase II/III clinical) study, published in "The New England Journal of Medicine," indicate that the effectiveness of Paxlovid (nirmatrelvir/ritonavir) in improving symptoms in standard-risk populations is not significantly different from a placebo.
Currently, Paxlovid is approved in China for the treatment of adult patients with mild to moderate COVID-19 who are at high risk of progressing to severe conditions. High-risk populations not only exhibit flu-like symptoms upon infection but also face a higher risk of developing severe COVID-19. Guidelines both in China and internationally clearly recommend that the primary treatment goal should be to reduce the risk of hospitalization and death.
To thoroughly explore the value of small-molecule antivirals in preventing and treating COVID-19, Paxlovid has conducted four Phase III registration studies targeting different groups: high-risk patients (EPIC-HR study), lower-risk severe cases (EPIC-SR study), close contacts (EPIC-PEP study), and patients under 18 at high risk (EPIC-Peds study). Currently, except for the ongoing EPIC-Peds study, the other three clinical trials have concluded.
The results from the EPIC-SR study published in "The New England Journal of Medicine" show that nearly 1,300 participants, both vaccinated and unvaccinated and primarily from lower-risk severe groups, exhibited similar durations to symptom resolution in both the Paxlovid and placebo groups. The EPIC-PEP study demonstrated that Paxlovid reduced the risk of contracting the virus by 32% and 37% after 5 and 10 days, respectively, though these results were not statistically significant.
The EPIC-HR study revealed that, compared to the placebo, the risk of hospitalization or death in high-risk groups decreased by 89% and 88% within 3 and 5 days of symptom onset, respectively, and viral load decreased tenfold. This indicates that Paxlovid significantly reduces the risk of hospitalization or death in high-risk populations.
Paxlovid is supported by robust real-world evidence from studies conducted in China, the United States, Israel, and other locations. These studies confirm that Paxlovid reduces the risk of hospitalization and death in vaccinated/unvaccinated individuals and those reinfected, including immunocompromised and elderly patients.
The outcomes of the EPIC-SR trial may relate to various factors such as the timing of treatment initiation, participant characteristics, and how symptom improvement was assessed. Moreover, these findings align with WHO guidelines, which recommend using Paxlovid primarily for high-risk groups. Even if patients are vaccinated, considering the effectiveness of vaccines against new variants and the duration of protection, those with high-risk factors should still prioritize antiviral treatment post-infection. For high-risk populations, targeting the reduction of severe cases and deaths, Paxlovid remains an essential option.
