In a recent study published in the medRxiv * prepress server, researchers investigated the effectiveness of nirmatrelvir plus ritonavir in preventing hospitalizations among people 50 years of age and older and vaccinated against coronavirus disease 2019 (COVID-19).
Study: Nirmatrelvir plus ritonavir for early COVID-19 and hospitalization in a large U.S. health system. Image credit: Cryptographer / Shutterstock
Fund
The combination of the nirmatrelvir protease inhibitor of severe acute acute respiratory syndrome of coronavirus 2 (SARS-CoV-2) and its pharmacokinetic booster ritonavir received emergency use (US) in the United States (USA) in December 2021 to reduce the risk of progression to severe COVID-19. The World Health Organization (WHO) also recommended nirmatrelvir plus ritonavir in April 2022 for people at risk of more than 10% hospitalization, but postponed its use for those vaccinated by COVID. -19 and with a lower risk.
In the midst of the continuing development of SARS-CoV-2 lineages with immune evasion properties, such as Omicron, a better understanding of the clinical efficacy of nirmatrelvir plus ritonavir is needed among Omicron-infected vaccinees to report public health.
About the study
In the present study, researchers used Mass General Brigham (MGB) integrated health care data to identify COVID-19 infections recorded between January 1 and May 15, 2022, subsequent hospitalizations until May 29, 2022 and deaths until June 12, 2022.
SARS-CoV-2 infection, treatment with nirmatrelvir plus ritonavir, and hospitalization among study patients. Infections and start of treatment included from January 1 to May 15, 2022. Hospitalizations included until May 29, 2022.
The MGB, a non-profit organization, has been providing excellent COVID-19 care to 1.5 million people annually in Massachusetts and New Hampshire in the United States through its academic and community hospitals and a network of outpatient clinics. and community health centers. The MGB uses a shared electronic health record (EHR) and electronically prescribes nirmatrelvir plus ritonavir to those most at risk and to all patients eligible for the US.
The study cohort included people 50 years of age or older with newly emerging COVID-19 between January 1 and May 15, 2022 and residing in Massachusetts or New Hampshire. The team obtained the medical condition of each participant, the date of the positive test for SARS-CoV-2, the status of vaccination and treatment against COVID-19, the drugs used in the diagnosis, height, weight, race and ethnicity and home postcode of their EHR.
The researchers used recorded medical conditions and age to calculate the monoclonal antibody (MASS) screening score. They also calculated a comorbidity index for each patient that indicated a risk of hospitalization for COVID-19. The main outcome of the study was to determine the effectiveness of nirmatrelvir plus ritonavir in reducing the risk of hospitalization within 14 days of an outpatient diagnosis of COVID-19 among all study participants aged 50 years or older. . In addition, the researchers compared patients who prescribed the drug with patients who were not prescribed nirmatrelvir plus ritonavir to estimate the effectiveness of the treatment. In addition, they reviewed deaths that occurred within 28 days of the diagnosis of COVID-19.
Study results
Between January 1 and May 15, 2022, 31,460 patients with MGB aged 50 years or older were diagnosed with COVID-19. Of these, 1,138 were only included in the development of trial weights, while the remaining 30,322 outpatients were eligible for treatment with nirmatrelvir plus ritonavir. Notably, nirmatrelvir plus ritonavir was prescribed to 6,036 vaccinated patients, older and with higher comorbidity scores. In fact, between January and February 2022, access to nirmatrelvir plus ritonavir was very limited. Later, a spring wave between April and May 2022 increased the willingness of suppliers to prescribe nirmatrelvir plus ritonavir.
Subgroup analysis of the hospitalization risk ratio comparing patients with nirmatrelvir prescribed and over-prescribed ritonavir. Estimation and confidence interval calculated from a weighted inverse probability model performed in strata. Value p of modification of the effect calculated from nested models.
Patients who resided in socioeconomically vulnerable zip codes and belonged to Hispanic or Latino ethnic groups were less likely to receive nirmatrelvir than ritonavir compared to whites in high-income localities. The authors found that only 40 (0.66%) patients who prescribed nirmatrelvir plus ritonavir were hospitalized within 14 days of COVID-19 infection. None of the hospitalizations between nirmatrelvir and ritonavir receptors were attributed to rebound syndrome.
The reduction in risk due to nirmatrelvir / ritonavir was similar in age, comorbidities, and socioeconomic vulnerability; however, it increased the protective activity among obese patients with a body mass index of approximately 30 kg / m2 or higher. In addition, nirmatrelvir plus ritonavir appeared to be more effective among incompletely vaccinated individuals. The authors noted that 39 deaths in the 28 days following the diagnosis of COVID-19 occurred among patients without a prescription for nirmatrelvir plus ritonavir. A staggering 74% of deaths occurred in vaccinated patients.
Conclusions
Amid an intense Omicron outbreak and a high prevalence of vaccines between the ages of 50 and over, the current study tested the effectiveness of nirmatrelvir plus ritonavir in preventing COVID-19-related hospitalization and death. The hospitalization rate was less than 1% (low) among patients diagnosed with COVID-19 as outpatients. The use of nirmatrelvir plus ritonavir further reduced the risk of hospitalization by 45%.
In contrast to the EPIC-HR study, 35% of the hospitalizations in the nirmatrelvir plus ritonavir arm of the present study occurred within two days after the prescription. Note that the EPIC-HR trial only included unvaccinated individuals with a mean age of less than 50 years and had a 7% hospitalization rate on the placebo arm compared to the current study.
Overall, nirmatrelvir plus ritonavir consistently protected hospitalization and death despite variable hospitalization rates between groups. Therefore, the authors emphasized the ongoing evaluation of the clinical efficacy of nirmatrelvir plus ritonavir with other therapeutic options as future SARS-CoV-2 variants continue to emerge.
* Important news
medRxiv publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guided by clinical practice or health-related behavior, or treated as established information.
Magazine reference:
- Nirmatrelvir plus ritonavir for early COVID-19 and hospitalization in a large U.S. health system, Scott Dryden-Peterson, Andy Kim, Arthur Y Kim, Ellen C Caniglia, Inga Lennes, Rajesh Patel, Lindsay Gainer, Lisa Dutton, Elizabeth Donahue , Rajesh T Gandhi, Lindsey R Baden, Ann E Woolley, medRxiv prepress 2022, DOI: