Cost-effectiveness of casirivimab/imdevimab in patients with COVID-19 in the ambulatory setting.

BACKGROUND: Most patients infected with SARS-CoV-2, resulting in COVID-19, have only mild symptoms that can be managed in an ambulatory setting. However, a significant number of patients develop a more severe form of the disease and require hospital care, with the risk of long-term sequelae or death. Casirivimab/imdevimab is a combination of 2 recombinant human monoclonal antibodies that has been shown to significantly reduce the risk of hospitalization or death in patients with mild to moderate COVID-19 in the ambulatory setting. OBJECTIVE: To establish the cost-effectiveness of casirivimab/imdevimab in ambulatory individuals with COVID-19. METHODS: A cost-effectiveness model was constructed to simulate the natural history of COVID-19 in ambulatory patients and to identify those patients for whom casirivimab/imdevimab may be a cost-effective treatment from a US payer perspective. Patients enter the model in the ambulatory health state and can receive either active treatment with casirivimab/imdevimab or usual care. Patients can either recover from the infection or be hospitalized, from where they can recover from infection or die. Following this acute phase, patients enter a Markov model to estimate lifetime quality-adjusted life years. The model uses the risk of hospitalization in both the active treatment and usual care cohorts, and age- and sex-specific risk of mortality. Other model inputs include hospitalization costs and health-related utilities in the ambulatory acute treatment phase, the hospitalized setting, and the post-acute phase. Accounting for the heterogeneity of risk by age and comorbidities, results are presented separately for various combinations of baseline age and usual care risk in a 7 × 9 matrix. Outcomes related to "long COVID" are assessed in scenario analyses. RESULTS: In the base case, at a willingness-to-pay threshold of $100,000, treatment with casirivimab/imdevimab was found to be cost-effective in most patients, including those older than 40 years of age with a baseline hospitalization risk greater than or equal to 2% and patients aged 20 years with a baseline risk of hospitalization greater than or equal to 4%, whereas for hospitalization risk greater than or equal to 10%, casirivimab/imdevimab is dominant. Casirivimab/imdevimab was not cost-effective in patients aged 20 years with a 3% or lower risk of hospitalization or in patients aged 30 years with a 2% risk. CONCLUSIONS: This economic analysis found that casirivimab/imdevimab is a cost-effective treatment for most ambulatory patients with COVID-19. DISCLOSURES: N. Jovanoski and U. Becker are employees of F Hoffman-La Roche Ltd.; A. Kuznik and M. Hussein are employees of Regeneron Pharmaceuticals Inc. and hold stock and stock options; A. Briggs has provided consultancy to F Hoffman-La Roche Ltd. and has received consultancy fees from Merck and Co., Inc., GlaxoSmithKline plc., and Novartis. This study was funded by Regeneron Pharmaceuticals, Inc.

Severity of COVID-19 and adverse long-term outcomes: a retrospective cohort study based on a US electronic health record database.

OBJECTIVE: To identify potential risk factors for adverse long-term outcomes (LTOs) associated with COVID-19, using a large electronic health record (EHR) database. DESIGN: Retrospective cohort study. Patients with COVID-19 were assigned into subcohorts according to most intensive treatment setting experienced. Newly diagnosed conditions were classified as respiratory, cardiovascular or mental health LTOs at >30-≤90 or >90-≤180 days after COVID-19 diagnosis or hospital discharge. Multivariate regression analysis was performed to identify any association of treatment setting (as a proxy for disease severity) with LTO incidence. SETTING: Optum deidentified COVID-19 EHR dataset drawn from hospitals and clinics across the USA. PARTICIPANTS: Individuals diagnosed with COVID-19 (N=57 748) from 20 February to 4 July 2020. MAIN OUTCOMES: Incidence of new clinical conditions after COVID-19 diagnosis or hospital discharge and the association of treatment setting (as a proxy for disease severity) with their risk of occurrence. RESULTS: Patients were assigned into one of six subcohorts: outpatient (n=22 788), emergency room (ER) with same-day COVID-19 diagnosis (n=11 633), ER with COVID-19 diagnosis≤21 days before ER visit (n=2877), hospitalisation without intensive care unit (ICU; n=16 653), ICU without ventilation (n=1837) and ICU with ventilation (n=1960). Respiratory LTOs were more common than cardiovascular or mental health LTOs across subcohorts and LTO incidence was higher in hospitalised versus non-hospitalised subcohorts. Patients with the most severe disease were at increased risk of respiratory (risk ratio (RR) 1.86, 95% CI 1.56 to 2.21), cardiovascular (RR 2.65, 95% CI 1.49 to 4.43) and mental health outcomes (RR 1.52, 95% CI 1.20 to 1.91) up to 6 months after hospital discharge compared with outpatients. CONCLUSIONS: Patients with severe COVID-19 had increased risk of new clinical conditions up to 6 months after hospital discharge. The extent that treatment setting (eg, ICU) contributed to these conditions is unknown, but strategies to prevent COVID-19 progression may nonetheless minimise their occurrence.