ABSTRACT
Background: During the COVID-19 pandemic, trials on convalescent plasma (ConvP) were performed without preceding dose-finding studies. This study aimed to assess potential protective dosing regimens by constructing a population pharmacokinetic (popPK) model describing neutralizing antibody (Nab) titers following the administration of ConvP or hyperimmune globulins(COVIg). Methods: Immunocompromised patients, testing negative for anti-SARS-CoV-2 spike antibodies despite vaccination received a range of anti-SARS-CoV-2 antibodies in the form of COVIg or ConvP infusion. The popPK analysis was performed using NONMEM v7.4. Monte Carlo simulations were performed to assess potential COVIg and ConvP dosing regimens for prevention of COVID-19. Results: 44 patients were enrolled, and data from 42 were used for constructing the popPK model. A two-compartment elimination model with mixed residual error best described the Nab-titers after administration. Inter individual variation was associated to CL (44.3%), V1 (27.3%), and V2 (29.2%). Lean body weight and type of treatment (ConvP/COVIg) were associated with V1 and V2, respectively. Median elimination half-life was 20 days (interquartile-range: 17-25 days). Simulations demonstrated that even monthly infusions of 600ml of the ConvP or COVIg used in this trial would not achieve potentially protective serum antibody levels for >90% of the time. However, as a result of hybrid immunity and/or repeated vaccination plasma donors with extremely high Nab-titers are now readily available, and a >90% target attainment should be possible. Conclusion: The results of this study may inform future intervention studies on the prophylactic and therapeutic use of antiviral antibodies in the form of ConvP or COVIg.
Subject(s)
COVID-19ABSTRACT
Objective: Chloroquine has been frequently administered for treatment of coronavirus disease 2019 but there are serious concerns about its efficacy and cardiac safety. Our objective was to investigate the pharmacokinetics and safety of chloroquine in hospitalized COVID-19 patients. Design: A prospective observational study. Setting: Dutch hospitals Patients: Patients admitted to the hospital for treatment of COVID-19. Interventions: Pharmacokinetic sampling Measurements: The plasma concentrations of chloroquine and desethylchloroquine and QTc time. Main Results: A total of 83 patients were included. The median (IQR) plasma concentration chloroquine during treatment was 1.05 mol/L (0.63 - 1.55 mol/L). None of the patients reached exposure exceeding the concentration to inhibit SARS-CoV-2 replication by 90% (IC90) of 6.9 M. Furthermore, {Delta}QTc >60 milliseconds occurred after initiation of chloroquine treatment in 34% patients and during treatment QTc [≥]500 milliseconds was observed in 46% of patients. Conclusions: Recommended dose chloroquine treatment results in plasma concentrations that are unlikely to inhibit viral replication. Furthermore, the incidence of QTc prolongation was high. The preclinical promise of chloroquine as antiviral treatment in patients with COVID-19 is overshadowed by its cardiac toxicity and lack of effective exposure. It is unlikely that a positive clinical effect will be found with chloroquine for treatment of COVID-19.