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
Background: Sotrovimab is a monoclonal antibody that neutralizes SARS-CoV-2 by binding to a highly conserved epitope in the receptor binding domain. It retains activity against the Omicron BA.1 variant and is used to treat immunocompromised patients as they are at increased risk for a severe outcome of COVID-19. Methods: We studied viral evolution in 47 immunocompromised patients infected with Omicron BA.1 or 2 and treated with sotrovimab. SARS-CoV-2 PCR was performed at baseline and weekly thereafter until Ct-value was [≥] 30. All RNA samples were sequenced to determine the variant and occurrence of mutations, in particular in the Spike protein, after treatment. Results: Twenty-four (51%) of the 47 patients were male and their median age was 63 years. Thirty-one (66%) had undergone a solid organ transplantation and 13 (28%) had received prior B-cell depleting therapy. Despite a history of vaccination, 24 of 30 patients with available data on anti-SARS-CoV-2 IgG Spike antibodies prior to treatment with sotrovimab had very low or no antibodies. Median time to viral clearance (Ct-value [≥] 30) after treatment was 15 days (IQR 7-22). However, viral RNA with low Ct-values was continuously detected for at least 28 days after treatment in four patients infected with BA.1. Mutations in the Spike protein at position 337 or 340 were observed in all four patients. Similar mutations were also found after treatment of two patients with a BA.2 infection but both cleared the virus within two weeks. Thus following treatment with sotrovimab, spike mutations associated with reduced in vitro susceptibility were detected in 6 of 47 (13%) patients. Conclusion: Viral evolution towards resistance against sotrovimab can explain treatment failure in most immunocompromised patients and these patients can remain infectious after treatment. Therefore, documenting viral clearance after treatment is recommended to avoid that these patients unintentionally become a source of new, sotrovimab resistant, variants. Research on direct acting antivirals and possibly combination therapy for the treatment of COVID-19 in immunocompromised patients is needed.
Subject(s)
COVID-19ABSTRACT
Background: Severely immunocompromised patients are at risk for severe COVID-19. Benefit from convalescent plasma in these patients is suggested but data from randomised trials are lacking. The aim of this study is to determine efficacy of SARS-CoV-2 hyperimmune globulin (COVIG) in treatment of severely immunocompromised, hospitalised COVID-19 patients. Methods: In this randomised, controlled, double-blind, multicentre, phase 3 trial, severely immunocompromised patients who were hospitalised with symptomatic COVID-19 were randomly assigned (1:1) to receive 15 grams of COVIG or 15 grams of intravenous immunoglobulin without SARS-CoV-2 antibodies (IVIG, control). Patients included were solid organ transplant patients with three drugs from different immunosuppressive classes or patient with disease or treatment severely affecting B-cell function. Patients that required mechanical ventilation or high flow nasal oxygen were excluded. All investigators, research staff, and participants were masked to group allocation. The primary endpoint was occurrence of severe COVID-19 evaluated up until day 28 after treatment, defined as the need for mechanical ventilation, high-flow nasal oxygen, readmission for COVID-19 after hospital discharge or lack of clinical improvement on day seven or later. This trial is registered with Netherlands Trial Register (NL9436). Findings: From April, 2021, to July, 2021, 18 participants were enrolled at three sites in the Netherlands; 18 patients were analysed. Recruitment was halted prematurely when casirivimab/imdevimab became the recommended therapy in the Dutch COVID-19 treatment guideline for seronegative, hospitalised COVID-19 patients. Median age was 58 years and all but two were negative for SARS-CoV-2 spike IgG at baseline. Severe COVID-19 was observed in two out of ten (20%) patients treated with COVIG compared to seven of eight (88%) in the IVIG control group (p = 0.015, Fisher's exact test). Interpretation: COVIG reduced the incidence of severe COVID-19 in severely immunocompromised patients, hospitalised with COVID-19. COVIG may be a valuable treatment in this patient group and can be used when no monoclonal antibody therapies are available. Funding: The Netherlands Organisation for Health Research and Development, Sanquin Blood Supply Foundation.