DRK-Blutspendedienst Baden-Württemberg - Hessen GmbH

* Research Question: Does convalescent plasma (CCP) collected from donors who have recovered from COVID-19 and who have a very high titre of anti-SARS-CoV-2 antibodies reduce the risk of hospitalisation (for COVID-19) or death in patients with early symptoms of acute COVID-19 who are vulnerable to this disease compared to standard of care?
* Study product: Very high antibody titre COVID-19 convalescent plasma collected more than 15 days after end of symptoms in COVID-19 patients who also had received at least one dose of a SARS-CoV-2 vaccine.
* Methodology: Multicentre, randomised, open-label, adaptive superiority trial: COVID-19 very high neutralizing Ab titre convalescent plasma vs standard care in 2 cohorts of vulnerable patients (cohort 1: elderly (≥ 70 years) and younger with comorbidities, cohort 2: immunosuppressed patients).
* Study phase: Phase 3
* Intervention: Two units of high antibody titre COVID-19 convalescent plasma to individuals randomised to the intervention group, 2 units from 2 different donors, preferably transfused on the same day. Plasma provided by convalescent vaccinated donors with a minimum antibody titre of 1:640 against delta variant (B1.617.2) or antibody concentration >=4.000 BAU/ml in the QuantiVac anti-SARS-CoV-2 IgG ELISA or >=20.000 U/ml in the Elecsys anti-SARS-CoV-2 CLIA
* Randomisation: 1:1 (standard of care + convalescent plasma vs. standard of care) stratified by centre (cohorts 1 and 2)

This is a randomized, prospective, multicenter, open label clinical trial of convalescent plasma compared to best supportive care for treatment of patients with severe COVID-19.
The aim of the study is to explore the therapeutic effect of convalescent plasma transfusions on the survival and course of disease of patients with severe COVID-19. Convalescent plasma will be collected from recovered COVID-19 patients.
Patients with severe COVID-19 will be randomly assigned to two groups. Patients in the treatment group will receive covalescent plasma (250 - 325 ml) on days 1, 3 and 5. Patients in the control group will receive best supportive care. Clinical condition in all patients will be evaluated on day 14. In case of progressive COVID-19 on day 14 compared to baseline, patients in the control group may be switched to treatment with convalescent plasma on days 15, 17 and 19.
Fifty-three patients will be included in each group. Data of each patient will be collected until discharge but nor longer than day 60.

The current phase 0 trial is preceding the phase 1/2 trial of a newly developed drug, NAITgam, for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT) - a rare, but potentially very severe bleeding condition in the fetus or newborn. FNAIT may occur in women whose blood platelets do not express HPA-1a. If the fetus has inherited HPA-1a from the father, the mother's immune system may be stimulated to produce HPA-1a antibodies if HPA-1a positive fetal blood platelets enter the maternal circulation during delivery. In a subsequent pregnancy, such antibodies will cross the placenta and may reduce the number of HPA-1a positive blood platelets in the fetus, which in turn may result in severe bleeding in the fetus or newborn.
The phase 1/2 study of NAITgam will examine NAITgam's ability to eliminate HPA-1a positive blood platelets that has been transfused to healthy male subjects, whose blood platelet do not express HPA-1a. The ability to quickly eliminate transfused HPA-1a positive platelets is considered as a surrogate endpoint for NAITgam's ability to prevent formation of antibodies against HPA-1a after delivery of an HPA-1a positive child.
The current phase 0 trial will examine the survival of blood platelets transfused to healthy male individuals without subsequent administration of NAITgam. The natural survival of transfused platelet, as determined in the phase 0 trial, will be compared with the survival of transfused HPA-1a positive platelets after administration of NAITgam in the phase 1/2 trial. The aim of the phase 0 trial is first, to determine the dose of blood platelet that should be transfused to the healthy subjects in the phase 1/2 trial; and secondly, to determine the optimal time point, after transfusion of platelets, for administration of NAITgam in the phase 1/2 trial.
Eight to 24 healthy male subjects will be included in the phase 0 trial. After transfusion of platelets, blood samples will be collected at regular intervals to determine the proportion of transfused blood platelets. Differences between tissue type antigens between donor and recipient will be used to determine the proportion of transfused platelets. Survival of transfused platelets will be performed by flow cytometry - a method that can be used to quantify very small proportions of cells in the blood. Fluorochrome-conjugated monoclonal antibodies against HLA-A2 and HLA-A9 will be used for flow cytometric identification the transfused platelets.