NCT03561909

Kinetics of Blood Platelets Transfused to Healthy Subjects

Completed NA Last updated 10 May 2019

What this trial tests

NA trial testing Platelet transfusion in Fetal and Neonatal Alloimmune Thrombocytopenia in 25 participants. Completed in 10 December 2018.

Timeline

17 April 2018

Primary endpoint
10 December 2018

10 December 2018

Quick facts

Lead sponsor	Prophylix Pharma AS
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	na
Design	single group
Masking	none
Primary purpose	other
Enrollment	25
Start date	17 April 2018
Primary completion	10 December 2018
Estimated completion	10 December 2018
Sites	1 location across Germany

Drugs / interventions tested

• Platelet transfusion — full drug profile →

Conditions studied

• Fetal and Neonatal Alloimmune Thrombocytopenia — all drugs for Fetal and Neonatal Alloimmune Thrombocytopenia →

Sponsor

Prophylix Pharma AS

Who can join

Adults 18 to 50, male only, with Fetal and Neonatal Alloimmune Thrombocytopenia. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

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.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.