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Prophylactic Plasma Infusion Therapy for Congenital Thrombotic Thrombocytopenic Purpura

Phase 4
Withdrawn
Conditions
Purpura, Thrombotic Thrombocytopenic
Interventions
Drug: Octaplas infusion and placebo (group 1)
Drug: Octaplas infusion and placebo (group 2)
Registration Number
NCT01754545
Lead Sponsor
St. Olavs Hospital
Brief Summary

Congenital thrombotic thrombocytopenic purpura (TTP), also called Upshaw-Schulman Syndrome or hereditary or familial TTP is a rare, but severe disease. The purpose of this study is to determine how infusions of plasma to patients with congenital TTP correlate with symptoms and signs of activity of the disease, and to determine why some patients need more frequent infusions of plasma than others to prevent acute attacks of the disease.

Detailed Description

Patients with congenital TTP have an inherited lack of function or amount of a protein in plasma called ADAMTS13, that otherwise is responsible for cleaving large von Willebrand-molecules into smaller parts. The patients suffer recurrent attacks of clotting of small blood vessels, that can cause damage to major organs, including the central nervous system. Acute attacks can be treated successfully with infusions of human plasma, and some patients also receive regular plasma therapy for prevention of acute attacks. A small group of patients receive preventive plasma infusions twice or more weekly, indicating a much higher need for plasma than what is otherwise recommended for preventive therapy. Do these patients have an ongoing activity of their disease despite a stimulus? Or a higher turn-over of transfused ADAMTS13? Have these patients developed antibodies against transfused ADAMTS13? Are any symptoms correlated with signs of disease activity?

Recruitment & Eligibility

Status
WITHDRAWN
Sex
All
Target Recruitment
Not specified
Inclusion Criteria
  • Confirmed diagnosis of congenital TTP
  • On regular prophylactic plasma treatment: > Once weekly (group 1) or >1 <3 times monthly (group 2)
  • Between 18 and 65 years
  • Capable of understanding and complying with the protocol
Exclusion Criteria
  • Pregnancy
  • Acute bout of TTP requiring daily plasma infusions or -exchange for more than 3 days, within the last 2 weeks before intervention period

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Octaplas infusion and placebo (group 1)Octaplas infusion and placebo (group 1)Active treatment with randomly assigned 400 ml octaplas intravenously 2-3 times a week and 400 ml placebo (for octaplas)intravenously 2-3 times a week over two weeks.
Octaplas infusion and placebo (group 2)Octaplas infusion and placebo (group 2)Active treatment with randomly assigned 400 ml octaplas intravenously once and 400 ml placebo (for octaplas)intravenously twice in two separate intervention weeks
Primary Outcome Measures
NameTimeMethod
A composite score of clinical and biochemical signs of disease activity4 hours and 24 hours after intervention

Biochemical signs of disease activity are scored by measurements of lactate dehydrogenase, hemoglobin, platelet counts and ADAMTS13 activity.

Clinical signs of disease activity are measured by an evaluator's score and subjects symptom screening

Secondary Outcome Measures
NameTimeMethod
ADAMTS13 activity half-life4 hours and 24 hours after intervention

Calculation of half-life of ADAMTS13 activity based on serial measurements of ADAMTS13 activity before and after plasma infusions

ADAMTS13 allo-antibodiesAt baseline

Presence of allo-antibodies towards ADAMTS13

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