In short
RADAMTS13, also known as apadamtase alfa and sold under the brand name ADZYNMA, is an enzyme replacement therapy authorised in the European Union for adults and children with congenital thrombotic thrombocytopenic purpura (cTTP), a rare blood clotting disorder caused by ADAMTS13 deficiency. It is currently being investigated in a Phase 2 trial for acute ischemic stroke, a condition where a blood clot blocks blood flow to the brain.
Key points
- RADAMTS13 is an enzyme replacement therapy authorised in the EU as ADZYNMA for congenital thrombotic thrombocytopenic purpura (cTTP).
- It is being studied in a Phase 2 trial for acute ischemic stroke, with 222 participants planned.
- The trial is currently authorised but not yet recruiting.
- The main outcome measure is the proportion of participants who develop symptomatic intracranial hemorrhage within 120 hours after treatment.
- RADAMTS13 is given as a powder and solvent for solution for injection by intravenous administration.
- The trial compares TAK-755 with ADZYNMA at different intravenous doses.
What is RADAMTS13?
RADAMTS13, also known as apadamtase alfa and sold under the brand name ADZYNMA, is an enzyme replacement therapy. It is a protein-based substance that replaces a missing or deficient enzyme in the body called ADAMTS13. The medicine is authorised in the European Union for the treatment of ADAMTS13 deficiency in adults and children with congenital thrombotic thrombocytopenic purpura (cTTP), a rare inherited blood disorder. The active ingredient in ADZYNMA is apadamtase alfa, which is the same substance as RADAMTS13.
How does RADAMTS13 work?
ADAMTS13 is an enzyme that normally breaks down very large protein complexes in the blood called von Willebrand factor. When ADAMTS13 is missing or does not work properly, these large complexes accumulate and cause platelets to clump together, forming blood clots in small blood vessels. RADAMTS13 replaces the missing enzyme, helping to prevent the abnormal blood clotting that causes the symptoms of cTTP. In acute ischemic stroke, a blood clot blocks blood flow to part of the brain, and the trial is investigating whether providing this enzyme could help in that setting.
Which conditions is RADAMTS13 used or studied for?
- Congenital thrombotic thrombocytopenic purpura (cTTP) – a rare inherited condition where the body does not produce enough working ADAMTS13 enzyme, leading to blood clots in small vessels. RADAMTS13 is authorised in the EU to treat this condition in adults and children.
- Acute ischemic stroke – a condition where a blood clot blocks blood flow to part of the brain. A Phase 2 trial is currently investigating whether RADAMTS13 is safe and tolerable for people with this condition.
How is RADAMTS13 given?
ADZYNMA is available as a powder and solvent for solution for injection, given by intravenous administration. It comes in two strengths: 500 IU and 1500 IU, each with 5 ml of solvent. The powder is supplied in a glass vial together with a vial of solvent, a reconstitution device, a syringe, an infusion set, and alcohol swabs. In the Phase 2 stroke trial, the intervention is described as a lyophilized product with the same form and functional characteristics as TAK-755, given intravenously, and ADZYNMA at different intravenous doses.
What do the clinical trials show?
One clinical trial is currently listed for RADAMTS13 in the EU Clinical Trials Information System. It is a Phase 2 interventional trial for acute ischemic stroke with a planned enrolment of 222 participants. The trial is authorised but not yet recruiting. It is divided into two parts: Part A and Part B, both designed to evaluate the safety and tolerability of TAK-755 in participants.
What is the trial measuring?
The primary outcome measure for both parts of the trial is the proportion of participants who develop symptomatic intracranial hemorrhage (sICH) within 120 hours after the trial intervention. This means bleeding inside the skull that causes symptoms, defined according to the Heidelberg Bleeding Classification system.
Who can take part in the trial?
The trial enrols participants with acute ischemic stroke. The registry record does not list detailed eligibility criteria in the data provided, but the condition under study is acute ischemic stroke, and the intervention is given intravenously.
What side effects are known?
The supplementary sources provided do not list specific side effects for RADAMTS13. The ongoing Phase 2 trial is designed to evaluate safety and tolerability, and its primary outcome measure focuses on the occurrence of symptomatic intracranial hemorrhage within 120 hours after treatment.