A Study of TAK-755 in Participants With Congenital Thrombotic Thrombocytopenic Purpura
Trial Parameters
Brief Summary
Thrombotic thrombocytopenic purpura (or TTP for short) is a condition where blood clots form in small blood vessels throughout the body. The clots can limit or block the flow of oxygen-rich blood to the body's organs, such as the brain, kidneys, and heart. As a result, serious health problems can develop. The increased clotting that occurs in TTP uses up the cells that help the blood to clot, called platelets. With fewer platelets available in the blood, bleeding problems can also occur. People who have TTP may bleed underneath the skin forming purple bruises, or purpura. TTP also can cause anemia, a condition in which red blood cells break apart faster than the body can replace them, leading to fewer red blood cells than in normal. TTP is caused by a lack of activity in the ADAMTS13 enzyme, a protein in the blood involved in controlling clotting of the blood. The ADAMTS13 enzyme breaks up another blood protein called von Willebrand factor that forms blood clots by clumping together with platelets. Some people are born with this condition, while others develop the condition during their life. Many people who are born with TTP experience frequent flare-ups that need to be treated right away. TAK-755 is a medicine that replaces ADAMTS13 and may prevent or control TTP flare-ups, called acute TTP events. The main aim of the study is to check for side effects of long-term treatment with TAK-755. Treatment will be given in 2 ways: 1. TAK-755 treatment given either every week or every other week to prevent acute TTP events from happening (the "prophylactic" cohort). 2. TAK-755 treatment given to control an acute TTP event when it happens (the "on-demand" cohort). Participants in the prophylactic cohort will receive treatment in the clinic or at home for up to approximately 3 years. They will visit the clinic at least every 12 weeks. Participants in the on-demand cohort will receive daily treatment for the acute TTP event until the flare-up has gotten better. They will have a follow-up visit at the clinic 4 weeks later.
Eligibility Criteria
Inclusion Criteria: Participants who have completed TAK-755 Phase 3 pivotal Study 281102 (NCT03393975) in the prophylactic cohort and who meet all of the following criteria are eligible for this study: * Participants or legally authorized representative has provided signed informed consent \>=18 years of age and/or assent form \<18 years of age. * Participant 0 to 70 years of age at the time of screening of the 281102 (NCT03393975) study. * Participant has been diagnosed with severe congenital ADAMTS-13 deficiency. * Participant does not display any severe thrombotic thrombocytopenic purpura (TTP) signs (platelet count \<100,000/ microliter (mcL) and elevation of lactate dehydrogenase (LDH) greater than (\>) 2 × ULN at screening (prophylactic cohort only). * Participants \>=16 years of age must have a Karnofsky score \>= 70% and participants \<16 years of age must have a Lansky score \>=80%. * If female of childbearing potential, participant presents with a negative serum or urine preg