An ASTCT, CIBMTR, EBMT, and APBMT Consensus Statement Defining Response Criteria for Hematopoietic Cell Transplantation Associated Thrombotic Microangiopathy (TA-TMA) Directed Therapy

The consensus response criteria proposed by this expert panel are a step towards standardizing the assessment of treatment responses of TA-TMA directed agents for future studies and interventional clinical trials. Adoption of these criteria will enhance consistency of response assessment and facilitate the comparison of TA-TMA treatments. Since achieving an early overall CR may be challenging/protracted in patients with organ injury; establishment of criteria for clinically meaningful PR is important and may be a more useful early endpoint in studies. Given the complexity of these patients and assessment of response, these definitions may need be revised in the future after application in large cohorts diverse in age, HCT approaches, and interventional agents.