Assessing the Incidence of Transplant Associated Thrombotic Microangiopathy (TA-TMA) in Adult Patients Undergoing Allogeneic Stem Cell Transplant (SCT)

Primary Objectives

The primary objective of the study is to report the rates of high-risk TA-TMA in a cohort for high-risk patients undergoing allogeneic SCT. High-risk TA-TMA will be defined as per the ASTCT Harmonization Criteria which will include the TMA Harmonization panel consensus recommended diagnostic criteria and any of the high-risk TA-TMA features (Schoettler et al. TCT March 2023).

Co-Primary Objective

To evaluate rates of Non-Relapse Mortality (NRM) in patients with and without TA-TMA. NRM is defined as the rate of death from any cause in patients who do not exhibit any sign of relapse or progression of their underlying hematologic malignancy

Secondary Objectives

* To evaluate rates of Overall Survival (OS) in patients with and without high-risk TA-TMA * OS is defined as the time from the date of SCT until death.

Secondary Objective

-To evaluate rates of Graft Versus Host Free Relapse Free Survival (GFRS) in patients with and without high-risk TA-TMA. GRFS is defined as the time from the date of SCT until occurrence of grade III-IV aGVHD, and or cGVHD requiring systemic immune suppression, and or disease progression or death whichever comes first.

Secondary Objective

-To validate previously described risk factors and prognostic scores for the development of high-risk TA-TMA -We will compare other prognostic markers that have been described in the literature such as EASIX score, degree of proteinuria among others to evaluate their correlation with rate and severity of TA-TMA

Secondary Objective

-To evaluate kinetics of sC5b-9 in patients with and without high-risk TA-TMA -These analytes will be obtained as per study procedure and their changes will be described.

Exploratory Objectives

-To evaluate the impact of therapeutic interventions by treating physicians on biomarkers and clinical outcomes These analytes will be obtained as per study procedure and their changes will be described both in isolation and in association with prespecified variables

Exploratory Objective

-To evaluate the association between high-risk TA-TMA development and relapse. Relapse is defined as the rate of patients having their underlying hematologic malignancy relapse or progress after SCT

Exploratory Objective

To evaluate, using cohort 3, the association between CH50 levels, eculizumab through levels and high-risk TA-TMA response to eculizumab treatment. These analytes will be obtained as per study procedure and their changes will be described both in isolation and in association with other, pre-specified, variables

Exploratory Objective

-To evaluate Patient Reported Outcomes (PROs) in patients with and without high-risk TA-TMA PROs will be obtained at pre-determined times for all patients in the study, the results will be reported descriptively.