OMS721-HCT-002 narsoplimab (high-risk HSCT-TMA)

Recruiting

Who can enter

• Children with high-risk hematopoietic stem cell transplant associated thrombotic microangiopathy (HSCT-TMA)

• Age: 28 days to 18 years old
  

Goal

The goal of this study is to look at how safe the new study drug narsoplimab is for the treatment of children with hematopoietic stem cell transplant associated thrombotic microangiopathy (HSCT-TMA). We will also look at how well it works.

Background

This study will use an investigational study drug called narsoplimab in children with a condition called thrombotic microangiopathy (TMA). TMA is a rare blood-related condition that results in abnormal blood clots (clumps that occur when blood hardens from a liquid to a solid) in small blood vessels of the body.

There are several types of TMA. The type that will be part of this study is hematopoietic stem cell transplant associated TMA (HSCT-TMA). This is a form of TMA that sometimes occurs in patients who have received an allogeneic hematopoietic stem cell transplant. This type of transplant is a procedure in which a person receives stem cells (cells from which all blood cells develop) from a genetically similar, but not identical, donor.

HSCT-TMA is a serious multisystem disease (various organs may be affected) influencing post-transplant outcomes. Mortality can be 90% or higher in severe high-risk cases. No treatment is approved for HSCT-TMA, and this condition represents a serious unmet medical need. Modification of the increased activity of the immune system is generally performed, and patients may improve with this conservative treatment alone.

The purpose of this study is to test the safety and describe the effect of narsoplimab, an ‘investigational drug’, in patients with this type of disease. ‘Investigational drug’ means that the drug has not been approved by the US Food and Drug Administration (FDA).

In order to participate in a study please refer to your/your child’s doctor.
For international patients: please feel welcome to contact our International Patients Office.

Last reviewed

March 23, 2026

The above information is intended as a brief summary only and may not reflect the most up-to-date information. For full details and the current status of a protocol, physicians can contact the Princess Máxima Center directly.