News Report · Hematology

FDA Approves Yartemlea for TA-TMA: First Treatment for Stem Cell Transplant Complication

June 10, 2026

Clinical Perspective

Yartemlea provides a targeted treatment option for TA-TMA, addressing a critical need in the management of this serious complication following hematopoietic stem cell transplantation.

Dr. Shruti Pandey · Hematology

The FDA approved Yartemlea (narsoplimab-wuug) for treating hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) on December 23, 2025, based on the TA-TMA Study showing a 61% response rate in patients receiving the treatment ^[1].

Clinical Context

Hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication that can occur after a stem cell transplant, characterized by the formation of small blood clots in blood vessels, leading to potential organ damage, particularly affecting the kidneys, cardiovascular system, and gastrointestinal tract. Current treatment options are limited, primarily focusing on supportive care and managing symptoms rather than addressing the underlying condition. The gap in effective treatment options highlights the need for a targeted therapy for TA-TMA. The approval of Yartemlea represents a significant advancement in the management of this life-threatening condition, providing a specific therapeutic option for affected patients.

Key Findings

The TA-TMA Study showed Yartemlea reduced TMA response by 61% versus historical controls (HR not applicable) ^[1].
The trial enrolled 28 patients with TA-TMA, including both adults and pediatric patients ^[1].
Event rates: 61% of patients achieved TMA response with Yartemlea ^[1].
The primary endpoint was defined as improvement in laboratory TMA markers (lactate dehydrogenase and platelet counts) and either organ function improvement or no need for transfusions ^[1].
In an expanded access program, TMA response was achieved in 67% of pediatric patients and 69% of adult patients ^[1].
Yartemlea is administered at a dose of 4 mg/kg or 370 mg intravenously once weekly ^[1].
Clinicians should consult current prescribing information for full dosing guidance.

Safety & Tolerability

Viral infections reported with Yartemlea — exact frequency not available in public source summary ^[1].
Sepsis reported — exact frequency not available in public source summary ^[1].
Hemorrhage reported ^[1].
Diarrhea reported ^[1].
Nausea reported ^[1].
Embryo-fetal toxicity — advise patients of reproductive potential to use effective contraception ^[1].
Discontinuation rates due to adverse events not available in public source summary.
Complete adverse event profile available in the full prescribing information for Yartemlea (narsoplimab-wuug) ^[1].

What This Means for Clinical Practice

Yartemlea is indicated for patients aged 2 years and older with TA-TMA following hematopoietic stem cell transplantation. The data supports a 61% response rate in the TA-TMA Study, indicating its potential efficacy in this challenging patient population. What additional long-term outcomes can be expected with Yartemlea treatment in diverse patient populations?

Study Design

The TA-TMA Study was a single-arm, open-label trial involving 28 patients diagnosed with TA-TMA. The primary endpoint was the TMA response, assessed based on improvements in laboratory markers and organ function over a specified follow-up duration. The study was funded by the manufacturer, and key limitations include the small sample size and lack of a control group for comparison. Further data regarding long-term efficacy and safety in broader populations is still pending.

FAQ

What is Yartemlea approved for?

Yartemlea (narsoplimab-wuug) is approved for treating hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) in adults and children aged 2 years and older as of December 23, 2025.

How does Yartemlea work?

Yartemlea is a monoclonal antibody that targets and inhibits the complement system, which is involved in the pathogenesis of thrombotic microangiopathy, thereby helping to reduce the formation of blood clots in small blood vessels.

What is the recommended dose of Yartemlea?

Yartemlea is administered at a dose of 4 mg/kg or 370 mg intravenously once weekly. Clinicians should consult current prescribing information for full dosing guidance. Full dosing guidance is available in the prescribing information for Yartemlea (narsoplimab-wuug).

What are the most common side effects of Yartemlea?

Common side effects associated with Yartemlea include viral infections, sepsis, hemorrhage, diarrhea, nausea, and fatigue. Patients should be monitored for signs of serious infections.

FDA Approves Yartemlea for TA-TMA: First Treatment for Stem Cell Transplant Complication

FDA Approves Yartemlea for TA-TMA: First Treatment for Stem Cell Transplant Complication

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

What This Means for Clinical Practice

Study Design

FAQ

References

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