FDA

FDA OKs first treatment for HSCT-associated thrombotic microangiopathy

January 20, 2026

Brand name: Yartemlea

Generic name: narsoplimab-wuug

Manufacturer: Omeros Corporation

Approval date: January 13, 2026

FDA has approved Yartemlea (narsoplimab-wuug) injection to treat adults and children ≥2 years of age with hematopoietic stem cell transplant (HSCT)-associated thrombotic microangiopathy (TA-TMA).

Efficacy

Approval was based on data from a single-arm, open-label TA-TMA study (NCT02222545) involving 28 patients, with additional data from 19 patients (6 pediatric patients and 13 adult patients) enrolled in an expanded access program. In the TA-TMA Study, patients either received Yartemlea 4 mg/kg or 370 mg IV once weekly.

The primary efficacy assessment was the TMA response, defined as improvement in both laboratory TMA markers (LDH and platelet counts) and either organ function improvement or no need for transfusions. The TA-TMA response was achieved in 61% of patients. In the expanded access program, TA-TMA response was achieved in 67% of pediatric patients and 69% of adult patients.

Safety

The most common adverse effects in the trial were viral infections, sepsis, hemorrhage, diarrhea, vomiting, nausea, neutropenia, fever, fatigue, and hypokalemia. Patients should be monitored for signs of serious infections.

Sources:

FDA approves first drug to treat serious complication of stem cell transplant. [News release]. 2026. https://www.fda.gov/drugs/news-events-human-drugs/fda-approves-first-drug-treat-serious-complication-stem-cell-transplant

Yartemlea (narsoplimab-wuug) [package insert]. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/761152Orig1s000lbl.pdf

FDA approves Omeros’ Yartemlea® – first and only therapy indicated for TA-TMA. [News release]. 2026. https://investor.omeros.com/news-releases/news-release-details/fda-approves-omeros-yartemlear-first-and-only-therapy-indicated