Brand Name
Yartemlea
Generic Name
Narsoplimab
View Brand Information FDA approval date: January 20, 2026
Form: Injection
What is Yartemlea (Narsoplimab)?
YARTEMLEA is indicated for the treatment of adult and pediatric patients 2 years of age and older with hematopoietic stem cell transplant-associated thrombotic microangiopathy . YARTEMLEA is a MASP-2 inhibitor indicated for the treatment of adult and pediatric patients 2 years of age and older with hematopoietic stem cell transplant-associated thrombotic microangiopathy .
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Related Clinical Trials
A Phase 2 Study Evaluating the Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Narsoplimab in Pediatric Patients (28 Days to ≤ 18 Years of Age.) With High-Risk Hematopoietic Stem Cell Transplant Thrombotic Microangiopathy
Summary: The purpose of this study is to evaluate the safety and efficacy of narsoplimab in pediatric patients with thrombotic microangiopathies (TMA) following hematopoietic stem cell transplant (HSCT).
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Brand Information
YARTEMLEA (narsoplimab)
1INDICATIONS AND USAGE
YARTEMLEA is indicated for the treatment of adult and pediatric patients 2 years of age and older with hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA).
2DOSAGE FORMS AND STRENGTHS
Injection: 370 mg/2 mL (185 mg/mL) as a clear to slightly opalescent, slightly yellow to yellow-brown solution in a single-dose vial.
3CONTRAINDICATIONS
None
4ADVERSE REACTIONS
The following clinically significant adverse reactions are described elsewhere in the labeling:
- Serious Infections
4.1Clinical Trial Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The safety data described in this section reflect exposure to YARTEMLEA in the TA-TMA Study in which 28 adult patients received YARTEMLEA. In total, 24 patients received YARTEMLEA at a dose of 4 mg/kg intravenously once weekly for 4 or 8 weeks and 4 patients received 370 mg intravenously weekly for 8 weeks
Serious adverse reactions were reported in 61% of patients receiving YARTEMLEA. Serious adverse reactions in > 5% of patients who received YARTEMLEA included acute kidney injury, confusional state, acute respiratory failure, neutropenic sepsis, septic shock, pulmonary edema, and vomiting. Fatal adverse reactions occurred in 7% of patients, including neutropenic sepsis and septic shock.
Adverse reactions leading to dosage interruptions occurred in 7% of patients who received YARTEMLEA and included
The most common adverse reactions (≥ 20%) were viral infections, sepsis, hemorrhage, diarrhea, vomiting, nausea, neutropenia, pyrexia, fatigue, and hypokalemia.
Table 2summarizes the adverse reactions, without regard to causality or relatedness to YARTEMLEA, in the TA-TMA Study.
An additional 221 adult and pediatric patients with TA-TMA were treated with YARTEMLEA in a global expanded access program (EAP) that included patients for whom YARTEMLEA was their initial treatment following diagnosis of TA-TMA as well as patients who had previously failed or stopped other treatments. The median number of YARTEMLEA doses received by the 221 patients in the EAP was 8 and the median duration of therapy was 5.5 weeks. No new clinically significant safety signals were identified in patients treated in the EAP.
5OVERDOSAGE
There is no known antidote for YARTEMLEA and YARTEMLEA is not dialyzable. If an overdose occurs, institute general supportive measures. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdose management recommendations.
6DESCRIPTION
Narsoplimab-wuug, a mannan-binding lectin-associated serine protease 2 (MASP-2) inhibitor, is a recombinant human immunoglobulin G4 (IgG4) monoclonal antibody produced in Chinese Hamster Ovary cells. The approximate molecular weight is 143 kDa.
YARTEMLEA (narsoplimab-wuug) injection is a sterile, preservative-free, clear to slightly opalescent, slightly yellow to yellow-brown solution for intravenous infusion. Each 2-mL single-dose glass vial contains 370 mg of narsoplimab-wuug, arginine hydrochloride (84.3 mg), citric acid monohydrate (1.42 mg), polysorbate 80 (0.2 mg), sodium citrate (8.6 mg), and Water for Injection, USP. Sodium hydroxide and hydrochloric acid were added to adjust the pH to 5.8.
7CLINICAL STUDIES
The efficacy of YARTEMLEA was assessed in (i) a single-arm, open-label study (TA-TMA Study) that enrolled 28 adult patients who developed TA-TMA following hematopoietic stem-cell transplantation (HCT) and (ii) 19 adult and pediatric patients with TA-TMA with evaluable patient-level response data enrolled in an expanded access program (EAP). In the TA-TMA Study, 24 patients received YARTEMLEA 4 mg/kg intravenously once weekly and 4 patients received YARTEMLEA 370 mg intravenously once weekly. The median number of YARTEMLEA administrations received by the 28 TA-TMA Study patients plus the 19 EAP patients was 8 (range: 2-34), and the median duration of therapy was 8 weeks (range: 2-16 weeks).
Baseline demographic and disease-related characteristics are shown in
Among patients in the TA-TMA Study, the median time from HCT to TMA diagnosis was 73.5 days (range: 21–436) and the median time from TMA diagnosis to first dose of narsoplimab was 13.5 days (range: 4–196). Among the 19 adult and pediatric patients in the EAP, the median time from HCT to TMA diagnosis was 81 days (range: 24–452) and the median time from TMA diagnosis to first dose of narsoplimab was 3 days (range: 0–52).
The primary efficacy assessment of YARTEMLEA was based on TMA response defined as improvement in both of two laboratory TMA markers (LDH and platelet counts) and either improvement in organ function or independence from transfusions. The same response criteria were applied to both the TA-TMA Study and EAP patients.
Improvement in platelet count was defined as follows:
- For baseline platelet count ≤ 20,000/μL: (i) ≥ 3-fold increase in platelet count, (ii) post-baseline platelet count ≥ 30,000/μL, and (iii) receipt of no platelet transfusions within 2 days prior to the platelet count assessment.
- For baseline platelet count > 20,000/μL: (i) ≥ 50% increase in platelet count, (ii) platelet count ≥ 75,000/μL, and (iii) receipt of no platelet transfusions within 2 days prior to the platelet count assessment.
To meet LDH improvement criteria, LDH levels were required to be < 1.5x ULN.
In the TA-TMA Study and the EAP, TA-TMA response was achieved in 17/28 (60.7%) and 13/19 (68.4%) patients, respectively (
In the TA-TMA Study, the 100-day survival from time of TMA diagnosis was 73.4% (95% CI: 52.2, 86.4). In the EAP cohort (N = 19), 100-day survival from time of TMA diagnosis was 73.7% (95% CI: 47.9, 88.1)
8HOW SUPPLIED/STORAGE AND HANDLING
YARTEMLEA (narsoplimab-wuug) injection is a sterile, preservative-free, clear to slightly opalescent, slightly yellow to yellow-brown solution supplied as one 370 mg/2 mL (185 mg/mL) single-dose vial in a carton (NDC 62225-300-00).
Store YARTEMLEA vials refrigerated at 2°C to 8°C (36°F to 46°F) in the original carton to protect from light until time of use. Do not freeze. Do not shake. Do not use beyond the expiration date stamped on the carton.
9PATIENT COUNSELING INFORMATION
Serious infections: Inform patients and caregivers that treatment with complement inhibitors has been associated with an increased risk of serious infections. As YARTEMLEA is a complement inhibitor, advise patients and/or caregivers to immediately report any signs or symptoms suggestive of infections
Manufactured by:
Omeros Corporation
201 Elliott Avenue West
Seattle, WA 98119
US license 2141
This product, or its use, may be covered by one or more US patents, including US Patent Nos. 9,011,860, 10,047,165, and 10,683,367, in addition to others, including patents pending.
YARTEMLEA is a trademark of Omeros Corporation.
© 2025 Omeros Corporation