Yartemlea (narsoplimab): Uses, Dosage, Side Effects & Warnings

Uses

1 INDICATIONS 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). 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 (TA-TMA). ( 1 )

Dosage and administration

Weight (kg) Recommended Dosage Greater than or equal to 50 kg 370 mg given as an intravenous infusion over 30 minutes once weekly. Increase frequency to twice weekly if there is inadequate improvement in TA-TMA signs and symptoms. ( 2.1 ) Less than 50 kg 4 mg/kg given as an intravenous infusion over 30 minutes once weekly. Increase frequency to twice weekly if there is inadequate improvement in TA-TMA signs and symptoms. ( 2.1 ) See Full Prescribing Information for instructions on preparation and administration. ( 2.2 , 2.3 , 2.4 , 2.5 ) 2.1 Recommended Dosage The recommended dosage of YARTEMLEA is provided in Table 1 . Table 1: Recommended Dosage of YARTEMLEA in Adult and Pediatric Patients Two Years of Age and Older with TA-TMA Weight (kg) Recommended Dosage Greater than or equal to 50 kg 370 mg given as an intravenous infusion over 30 minutes once weekly. Increase frequency to twice weekly if there is inadequate improvement in TA-TMA signs and symptoms. Less than 50 kg 4 mg/kg given as an intravenous infusion over 30 minutes once weekly. Increase frequency to twice weekly if there is inadequate improvement in TA-TMA signs and symptoms. If a dose is missed, administer the dose as soon as possible. Thereafter, resume dosing at the regular scheduled time. 2.2 Important Preparation and Administration Instructions Administer diluted YARTEMLEA as an intravenous infusion through a polyvinyl chloride (PVC) or PVC-lined infusion line with a 0.2-micron polyethersulfone (PES) in-line filter and a polyurethane catheter. For adults and pediatric patients weighing 10 kg or more , prepare YARTEMLEA in an intravenous bag, diluted to final concentration of 0.8 mg/mL to 8 mg/mL and administer by gravity infusion or via an infusion pump [see Dosage and Administration ( 2.3 and 2.5 )] . For pediatric patients weighing less than 10 kg , prepare YARTEMLEA in a polypropylene syringe, diluted to final concentration of 0.8 mg/mL and administer via a syringe pump [see Dosage and Administration ( 2.4 and 2.5 )] . 2.3 Preparation Instructions into an Intravenous Bag This section describes preparation of YARTEMLEA for adults and pediatric patients weighing 10 kg or more in an intravenous bag. 1. Preparation Use aseptic technique to prepare YARTEMLEA. Parenteral drug-product vial should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. YARTEMLEA is a clear to slightly opalescent, slightly yellow to yellow-brown solution. If discoloration or particles are observed in the vial, discard it. Calculate the dose (mg) based on the patient's body weight and the total volume (mL) of YARTEMLEA solution required. Remove the YARTEMLEA vial from the refrigerator and allow the vial to come to room temperature (18°C to 25°C [64°F to 77°F]) for 30 minutes. Vial must be used to prepare the appropriate dosing solution within 4 hours following removal from refrigerated storage. 2. Dilution for Intravenous Bag Infusion Withdraw the required volume of YARTEMLEA solution from the vial using a polypropylene syringe and dilute in a polyvinyl chloride (PVC) infusion bag of 5% Dextrose Injection, USP to make a final concentration of 0.8 mg/mL to 8 mg/mL with a total volume not to exceed 50 mL. Discard any unused portion left in the vial. Gently invert infusion bag 10 times to mix the diluted solution. Do not shake. Following dilution of YARTEMLEA in the infusion bag, the solution may become opalescent, and small translucent-to-white particles may appear. Discard prepared solution if particulate matter, other than translucent-to-white particles, is observed. 2.4 Preparation Instructions into an Intravenous Syringe This section describes preparation of YARTEMLEA for pediatric patients weighing less than 10 kg in a syringe. 1. Preparation Use aseptic technique to prepare YARTEMLEA. Parenteral drug-product vial should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. YARTEMLEA is a clear to slightly opalescent, slightly yellow to yellow-brown solution. If discoloration or particles are observed in the vial, discard it. Calculate the dose (mg) based on the patient's body weight and the total volume (mL) of YARTEMLEA solution required. Remove the YARTEMLEA vial from the refrigerator and allow the vial to come to room temperature (18°C to 25°C [64°F to 77°F]) for 30 minutes. Vial must be used to prepare the appropriate dosing solution within 4 hours following removal from refrigerated storage. 2. Dilution for Intravenous Syringe Infusion Withdraw the required volume of YARTEMLEA solution from the vial using a polypropylene syringe. Discard any unused portion left in the vial. Dilute in 5% Dextrose Injection, USP to make a final concentration of 0.8 mg/mL with a total volume not to exceed 50 mL. Gently invert syringe 10 times to mix the diluted solution. Do not shake. Following dilution of YARTEMLEA in the syringe, the solution may become opalescent, and small translucent-to-white particles may appear. Discard prepared solution if particulate matter, other than translucent-to-white particles, is observed. Remove air bubbles from the syringe before administration. 2.5 Storage and Administration Storage of Diluted Product If the prepared diluted solution is not used immediately, store the diluted YARTEMLEA solution at room temperature at 18°C to 25°C (64°F to 77°F) for up to 4 additional hours. Discard unused YARTEMLEA solution if not used within 4 hours from the time of dilution to the end of the infusion. Administration Administer YARTEMLEA diluted solution intravenously by gravity infusion or via infusion pump (for solution prepared in an intravenous bag) or via syringe pump (for solution prepared in a syringe) over 30 minutes through a PVC or PVC-lined infusion line with a 0.2-micron polyethersulfone (PES) in-line filter and a polyurethane catheter.

Dosage 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. Injection: 370 mg/2 mL (185 mg/mL) in a single-dose vial. ( 3 )

Contraindications

None None ( 4 )

Warnings and precautions

Serious infections: Monitor patients for signs/symptoms and treat appropriately. ( 5.1 ) 5.1 Serious Infections Serious and life-threatening infections have occurred in patients treated with YARTEMLEA. Serious infections, independent of causality, were reported in 36% (10/28) of patients with TA-TMA receiving YARTEMLEA in clinical trials. These infections included sepsis, viral infections, pneumonia, bacteremia, fungal infection, gastroenteritis, respiratory tract infection and urosepsis. If YARTEMLEA is administered to patients with active infections, monitor closely for signs and symptoms of worsening infection and treat promptly.

Side effects

The following clinically significant adverse reactions are described elsewhere in the labeling: Serious Infections [see Warnings and Precautions ( 5.1 )] Most common adverse reactions (incidence > 20% and independent of causality) are viral infections, sepsis, hemorrhage, diarrhea, vomiting, nausea, neutropenia, pyrexia, fatigue and hypokalemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Omeros Corporation at 1-844-YARTEM1 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical 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 [see Clinical Studies ( 14 )] . The median duration of treatment with YARTEMLEA was 8 weeks (range: 2 to 16.4 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 Escherichia sepsis, pyrexia, pulmonary alveolar hemorrhage, and acute myocardial infarction. The most common adverse reactions (≥ 20%) were viral infections, sepsis, hemorrhage, diarrhea, vomiting, nausea, neutropenia, pyrexia, fatigue, and hypokalemia. Table 2 summarizes the adverse reactions, without regard to causality or relatedness to YARTEMLEA, in the TA-TMA Study. Table 2: Adverse Reactions (≥ 15%) in Patients Receiving YARTEMLEA in the TA-TMA Study * Grouped terms Adverse Reaction All Grades n (%) N = 28 Grade ≥ 3 n (%) N = 28 Hemorrhage* 12 (43) 2 (7) Diarrhea 10 (36) 2 (7) Infection, viral* 10 (36) 2 (7) Neutropenia* 10 (36) 10 (36) Pyrexia 10 (36) 1 (4) Vomiting 9 (32) 2 (7) Fatigue* 8 (29) 1 (4) Hypokalemia* 7 (25) 3 (11) Nausea 7 (25) 1 (4) Sepsis* 7 (25) 6 (21) Pneumonia* 5 (18) 4 (14) Hypotension* 5 (18) 3 (11) Abdominal pain* 5 (18) 1 (4) Anemia* 5 (18) 3 (11) Back pain 5 (18) 0 (0) 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.

Use in specific populations

8.1 Pregnancy Risk Summary The available data on the use of YARTEMLEA during pregnancy are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. In animal reproduction studies, narsoplimab-wuug was administered subcutaneously and intravenously twice weekly to pregnant mice and rabbits during organogenesis at dose exposures up to 22 and 91-fold, respectively, the human exposure at the maximum recommended human dose (MRHD) based on area under the concentration-time curve (AUC). There were no adverse effects observed in the absence of maternal toxicity (see Data ) . The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Transport of endogenous IgG antibodies across the placenta increases as pregnancy progresses and peaks during the third trimester. Therefore, it is expected that YARTEMLEA, following administration, will be present in infants exposed in utero during the third trimester. The potential clinical impact of narsoplimab-wuug exposure on infants exposed in utero should be considered. Data Animal Data Narsoplimab-wuug was administered to pregnant mice at doses of 50, 150, or 300 mg/kg by subcutaneous injection and 300 mg/kg by intravenous injection approximately twice weekly during the major period of organogenesis. Intravenous administration caused reduced body weight gain in dams, reduced fetal body weight up to 4.8%, and an increase of approximately 33% in post-implantation loss at 22-fold the exposure expected at the MRHD (based on AUC) of 4 mg/kg intravenously once weekly in humans. Narsoplimab-wuug was administered to pregnant rabbits at doses of 50 or 150 mg/kg by subcutaneous injection and 150 mg/kg by intravenous injection approximately twice weekly during the major period of organogenesis. Intravenous administration increased post-implantation loss during early gestation days and reduced fetal body weights up to 8.5% below controls at 91-fold the exposure expected at the MRHD (based on AUC) of 4 mg/kg intravenously once weekly in humans. In an enhanced pre- and postnatal development study, pregnant mice were dosed with narsoplimab-wuug at doses up to 300 mg/kg intravenously twice weekly from day 6 of gestation through lactation. There was a transiently reduced maternal body weight gain but no adverse effects of narsoplimab-wuug on pregnancy nor on the viability, growth, or development of the infants up to 22-fold the exposure expected at the MRHD (based on AUC). 8.2 Lactation Risk Summary There are no data on the presence of narsoplimab-wuug in human milk, the effects on the breastfed child, or the effects on milk production. Narsoplimab-wuug is present in the milk of lactating mice (see Data ) . When a drug is present in animal milk, it is likely that the drug will be present in human milk. Endogenous maternal IgG and monoclonal antibodies are transferred into human milk. The effects of local gastrointestinal exposure and the extent of systemic exposure in the breastfed child to narsoplimab-wuug are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for YARTEMLEA and any potential adverse effects on the breastfed child from YARTEMLEA or from the underlying maternal condition. Data In a pre- and postnatal development study, after subcutaneous and intravenous administration of narsoplimab-wuug to maternal mice, narsoplimab-wuug was detected in the blood of preweaning pups when measured on lactation day 21. 8.4 Pediatric Use The safety and effectiveness of YARTEMLEA for treatment of TA-TMA have been established in pediatric patients aged 2 years and older. Use of YARTEMLEA for this indication is supported by evidence from studies in adults and in 6 pediatric patients, and additional safety data from 83 more pediatric patients aged 2 years and older [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.1 )] . The safety and effectiveness of YARTEMLEA have not been established in pediatric patients younger than 2 years old. 8.5 Geriatric Use Of the total number of YARTEMLEA-treated patients in the clinical trial and EAP for TA-TMA, 21 (8.4%) were 65 years of age and older, while 1 (0.4%) was at least 75 years of age [see Clinical Studies ( 14 )]. Clinical studies of YARTEMLEA did not include sufficient numbers of subjects at least 65 years of age to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in responses between elderly and younger patients.

Pregnancy

8.1 Pregnancy Risk Summary The available data on the use of YARTEMLEA during pregnancy are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. In animal reproduction studies, narsoplimab-wuug was administered subcutaneously and intravenously twice weekly to pregnant mice and rabbits during organogenesis at dose exposures up to 22 and 91-fold, respectively, the human exposure at the maximum recommended human dose (MRHD) based on area under the concentration-time curve (AUC). There were no adverse effects observed in the absence of maternal toxicity (see Data ) . The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Transport of endogenous IgG antibodies across the placenta increases as pregnancy progresses and peaks during the third trimester. Therefore, it is expected that YARTEMLEA, following administration, will be present in infants exposed in utero during the third trimester. The potential clinical impact of narsoplimab-wuug exposure on infants exposed in utero should be considered. Data Animal Data Narsoplimab-wuug was administered to pregnant mice at doses of 50, 150, or 300 mg/kg by subcutaneous injection and 300 mg/kg by intravenous injection approximately twice weekly during the major period of organogenesis. Intravenous administration caused reduced body weight gain in dams, reduced fetal body weight up to 4.8%, and an increase of approximately 33% in post-implantation loss at 22-fold the exposure expected at the MRHD (based on AUC) of 4 mg/kg intravenously once weekly in humans. Narsoplimab-wuug was administered to pregnant rabbits at doses of 50 or 150 mg/kg by subcutaneous injection and 150 mg/kg by intravenous injection approximately twice weekly during the major period of organogenesis. Intravenous administration increased post-implantation loss during early gestation days and reduced fetal body weights up to 8.5% below controls at 91-fold the exposure expected at the MRHD (based on AUC) of 4 mg/kg intravenously once weekly in humans. In an enhanced pre- and postnatal development study, pregnant mice were dosed with narsoplimab-wuug at doses up to 300 mg/kg intravenously twice weekly from day 6 of gestation through lactation. There was a transiently reduced maternal body weight gain but no adverse effects of narsoplimab-wuug on pregnancy nor on the viability, growth, or development of the infants up to 22-fold the exposure expected at the MRHD (based on AUC).

Pediatric use

8.4 Pediatric Use The safety and effectiveness of YARTEMLEA for treatment of TA-TMA have been established in pediatric patients aged 2 years and older. Use of YARTEMLEA for this indication is supported by evidence from studies in adults and in 6 pediatric patients, and additional safety data from 83 more pediatric patients aged 2 years and older [see Adverse Reactions ( 6.1 ) and Clinical Studies ( 14.1 )] . The safety and effectiveness of YARTEMLEA have not been established in pediatric patients younger than 2 years old.

Geriatric use

8.5 Geriatric Use Of the total number of YARTEMLEA-treated patients in the clinical trial and EAP for TA-TMA, 21 (8.4%) were 65 years of age and older, while 1 (0.4%) was at least 75 years of age [see Clinical Studies ( 14 )]. Clinical studies of YARTEMLEA did not include sufficient numbers of subjects at least 65 years of age to determine whether they respond differently than younger subjects. Other reported clinical experience has not identified differences in responses between elderly and younger patients.

Overdosage

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.

Description

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.

Mechanism of action

12.1 Mechanism of Action Narsoplimab-wuug inhibits MASP-2, the effector enzyme of the lectin pathway of the complement system, blocking lectin-dependent activation of complement component 3 (C3) and C4 without affecting the classical and alternative pathways of complement. In hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA), MASP-2 inhibition is thought to prevent lectin pathway-mediated cellular injury, including endothelial cell injury in small blood vessels.

How supplied

(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.

Patient 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 [see Warnings and Precautions ( 5.1 )] . 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

Active ingredients

Narsoplimab in 1 product

Yartemlea NDC products (1)

NDC	Strength & form	Labeler	Type
62225-300	Narsoplimab 370 mg/2mL Injection	Omeros Corporation	BLA

Frequently asked questions

What is Yartemlea used for?

1 INDICATIONS 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). 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…

What are the side effects of Yartemlea?

The following clinically significant adverse reactions are described elsewhere in the labeling: Serious Infections [see Warnings and Precautions ( 5.1 )] Most common adverse reactions (incidence > 20% and independent of causality) are viral infections, sepsis, hemorrhage, diarrhea, vomiting, nausea, neutropenia, pyrexia, fatigue and hypokalemia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS,… See the full label for the complete list.

Who makes Yartemlea?

Yartemlea is listed by 1 labeler in the FDA NDC directory, including Omeros Corporation.