Respiratory Syncytial Virus Anti-F Protein Monoclonal AntibodyPrescription OnlyPregnancy Cat. Not classifiedFDA Yes
Enflonsia
CLESROVIMAB
1 INDICATIONS AND USAGE ENFLONSIA is indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season. ENFLONSIA is a respiratory syncytial virus (RSV) F protein-directed fusion inhibitor indicated for the prevention of RSV lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season. ( 1 )
Medically reviewed by MedCentralHub Medical Review Board, Licensed Pharmacists & Physicians ·
Brand names:ENFLONSIA
Quick Reference
Medicine ClassRespiratory Syncytial Virus Anti-F Protein Monoclonal Antibody
FDA ApprovedYes
PregnancyCategory Not classified
Quick Facts
- Active ingredient
- CLESROVIMAB
- Brand names
- ENFLONSIA
- Availability
- Prescription only (Rx)
- Pregnancy category
- Not classified
- Half-life
- half-life is approximately 44
- FDA approved
- Yes
What Is Enflonsia?
1 INDICATIONS AND USAGE ENFLONSIA is indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season. ENFLONSIA is a respiratory syncytial virus (RSV) F protein-directed fusion inhibitor indicated for the prevention of RSV lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season. ( 1 )
Enflonsia (CLESROVIMAB) belongs to the Respiratory Syncytial Virus Anti-F Protein Monoclonal Antibody class of medications. It was first approved by the FDA in Yes. This medication requires a prescription from a licensed healthcare provider.
Key Safety Information
- •Always follow the dose recommended by your healthcare professional. Taking more than prescribed increases the risk of side effects including serious complications.
- •Seek emergency care if you experience signs of an allergic reaction — hives, swelling, difficulty breathing, or rash. Stop the medication and call your doctor immediately.
- •Some medications can increase the risk of cardiovascular events. Tell your doctor if you have high blood pressure, a history of heart attack or stroke, or any pre-existing health condition.
- •Avoid or limit alcohol while taking Enflonsia. Do not drink alcohol without first discussing it with your healthcare provider as it may increase adverse effects.
- •Take Enflonsia with food or a full glass of water if stomach upset occurs. Stop use and talk to your doctor if you experience persistent stomach pain or GI symptoms.
- •Tell your doctor about all medications, supplements, and vitamins you take. Some combinations significantly increase the risk of harm.
This is a summary only. Always read the full prescribing information and consult your healthcare provider for personalized medical advice.
Uses & Indications
Enflonsia is prescribed for the following conditions. Some uses are FDA-approved indications; others may be evidence-based off-label uses. Consult your healthcare provider for personalized guidance.
1 INDICATIONS AND USAGE ENFLONSIA is indicated for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season.
ENFLONSIA is a respiratory syncytial virus (RSV) F protein-directed fusion inhibitor indicated for the prevention of RSV lower respiratory tract disease in neonates and infants who are born during or entering their first RSV season.
Dosage Guide
The following are general dosing guidelines only. Your actual dose should be determined by your healthcare provider based on your condition, renal/hepatic function, and other medications.
AD
Adult Dosage
2 DOSAGE AND ADMINISTRATION Recommended dosage: 105 mg administered as a single intramuscular (IM) injection. ( 2.1 ) 2.1 Recommended Dosage The recommended dose for neonates and infants born during or entering their first RSV season is 105 mg administered as a single intramuscular (IM) injection. For neonates and infants born during the RSV season, administer ENFLONSIA once starting from birth. For infants born outside the RSV season, administer ENFLONSIA once prior to the start of their first RSV season considering the duration of protection provided by ENFLONSIA [see Clinical Pharmacology (12.2) ]. Infants Undergoing Cardiac Surgery with Cardiopulmonary Bypass For infants undergoing cardiac surgery with cardiopulmonary bypass during or entering their first RSV season, an additional 105 mg dose administered as an IM injection is recommended as soon as the infant is stable after surgery to ensure adequate clesrovimab-cfor serum levels. 2.2 Administration Instructions ENFLONSIA must be
Available Forms
Available Strengths
Side Effects
Common
- 6 ADVERSE REACTIONS Most common adverse reactions were injection-site erythema (3.8%), injection-site swelling (2.7%) and rash (2.3%).
- ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .
- 6.1 Clinical Trials 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 of ENFLONSIA was evaluated in 2,858 infants who received ENFLONSIA in Phase 2b/3 and Phase 3 clinical trials (Trial 004 and Trial 007).
- Neonates and Infants Entering Their First RSV Season (Trial 004) Trial 004 was a Phase 2b/3, randomized, double-blind placebo-controlled, multisite trial conducted in early and moderate preterm infants (≥29 to <35 weeks gestational age (GA)) and late preterm and full-term infants (≥35 weeks GA).
- Participants were randomized 2:1 and received a single 105 mg dose of ENFLONSIA (N=2,412, including 422 early and moderate preterm infants) or saline placebo (N=1,202, including 209 early and moderate preterm infants) by IM injection.
- Participants were monitored for 30 minutes post-dose.
Serious
- 5 WARNINGS AND PRECAUTIONS Hypersensitivity Including Anaphylaxis: Serious hypersensitivity reactions, including anaphylaxis, have been observed with other human immunoglobulin G1 (IgG1) monoclonal antibodies.
- Initiate appropriate medications and/or supportive care if such reactions occur.
- ( 5.1 ) 5.1 Hypersensitivity Including Anaphylaxis Serious hypersensitivity reactions, including anaphylaxis, have been observed with other human immunoglobulin G1 (IgG1) monoclonal antibodies.
- If signs or symptoms of a clinically significant hypersensitivity reaction or anaphylaxis occur, initiate appropriate medications and/or supportive therapy.
- 5.2 RSV Diagnostic Test Interference Clesrovimab-cfor may interfere with some immunologically-based RSV diagnostic assays (i.e., rapid antigen tests) as observed in laboratory studies.
Rare
Medicine Interactions
Always inform your healthcare provider and pharmacist about ALL medications you take, including prescriptions, OTC medicines, vitamins, and supplements.
MajorModerateMinor
Warnings & Contraindications
5 WARNINGS AND PRECAUTIONS Hypersensitivity Including Anaphylaxis: Serious hypersensitivity reactions, including anaphylaxis, have been observed with other human immunoglobulin G1 (IgG1) monoclonal antibodies. Initiate appropriate medications and/or supportive care if such reactions occur. ( 5.1 ) 5.1 Hypersensitivity Including Anaphylaxis Serious hypersensitivity reactions, including anaphylaxis,
How Enflonsia Works
12.1 Mechanism of Action ENFLONSIA is a monoclonal antibody with anti-RSV activity [see Microbiology (12.4) ].
Pharmacokinetics
Absorption
Absorption The median time to maximum concentration is 6
Half-Life
half-life is approximately 44
Metabolism
Metabolism Clesrovimab-cfor is degraded into small peptides by catabolic pathways
Pregnancy & Breastfeeding Safety
Not classified
Breastfeeding
Many medications pass into breast milk in varying amounts. Before using Enflonsiawhile breastfeeding, discuss the benefits and risks with your healthcare provider or pharmacist — they can weigh your dose, your infant's age, and available lactation safety data to find the safest option for you and your baby.
Storage & Handling
Storage and Handling Store prefilled syringes under refrigeration at 36°F to 46°F (2°C to 8°C). Keep the prefilled syringe in the original carton to protect from light until time of use. ENFLONSIA may be kept at room temperature between 68°F to 77°F (20°C to 25°C) for a maximum of 48 hours. After re
Frequently Asked Questions
Related on MedCentralHub
- Class hub
Respiratory Syncytial Virus Anti-F Protein Monoclonal Antibody alternatives
Compare all Respiratory Syncytial Virus Anti-F Protein Monoclonal Antibody medications — uses, side effects, and cost differences
- Detail
Enflonsia dosage guide
Adult, pediatric, renal, and hepatic dosing for Enflonsia
- Detail
Enflonsia side effects
Complete adverse effect profile including common, serious, and rare reactions
Sources & References
- • FDA Prescribing Information — Official labeling and package insert for Enflonsia
- • U.S. National Library of Medicine — MedlinePlus drug information
- • American Hospital Formulary Service (AHFS) — Clinical pharmacology monograph
- • PubMed / MEDLINE — View clinical studies
Last reviewed by MedCentralHub Medical Review Board · MedCentralHub Editorial Policy
Medical Disclaimer
The information on this page is for educational purposes only and is not intended as medical advice, diagnosis, or treatment. Always consult your doctor, pharmacist, or qualified healthcare provider before starting, stopping, or changing any medication.