Enflonsia (clesrovimab)
Enflonsia has been approved to help prevent respiratory syncytial virus (RSV) lower respiratory tract (lung) disease in neonates and infants who are born during or entering their first RSV season. Enflonsia contains the active ingredient clesrovimab.
Enflonsia is a long-acting single injection approved to help prevent respiratory syncytial virus (RSV) lower respiratory tract (lung) disease in:
- neonates (newborn babies up to 4 weeks old) who are born during their first RSV season
- infants (babies up to one year old) who are entering their first RSV season.
RSV is a common and highly infectious virus that affects the lungs and airways, especially in babies and young children.
Most RSV cases are mild and can be treated at home, but some babies develop complications and need hospital care. In severe cases, RSV can cause bronchiolitis (small airway infection) or pneumonia (lung infection), which can make breathing difficult and may need medical treatment.
The ‘first RSV season’ refers to the first period in a baby’s life when RSV is most likely to be spread, often during autumn to winter.
The active ingredient in Enflonsia is an antibody that helps to prevent RSV from entering and infecting the body’s cells, including cells in the lungs.
Antibodies are protective proteins that recognise and block specific viruses or bacteria to help prevent infection or reduce disease severity. Some antibodies are made naturally by the immune system after infection or vaccination, while others can be given as a medicine to provide temporary protection.
Prevention of severe RSV in babies and young children is important. Currently, there is no vaccine and limited treatment options for RSV in babies and young children.
The effectiveness and safety of Enflonsia were assessed in one main clinical study and one supporting clinical study.
The main study looked at how well Enflonsia worked and how safe it was compared with a placebo (a treatment with no active medicine). It included healthy preterm and full-term babies.
A second study compared Enflonsia with palivizumab, a medicine commonly used to help protect babies from RSV. This study included babies at higher risk of severe RSV, including preterm babies, those with lung problems related to early birth, and congenital heart disease.
Together, these studies showed that Enflonsia was highly effective, well tolerated and provides an alternative to existing medicines.
Key findings from the clinical studies
- Babies who received Enflonsia were about 60% less likely to need medical care for RSV lung infections than babies who received the placebo.
- Fewer babies who received Enflonsia needed hospital treatment than those who received the placebo (about 84% fewer).
- Protection against RSV lasted for at least 5-6 months, covering a typical RSV season.
- In babies at higher risk of severe RSV, Enflonsia provided similar RSV protection to palivizumab.
- Adverse events (side effects or unexpected outcomes) in babies who received Enflonsia were similar to those reported with palivizumab or placebo.
- The most common adverse events were reactions at the injection site and rash. Most adverse events were mild to moderate.
The TGA decided that the application provided sufficient evidence supporting the safety and effectiveness of Enflonsia and the medicine can be registered in Australia.
More detailed information on why the TGA approved Enflonsia will be published in the upcoming Australian Public Assessment Report (AusPAR).
For comprehensive information on potential side effects and risks, refer to the Consumer Medicine Information (CMI) leaflet or Product Information (PI) document.
This decision summary will not be updated to reflect any subsequent changes and may therefore not contain the most current information about the medicine. For the latest information, refer to the medicine’s CMI or PI.
The CMI leaflet offers guidance for consumers to support safe and effective use of the medicine. The CMI includes information on dose, how to use the medicine properly, potential side effects, safety precautions, storage instructions and more.
The Australian CMI for Enflonsia can be accessed through the searchable TGA eBusiness Services or ARTG databases.
The PI document provides essential prescribing information for health professionals, including details on dosage recommendations, pregnancy category, contraindications, precautions and potential side effects.
The Australian PI for Enflonsia can be accessed through the searchable TGA eBusiness Services or ARTG databases.
For health advice and information, including a symptom checker and service finder refer to the healthdirect website.
For advice on prescription medicines, over the counter medicines and other medicines (including complementary medicines) call Medicines Line.
For information on medicines subsidised by the Australian Government refer to the Pharmaceutical Benefits Scheme (PBS) website.
For data and reports on health and welfare topics in Australia refer to the Australian Institute of Health and Welfare website.
This application was assessed under the Access Initiative.