Peer-reviewed article
Safety and Pharmacokinetics of Nirsevimab in Immunocompromised Children
Joseph B. Domachowske, Ulrika Wählby Hamrén, Irfana Banu, Roberta Baronio, Bhanu Basavaraju et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This study tested nirsevimab, a monoclonal antibody against respiratory syncytial virus (RSV), in 100 immunocompromised children aged 24 months or younger. The children received a single injection and were monitored for safety and how the drug moved through their bodies over one year. The drug was well tolerated with no serious safety concerns, and the drug levels in children's blood were high enough to potentially prevent severe RSV infection.
Key points
- 100 immunocompromised children received nirsevimab; conditions included primary immunodeficiency, previous transplantation, HIV infection, high-dose corticosteroid treatment, chemotherapy, or other immunosuppressive therapies
- Only 6 children experienced 8 treatment-related adverse events, none serious; 3 deaths occurred but were unrelated to treatment
- 11 children developed antibodies against the drug, with minimal effects on drug levels and no safety impact
- Drug serum concentrations at day 151 were similar to levels shown to prevent RSV lower respiratory tract infection in healthy infants
- No medically attended RSV lower respiratory tract infections occurred through day 151 in the study population
Limitations
This was an open-label trial without a comparison group, so we cannot determine efficacy or compare outcomes to untreated children. A subset of children with increased drug clearance (potentially associated with protein loss) may have reduced protection, but the actual impact on whether the drug prevents infection remains unknown.
Abstract
BACKGROUND AND OBJECTIVES: Immunocompromised children may have increased risk for severe respiratory syncytial virus (RSV) lower respiratory tract infection (LRTI), potentially leading to prolonged hospitalization, intensive care, and death. The open-label phase II MUSIC trial evaluated the safety and pharmacokinetics of nirsevimab, an extended half-life monoclonal antibody against RSV, in immunocompromised children aged ≤24 months. METHODS: Participants received a single intramuscular injection of nirsevimab (first RSV season: 50 mg if <5 kg/100 mg if ≥5 kg; second season: 200 mg). Safety, antidrug antibodies, and pharmacokinetics were evaluated to day 361. RESULTS: Participants (n = 100) had ≥1 immunocompromising conditions: primary immunodeficiency (n = 33), previous transplantation (n = 16), HIV infection (n = 8) or treatment with high-dose systemic corticosteroids (n = 29), immunosuppressive chemotherapy (n = 20), or other immunosuppressive therapies (n = 15). Six children experienced eight treatment-related adverse events (none categorized as serious). Three deaths occurred, all were unrelated to treatment. Eleven children, developed antidrug antibodies, with minimal effects on pharmacokinetics and no apparent impact on safety. Nirsevimab serum concentrations at day 151 were similar to those effective in preventing medically attended RSV LRTI in healthy infants. Fourteen children had increased nirsevimab clearance. No protocol-defined medically attended RSV LRTIs occured through day 151. CONCLUSIONS: Among immunocompromised children aged ≤24 months, nirsevimab was well tolerated with no safety concerns and serum concentrations were supportive of efficacy. A subset of children with increased nirsevimab clearance, had conditions potentially associated with protein loss; however, the impact on efficacy is unknown.
Findings the Hub has extracted
Each claim below is labelled by its type of design and links back to this report.
- Intervention
- Single intramuscular injection of nirsevimab (50 mg if <5 kg, 100 mg if ≥5 kg in first season; 200 mg in second season)
- Population
- 100 immunocompromised children aged ≤24 months with conditions including primary immunodeficiency, previous transplantation, HIV infection, high-dose systemic corticosteroid treatment, immunosuppressive chemotherapy, or other immunosuppressive therapies