Intranasal Palivizumab Fails to Prevent RSV Infection in Preterm Babies

A recent double-blind, randomized placebo-controlled trial found that daily intranasal palivizumab, a mucosal monoclonal antibody (mAb) did not prevent Respiratory Syncytial Virus (RSV) infection in late preterm infants. The findings were published in eClinicalMedicine of Lancet.

A total of 268 infants were enrolled from January 14, 2019 to January 28, 2021, with half receiving intranasal palivizumab and the other half a placebo once daily during the RSV season. The trial was halted for futility following a planned interim analysis.

Adverse events were observed to be similar in both groups, with 22 (16.4%) in the palivizumab arm and 26 (19.4%) in the placebo arm. But, 168 infants were excluded from efficacy analyses due to the absence of RSV circulation during the SARS-CoV-2 pandemic.

The primary outcome  showed no significant difference between groups (38.3% in the palivizumab arm versus 23.4% in the placebo arm) in regard to RSV infection. Also, the findings underscore the importance of timely interim analyses in mucosal mAb clinical development.

The outcomes of this study questions the efficacy of intranasal palivizumab for preventing RSV infection in late preterm infants. The results carry broader implications for the clinical development of mucosal mAbs by emphasizing the importance of interim analyses and the need for further research to comprehend the half-life of mucosal antibody. This supports clinicians to reevaluate strategies in the pursuit of effective mucosal antibody-based interventions against respiratory pathogens.

Reference:

Mazur, N. I., Löwensteyn, Y. N., Terstappen, J., Leusen, J., Schobben, F., Cianci, D., van de Ven, P. M., Nierkens, S., Bont, L. J., Nibbelke, E. E., Buiteman, B., Rave, N., Putten, M. V., Smit-Kleinlugtenbeld, E. A., de Lege-Korstanje, J. P., Peetsold, M. G., Hulsmann, A., van Gool, S., Snepvangers, Y., … Schuurman, R. (2023). Daily intranasal palivizumab to prevent respiratory syncytial virus infection in healthy preterm infants: a phase 1/2b randomized placebo-controlled trial. In eClinicalMedicine (Vol. 66, p. 102324). Elsevier BV. https://doi.org/10.1016/j.eclinm.2023.102324