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Clinical Trial
. 2021 Dec 6;73(11):e4400-e4408.
doi: 10.1093/cid/ciaa951.

Suptavumab for the Prevention of Medically Attended Respiratory Syncytial Virus Infection in Preterm Infants

Affiliations
Clinical Trial

Suptavumab for the Prevention of Medically Attended Respiratory Syncytial Virus Infection in Preterm Infants

Eric A F Simões et al. Clin Infect Dis. .

Abstract

Background: Respiratory syncytial virus (RSV) is a major cause of childhood medically attended respiratory infection (MARI).

Methods: We conducted a randomized, double-blind, placebo-controlled phase 3 trial in 1154 preterm infants of 1 or 2 doses of suptavumab, a human monoclonal antibody that can bind and block a conserved epitope on RSV A and B subtypes, for the prevention of RSV MARI. The primary endpoint was proportion of subjects with RSV-confirmed hospitalizations or outpatient lower respiratory tract infection (LRTI).

Results: There were no significant differences between primary endpoint rates (8.1%, placebo; 7.7%, 1-dose; 9.3%, 2-dose). Suptavumab prevented RSV A infections (relative risks, .38; 95% confidence interval [CI], .14-1.05 in the 1-dose group and .39 [95% CI, .14-1.07] in the 2-dose group; nominal significance of combined suptavumab group vs placebo; P = .0499), while increasing the rate of RSV B infections (relative risk 1.36 [95% CI, .73-2.56] in the 1-dose group and 1.69 [95% CI, .92-3.08] in the 2-dose group; nominal significance of combined suptavumab group vs placebo; P = .12). Sequenced RSV isolates demonstrated no suptavumab epitope changes in RSV A isolates, while all RSV B isolates had 2-amino acid substitution in the suptavumab epitope that led to loss of neutralization activity. Treatment emergent adverse events were balanced across treatment groups.

Conclusions: Suptavumab did not reduce overall RSV hospitalizations or outpatient LRTI because of a newly circulating mutant strain of RSV B. Genetic variation in circulating RSV strains will continue to challenge prevention efforts.

Clinical trials registration: NCT02325791.

Keywords: efficacy; infants; respiratory syncytial virus; safety.

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Figures

Figure 1.
Figure 1.
Randomization, trial assignment, and follow-up. aOne subject eligible for the trial was not randomized but was dosed. Note: The full analysis set (all infants randomized and dosed with study drug) is used for analysis. Abbreviation: AE, adverse events.
Figure 2.
Figure 2.
Cumulative incidence of (A) overall RSV primary endpoint (RSV hospitalization or outpatient LRTI) over time, by treatment group, and (B) by RSV-A and RSV-B subtype primary endpoint, by treatment group. Subjects who had no event during the 150-day efficacy assessment period were censored at the last time point when their primary endpoint was assessed, ie, day 150 visit (day 150 ± 5 days) for completers of that visit, or the last visit (scheduled or unscheduled) completed by a subject up to day 150 for noncompleters of the day 150 visit. Abbreviations: LRTI, lower respiratory tract infection; RSV, respiratory syncytial virus.
Figure 3.
Figure 3.
Neutralization assay indicating that suptavumab is able to neutralize RSV-A clinical isolates from trial participants but not RSV-B isolates. A neutralization assay using the indicated RSV strain was performed using suptavumab or palivizumab. To determine neutralization ability, each antibody was incubated with clinical trial sample subtype A (MOI: .02) or subtype B (MOI: .05) for 2 hours (37°C, 5% CO2). Virus-free and antibody-free controls were included. Postincubation, the antibody–virus mixture was added to the HEp-2 cells and the infection was maintained for 3 days. The degree of infection was determined by enzyme-linked immunosorbent assay. Luminescence values were analyzed by a 3-parameter logistic equation over an 11-point response curve (GraphPad Prism). Abbreviations: MOI, multiplicity of infection; RSV, respiratory syncytial virus.

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References

    1. Shi T, McAllister DA, O’Brien KL, et al. . Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in young children in 2015: a systematic review and modelling study. Lancet 2017; 390:946–58. - PMC - PubMed
    1. Mazur NI, Higgins D, Nunes MC, et al. ; Respiratory Syncytial Virus Network (ReSViNET) Foundation . The respiratory syncytial virus vaccine landscape: lessons from the graveyard and promising candidates. Lancet Infect Dis 2018; 18:e295–311. - PubMed
    1. IMpact-RSV. Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. Pediatrics 1998; 102:531–7. - PubMed
    1. American Academy of Pediatrics Committee on Infectious Diseases; American Academy of Pediatrics Bronchiolitis Guidelines Committee. Updated guidance for palivizumab prophylaxis among infants and young children at increased risk of hospitalization for respiratory syncytial virus infection. Pediatrics 2014; 134:e620–38. - PubMed
    1. Adis Insight. Suptavumab. Available at: https://adisinsight.springer.com/drugs/800040470. Accessed 5 March 2019.

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