Arexvy

Efficacy in Adults 60 Years of Age and Older 

The efficacy of Arexvy against RSV-associated LRTD in adults ≥60 years of age was evaluated in Study 1 (ClinicalTrials.gov Identifier: NCT04886596), an ongoing, Phase 3, randomized, placebo-controlled, observer-blind clinical study conducted in 17 countries from Northern and Southern Hemispheres. Participants are planned to be followed for up to 36 months. 

Primary population for the efficacy analysis included 24,960 participants who were randomly assigned equally to receive 1 dose of Arexvy (n=12,466) or placebo (n=12,494). At the time of the primary efficacy analysis, participants had been followed for the development of RSV-associated LRTD for up to 10 months (median of 6.7 months).

Efficacy against Respiratory Syncytial Virus-associated Lower Respiratory Tract Disease 

• The primary objective was to demonstrate the efficacy of Arexvy in the prevention of a first episode of confirmed RSV-A and/or B-associated LRTD during the first season.
• Compared with placebo, Arexvy significantly reduced the risk of developing RSV-associated LRTD by 82.6% (96.95% CI [57.9, 94.1]) in participants ≥60 years of age, which met the pre-specified success criterion for the primary study objective. 
• The vaccine efficacy against RSV A-associated LRTD cases and RSV B-associated LRTD cases was 84.6% (95% CI [32.1, 98.3]) and 80.9% (95% CI [49.4, 94.3]), respectively.
• Compared with placebo, Arexvy significantly reduced the risk of developing RSV-associated LRTD by 84.4% (95% CI [46.9, 97.0]) in participants ≥70 years of age. The vaccine efficacy in the subgroup of participants ≥80 years of age (1,016 participants who received Arexvy versus 1,028 participants who received placebo) cannot be concluded due to the low number of total cases accrued (2 cases among participants who received Arexvy and 3 cases among participants who received placebo).

Efficacy Against Severe Respiratory Syncytial Virus-associated Lower Respiratory Tract Disease

• In Study 1, a severe RSV-associated LRTD was defined as an Reverse Transcription Polymerase Chain Reaction (RT-PCR) confirmed RSV-associated LRTD with at least 2 lower respiratory signs, or as an RT-PCR confirmed RSV-associated LRTD episode preventing normal, everyday activities. One case of severe RSV-associated LRTD in the group that received Arexvy and 17 cases in the group that received placebo were reported, amongst which 2 cases required supportive therapy. 
• Compared with placebo, Arexvy significantly reduced the risk of developing severe RSV-associated LRTD by 94.1% (95% CI [62.4, 99.9]) in participants ≥60 years of age.