Beyfortus Efficacy and Safety for RSV Protection

Studied across a broad range of infant populations entering their first respiratory syncytial virus (RSV) season¹

Trial 04 continued monitoring for the Primary Cohort and an additional 1,522 subjects to include all subjects.⁴

*For neonates and infants in their first season, the recommended dosage is 50 mg for infants <5 kg or 100 mg for infants ≥5 kg via IM injection. For children up to 24 months of age who remain at increased risk for severe RSV disease in their second season, the recommended dosage is a single 200 mg dose administered as 2 IM injections (2 x 100 mg).¹
†Included 128 preterm infants born at <29 wGA.¹
‡Incidence of RSV-LRTI (inpatient or outpatient) due to confirmed RSV through 150 days (descriptive).³

Proven strong and consistent efficacy against RSV disease¹

Trial 04 (Primary Cohort): healthy term and late preterm infants (≥35 wGA)^1*†‡

Primary endpoint: incidence of MA RSV-LRTI vs placebo through 150 days post 1 dose 
Medically attended (MA) includes all healthcare provider visits such as physician’s office, urgent care, emergency room, and hospitalizations.

Signs of LRTI involvement included rhonchi, rales, crackles, or wheezing and at least one sign of worsening clinical severity, including at least one of the following: increased respiratory rate, hypoxemia, acute hypoxic or ventilatory failure, new onset apnea, nasal flaring, retractions, grunting, or dehydration due to respiratory distress.

CI, confidence interval; RRR, relative risk reduction.

*1,490 healthy term and late preterm infants (≥35 wGA) in Trial 04.
†The primary efficacy analysis for Trial 04 is based on infants from the Primary Cohort.
‡Efficacy for MA RSV-LRTI based on relative risk reduction against placebo adjusted for age at randomization.

Randomized, double-blind, placebo-controlled multicenter Trial 04^1,5

Baseline characteristics: at randomization, 14% were ≥35 to <37 wGA; 86% were ≥37 wGA.¹

ITT, intention-to-treat; RT-PCR, reverse transcription polymerase chain reaction.

*Signs of LRTI involvement included rhonchi, rales, crackles, or wheezing and at least one sign of worsening clinical severity, including at least one of the following: increased respiratory rate, hypoxemia, acute hypoxic or ventilatory failure, new onset apnea, nasal flaring, retractions, grunting, or dehydration due to respiratory distress.

Lower respiratory tract infections (LRTIs) associated with respiratory syncytial virus (RSV)⁵

Study design with efficacy monitoring for 151 days and safety monitoring for 361+ days⁶

Post-dose follow-up visits: Day 151 is an efficacy evaluation;
Days 361 and 511 are both safety evaluations before and after second season;
Final assessment via telephone call.

Beyfortus exhibited a reduction in RSV-LRTI hospitalizations compared with placebo^1,4,7,8

Trial 04: incidence of RSV-LRTI requiring hospitalization through Day 150 vs placebo

Primary cohort: hospitalization endpoint^1,6
CONTENT TYPE
The Primary Cohort of Trial 04 included 1,490 infants randomized to receive Beyfortus (n=994) or placebo (n=496)

RRR based on a comparison of infants hospitalized⁶:
6 infants receiving Beyfortus (0.6%)
8 infants receiving placebo (1.6%)

Full study cohort: exploratory post hoc analysis of the hospitalization endpoint^4,5

Trial 04 continued to enroll infants following the primary analysis; the full study cohort included 3,012 infants randomized to receive Beyfortus (n=2,009) or placebo (n=1,003) in this post hoc analysis

RRR based on a comparison of infants hospitalized:
9 infants receiving Beyfortus (0.4%)
20 infants receiving placebo (2.0%)

The dose given was 50 mg for infants <5 kg or 100 mg for infants ≥5 kg via IM injection

Most common adverse reactions with Beyfortus were rash (0.9%) and injection site reactions (0.3%)¹

Proven strong and consistent efficacy against RSV disease¹

Trial 03: healthy preterm infants (≥29 to <35 wGA)^1*†

Primary endpoint: incidence of MA RSV-LRTI vs placebo through 150 days post 1 dose

Medically attended (MA) includes all healthcare provider visits such as physician’s office, urgent care, emergency room, and hospitalizations.

*1,453 healthy preterm infants (≥29 to <35 wGA) in Trial 03.
†Efficacy for MA RSV-LRTI based on relative risk reduction against placebo adjusted for age at randomization and hemisphere.

Randomized, double-blind, placebo-controlled multicenter Trial 03^1,9

Baseline characteristics: at randomization, 20% were ≥29 to <32 wGA, 80% were ≥32 to <35 wGA.¹

ITT, intention-to-treat; RT-PCR, reverse transcription polymerase chain reaction.

*Signs of LRTI involvement included rhonchi, rales, crackles, or wheezing and at least one sign of worsening clinical severity, including at least one of the following: increased respiratory rate, hypoxemia, acute hypoxic or ventilatory failure, new onset apnea, nasal flaring, retractions, grunting, or dehydration due to respiratory distress.

Time to first medically attended RSV lower respiratory tract infection⁹

Study design with efficacy monitoring for 151 days and safety monitoring for 361 days¹⁰

Post-dose follow-up visits: Day 151 is an efficacy evaluation;
Day 361 was a safety evaluation entering second season.

Beyfortus demonstrated consistent safety profile across multiple infant cohorts^1,2,5-9

Trial 04 and Trial 03 were pooled to evaluate the safety of Beyfortus (N=2,570) compared to placebo (N=1,284) 

Adverse reactions were reported in 1.2% of infants who received Beyfortus; most (97%) of adverse reactions were mild to moderate in severity

Most Common Adverse Reactions Reported at an Incidence Higher Than Placebo in the Safety Population (Trial 04 and Trial 03)^1*

Adverse reaction	Beyfortus N=2,570	Placebo N=1,284
Rash† (occurring within 14 days post dose)	0.9%	0.6%
Injection Site Reaction‡ (occurring within 7 days post dose)	0.3%	0.0%

*The Safety Population includes all infants who received the recommended dose of Beyfortus in Trials 04 and 03: Primary and Safety cohorts from Trial 04; infants who weighed <5 kg and who received the recommended dose of Beyfortus (single 50 mg IM dose) in Trial 03.
†Rash was defined by the following grouped preferred terms: rash, rash macular, rash maculopapular, rash papular.
‡Injection site reaction was defined by the following grouped preferred terms: injection site reaction, injection site pain, injection site induration, injection site edema, injection site swelling.

Safety studied in infants and children at higher risk for severe RSV disease¹

The safety of Beyfortus was evaluated in Trial 05, a Phase 2/3, randomized, double-blind, palivizumab-controlled multicenter trial in infants and children at high risk for severe RSV disease. 

First RSV season¹: infants born at <35 wGA and infants with CLD of prematurity or hemodynamically significant CHD

Adverse reactions reported among Trial 05 infants who received Beyfortus in their first RSV season were similar to those reported in infants who received Beyfortus in Trials 03 and 04

Second RSV season¹: children up to 24 months with CLD of prematurity or hemodynamically significant CHD

The safety profile of Beyfortus in these children during their second RSV season was consistent with the safety profile of Beyfortus observed during their first RSV season

CHD, congenital heart disease; CLD, chronic lung disease.

Trial 05: analysis of Beyfortus vs palivizumab in infants at higher risk of severe RSV disease^1,2

First season study design: randomized, double-blind, palivizumab-controlled multicenter safety study^1,2

Second season study design: randomized, double-blind, palivizumab-controlled multicenter safety study^1,2

Forty children who received palivizumab in the first RSV season received Beyfortus in their second RSV season; and 42 children received palivizumab in both first and second RSV seasons.

Baseline characteristics: at randomization, in the preterm cohort, 77 infants (13%) were <29 wGA; and 499 (81%) were ≥29 to <35 wGA. In the CLD/CHD cohort, 70% had CLD; 34% had hemodynamically significant CHD; 123 infants (40%) were <29 wGA, 28% were ≥29 to <35 wGA; and 32% were ≥35 wGA.

PK, pharmacokinetic.

Exploratory efficacy: in preterm infants (<35 wGA) or those with CLD/CHD there was a numerically lower incidence of MA RSV-LRTI with Beyfortus compared with palivizumab^1,3†

Trial 05 was not powered for efficacy but efficacy was assessed as a secondary endpoint
The clinical significance of these data is not known

There were no cases of MA RSV-LRTI through 150 days in the second RSV season

†Trial 05 was a Phase 2/3, randomized, double-blind, palivizumab-controlled study evaluating the safety of Beyfortus in infants with CLD or CHD and preterm infants (<35 wGA) entering their first RSV season. Children up to 24 months with CLD or CHD could continue in Trial 05 and receive Beyfortus or palivizumab prior to their second RSV season. The efficacy was established based on extrapolation of the efficacy from Trial 04 and Trial 03 to the population enrolled in Trial 05 based on similar Beyfortus exposures among infants enrolled in Trials 04 and 05.

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