AstraZeneca’s Beyfortus recommended for approval in the EU by CHMP

AstraZeneca plc (LON:AZN) and Sanofi’s Beyfortus (nirsevimab) has been recommended for marketing authorisation in the European Union (EU) for the prevention of respiratory syncytial virus (RSV) lower respiratory tract disease in newborns and infants during their first RSV season. If approved, Beyfortus would be the first and only single-dose passive immunisation for the broad infant population, including those born healthy, at term or preterm, or with specific health conditions. 

The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Authority based its positive opinion on results from the Beyfortus clinical development programme, including the MELODY Phase III, MEDLEY Phase II/III, and Phase IIb trials.^1-8

In the MELODY and Phase IIb trials, Beyfortus met its primary endpoint of reducing the incidence of medically attended lower respiratory tract infections (LRTI) caused by RSV during the RSV season vs. placebo with a single dose.^1-6 No clinically meaningful differences in safety results between the Beyfortus and placebo groups were seen. Beyfortus also demonstrated a comparable safety and tolerability profile to Synagis (palivizumab) in the MEDLEY Phase II/III trial, with occurrence of treatment emergent adverse events (TEAEs) or treatment emergent serious adverse events (TESAEs) similar between groups.^7-8

Iskra Reic, Executive Vice President, Vaccines and Immune Therapies, AstraZeneca, said: “This positive CHMP opinion underscores Beyfortus’ potential as a ground breaking, first-in-class passive immunisation that could transform the medical community’s approach to respiratory syncytial virus prevention in infants.”

Jean-François Toussaint, Global Head of Research and Development Vaccines, Sanofi, said: “Today’s positive CHMP opinion is one of the most significant public health achievements in respiratory syncytial virus in decades and has the potential to alleviate the enormous physical and emotional burden that RSV can place on families and healthcare systems. With this endorsement, we are one step closer to achieving our goal of protecting all infants against RSV with a single dose.”

RSV is the most common cause of LRTIs and a leading cause of hospitalisation in all infants.^9-11 RSV-related direct medical costs, globally – including hospital, outpatient and follow-up care – were estimated at €4.82 billion in 2017.¹² The current standard of care for the prevention of serious LRTIs caused by RSV focuses on to preterm infants and infants at higher risk of severe disease, and treatment is limited to symptomatic relief.^13-14

Beyfortus

Beyfortus (nirsevimab), an investigational long-acting antibody designed for all infants for protection against RSV disease from birth through their first RSV season with a single dose, is being developed jointly by AstraZeneca and Sanofi using AstraZeneca’s YTE technology.

Beyfortus has been developed to offer newborns and infants direct RSV protection via an antibody to help prevent LRTI caused by RSV. Monoclonal antibodies do not require the activation of the immune system to help offer timely, rapid and direct protection against disease.¹⁵ The recommended dose of Beyfortus is a single intramuscular injection of 50 mg for infants with body weight <5 kg and a single intramuscular injection of 100 mg for infants with body weight ≥5 kg.

Beyfortus has been granted regulatory designations to facilitate expedited development by several major regulatory agencies around the world. These include Breakthrough Therapy Designation by The China Center for Drug Evaluation under the National Medical Products Administration; Breakthrough Therapy Designation from the US Food and Drug Administration; access granted to the European Medicines Agency (EMA) PRIority Medicines (PRIME) scheme; and named “a medicine for prioritized development” under the Project for Drug Selection to Promote New Drug Development in Pediatrics by the Japan Agency for Medical Research and Development (AMED). The safety and efficacy of Beyfortus was evaluated under an accelerated assessment procedure by the EMA. Beyfortus has not been approved by any regulatory authority.

Pivotal clinical trials

The Phase IIb study was a randomised, placebo-controlled trial designed to measure the efficacy of Beyfortus (nirsevimab) against medically attended LRTI through 150 days postdose. Healthy preterm infants of 29-35 weeks’ gestation were randomised (2:1) to receive a single 50mg intramuscular injection of Beyfortus or placebo.^3-4

The dosing regimen was recommended based on further exploration of the Phase IIb data.³ The subsequent Phase III study, MELODY, applied the recommended dosing regimen.²

The MELODY Phase III study was a randomised, placebo-controlled trial conducted across 21 countries designed to determine efficacy of Beyfortus against medically attended LRTI due to RSV confirmed by reverse transcriptase polymerase chain reaction testing through 150 days after dosing, versus placebo, in healthy late preterm and term infants (35 weeks gestational age or greater) entering their first RSV season.^1-2

MEDLEY was a Phase II/III, randomised, double-blind, Synagis-controlled trial with the primary objective of assessing safety and tolerability for Beyfortus in preterm infants and infants with congenital heart disease (CHD) and/or chronic lung disease of prematurity (CLD) eligible to receive Synagis.^7-8 Between July 2019 and May 2021 approximately 918 infants entering their first RSV season were randomised to receive a single 50mg (in infants weighing <5kg) or 100mg (in infants weighing ≥5kg) intramuscular injection of Beyfortus or Synagis. Safety was assessed by monitoring the occurrence of TEAEs and TESAEs through 360 days post-dose.^7-8 Serum levels of nirsevimab following dosing (on day 151) in this trial were comparable with those observed in the MELODY Phase III trial, indicating similar protection in this population to that in the healthy term and late preterm infants is likely.⁷ Data was published in the New England Journal of Medicine (NEJM) in March 2022. The results of MELODY, MEDLEY Phase II/III and the Phase IIb trials demonstrate that Beyfortus helps protect infants during their first RSV season against RSV disease with a single dose.^1-8 This all-infant population includes preterm, healthy late preterm and term infants, as well as infants with specific conditions.

These trials form the basis of regulatory submissions which began in 2022.

Results from the Phase IIb trial

The primary endpoint of the Phase IIb study was met, reducing the incidence of medically attended LRTI, caused by RSV by 70.1% (95% CI: 52.3, 81.2) compared to placebo. Between November 2016 and December 2017, 1,453 infants were randomised (Beyfortus, n=969; placebo, n=484) at the RSV season start. Research was conducted by AstraZeneca in both hemispheres, at 164 sites in 23 countries.^3-4 Data was published in NEJM in July 2020.

Medically Attended LRTI and Hospitalisation for RSV LRTI Through 150 Days Postdose (ITT population)

^*Data were imputed for participants who had no events and were not followed through 150 days postdose. Analyses were conducted using Poisson regression with robust variance. CI, confidence interval; ITT, intent-to-treat; LRTI, lower respiratory tract infection; RRR, relative risk reduction; RSV, respiratory syncytial virus.

Results from the MELODY Phase III trial

The primary endpoint of the MELODY Phase III trial was met, reducing the incidence of medically attended LRTI, such as bronchiolitis or pneumonia, caused by RSV by 74.5% (95% CI 49.6, 87.1; P<0.001) compared to placebo. Infants were randomised (2:1) to receive a single 50mg (in infants weighing <5kg) or 100mg (in infants weighing ≥5kg) intramuscular injection of Beyfortus or placebo. Between July 2019 and March 2020, 1,490 infants were randomised to either Beyfortus or placebo at the RSV season start.^1-2 Data was published in NEJM in March 2022.

Medically Attended LRTI and Hospitalisation for RSV LRTI Through 150 Days Postdose (ITT population)

^*Data were imputed for participants who had no events and were not followed through 150 days postdose. Analyses were conducted using Poisson regression with robust variance. CI, confidence interval; ITT, intent-to-treat; LRTI, lower respiratory tract infection; RRR, relative risk reduction; RSV, respiratory syncytial virus.

Results from the pre-specified pooled analysis of the Phase IIb and MELODY trials

A prespecified pooled analysis of the MELODY Phase III trial and the recommended dose from the Phase IIb trial, in which an efficacy (relative risk reduction versus placebo) of 79.5% (95% CI 65.9, 87.7; P<0.0001) was seen against medically attended LRTI, such as bronchiolitis or pneumonia, caused by RSV in infants born at term or preterm entering their first RSV season.⁵ The pooled analysis studied healthy preterm and term infants who received the recommended dose of Beyfortus based on weight compared to placebo through Day 151 and showed an efficacy of 77.3% (95% CI 50.3, 89.7; P<0.001) against RSV LRTI hospitalisations.^1,5

Medically Attended LRTI and Hospitalisation for RSV LRTI Through 150 Days Postdose (ITT population)

^*Data were inputed for participants who had no events and were not followed through 150 days postdose. Analyses were conducted using Poisson regression with robust variance. CI, confidence interval; ITT, intent-to-treat; LRTI, lower respiratory tract infection; RRR, relative risk reduction; RSV, respiratory syncytial virus.

RSV

RSV is the most common cause of LRTI, including bronchiolitis and pneumonia, in infants.⁹ It is also a leading cause of hospitalisation in all infants, with most hospitalisations for RSV occurring in healthy infants born at term.^10-11,16-17 Globally, in 2019, there were approximately 33 million cases of acute lower respiratory infections leading to more than three million hospitalisations, and it was estimated that there were 26,300 in-hospital deaths of children younger than five years.¹⁸ RSV-related direct medical costs, globally – including hospital, outpatient and follow-up care – were estimated at €4.82 billion in 2017.¹² Currently, Synagis (palivizumab) is the only approved option for the prevention of serious LRTIs caused by RSV in high risk and preterm infants and requires up to five injections to cover a typical RSV season.¹³

Sanofi Alliance

In March 2017, AstraZeneca and Sanofi announced an agreement to develop and commercialise nirsevimab. Under the terms of the agreement, AstraZeneca leads all development and manufacturing activities, and Sanofi will lead commercialisation activities and record revenues. Under the terms of the global agreement, Sanofi made an upfront payment of €120m, has paid a development milestone of €30m and will pay up to a further €465m upon achievement of certain development and sales-related milestones. The two companies share all costs and profits. Revenue from the agreement is reported as Collaboration Revenue in the Company’s financial statements.