Sanofi Ramps Up Beyfortus Production Amid Looming Competition in RSV Market

Sanofi Unveils Aggressive Supply Strategy for Beyfortus

Sanofi has announced an ambitious supply plan for its respiratory syncytial virus (RSV) antibody, Beyfortus, developed in partnership with AstraZeneca. The company aims to begin shipping the product early in the third quarter, with current supply levels already matching the total doses distributed last year. This move comes just one day before the potential FDA approval of a rival RSV monoclonal antibody from Merck & Co.

Thomas Triomphe, Sanofi's vaccine chief, emphasized the significance of this development, stating, "Our third year of providing RSV protection marks a transformative era in infant health." He highlighted the extensive real-world evidence supporting Beyfortus, citing over 40 studies involving 250,000 immunized infants.

Production Capacity Tripled to Meet Demand

In response to growing market demand and potential competition, Sanofi and AstraZeneca have significantly expanded their manufacturing capabilities. The companies have tripled production capacity and doubled their number of manufacturing sites since Beyfortus' launch in 2023. This expansion underscores the importance of Beyfortus in Sanofi's portfolio, which generated sales of 1.7 billion euros ($1.8 billion) last year.

Competitive Landscape in RSV Prevention

The RSV prevention market is becoming increasingly competitive, with Merck's clesrovimab (MK-1654) poised for potential FDA approval. Merck's antibody has shown promising results in clinical trials, demonstrating an 84% reduction in RSV hospitalization and a 91% reduction in medically attended lower respiratory infection (MALRI) hospitalization compared to placebo through five months.

While direct comparisons between Beyfortus and clesrovimab are challenging due to differences in trial designs and antigenic targets, both products have shown significant efficacy in preventing RSV-related complications in infants. Sanofi has emphasized Beyfortus' 75% reduction in MALRI incidence and its six-month duration of protection, now reflected on its European label.

Pfizer's Abrysvo, a maternal vaccine administered during pregnancy, represents another approach to infant RSV protection. Its potential for more widespread use due to lower production costs compared to monoclonal antibodies adds another dimension to the competitive landscape.

As the 2025 RSV season approaches, industry stakeholders await the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) meeting in June, where recommendations for RSV immunizations will be formulated, potentially shaping the market dynamics for these competing products.