Shares of Swedish Orphan Biovitrum (STO: SOBI) declined by 4% after the U.S. FDA approved Merck’s new RSV vaccine, Enflonsia (clesrovimab). This development signals the emergence of a major competitor to Beyfortus, the Sanofi-developed RSV prevention therapy that generates significant royalties for Sobi.
🧬 Why It Matters
The approval of Enflonsia was expected, but its official entry now presents real competitive pressure on Beyfortus in the U.S. market. Analysts have already forecasted a 10% decline in Beyfortus sales this year, reflecting anticipated erosion due to Enflonsia’s launch.
While Sanofi remains optimistic about RSV market growth, the introduction of a new rival therapy changes the competitive landscape—especially in a market where early shipments and physician confidence are crucial.
💬 Analyst Take
RBC Capital Markets commented:
“We assume Beyfortus sales fall 10% in the U.S. this year, despite Sanofi’s confidence that the market has clear room for growth… Enflonsia’s impact is already priced into our assumptions.”
🏛️ ACIP Panel Uncertainty Looms
Though Enflonsia has FDA approval, its full commercial rollout hinges on a favorable recommendation from the U.S. Advisory Committee on Immunization Practices (ACIP)—now in turmoil.
Key Update:
U.S. Secretary of Health Robert F. Kennedy has reportedly removed all 17 ACIP members, raising questions about the timing and direction of the next ACIP meeting scheduled for June 25–27. Any delay or lack of consensus could impact Enflonsia’s market penetration and give Beyfortus a temporary reprieve.
📉 Market Impact
- Sobi down 4% amid fears of reduced royalty income.
- Market awaits clarity on ACIP’s stance, which could shift competitive dynamics again.
- Both Sanofi and Merck now face uncertainty, not from regulators, but from policy disruptions.
