Sanofi Shares Surge 95% in Daily Trading Volume to Rank 474th Most Actively Traded on Regulatory Momentum for Rare Disease Drug

Sanofi (SNY) saw its daily trading volume surge by 95.47% on August 18, 2025, reaching $200 million, ranking 474th in market activity. The stock closed with a 0.14% gain, reflecting cautious investor sentiment amid regulatory developments. The European Medicines Agency (EMA) granted orphan drug designation for rilzabrutinib, a BTK inhibitor targeting IgG4-related disease (IgG4-RD), a rare immune-mediated condition. This approval follows positive Phase II trial results showing reduced disease flares and glucocorticoid use over 52 weeks in patients. Rilzabrutinib also holds orphan status for immune thrombocytopenia (ITP) in the EU, US, and Japan, with a pivotal FDA decision on ITP treatment expected on August 29, 2025. The drug remains investigational, pending final regulatory validation of its safety and efficacy profile.

Sanofi’s broader pipeline momentum includes recent European Commission approval of Sarclisa for multiple myeloma in July 2025, based on GMMG-HD7 trial data. The company is advancing rilzabrutinib through regulatory reviews in the US, EU, and China for ITP applications. The therapy’s TAILORED COVALENCY technology positions it as a differentiated BTK inhibitor with potential for multiple rare disease indications, including warm autoimmune hemolytic anemia and sickle cell disease. Analysts note that orphan designations provide market exclusivity and financial incentives, which could bolster Sanofi’s long-term growth in high-unmet-need therapeutic areas.

Despite these advancements, rilzabrutinib’s commercial viability remains contingent on final regulatory approvals. IgG4-RD, a chronic condition with systemic inflammatory effects, affects fewer than 5 in 10,000 EU residents, aligning with EMA’s criteria for orphan designations. The drug’s ability to reduce flare-ups and steroid dependence addresses a critical unmet need in managing this progressive disease. Sanofi’s strategic focus on rare and immune-mediated diseases underscores its R&D-driven approach, though near-term revenue contributions from rilzabrutinib are unlikely until regulatory clearances are finalized.

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