One drug — Dupixent — generated $14.3 billion in FY2024 sales and constituted 31.8 percent of Sanofi's total revenue. That single molecule, a biologic antibody that blocks the IL-4 and IL-13 signaling pathways implicated in atopic dermatitis and asthma, has been approved for seven conditions with an eighth — COPD — approved in 2024. More than one million patients receive it. The drug's safety profile, which avoids the immunosuppression risks of systemic corticosteroids and JAK inhibitors, distinguishes it from alternatives in ways that physicians reward with prescription volume. Sanofi S.A. Was formed in 2004 through the hostile takeover of Aventis, creating a French multinational biopharmaceutical company headquartered in Paris with 76,493 employees and a $107.8 billion market capitalization. FY2024 revenue of $44.6 billion made it one of the largest pharmaceutical companies in Europe. The company operates across immunology, rare diseases, oncology, vaccines, and general medicines — a portfolio breadth that reflects multiple decades of acquisition-driven diversification. The planned separation of the Opella consumer healthcare division in Q2 2025 is the most significant structural decision Sanofi has made in recent years. Removing $4.9 billion in consumer healthcare revenue transforms the company into a pure-play biopharma entity. The rationale is straightforward: consumer healthcare — over-the-counter products like Allegra and Doliprane — requires different manufacturing, distribution, marketing, and capital allocation than prescription biologics. The separation focuses capital and management attention on the high-margin biopharma business while potentially unlocking valuation for the consumer division separately. The $9.5 billion Blueprint Medicines acquisition in 2025, the largest transaction in the company's history in a single purchase, and more than $13 billion in total acquisitions in the first seven months of 2025 represent the most aggressive business development period Sanofi has executed, reflecting urgency to diversify the revenue base beyond the Dupixent dependency before that drug's competitive environment changes.