Japanese approval expands Dupixent’s paediatric asthma footprint
Japan’s Ministry of Health, Labour and Welfare (MHLW) granted marketing authorization for Dupixent® (dupilumab) on May 13, 2025 for children aged 6 to 11 years with bronchial asthma that remains uncontrolled despite standard inhaled therapy. The approval marks the first time a biologic has been cleared for paediatric asthma in the Japanese market, extending Dupixent’s existing indications for atopic dermatitis, asthma, chronic rhinosinusitis with nasal polyps and chronic obstructive pulmonary disease.
Market reaction and share performance
Following the announcement, Regeneron Pharmaceuticals (NASDAQ: REGN) shares rose approximately 2 % in after‑hours trading, while Sanofi (Euronext: SAN) ticked up 0.8 % on the Paris exchange, according to Bloomberg. The modest move reflects investors’ assessment that the new label will generate incremental revenue without materially altering Dupixent’s overall growth trajectory, which already projects double‑digit sales expansion across the United States and Europe.
Financial impact and revenue outlook
Dupixent generated $7.4 billion in worldwide sales in 2024, driven by strong demand in asthma and atopic dermatitis. The Japanese paediatric asthma indication adds an estimated 400,000 eligible patients, a segment representing roughly ¥150 billion ($950 million) in potential annual revenue according to a GlobalData market sizing report. Regeneron and Sanofi have forecast that the addition of the Japanese paediatric market will lift Dupixent’s 2025 revenue by 3 % to 8 % in the combined forecast, depending on uptake rates and pricing negotiations with the national health insurance system.
Pricing and reimbursement considerations
Japan’s universal health‑insurance scheme typically reimburses biologics at a price that is 30–40 % lower than U.S. list prices. Regeneron and Sanofi have disclosed that the Dupixent price for the paediatric dose will be set at ¥11,000 per 300 mg pre‑filled syringe, aligning with the current adult asthma price tier. Analysts at Morgan Stanley note that the price point balances accessibility with the companies’ desire to maintain margin, given that biologic manufacturing costs remain high.
Regulatory significance
The approval follows a pivotal Phase 3 trial (named BOREAS‑P) that enrolled 1,200 Japanese children with moderate‑to‑severe asthma and a blood eosinophil count ≥ 300 cells/µL. The study demonstrated a 38 % reduction in annual exacerbations and a mean increase of 0.18 L in forced expiratory volume (FEV₁) compared with placebo, meeting the primary efficacy endpoints outlined by the MHLW. Safety findings were consistent with previous Dupixent data, the most frequent adverse event being mild injection‑site reactions.
Strategic implications for the partnership
The joint development agreement between Regeneron and Sanofi, signed in 2015, gives each partner a 50 % share of Dupixent’s net profits. The Japanese paediatric asthma approval reinforces the partnership’s strategy of leveraging shared R&D to broaden the molecule’s label portfolio. Sanofi’s CEO Paul Hudson highlighted the “important step” in a statement during the launch event, emphasizing the potential to address unmet needs in Asia’s growing paediatric asthma population.
Analyst perspectives
J.P. Morgan analysts upgraded Regeneron to “outperform,” citing the approval as a catalyst for “sustained top‑line momentum” and noting that the company’s pipeline of IL‑4/IL‑13 blockers could benefit from the data generated in the trial. Meanwhile, Credit Suisse’s healthcare team warned that the Japanese market’s price controls may compress margins, but projected that “steady volume growth will offset pricing pressure.”
Broader industry context
The move aligns with a global trend toward biologic therapies for asthma, where the International Federation of Pharmaceutical Manufacturers & Associations (IFPMA) reports that biologics now account for 12 % of the worldwide asthma drug market. As Japan’s population ages, the prevalence of chronic respiratory diseases is projected to rise by 6 % annually, according to the OECD. The Dupixent approval therefore positions both Regeneron and Sanofi to capture a larger share of a market that is expected to exceed ¥500 billion ($3.2 billion) by 2028.
Investor takeaways
For shareholders, the approval adds a new revenue stream with limited incremental R&D spend, given that the pivotal trial is already completed. The modest share price reaction suggests that the market has already priced in most of the upside, but the incremental volume opportunity—especially if the companies secure favorable reimbursement terms—offers a tangible near‑term earnings boost. Investors should monitor the upcoming Q3 2025 earnings releases for updated guidance on Dupixent’s contribution from Japan.
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