Daiichi Sankyo

Daiichi Sankyo (第一三共株式会社) is a Japanese pharmaceutical company formed in 2005 by the merger of Sankyo and Daiichi Pharmaceutical. Its Enhertu franchise anchors a five-year plan targeting more than ¥3 trillion in revenue by fiscal 2030.¹

History and formation

The merger was announced in February 2005, when Sankyo agreed to buy its smaller rival Daiichi Pharmaceutical for $7.7 billion. The combination secured Sankyo's place as Japan's second-largest drug maker behind Takeda; the combined company, named Daiichi Sankyo from October 2005, had sales of about ¥910 billion ($8.6 billion), against Takeda's forecast ¥1.11 trillion that year.² The deal was part of a string of mergers among Japanese drug makers amid falling drug prices, rising development costs, and worries about becoming targets of foreign takeover.²

Structure and rationale. The transaction was executed as a joint share transfer under Article 364 of the Commercial Code, with the share transfer date set for September 28, 2005; both parties were delisted and the holding company was newly listed.³ The merger filing cited the complementary nature of the two pipelines and combined annual R&D expenditures of over ¥150 billion, and targeted annual cost savings of approximately ¥50 billion in the year ending March 31, 2008, primarily in domestic pharmaceutical operations.⁷

Business today

Growth trajectory. In fiscal 2024 (year ended March 31, 2025) revenue rose 17.8% to ¥1,886.3 billion, driven by Enhertu and Lixiana plus a ¥51.3 billion positive currency effect. Core operating profit rose 60.2% to ¥312.8 billion, and operating profit rose 56.9% to ¥331.9 billion; SG&A rose 15.5% to ¥724.8 billion, largely because of increased profit sharing with AstraZeneca on Enhertu.⁴ In fiscal 2025 revenue reached ¥2,123.0 billion, up 12.6%, with core operating profit of ¥360.0 billion, up 15.1%; reported operating profit fell 31.0% to ¥229.1 billion because of ¥153.0 billion of temporary expenses.¹

R&D intensity and dividends. R&D expenses rose 18.8% to ¥432.9 billion in FY2024, driven by investment in the five DXd ADC programs (T-DXd, Dato-DXd, HER3-DXd, I-DXd, and DS-6000).⁴ Guidance presented in January 2026 put FY2025 R&D at ¥460.0 billion, 21.9% of revenue, with an ROE target above 16%.⁸ The dividend has climbed with Enhertu-driven profit: the FY2024 annual dividend was raised ¥10 to ¥60 per share, FY2025 was set at ¥78 (up ¥18), and the FY2026 forecast is ¥100 per share.^{4 • 1} The five-year plan also commits to an adjusted dividend-on-earnings ratio of 10.0% or higher each year.¹

Key products and the ADC platform

How Enhertu works. Trastuzumab deruxtecan (T-DXd, brand name Enhertu) is built on Daiichi Sankyo's DXd ADC technology: a humanized anti-HER2 antibody attached to a topoisomerase I inhibitor payload by a tetrapeptide-based linker, designed to deliver chemotherapy inside cancer cells and reduce systemic cytotoxic exposure. Daiichi Sankyo is solely responsible for manufacturing and supply.⁵ For HER2-positive unresectable or recurrent gastric cancer, the drug was approved by Japan's MHLW in September 2020 and by the US FDA in January 2021, with the DESTINY-Breast trial program spawning many further trials.⁹

Commercial weight. Enhertu-related revenue reached ¥651.4 billion in FY2024, up 45.0% from ¥449.2 billion in FY2023, and ¥698.4 billion in FY2025, up 26.3%, with a FY2026 forecast of ¥861.3 billion.^{4 • 1} Combined Daiichi Sankyo and AstraZeneca booked sales passed the $5 billion milestone, triggering a $537.5 million (¥86.0 billion) milestone payment to Daiichi Sankyo.¹ Total 5DXd ADC revenue was ¥925.3 billion in FY2025, forecast at ¥1,157.9 billion in FY2026.¹

Partnerships and deal economics

AstraZeneca (2019). On March 28, 2019, AstraZeneca agreed to pay up to $6.90 billion in total for trastuzumab deruxtecan: a $1.35 billion upfront payment plus up to $5.55 billion contingent on future regulatory and sales milestones. The companies share development and commercialization costs and profits equally worldwide, except Japan, where Daiichi Sankyo retains exclusive rights; Daiichi Sankyo books sales in the US, certain European countries, and affiliate markets, while AstraZeneca books sales elsewhere, including China, Australia, Canada, and Russia.⁵

Merck (2023). Merck agreed to pay a $4 billion upfront payment plus $1.5 billion in continuation payments over 24 months, and up to $16.5 billion in sales milestones, for total potential consideration of up to $22 billion across three DXd ADC programs.⁶ The agreement also provides for up to $5.5 billion in sales milestones per ADC and a $1 billion refundable upfront payment. For raludotatug deruxtecan, Merck is responsible for 75% of the first $2 billion of R&D expenses; outside that, the companies equally share expenses and profits worldwide, except Japan, where Daiichi Sankyo retains exclusive rights and Merck receives a royalty on sales.⁶ The two deals together value the platform in the tens of billions of dollars and show the pattern Daiichi Sankyo has used throughout: full Japanese rights retained, profit sharing abroad, and Daiichi Sankyo manufacturing.^{5 • 6}

Pipeline and R&D

Datroway. Datopotamab deruxtecan (Datroway) recorded FY2025 global product sales of ¥47.6 billion, up ¥46.2 billion, treating more than 4,900 patients globally, with a FY2026 forecast of ¥111.4 billion.¹

Setbacks and near-term decisions. Patritumab deruxtecan failed to earn FDA approval for locally advanced or metastatic non-small cell lung cancer in June 2024.¹⁰ I-DXd (ifinatamab deruxtecan) received US Breakthrough Therapy Designation in 2025, with a PDUFA review date of October 2026 for extensive-stage small cell lung cancer.¹

References

1. FY2025 Financial Results and 5-Year Business Plan Presentation (FY2026–FY2030), Daiichi Sankyo
2. Japan Drug Maker to Buy a Rival for $7.7 Billion, The New York Times (2005)
3. Joint Share Transfer Agreement, SEC EDGAR
4. Consolidated Financial Results for Year Ended March 31, 2025 (Fiscal 2024) under IFRS, Daiichi Sankyo
5. [Daiichi Sankyo and AstraZeneca Announce Global Development and Commercialization Collaboration for [Fam-] Trastuzumab Deruxtecan (DS-8201), Daiichi Sankyo US](https://daiichisankyo.us/press-releases/-/article/daiichi-sankyo-and-astrazeneca-announce-global-development-and-commercialization-collaboration-for-daiichi-sankyo-s-her2-targeting-antibody-drug-conju)
6. Daiichi Sankyo and Merck Announce Global Development and Commercialization Collaboration for Three Daiichi Sankyo DXd ADCs, Merck
7. Rule 424(b)(3) filing, SEC EDGAR
8. J.P. Morgan Healthcare Conference presentation (January 2026), Daiichi Sankyo
9. Discovery research and translation science of trastuzumab deruxtecan, from non-clinical study to clinical trial, J-STAGE
10. Daiichi's pipeline falls behind rivals as cash flow nears peak: analysts, BioSpace

Topic: Encyclopedia › Society and history › Economics and business › Business and work › Companies and commercial industries › Pharmaceutical and healthcare companies

Initially written Oct 10, 2026 · Edited: Oct 11, 2026; Oct 15, 2026; Oct 21, 2026

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