# Daiichi Sankyo

Canonical page: https://technooptimist.io/companies/daiichi-sankyo
Japanese drugmaker whose DXd technology produced the most successful antibody-drug conjugates: Enhertu (HER2) and Datroway (TROP2), both co-developed and sold with AstraZeneca.

## In brief

- Enhertu is approved in 90+ countries for HER2-positive breast cancer and now used from early disease to first-line metastatic.
- Datroway won a survival benefit in first-line triple-negative breast cancer; US approval May 2026.
- AstraZeneca partnerships: Enhertu since March 2019, Datroway since July 2020; Daiichi keeps Japan and makes the drugs.

## Facts

- Headquarters: JP
- Status: public
- Website: https://www.daiichisankyo.com
- Frontiers: [Biotech](https://technooptimist.io/biotech.md) (Antibody drugs)

## Programs

- [Enhertu](https://technooptimist.io/biotech/enhertu.md) (Biotech): Scaling. Approved in 5 cancer types; added first-line HER2+ (Dec 2025) and early breast cancer (May 2026).
- [Datroway](https://technooptimist.io/biotech/datroway.md) (Biotech): Deploy; next: EU, China and Japan reviews in triple-negative breast cancer (2026). Three US approvals; May 2026 first-line triple-negative breast cancer after a survival win.

## Technical approach

- **DXd platform: Antibody + cleavable linker + payload**: An antibody carries a potent chemotherapy (DXd, a topoisomerase I poison) on a linker cut only inside cells.
- **Heavy loading: Many payloads per antibody**: Each antibody carries several DXd molecules, delivering far more drug per tumour cell than older conjugates.
- **Spill-over: Kills neighbouring cells too**: Released payload can cross into nearby cancer cells, which helps when the target is patchy (HER2-low tumours).

## Open problems

- **Lung inflammation** (active research): Interstitial lung disease, sometimes fatal, is the class's main risk; with Enhertu + pertuzumab it hit 12% of patients.
- **Who benefits from TROP2?** (open): TROP2 is on most tumours, but its level predicts response poorly; better patient selection is still being worked out.

## Latest updates

- **22 May 2026**: Datroway approved in the US for first-line triple-negative breast cancer after extending survival. The FDA approved Datroway for metastatic triple-negative breast cancer in patients who cannot receive PD-1/PD-L1 immunotherapy. ([our story](https://technooptimist.io/stories/datroway-approved-in-the-us-for-first-line-triple-negative-breast-6f00b0bf.md) · [original source](https://www.astrazeneca.com/media-centre/press-releases/2026/datroway-approved-in-us-for-1l-triple-negative-bc.html))
- **15 May 2026**: FDA approves Enhertu for early HER2-positive breast cancer, both before and after surgery. Enhertu moved into curative-intent treatment with two US approvals for early HER2-positive breast cancer. ([our story](https://technooptimist.io/stories/fda-approves-enhertu-for-early-her2-positive-breast-cancer-both-before-21ce340f.md) · [original source](https://www.curetoday.com/view/fda-approves-enhertu-for-her2-positive-early-stage-breast-cancer))
- **10 Dec 2025**: Enhertu plus pertuzumab approved in the US as first-line treatment for HER2-positive metastatic breast cancer. The FDA approved Enhertu with pertuzumab as the first treatment for HER2-positive metastatic breast cancer, the first new first-line option in more than a decade. ([our story](https://technooptimist.io/stories/enhertu-plus-pertuzumab-approved-in-the-us-as-first-line-treatment-for-b68a6253.md) · [original source](https://www.biospace.com/press-releases/enhertu-plus-pertuzumab-approved-in-the-u-s-as-first-new-treatment-in-more-than-a-decade-for-first-line-treatment-of-patients-with-her2-positive-metastatic-breast-cancer))
- **5 Aug 2022**: FDA approves Enhertu as the first treatment for HER2-low breast cancer. The FDA approved Enhertu for metastatic breast cancer with low HER2 levels, a group that had been treated as HER2-negative and had no targeted option. ([our story](https://technooptimist.io/stories/fda-approves-enhertu-as-the-first-treatment-for-her2-low-breast-cancer-18b553b7.md) · [original source](https://www.onclive.com/view/fda-approves-trastuzumab-deruxtecan-for-unresectable-or-metastatic-her2-low-breast-cancer))

## Partners, customers and investors

- AstraZeneca (partner): Co-develops and co-sells Enhertu (since March 2019) and Datroway (since July 2020) worldwide except Japan.

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