AstraZeneca (NYSE: AZN) owes Daiichi Sankyo $75 million after Enhertu wins EU approval

Posted by Anthony Miller on Oct 27th, 2026

What happened

AstraZeneca PLC (NYSE: AZN) owes Daiichi Sankyo $75 million after the EU approved Enhertu for early breast cancer.

The European Commission approved Enhertu on Oct. 27 as a monotherapy for adults with resected HER2-positive breast cancer. Eligible patients have residual invasive disease after neoadjuvant taxane-based and HER2-targeted treatment. The approval follows a positive opinion from the Committee for Medicinal Products for Human Use of the European Medicines Agency.

The filing calls it the first EU approval of Enhertu in the curative-intent early breast cancer setting. It rests on the DESTINY-Breast05 Phase III trial, which enrolled 1,635 patients. Enhertu is now approved in more than 35 countries for this use.

Key numbers

Metric	Latest	Source
Milestone payment due from AstraZeneca to Daiichi Sankyo	$75 million	SEC 6-K
Reduction in risk of invasive disease recurrence or death vs. T-DM1	53%	SEC 6-K
Three-year invasive disease-free survival, Enhertu	92.4%	SEC 6-K
Three-year invasive disease-free survival, T-DM1	83.7%	SEC 6-K
Patients enrolled in DESTINY-Breast05	1,635	SEC 6-K

Read more: AstraZeneca (AZN) company research

Why it matters

The trial result is strong. Enhertu cut the risk of invasive disease recurrence or death by 53% against trastuzumab emtansine (T-DM1), a hazard ratio of 0.47. Three-year invasive disease-free survival was 92.4% for Enhertu and 83.7% for T-DM1.

The filing says no new safety concerns were identified. It describes the safety profile as consistent with the known profile of Enhertu.

DESTINY-Breast05 compared Enhertu directly with T-DM1. Patients in the trial had disease that remained after neoadjuvant taxane-based and HER2-targeted treatment. That is the same population the approval covers.

The money flow is the catch. Sales of Enhertu in most EU territories are recognised by Daiichi Sankyo, the filing says. For AstraZeneca, the approval therefore comes with a payment owed, while Daiichi Sankyo records most EU sales.

OptimistFi has argued that AstraZeneca works when clinical differentiation turns into high-margin global revenue. The trial data supports the differentiation half of that view. The EU sales arrangement leaves the revenue half unproven in AstraZeneca's own reported numbers.

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What's next

The next test is AstraZeneca's next quarterly report. Growth in the Enhertu sales AstraZeneca reports would show the label expansion reaching its own revenue. Flat sales would support the view that most EU sales sit with Daiichi Sankyo.