EU clears Enhertu plus pertuzumab as first-line HER2-positive metastatic breast cancer therapy

AstraZeneca and Daiichi Sankyo announced that Enhertu plus pertuzumab has been approved in the European Union as the first new first-line regimen in more than a decade for HER2-positive metastatic breast cancer.¹ The companies' release describing the news is dated 01 September 2026, though the source does not specify the exact date of the European Commission's approval decision itself.

The approval rests on the Phase III DESTINY-Breast09 trial. In the trial, Enhertu combined with pertuzumab reduced the risk of disease progression or death by 44% versus a taxane, trastuzumab and pertuzumab, based on a hazard ratio of 0.56 (95% CI 0.44-0.71, p<0.00001), with median progression-free survival of 40.7 months compared to 26.9 months for the standard regimen.¹ The companies said the safety profile of the combination was consistent with the known profiles of each individual treatment, with no new safety concerns identified.¹

DESTINY-Breast09 enrolled 1,157 patients across sites in Africa, Asia, Europe, North America and South America.¹ Based on these results, the combination has also been included in ESMO Clinical Practice Guidelines as a Category IA first-line option for metastatic HER2-positive breast cancer regardless of hormone receptor status.¹ Separately, Enhertu is also under review in the EU for patients with HER2-positive breast cancer who have residual invasive disease after neoadjuvant HER2-targeted treatment, based on data from the DESTINY-Breast05 trial;¹ the release does not specify whether that pending review involves Enhertu alone or in combination with another agent.

On the financial side, the EU approval triggers a $100 million milestone payment from AstraZeneca to Daiichi Sankyo for the first-line unresectable or metastatic HER2-positive breast cancer indication.¹ Sales of Enhertu in most EU territories are recognized by Daiichi Sankyo.¹