Enhertu's next step to breast cancer domination

A month after scoring in the first-line breast cancer study Destiny-Breast09, Daiichi Sankyo/AstraZeneca's Enhertu has the neoadjuvant setting in its sights. This could come thanks to a win toplined on Wednesday in the Destiny-Breast11 study, whose data the companies say will be shared with regulatory agencies. However, so far the win has come only on the primary endpoint of pathological complete response rate, and regulators might choose to wait for results from the more robust secondary endpoint of event-free survival; at present EFS numbers are immature, but are said to be showing an early positive trend. There is further nuance here: Destiny-Breast11, which used chemo followed by paclitaxel, Herceptin and Perjeta (THP) as control, has shown a positive result only for Enhertu followed by THP, and not for Enhertu alone. An Enhertu-only cohort was closed after failing an interim efficacy assessment versus THP, the companies disclosed. If nothing else this raises questions about the cost of having to use three HER2-directed therapies in the neoadjuvant setting, though Astra/Daiichi argue that Enhertu followed by THP showed better safety than chemo followed by THP. Enhertu faces one more phase 3 breast cancer readout this year, from the adjuvant study Destiny-Breast05.

Phase 3 trials of Enhertu in breast cancer

Source: OncologyPipeline.