AstraZeneca and Daiichi Sankyo reported new data at ESMO showing Enhertu (trastuzumab deruxtecan) produces meaningful responses when used earlier in the breast cancer treatment pathway. Trial results disclosed at the meeting indicate improved tumor shrinkage and higher rates of pathological response in preoperative and adjuvant settings, expanding the drug beyond metastatic use. The companies presented topline and detailed phase 3 datasets discussed at ESMO that could widen patient eligibility and materially increase addressable market for the ADC. The broader finding at ESMO — that antibody‑drug conjugates (ADCs) can be effective in earlier-stage disease — was reinforced by presentations on next‑generation ADC platforms. Investigators highlighted how improved payloads, linkers and targeting moieties raise the possibility of substituting or truncating conventional chemo regimens in curative‑intent settings. For industry players, the move of ADCs up the treatment ladder implies larger commercial opportunity and earlier regulatory activity for ADC developers. For clinicians and drug developers, the takeaways are practical: trial designs should now consider ADCs in neoadjuvant and adjuvant cohorts, and payers will soon face assessments of ADCs’ curative‑intent cost‑effectiveness. ADC technical terms: an ADC links an antibody to a cytotoxic drug to deliver payloads selectively to tumor cells.