Neoadjuvant endocrine therapy versus de-escalated chemotherapy, both with dual HER2 blockade, for HR-positive, HER2-positive EBC

The multicenter WSG-TP-II randomized trial in Germany compared 12 weeks of neoadjuvant de-escalated endocrine therapy (ET, aromatase inhibitor or tamoxifen) versus de-escalated chemotherapy (CT, paclitaxel), both in combination with HER2-blockade with trastzumab and pertuzumab, for HR-positive, HER2-positive early-stage breast cancer. The pathological complete response (pCR) rate was 56% with CT versus 24% with ET. Comparable high pCR rates were observed only in tumors with highest ERBB2-expression by mRNA. The authors conclude that the trial demonstrated an excellent pCR rate after 12 weeks of de-escalated CT plus dual HER2 blockade, that was clearly superior to the pCR rate after 12 weeks of ET plus dual HER2 blockade (visual abstract).