The WSG TP-II randomized phase II trial showed that neoadjuvant endocrine therapy plus trastuzumab and pertuzumab results in lower pathologic complete response rates than paclitaxel plus dual HER2 blockade but achieves excellent 5-year overall survival and event-free survival. Grade 3-4 adverse events were lower with endocrine therapy, and polyneuropathy was more common with paclitaxel. This study supports the use of a de-escalated chemotherapy or endocrine therapy approach with pCR-guided adjuvant HER2 therapy in hormone receptor-positive/HER2-positive early breast cancer.
Study
|
Randomized, open-label, multicenter, phase II trial [WSG TP-II] |
| Hormone receptor-positive/HER2-positive early breast cancer |
| Neoadjuvant endocrine therapy plus trastuzumab and pertuzumab (ET+TP, n=100) vs paclitaxel plus trastuzumab and pertuzumab (paclitaxel + TP, n=107) with further pCR-guided adjuvant therapy
|
Efficacy
|
pCR: 23% vs. 53% (ET + TP vs. paclitaxel + TP) |
| 5yr OS: 100% vs 97.9% |
| 5yr EFS: 92.1% vs 94.8% |
| 5-year invasive disease-free survival: 97.7% vs 79.8%
|
Safety
|
Grade 3-4 adverse events: 14.1% vs 35.6% |
| More frequent polyneuropathy with paclitaxel (6.1% vs. 28.9%) |
| Serious adverse events occurred in 12.1% vs 17.0%
|
J Clin Oncol. Published online 2026-05-18
http://doi.org/10.1200/JCO-25-01047
Reviewed by Ulas D. Bayraktar, MD on Jun 15, 2026
