KEY TAKEAWAYS
- The phase 3 trial did a combined analysis of four neoadjuvant cohorts with HER2DX and clinical data to predict increases in pCR rate for HER2-positive breast cancer patients.
- The HER2DX test analyzed 27 genes and indicated pCR to neoadjuvant trastuzumab-based CT.
- HER2DX can help predict patients with HER2-positive breast cancer who benefit from neoadjuvant dual HER2 blockade in combination with a single taxane.
The HER2DX test is invaluable for aiding personalized treatment decisions for HER2-positive breast cancer patients. The HER2DX test analyzes 27 genes and indicates pathological complete response (pCR) to neoadjuvant trastuzumab-based chemotherapy. This phase 3 study demonstrated that adding a second anti-HER2 agent and using multi-agent chemotherapy can increase the pCR rate, and HER2DX can play a vital role in achieving successful outcomes.
Researchers examined four neoadjuvant cohorts with HER2DX and clinical data (i.e., DAPHNe, GOM-HGUGM-2018-05, CALGB-40601, and ISPY-2). The pts received neoadjuvant trastuzumab (n=568) alongside multi-agent chemotherapy (n=282), a single taxane (n=286), pertuzumab (n=264), lapatinib (n=103), or without a second anti-HER2 drug (n=201). There was a significant correlation between HER2DX pCR as continuous score and pCR in all patients (odds-ratio [OR]=1.62, 95% CI 1.43-1.85; AUC=0.75), with those treated with trastuzumab and chemotherapy (OR=1.48, 1.18-1.86) and those treated with dual HER2 blockade and chemotherapy (OR=1.69, 1.50-1.91). Patients who received dual HER2 blockade during chemotherapy (OR=4.10, 1.85-9.07; interaction test p=0.03) had higher pCR rates than those who only received trastuzumab, especially for individuals with HER2DX pCR-high tumors. Researchers used multi-agent chemotherapy instead of a single taxane significantly raised the pCR rate in HER2DX pCR-medium tumors that were treated with dual HER2 blockade (OR=2.52, 1.18-5.52; interaction test p=0.01). The type of treatment did not affect the pCR rates in HER2DX pCR-low tumors, which remained at ≤30.0%.
The trial results revealed that the utilization of HER2DX may aid in identifying HER2-positive breast cancer patients who respond well to neoadjuvant dual HER2 blockade along with a single taxane.
Source: https://oncologypro.esmo.org/meeting-resources/esmo-breast-cancer-congress/her2dx-and-pathological-complete-response-in-her2-positive-breast-cancer-a-combined-analysis-of-4-neoadjuvant-studies
Clinical Trial: https://classic.clinicaltrials.gov/ct2/show/NCT00770809
Waks, A.G., Villacampa, G, Pare Brunet, L., Tung, N. M., Bueno Muiño, C., Echavarria, I., Diaz-Guardamino, Lopez-Tarruella Cobo, S., Marín-Aguilera, M., Brasó-Maristany, F., Pascual, T., Martinez Saez, O., Wolff, A.C., Demichele, A., Perou, C.M., Fernandez-Martinez, A., Carey, L.A., Mittendorf, E.A., Martin, M., Prat, A., Tolaney, S.M. Annals of Oncology (2023) 8 (1suppl_4): 101220-101220. 10.1016/esmoop/esmoop101220
