HER2DX genomic test in HER2-positive/hormone receptor-positive breast cancer treated with neoadjuvant trastuzumab and pertuzumab: A correlative analysis from the PerELISA trial

Prognostic value of HER2DX in early-stage HER2-positive breast cancer: a comprehensive analysis of 757 patients in the Sweden Cancerome Analysis Network—Breast dataset (SCAN-B)

“…In a prior study, HER2DX ERBB2 mRNA score has shown to predict pCR following five cycles of trastuzumab-pertuzumab and endocrine therapy in hormone-sensitive HER2+ breast cancer in tumor samples from the PER-ELISA phase II trial, where the pCR rate in the HER2DX ERBB2 mRNA-low group was 0.0%, versus 7.7% and 53.3% in the HER2DX ERBB2 mRNA-med and -high groups, respectively. 20 Similarly, HER2DX E RBB2 mRNA score has been associated with overall response following T-DM1 monotherapy in the advanced HER2+ setting, with an observed overall response rate of 0%, 29%, and 56% in HER2DX ERBB2-low, -med, and -high groups, respectively. 34 Collectively, the results from the SCAN-B analysis and the two studies suggest a consistent pattern.…”

“…ERBB2 mRNA expression within HER2+ breast cancer can help identify patients with a high response to anti-HER2 therapies. 15 , 20 In SCAN-B, 171 patients with HER2+ disease did not receive trastuzumab. Thus, we explored the relationship between ERBB2 mRNA score and survival outcomes according to trastuzumab use in the SCAN-B cohort after adjusting for tumor size and nodal status.…”

“…In this direction, the HER2DX genomic test was created in 2022 based on the expression of 27 genes and clinical attributes. 15 , 16 , 17 , 18 , 19 , 20 , 21 The test delivers two scores that predict both long-term prognosis (i.e. risk-score) and the likelihood of pCR in early HER2+ breast cancer following trastuzumab-based neoadjuvant therapy.…”

Analytical validation of HER2DX genomic test for early-stage HER2-positive breast cancer

“…Embarking on this trajectory, the HER2DX genomic assay emerged in 2022, driven by the combination of 27 genes underlying 4 biological signatures, and clinical attributes. 5 , 6 , 7 , 8 , 9 , 10 , 11 The test delivers two scores trained to predict both long-term prognosis (i.e. relapse risk score) and the likelihood of pathological complete response (i.e.…”

“… 9 , 11 The HER2DX pCR likelihood score was validated in multiple clinical studies demonstrating its ability to inform neoadjuvant therapy strategies in the context of both European and US standard of care. 5 , 6 , 7 , 8 , 10 Notably, the 2022 SEOM-GEICAM-SOLTI guidelines endorsed its clinical utility in specific cases, 12 and the St. Gallen International Consensus Conference for the Primary Therapy of Individuals with Early Breast Cancer 2023 identified HER2DX as a practice-changing finding. 13 …”