In Vitro Diagnostic Test Accurately Predicts Response to Treatment in Breast Cancer

BioNTech AG, a drug developer that specializes in cancer immunotherapies, announced last month new results from a clinical performance evaluation study of a molecular in vitro diagnostic test for quantitative detection of mRNA expression of certain genes. The results were presented at the European Society for Medical Oncology’s Annual Meeting held in Munich, Germany, from October 19-23, 2018.

The diagnostic test, MammaTyper, detects mRNA expression status of human epidermal growth factor 2 (HER2), estrogen receptor (ER), progesterone receptor (PR), and MKI67 in the tumor tissue of female patients with newly diagnosed invasive breast cancer.

Samples from the TECHNO and PREPARE trials were used to validate a predefined score and cut-off integrating “highly standardized mRNA measurements" of HER2, ER, PR, and MKI67 by MammaTyper. The score then enables the prediction of pathological complete response after neoadjuvant chemotherapy based on the pretreatment biopsy. The cut-off accurately separates patients with an estimated good response rate from those with a low probability of a good response rate. For patients with a low probability of response, a treatment other than neoadjuvant chemotherapy may then be considered.

The studies also demonstrated that standardized measurements of these genes are comparable to the determination of the markers on immunohistochemistry level and are “strongly associated” with response to neoadjuvant chemotherapy as well as long-term outcome in these patients.

Researchers noted that the studies demonstrated the MammaTyper test accurately assessed the gene mRNA levels from pretreatment biopsies and thus could be used as a valid predictor of complete pathologic remission after neoadjuvant chemotherapy treatment.

“Achieving a [pathological complete response] after [neoadjuvant breast cancer] is strongly associated with long-term disease-free survival,” said Professor Sibylle Loibl, MD, PhD, CEO of GBG Forschungs GmbH. “Although the prognostic impact of [pathological complete response] on different breast cancer subtypes may vary, achieving [pathological complete response] remains an important factor in clinical decision-making.”