Myriad Genetics Announces Publication of a Prospective Clinical Study of the EndoPredict Test in Women with Early-Stage Breast Cancer

EndoPredict Predicts Response to Neoadjuvant Chemotherapy and Endocrine Therapy

SALT LAKE CITY, June 04, 2020 (GLOBE NEWSWIRE) -- Myriad Genetics, Inc. (NASDAQ: MYGN, “Myriad” or the “Company”), a global leader in molecular diagnostics and precision medicine, today announced the publication of a prospective study demonstrating that the EndoPredict test predicts which patients with ER+, HER2- early-stage breast cancer will benefit from neoadjuvant therapy.  The article titled, “The EndoPredict score predicts response to neoadjuvant chemotherapy and neoendocrine therapy in hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer patients from the ABCSG-34 trial,” appeared online in the European Journal of Cancer.

“This study demonstrated that the EndoPredict (EP) test predicted response to neoadjuvant chemotherapy or neoadjuvant endocrine therapy in women with ER+, HER2 negative early-stage breast cancer,” said Peter Dubsky, M.D., lead author, speaking on behalf of the Austrian Breast and Colorectal Cancer Study Group (ABCSG).  “Based on these findings and prior studies, we are confident the EndoPredict test can add valuable information to aid in personalized treatment selection in neoadjuvant therapy and provides an important basis for future design of neoadjuvant clinical trials.”

The primary objective of this prospective study was to test the predictive value of the EndoPredict test regarding tumor response after neoadjuvant chemotherapy (NaCT) or neoadjuvant endocrine therapy (NET) within the ABCSG-34 trial.  The analysis included data from 217 women with HR+ breast cancer.  Of these, 134 patients were assigned to receive NaCT (eight cycles of anthracycline/taxane) according to aggressive clinico-pathologic tumor features.  The remaining 83 patients were clinically identified as having luminal A-like types of breast cancer and were assigned to receive NET (six months of letrozole).  The primary endpoint was residual cancer burden RCB0/I (i.e., good tumor response) vs. RCB II/III (i.e., poor tumor response) at time of surgery.

In the neoadjuvant chemotherapy group, 125 patients had high EP scores and nine had a low EP score.  The results show that 26.4 percent of those with a high score showed a good tumor response (RCB0/I) to neoadjuvant chemotherapy, while all patients with a low score showed only a poor tumor response (Table 1).  In the “luminal A” group receiving neoendocrine therapy, 39 patients had a high EP score and 44 had a low EP score.  The results show that 27.3 percent of those with a low EndoPredict score and 7.7 percent with a high score achieved excellent tumor response (RCB0/I) to neoendocrine therapy (Table 1).