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Bayer Pays Systems Oncology $25M Upfront to License ER-Positive Breast Cancer Drug

NEW YORK – Bayer said on Tuesday that it will pay Systems Oncology $25 million upfront for rights to a compound in preclinical development for estrogen receptor (ER)-positive, metastatic breast cancer. 

Under the terms of the exclusive global licensing agreement, Bayer will globally develop and commercialize the compound, called Erso. In addition to receiving $25 million in upfront payments, Scottsdale, Arizona-based Systems Oncology is eligible to receive up to $345 million upon meeting certain development and commercialization milestones, as well as royalties on future global net sales.

Erso is a small-molecule activator of unfolded protein response in ER-positive breast cancer cells, and it is being investigated for ER-positive metastatic breast cancer. Although 70 percent of breast cancers are driven by abnormal signaling by ER, once cancers become metastatic, the survival rate is only 20 percent. In preclinical studies, Erso has demonstrated activity against ER-expressing breast cancer cells and against tumor cells characterized by ER mutations. Based on this mechanism, the drug is also being studied in other types of cancers.

"The collaboration with Systems Oncology combines their deep experience in identifying alternative treatment pathways with our global footprint and established profile in order to develop new treatment options that can improve patient outcomes," said Marianne De Backer, executive VP and head of strategy and business development and licensing, at Bayer's pharmaceutical division. "It underlines our commitment to explore partnerships on innovative treatment approaches at all levels."