Leica Biosystems, Merrimack Announced Partnership

Leica Biosystems and Merrimack Pharmaceuticals have announced a strategic partnership to develop companion diagnostic assays to aid in identification of patients who might best respond to current and future oncology therapies developed by Merrimack. The assays will be designed using Advanced Cell Diagnostics' (ACD's) RNAscope technology and will be processed on Leica Biosystems' BOND clinical advanced staining systems.

The initial focus of this partnership will be the development of a companion diagnostic assay for Merrimack's seribantumab, or MM-121, an investigational therapy. Seribantumab is a fully human, monoclonal antibody that targets ErbB3, a cell surface receptor that is activated by the ligand heregulin (HRG). Heregulin-driven ErbB3 signaling identifies a unique, more difficult to treat cancer phenotype characterized by increased tumor growth and increased resistance to targeted, cytotoxic and anti-endocrine therapies.

Seribantumab is being investigated primarily in combination settings, to block HRG activated ErbB3 signaling in order to enhance the anti-tumor effect of the combination therapy partner. "We are pleased to be working with Merrimack on cancer therapies with the BOND platform," added Matthias Weber MD, President of Leica Biosystems.

"The partnership utilizing RNAscope technology is an example of Leica Biosystems paving the way for in situ RNA detection in personalized medicine. The ease of use and high quality staining delivered by BOND systems makes them ideal platforms on which to deploy these very informative tests." "Our increased understanding of cancer cell biology is driving the need for companion diagnostic tests to ensure the right patients get the right therapies," said Jason Baum, Director, Companion Diagnostics at Merrimack."

The use of RNAscope technology on Leica Biosystems' automated staining platforms will allow us to detect HRG with high sensitivity and specificity, helping to identify the patients most likely to benefit from seribantumab treatment. HRG is the cognate ligand of the ErbB3 receptor and a powerful driver of cell survival signaling. HRG tumor expression has been implicated in defining a distinct, difficult to treat cancer phenotype that is found across multiple solid tumors at a prevalence rate of approximately 30-50% in major indications. We are pleased to have partnered with Leica Biosystems on this project."

Leica Biosystems' work program will be led from their Companion Diagnostics Research and Development site in Danvers, Greater Boston, Massachusetts, with kit manufacturing occurring in Newcastle.