Syndax Pharmaceuticals has entered into a collaboration agreement with Ventana Medical Systems to develop a companion diagnostic assay for its Entinostat.

The companion diagnostic assay is being developed to select non-small cell lung cancer (NSCLC) patients to treat with erlotinib as well as with Syndax’s proprietary entinostat.

Syndax’s entinostat is an oral small molecule inhibitor of class I histone deacetylases, key enzymes that alter the structure of chromatin to control gene expression.

Syndax president and CEO Joanna Horobin said in a randomized, phase 2 Encore 401 study comparing erlotinib plus entinostat to erlotinib plus placebo, the subset of patients with tumors expressing high levels of the protein E-cadherin, experienced a more favorable overall survival and we therefore intend to select this patient population in the confirmatory study planned to start in the second half of the year.

Ventana has developed an in vitro diagnostic kit for use on VENTANA platforms to measure levels of E-cadherin in epithelial tissues in 2010.

Ventana plans to validate the assay in its CAP/ CLIA certified laboratory and may then serve as the central laboratory for the upcoming Syndax clinical trial.