AstraZeneca has entered into collaboration with Roche to develop a plasma-based companion diagnostic test to support AZD9291, AstraZeneca’s investigational compound in clinical development for non-small-cell lung cancer (NSCLC), according to a company news release.

The companion diagnostic test is designed to identify epidermal growth factor receptor (EGFR) mutations in both tumour tissue and plasma derived from patients with NSCLC, and to optimise the clinical development of AZD9291 for patients who are resistant to first-generation EGFR tyrosine kinase inhibitors (TKI).

Currently, patients who have been treated with EGFR-TKIs in whom the disease has progressed have to undergo a repeat biopsy to assess whether they have a specific mutation, T790M. Diagnostic tests based on circulating DNA (ctDNA) in plasma samples provide an alternative method of identifying the T790M mutation.

“Currently, late-stage lung cancer patients have to undergo surgery to collect tissue from a tumor so it can be sent for molecular testing,” said Paul Brown, Head of Roche Molecular Diagnostics (RMD). “In some cases, collecting enough tissue for testing is not possible. This collaboration will enable molecular testing through plasma specimens and provide the information needed to inform treatment decisions without the complications of surgery, consequently increasing the level of care clinicians can give to the patient.”