Switzerland’s Roche has teamed up with the world renowned Mayo Clinic to develop a test that will enable patients with psychiatric disorders to receive targeted therapy, marking another move into the field of pharmacogenomics for the firm.

The first step will be to develop a tool that will offer drug selection and dosing information for a broad range of psychiatric drugs, using patient test results from Roche’s AmpliChip CYP450. Researchers at the Mayo Clinic have been genotyping their patients to identify the 2D6 and the 2C19 genes over the past two years, which in turn helps determine which drug and which dose an individual is going to best respond to – and with minimal side effects.

“This is an important step to aid in patient care in a specific therapeutic area, especially because psychiatric care often requires the need to fine-tune therapy,” said Heino von Prondzynski, chief executive of Roche Diagnostics. “Providing healthcare professionals with the information obtained by the AmpliChip CYP450 Test within this context may enable them to select the right medicine and the right dose for the individual patient.”

Roche has received European and US approval for its AmpliChip CYP450 Test, which is designed to analyse a patient’s DNA extracted from a blood sample, and so allows doctors to base an individual’s treatment regimen on their genetic make-up for a wide variety of common conditions such as cardiac diseases, pain, and cancer.

Understanding why certain people react differently to the same drugs could ultimately lead to individualised therapy by predicting who has a greater chance of benefiting from a given therapy, as well as tracking down the cause of certain rare, serious drug side effects. Some drugs already apply the technology. For example, genomic tests are helping to identify cancers that have a good chance of responding to a particular medication or regimen, which has helped in the development of targeted therapies, such as Roche's breast cancer drug, Herceptin (trastuzumab), Novartis' Gleevec (imatinib) for chronic myeloid leukemia and ImClone Systems' colorectal cancer drug, Erbitux (cetuximab).