Lung cancer gene test approved as 'companion diagnostic'

The US medicines regulator, the Food and Drug Administration (FDA), has approved a genetic test to help doctors select suitable lung cancer patients to be treated with the drug erlotinib (sold as Tarceva).

The diagnostic from Roche is the first licensed test for variants of the EGFR gene, which encodes the protein that erlotinib targets.

Dr Hal Barron, head of global product development at Roche says that 'ten to 30 percent of people worldwide with lung cancer have tumours that test positive for certain EGFR mutations'.

The test will be used to check whether patients with advanced, metastatic cancer — where the cancerous cells have spread to other parts of the body — have one of these mutations. If they do, then they are more likely to benefit from erlotinib in place of standard chemotherapy.

The EURTAC clinical trial validated this approach. In the study, patients with EGFR mutations treated with erlotinib lived for over ten months without their getting worse. In comparison, patients given standard chemotherapy lived without disease progression for only five months.

These non-small cell lung cancers (NSCLC) account for the majority of lung cancers, which themselves account for the majority of the cancer-related deaths. Personalised medicine regimes such as this aim to tailor drug courses to those patients for whom the drugs are most likely to be effective. It is hoped that this will provide better outcomes for patients, while using restricted healthcare funds more cost-effectively.

Erlotinib has been licensed in the UK and elsewhere in Europe as first-line treatment of NSCLC in patients harbouring appropriate EFGR mutations since 2012, after the EURTAC trial showed it to be effective. It is also indicated as a potential second-line treatment where previous chemotherapy courses have failed.