US regulators have granted Swiss drug giant Roche permission to market its veteran breast cancer drug Herceptin as a targeted treatment for advanced stomach cancer.

Following in the footsteps of its European counterpart earlier this year, the US Food and Drug Administration has agreed that Herceptin (trastuzumab) is a safe and effective treatment for patients with metastatic cancer of the stomach or gastroesophageal junction.

However, only patients with tumours expressing HER2 - a protein produced by a specific gene with cancer-causing potential - are eligible, and the approval also stipulates the drug should only be used if prior treatment for advanced disease has not been given.

The FDA’s green light is based on solid results from a 594-patient Phase III study, known as ToGA, which showed that patients with HER-2 positive forms of the disease given Herceptin in addition to chemotherapy lived longer than those taking the latter alone. 

Roche’s drug improved overall survival by 37% compared to standalone chemotherapy (13.5 months versus 11 months, respectively), and in patients expressing high levels of HER2 the benefit was found to be even greater, with average survival of 16 months compared to 11.8 for the control arm.

Commenting on the approval, Hal Barron, head of global development and chief medical officer at Roche, said Herceptin, which is already a blockbuster with sales overshooting $1 billion in the US alone, provides “an important new, personalised medicine for people with this life-threatening disease, who have few treatment options”. And presumably the firm will also be looking forward to the additional revenue the drug's expanded use will bring.