The U.S. Food and Drug Administration (FDA) has expanded the approval of Herceptin® (trastuzumab) to include the initial treatment of HER2-positive metastatic cancer of the stomach or gastroesophageal junction in combination with chemotherapy.
Herceptin is a targeted therapy that has made important contributions to improved outcomes among women with HER2-positive breast cancer. HER2 is also overexpressed in some stomach cancers. The HER2 pathway is a biological pathway involved in cellular replication and growth. Herceptin targets and blocks the HER2-protein and is used for the treatment of both early-stage and more-advanced HER2-positive breast cancer.
The safety and efficacy of Herceptin among patients with HER2-positive advanced and inoperable stomach cancer was evaluated in the ToGA study, an international Phase III clinical trial among 594 patients. The ToGA study demonstrated an improvement in survival for HER2-positive patients who underwent treatment with Herceptin combined with chemotherapy compared with chemotherapy alone.  Half the patients were treated with chemotherapy alone, and half the patients were treated with chemotherapy plus Herceptin. Chemotherapy consisted of a fluoropyrimidine (Xeloda® [capecitabine] or 5-FU) and cisplatin.
Based on these results, the FDA expanded the approval of Herceptin in combination with chemotherapy to include HER2-positive metastatic stomach cancer patients who had not received prior treatment for metastatic disease.
 Bang Y-J, Van Cutsem E, Feyereislova A et al.. Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial. Lancet. 2010; 376:687-697.