A Clinical Trial Evaluating the Effect of ASLAN001 in Patients With Recurrent/Metastatic Gastric Cancer Whose Tumors Are Either HER-2 Amplified or Co-expressing HER-1 and HER-2

About 1 million new cases of gastric cancer were estimated to have occurred in 2008 (988,000 cases, 7.8% of the total), making it currently the fourth most common malignancy in the world, behind cancers of the lung, breast, and colo-rectum. Gastric cancer is also the second leading cause of cancer-related death in both sexes worldwide with 700,000 deaths occurring annually. The incidence and mortality rates for gastric cancer vary widely in different regions of the world. The incidence has dramatically declined in the United States where it ranks seventh as a cause of cancer- related deaths. In the Asia-Pacific region, the highest incidences of gastric cancer can be found in China, Japan, and Korea, where the age standardized incidence rate (ASR) is greater than 20 per 100,000 populations. Intermediate risk countries (ASR 11-19/100,000 population) include Malaysia, Singapore, and Taiwan, while low-risk countries (ASR \< 10/100,000 population) include Australia, New Zealand, India, and Thailand. Approximately 95% of all malignant gastric neoplasms are adenocarcinomas. One of the most striking epidemiologic observations has been the increasing incidence of adenocarcinomas involving the proximal stomach and distal oesophagus including the oesophagogastric junction. These tumours are thought to have different etiologic factors; gastric body and antral lesions are associated with low acid production and Helicobacter pylori infection, whereas cardiac lesions are not associated with either. The treatment for advanced and un-resectable disease has remained essentially unchanged for the past 2 decades, with platinum and fluoro-pyridine-based combination chemotherapy being the mainstay of therapy. The molecular biology responsible for carcinogenesis, tumour biology, and response to therapy in gastric cancer are active areas of investigation. Amplification and/or over-expression of epidermal growth factor receptor-2 (HER 2) have been found to promote tumourigenesis and to be involved in the pathogenesis of gastric cancer. Recently, data from randomised studies of trastuzumab (Herceptin®) in patients with HER 2 amplification demonstrated significant improvement in outcome in comparison to chemotherapy alone. Studies on a number other molecularly targeted agents used alone or in combination with chemotherapy have been undertaken, or are ongoing. Translational research, undertaken as part of these studies, demonstrates the great molecular heterogeneity of the disease, with multiple growth factor and survival pathways being implicated. In view of this, successful therapeutic intervention is likely to require both the identification of molecularly defined subsets of disease, and the evaluation of rationally-selected combinations of targeted agents.