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

Inclusion Criteria:

* Male or female patients 21 years of age or older at the time written informed consent is obtained.
* Patients with histologically confirmed adenocarcinoma of the stomach, gastro-oesophageal junction or distal oesophagus with inoperable locally-advanced metastatic disease.
* Patients with tumours with immunohistochemical evidence of expression of HER-1 (at level of + or ++ or +++) and HER-2 (at level of + or ++ or +++) using standard criteria OR tumours with gene-amplification of HER-2 by standard FISH.
* Patient has received 1 or more prior chemotherapy for the treatment of adenocarcinoma of the stomach, gastro-oesophageal junction or distal oesophagus with metastatic disease.
* Patients with prior partial gastrectomy if they can take oral medications, and can undergo gastroendoscopic biopsies and meet all other inclusion/exclusion criteria.
* Patients with measurable and non-measurable disease per modified RECIST guidelines. All scans and x-rays used to document measurable or non-measurable disease must be done within a 28-day period prior to enrollment.
* Patient with Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 (within 14 days prior to enrolment).
* Patient with adequate organ and haematological function as evidenced by the following laboratory studies within 14 days prior to enrollment:
* Haematological function, as follows:
* Absolute neutrophil count (ANC) ≥ 1.5 x 109/L
* Platelet count ≥ 75 x 109/L
* Haemoglobin ≥ 9 g/dL
* Coagulation functions, as follows:
* Partial thromboplastin time (PTT) or activated partial thromboplastin time (aPTT) ≤ 1.5 x upper limits of normal (ULN) per institutional laboratory normal range
* International normalized ratio (INR) ≤ 1.5
* Renal functions, as follows:
* Serum creatinine ≤ 1.5 x ULN
* Urea ≤ 1.5 x ULN
* Hepatic function, as follows:
* Total bilirubin ≤ 1.5 x ULN
* Serum glutamic oxaloacetic transaminase (SGOT)/aspartate transaminase (AST) and serum glutamic pyruvic transaminase (SGPT)/ alanine transaminase (ALT) ≤ 2.5 x ULN (≤ 5 x ULN if liver metastases are present)\*.

  * Except where due to direct disease involvement of the liver at the discretion of the investigator.

Exclusion Criteria:

* Patients unable to swallow oral medications
* Patients with persistent gastric outlet obstruction, complete dysphagia or feeding jejunostomy.
* Patients who underwent radiotherapy to the gastric remnant ≤ 14 days prior to enrolment. Patients must have recovered from all radiotherapy-related toxicities.
* Patients with total gastrectomy.
* Patients who have uncontrolled, clinically significant symptomatic cardiovascular diseases within 6 months prior to enrolment, including myocardial infarction, unstable angina, grade 2 or greater peripheral vascular disease, cerebrovascular accident, transient ischemic attack, congestive heart failure or arrhythmias not controlled by outpatient medication.
* Patients with ongoing or clinically significant active infection as judged by the Investigator.
* Pregnant (i.e., positive beta-human chorionic gonadotropin test) or is breast-feeding women.