Disease	Esophageal cancer
Disease	Gastric cancer
Stage of Disease/Treatment	Metastatic/advanced
Prior Therapy	No designated number of regimens
Type of Study	Phase II, single arm
Primary Endpoint	Overall response rate
Secondary Endpoints	Toxicity, progression‐free survival, overall survival
Additional Details of Endpoints or Study Design
The response rate of interest in this trial was 15%. If one response was observed in the first 15 subjects, an additional 15 subjects would be enrolled for a total of 30. Observing zero responses in the first 15 subjects would exclude response rates as low as 15% with a 90% one‐sided upper confidence bound. If at least three responses were observed in a total of 30 evaluable patients, we would conclude that the drug is active and merited further study; if the true response rate was 15% or greater, three or more responses would be observed with a probability of at least 85%. If the true response rate was only 3%, three or more responses would be observed with a probability of only 6%. In addition to complete and partial responses, disease stabilization would be considered: if the proportion of patients with disease stabilization for 6 months exceeded 20%, we would conclude that the drug may warrant further investigation. With n = 30 subjects and a true response rate of 15%, the expected confidence interval width would be ±10.7% around the estimated proportion. Moreover, we would have 90% power to detect any unforeseen adverse effect that occurred in at least 7% of cases.
Investigator's Analysis	Level of activity did not meet planned endpoint