This study focuses on adults who have pancreatic cancer that has spread and caused unintentional weight loss. The purpose of the study is to evaluate whether a wearable device can be used to measure physical activity in people with cachexia (severe weight loss) and metastatic pancreatic cancer who are receiving or will be receiving first-line chemotherapy. The study device, the ActiGraph watch, is considered experimental. Participants will be asked to wear the wrist device for approximately 1 week on 2 separate occasions during the study. The results of this study may contribute insight into how digital health technology may be used to measure physical activity levels and compliance of a wearable device to support future clinical care.