Study of Romiplostim for Chemotherapy-induced Thrombocytopenia in Adult Subjects With Gastrointestinal, Pancreatic, or Colorectal Cancer

Inclusion Criteria: * Subject has provided informed consent prior to initiation of any study specific activities/procedures or subject's legally acceptable representative has provided informed consent prior to any study-specific activities/procedures being initiated when the subject has any kind of condition that, in the opinion of the investigator, may compromise the ability of the subject to give written informed consent. * Males or females greater than or equal to 18 years of age at signing of the informed consent. * Histologically or cytologically confirmed diagnosis of gastrointestinal, pancreatic, or colorectal adenocarcinoma, defined as cancers of the esophagus (including esophagogastric junction \[EGJ\] cancer), stomach, pancreas, colon, or rectum. Tumor stage will not affect eligibility. * Subjects must be receiving 1 of the following regimens: An oxaliplatin-based chemotherapy regimen, containing 5 FU or capecitabine plus oxaliplatin (irinotecan may be added for FOLFIRINOX or FOLFOXIRI) on a 14- or 21 day schedule, respectively; OR, subjects must have chemotherapy-induced thrombocytopenia from a non-protocol chemotherapy regimen, planning to start treatment with one of the protocol chemotherapy regimens which has been delayed greater than or equal to one week due to chemotherapy-induced thrombocytopenia. Note: Use of these regimens are permitted with (1) anti angiogenic agents (such as bevacizumab) or (2) targeted therapy (such as anti epidermal growth factor recep…