Not receiving administration of proton pump inhibitor, H2 antagonist, or pancreatic enzymes No requirement for constant administration of proton pump inhibitor, H2 antagonist, or pancreatic enzymes Requirement for constant administration of proton-pump inhibitor, histamine 2 (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed while patients are on dexamethasone; we strongly recommend that patients who require gastric protection to receive only antacids starting 24 hours before the first dose until 24 hours after the last dose of alisertib Requirement for constant administration of proton pump inhibitor, H2 antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Patients who have a requirement for constant administration of proton pump inhibitor, histamine-2 (H2) antagonist, or pancreatic enzymes are not eligible; intermittent usage of antacids or H2 antagonists are allowed Requirement for constant administration of proton pump inhibitor, histamine 2 (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Requirement for constant administration of proton pump inhibitor, histamine (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed as described Requirement for constant administration of proton pump inhibitor, histamine-2 (H2) antagonist, or pancreatic enzymes; histamine-2 (H2) receptor antagonists are not permitted from the day prior (day -1) through to the end of alisertib dosing (e.g., day 7), except as required for premedication for a protocol-specific agent (e.g., taxane); neutralizing antacids and calcium-containing supplements cannot be taken from 2 hours prior to alisertib dosing until up to 2 hours after dosing Requirement for constant administration of proton pump inhibitor or H2 antagonist; intermittent uses of antacids or H2 antagonists are allowed Requirement for constant administration of proton pump inhibitors, H2 antagonists, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Patient must not require constant administration of a proton pump inhibitor, histamine receptor 2 (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Requirement for constant administration of proton pump inhibitor from 5 days prior to D1 of alisertib, and/or requirement for constant administration of histone 2 (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Patients who are on daily proton pump inhibitor therapy must be able to discontinue use or only require use of antacid or hydrogen (H2) antagonist intermittently; patients who require daily administration of proton pump inhibitor, H2 antagonist, or pancreatic enzymes are not eligible; intermittent uses of antacids or H2 antagonists are allowed Requirement for constant administration of proton pump inhibitor, H2 antagonist, or pancreatic enzymes. Intermittent uses of antacids or H2 antagonists are allowed (see section 5.5) Requirement for constant administration of proton pump inhibitor, histamine (H2) antagonist, or pancreatic enzymes; intermittent uses of antacids or H2 antagonists are allowed Requirement for constant administration of H2 antagonist