Effect of Food and Antacid on BIIB021 With Advanced Solid Tumors

Inclusion Criteria: * Subjects with histologically or cytologically confirmed solid tumors who have failed or are not candidates for standard therapies or for whom no approved therapy is available. * Eastern Cooperative Oncology Group (ECOG) performance status of greater or equal to 2. * Medically able to tolerate a high fat meal and to fast as per protocol. * Expected survival time of at least 3 months in the opinion of the Investigator. * Ability to take ranitidine as per protocol. * Must be able to swallow and retain oral medication. * Lab values consistent with adequate renal, hepatic, and bone marrow functions. * Electrocardiogram (ECG) with QTc of ≤450 msec for men or ≤470 msec for women and no clinically significant findings. Exclusion Criteria: * Pregnant (positive pregnancy test) or nursing women. * Previous treatment with an Hsp90 inhibitor. * Use of antacids within 7 days of Study Day 1. * Prior antitumor therapies, including prior experimental agents or approved antitumor therapies within 28 days of the first dose of BIIB021. * Major surgery or radiation within 28 days of the first dose of BIIB021. * Uncontrolled, severe medical illness, which in the opinion of the Investigator and/or Sponsor could compromise protocol objectives. * History of gastrectomy or major surgery to small intestine. * History of exocrine pancreatic insufficiency. * Chronic diarrhea (excess of 2 to 3 stools/day above normal frequency). * Active bacterial or viral infection requiring concurrent treatment. * History of hepatitis B or C or human immunodeficiency virus. * History of central nervous system metastasis. * Any thrombotic event occurred \<3 months prior to Day 1. * Conditions that may predispose subjects to seizures: History of seizure, previous significant head trauma * Drug or alcohol abuse.