This is a Phase I, randomized, two-part, single-center pharmacokinetics (PK) study to assess the relative bioavailability of capsule and tablet formulations of GDC-0941 in the fasted state (Part 1) and to determine the effect of food and proton pump inhibition on the PK of the tablet formulation of GDC-0941 (Part 2). Approximately 18 subjects will be enrolled in Part 1 and up to 32 subjects will be enrolled in Part 2. Subjects who participate in Part 1 are not eligible to participate in Part 2.

Inclusion Criteria

• Male or female, between 18 and 65 years of age, inclusive (Part 1 only)
• Male or female, between 18 and 45 years of age, inclusive (Part 2 only)
• In good health, as determined by no clinically significant findings from medical history, 12-lead electrocardiogram (ECG), and vital signs assessment
• Body Mass Index (BMI) between 18-30 kg/m^2 inclusive, with a body weight >50 kg
• Clinical laboratory evaluations within the reference range for the test laboratory
• Negative test for selected drugs of abuse at screening (does not include alcohol) and at check-in (does include alcohol)
• Negative HIV, hepatitis B surface antigen (HBsAg), and hepatitis C virus antibody screens
• Agreement to use an effective form of contraception for the duration of the study

Exclusion Criteria

• History or clinical manifestations of significant metabolic (including type 1 and 2 diabetes), hepatic, renal, hematological, pulmonary, cardiovascular, endocrine, gastrointestinal, urological, neurological, psychiatric disorders, or cancer
• History of inflammatory arthritis
• History of symptomatic hypotension
• History of severe physical injury, direct impact trauma, or neurological trauma within a specified timeframe prior to Day 1
• History of seizure disorders
• History of bipolar or major depressive disorder
• History of stomach or intestinal surgery or resection that would potentially alter absorption and/or excretion of orally administered drugs (exceptions: appendectomy, hernia repair, and/or cholecystectomy)
• History or presence of an abnormal ECG
• Subjects with a history of ventricular dysrhythmias or with risk factors for ventricular dysrhythmias
• History of alcoholism, drug abuse, or drug addiction
• Use of any nicotine-containing or nicotine-replacement products within a specified timeframe prior to Day 1
• Participation in any other investigational study drug trial in which receipt of an investigational study drug occurred within a specified timeframe prior to Day 1
• Use of any prescription medications/products within a specified timeframe prior to Day 1 (exceptions: hormone replacement therapy [HRT], oral, implantable, or transdermal contraception)
• Receipt of any vaccination or immunization within a specified timeframe prior to Day 1
• Use of proton pump inhibitors or H2-receptor antagonists within a specified timeframe prior to Day 1
• Known hypersensitivity to rabeprazole or any of its components, or to derived products of benzimidazoles
• Use of any over-the-counter (OTC), non-prescription preparations within a specified timeframe prior to Day 1
• Use of alcohol-containing, grapefruit-containing, or caffeine-containing foods or beverages within a specified timeframe prior to Day 1
• Poor peripheral venous access
• Donation of blood or plasma within a specified timeframe prior to Day 1
• Receipt of blood products within a specified timeframe prior to Day 1
• Vegetarians who are unable to consume a high-fat meal
• Women who are pregnant or nursing