A Study Evaluating the Safety, Tolerability, and Pharmacokinetics of GDC-0623 in Patients With Locally Advanced or Metastatic Solid Tumors

Inclusion Criteria: * Histologically or cytologically documented, locally advanced or metastatic solid tumors for which standard therapy either does not exist or has proven ineffective or intolerable * Evaluable disease or disease measurable per RECIST * Life expectancy \>= 12 weeks * Adequate hematologic and end organ function * Agreement to use effective form of contraception for the duration of the study * Consent to provide archival tissue * For the cohort expansion stage (Stage II): Patients in this cohort must have had no more than four prior systemic therapies for cancer and must have KRAS mutant CRC (Stage II A and B), pancreatic cancer (Stage IIC, or KRAS mutant NSCLC \[Stage IID\]) Exclusion Criteria: * History of prior significant toxicity from a MEK pathway inhibitor requiring discontinuation of treatment * History of parathyroid disorder or history of malignancy-associated hypercalcemia requiring therapy in the last 6 months * History of retinal vein occlusion (RVO) or predisposing factors to RVO, including uncontrolled hypertension, uncontrolled diabetes, uncontrolled hyperlipidemia, and coagulopathy * Evidence of visible retinal pathology considered a risk factor for retinal vein thrombosis * History of glaucoma * Palliative radiotherapy, experimental therapy, or anti-cancer therapy or major surgical procedure within a specified timeframe prior to first dose of study drug * Current severe, uncontrolled systemic disease * History of clinically significant cardiac dysfunction * History of active gastrointestinal bleeding within 6 months prior to screening * Clinically significant history of liver disease, current alcohol abuse, or current known active infection with HIV, or hepatitis B or C virus * Active autoimmune disease * Uncontrolled ascites * Pregnancy, lactation, or breastfeeding * Known brain metastases that are untreated, symptomatic, or require therapy to control symptoms * For the Exploratory PK Cohorts (Stage IB and Stage IC): Patients who have a history of or ongoing gastro-esophageal reflux disease or peptic ulcer, or who have gastric pathology or history of gastric surgery which could affect absorption of GDC-0623 from the stomach, will be excluded from these cohorts