GDC-0449 and Erlotinib Hydrochloride With or Without Gemcitabine Hydrochloride in Treating Patients With Metastatic Pancreatic Cancer or Solid Tumors That Cannot Be Removed by Surgery

This phase I trial is studying the side effects and best dose of erlotinib hydrochloride when given together with GDC-0449 with or without gemcitabine hydrochloride in treating patients with metastatic pancreatic cancer or solid tumors that cannot be removed by surgery. Drugs used in chemotherapy, such as GDC-0449 and gemcitabine hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Erlotinib hydrochloride may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving GDC-0449 together with erlotinib hydrochloride with or without gemcitabine hydrochloride may kill more tumor cells.