Gemcitabine Hydrochloride With or Without Vismodegib in Treating Patients With Recurrent or Metastatic Pancreatic Cancer

This randomized phase I/II trial studies gemcitabine hydrochloride and vismodegib to see how well they work compared with gemcitabine hydrochloride alone in treating patients with recurrent or metastatic pancreatic cancer. Drugs used in chemotherapy, such as gemcitabine hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Vismodegib may slow the growth of tumor cells. It is not yet known whether giving gemcitabine hydrochloride together with vismodegib is more effective than gemcitabine hydrochloride alone in treating patients with pancreatic cancer.