Capecitabine

Capecitabine is a chemotherapy drug used to treat cancer in the breast, stomach and large intestine. Unlike other chemotherapy drugs, it is taken in pill form. 
It's side effects are typical and include abdominal pain, vomiting, diarrhea, weakness and rashes. It is contraindicated for patients with existing kidney problems and in pregnant women. It is fairly expensive, running about $2,000 for a typical treatment cycle in the United States. It works by preventing the synthesis of new DNA.
Capecitabine at Wikipedia