With most chemo drugs you can stay on them as long as they seem to be working and are not causing you alot of bad side effects. If my memory is correct my mom was on Taxotere along with Gemzar for about 8-9 months. It was her 4th type of chemo and she became very fatigued so decided she had had enough and opted to stop treatment. But had she not decided that who is to say how long the drug would have kept working for her? Hope this helps you some.