This trial is designed to examine the effect of exenatide once weekly compared to exenatide twice daily on glucose control and safety in subjects for at least 30 weeks. The study is also designed to examine glucose control during the transition from exenatide twice daily for 30 weeks to exenatide once weekly. Long-term safety and efficacy will be monitored during the open-ended assessment periods. This study will be conducted in approximately 300 subjects with type 2 diabetes treated with diet modification and exercise alone or in combination with a stable regimen of metformin, SU, thiazolidinedione (TZD), a combination of metformin and SU, a combination of metformin and TZD, or a combination of SU and TZD.
