The purpose of this study is evaluate the long term safety and efficacy of DWP16001 compared to placebo in the treatment of type 2 diabetes mellitus.

Inclusion Criteria:

1. Participated in the prior phase 3 study (Protocol No: DW_DWP16001301) for meeting the inclusion criteria and completed the study
2. Voluntarily decided to participate in the extension study and provided a written consent on the consent form

Exclusion Criteria:

1. Those who dropped out of the previously conducted phase 3 clinical trial (Protocol No: DW_DWP16001301)

2. Pregnant or lactating women or those who do not consent to the use of appropriate contraceptive methods during clinical trials Appropriate method of birth control for you or your partner: You must agree to one of the following

   • Either surgical sterilization (vasectomy, etc.) or insertion of an intrauterine device (copper loop, intrauterine hormone-containing system), or
   • A physical barrier method combined with either systemic hormonal contraceptives or spermicide, or
   • Use of male condom combined with either cervical cap or diaphragm

3. In case the investigator judges that participation in this extended clinical trial is inappropriate in consideration of the 24-week observation progress in the previously conducted phase 3 clinical trial (Protocol No: DW_DWP16001301)