Please assess the completion status of the following clinical trial:

Trial Title: 12-Week Study of DS-8500a in Subjects With Type 2 Diabetes Mellitus on Metformin

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE2
- Number of Arms: 5.0

Eligibility Criteria:
Inclusion Criteria:~* Able to provide written informed consent and adhere to the study visit schedule and treatment~* Diagnosed with Type 2 diabetes mellitus as defined in the American Diabetes Association Standards of Medical Care in Diabetes 2015~* Male or female ≥ 18 and ≤ 70 years of age~* Screening fasting C-peptide \> 0.5 ng/mL~* Women of child bearing potential (WOCBP) must be willing to use double-barrier contraception for the entire study~* WOCBP must have a negative pregnancy test (human chorionic gonadotropin, beta subunit \[βhCG\]) before entering the Lead-in Period~* Body mass index ≥ 25 kg/m2 and ≤ 45 kg/m2 at the Screening Visit~* On stable (≥ 8 weeks) metformin monotherapy ≥ 1000 mg/day~* Screening HbA1c ≥ 7.0% and ≤ 10%~* Taking ≥ 80% and ≤ 120% of both dispensed DS-8500a placebo tablets and sitagliptin placebo capsules during the Lead-in Period~Exclusion Criteria:~* History of type 1 diabetes and/or history of ketoacidosis~* History of insulin use for \> 2 weeks within 2 months prior to the Screening Visit~* Two or more readings of fasting Self-monitoring of Blood Glucose (SMBG) \> 240 mg/dL or worsening symptoms of hyperglycemia with one SMBG level of \> 240 mg/dL during the second week of Lead-in Period, confirmed by laboratory measurement~* Screening hemoglobin \<12 g/dL for males and \<11 g/dL for females~* Blood donation within 2 months prior to the Screening Visit or plans to donate blood or blood products during the study~* Subjects after bariatric surgery or any gastric bypass~* Screening thyroid stimulating hormone (TSH) levels not within normal range (based on reference laboratory values )~* Screening Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) \> 2.0 x upper limit of normal (ULN), and/or total bilirubin \> 1.5 x ULN. If a subject has total bilirubin \> 1.5 ULN, unconjugated and conjugated bilirubin fractions should be analyzed and only subjects documented to have Gilbert's syndrome may be enrolled~* Screening Serum creatinine ≥ 1.5 mg/dL for males and ≥ 1.4 mg/dL for females, or creatinine clearance (CrCl) \< 50 mL/min for both males and females~* Screening Creatine kinase (CK) \> 3.0 × ULN~* History of unstable angina, myocardial infarction, cerebrovascular accident, transient ischemic attack, peripheral arterial event or any revascularization procedure during the 6 months prior to the Screening Visit or planned vascular procedures or surgery during study period~* History of congestive heart failure (CHF)~* Exclusionary concomitant medications:~  a. Eight weeks prior to screening and throughout the duration of the study:~* Any diabetes medication other than metformin; any prescription or over the counter medication for weight-loss.~* Systemic corticosteroids (including nasal and inhaled), with the exception of use of topical and ophthalmic corticosteroids.~* Rosuvastatin \> 20 mg daily. b. During treatment periods, additional medications will be prohibited based on potential drug-drug interaction (DDI) (see Section 5.6)~* Subjects with anticipated interruption in metformin or study drug use during the course of the clinical trial (e.g., due to an imaging procedure involving iodinated contrast media)~* Subjects in whom treatment with sitagliptin 100 mg is contraindicated ( e.g., known hypersensitivity or intolerance to sitagliptin) or may not be medically advisable (e.g., history of pancreatitis)~* Abuse of or dependence on prescription medications, illicit drugs, or alcohol within the last 1 year~* Any history of a malignancy other than basal cell carcinoma within the past 5 years~* Pregnancy or breast-feeding, or intent to become pregnant during the study period~* Known (or evidence of) infection with human immunodeficiency virus~* Any condition, laboratory abnormality, or concomitant therapy which, in the opinion of the Investigator, might pose a risk to the subject or make participation not in the subject's best interest~* Subject is currently enrolled in or has not yet completed at least 30 days since ending another investigational device or drug study or is receiving other investigational agents~* A direct or familial relationship with the Sponsor, Investigator, or site personnel affiliated with the study

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 70 Years
- Healthy Volunteers: f

Study Arms:
- DS-8500a 25mg (Type: EXPERIMENTAL): One DS-8500a 25 mg tablet, 2 placebo tablets, and one placebo capsule in a once-daily oral dose
- DS-8500a 50 mg (Type: EXPERIMENTAL): Two DS-8500a 25 mg tablets, 1 placebo tablet, and one placebo capsule in a once-daily oral dose
- DS-8500a 75 mg (Type: EXPERIMENTAL): Three DS-8500a 25 mg tablets and one placebo capsule in a once-daily oral dose
- Placebo (Type: PLACEBO_COMPARATOR): Three placebo tablets and one placebo capsule in a once-daily oral dose
- Sitagliptin 100 mg (Type: ACTIVE_COMPARATOR): Three placebo tablets and one sitagliptin 100 mg over-capsule in a once-daily oral dose

Based on this trial design, predict the completion outcome and termination type (if applicable).