Please assess the completion status of the following clinical trial:

Trial Title: Metformin in Stage IV Lung Adenocarcinoma

Study Design Characteristics:
- Allocation: None
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE2
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~1. Histologically or cytologically confirmed lung adenocarcinoma.~2. Stage IV disease as defined by AJCC 7th edition staging.~3. At least one measurable lesion (as defined by RECIST v1.1).~4. No prior radiotherapy, chemotherapy, surgery, target therapy, or immunotherapy for NSCLC. (Except the surgery for biopsy or port-A implantation, palliative localized radiotherapy for bone metastasis).~5. Age ≤ 80 years old and ≥ 20 years old.~6. ECOG performance status of 0-2.~7. Adequate organ function, including followings~   Bone marrow:~   Absolute neutrophil count (ANC) ≥ 1.5 x 10\^9/L; WBC ≥ 3.0 x 10\^9/L Platelet count ≥ 100 x 10\^9/L Hemoglobin ≥ 9g/dL~   Hepatic:~   Total bilirubin level ≤ 1.0 x UNL AST and ALT ≤ 3.0 x UNL;~   Renal:~   Creatinine level ≤ 1.5 mg/dL in men, ≤1.4 mg/dL in women; or Estimated CCr ≥ 60 mL/min. (CCr is estimated by Cockcroft-Gault formula, as appendix II)(CCr is estimated by Cockcroft-Gault formula)~8. Estimated life expectancy of at least 6 months.~9. Written (signed) Informed Consent.~Exclusion Criteria:~1. With other primary malignancies, except those remain disease-free for 3 or more years after curative treatment, basal cell cancer of the skin or in situ cervical cancer.~2. Use of other anti-cancer therapy, including chemotherapy, target therapy, immunotherapy, radiotherapy, and hormone therapy.~3. Prior participation in any investigational drug study within 28 days.~4. Use of anti-IL-6 or IL-6-lowering agents.~5. Use of metformin in the past 6 months.~6. Poor controlled diabetes (HbA1c ≥ 8.0%).~7. Known hypersensitivity or intolerance to metformin.~8. Congestive heart failure with NYHA functional class II\~IV.~9. History of lactic acidosis.~10. Significant concurrent medical diseases, such as unstable angina, acute or recent myocardial infarction (\< 6 months before enrollment), COPD with frequent exacerbation, uncontrolled hypertension, or recent CVA (\< 6 months before enrollment).~11. Active uncontrolled infections or HIV infection.~12. Psychiatric disorders that would compromise the patient's compliance or decision.~13. Current or planned pregnancy, or breast feeding in women.~14. Poor compliance.

- Gender: ALL
- Minimum Age: 20 Years
- Maximum Age: 80 Years
- Healthy Volunteers: f

Study Arms:
- METFORMIN (Type: EXPERIMENTAL): For patients with stage IV lung adenocarcinoma and IL-6 level higher than 2.0 pg/ml after 2 cycles of standard treatment, metformin 500mg tid orally will be given.

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