This phase II trial determines the effect of metformin extended release on the risk for developing lung cancer in overweight/obese patients that are at high-risk for developing lung cancer. Metformin is widely used to treat type II diabetes and has a long history of safety and minimal side effects. At similar dosage, the drug may have potential anti-cancer activity. Metformin use has been associated with improved survival in patients with non-small cell lung carcinoma, a specific type of lung cancer, and it has also been shown to enhance immune mobilization against tumors. This trial aims to see whether metformin extended release as a preventative treatment may lower the chance of developing lung cancer, and whether it may help patients' immune system learn ("reprogram") to lower a certain type of immune cell (called regulatory T cells) that are linked to tumor development.
PRIMARY OBJECTIVE: I. To evaluate the effect of metformin treatment on the expression of programmed cell death protein 1 (PD-1) on airway regulatory T cells (Tregs) in overweight and obese individuals at high risk for lung cancer. SECONDARY OBJECTIVES: I. Estimated PD-1 expression of pulmonary Tregs change in Cohort B during the wait period (26 weeks with no treatment). II. To examine the impact of metformin on circulating immune cell subsets of blood. III. To evaluate the effect of metformin treatment on the expression of PD-1 on airway regulatory T cells (Tregs) in overweight and obese current smokers at high risk for lung cancer EXPLORATORY OBJECTIVES: I. To examine the impact of metformin on cancer-related transcriptome features of airway lesions. II. To examine the impact of metformin on immune profile of pulmonary parenchyma represented by bronchoalveolar lavage (BAL). III To examine the impact of metformin on histologic progression of abnormal airway lesions. IV. To examine the impact of metformin on serum adipokines and inflammatory cytokines. OUTLINE: Participants are randomized to 1 of 2 cohorts. COHORT A: Former Smokers - Participants receive metformin extended release (ER) orally (PO) once daily (QD) for 26 weeks in the absence of unacceptable toxicity. Participants undergo bronchoscopy biopsy and blood sample collection at screening, and week 13. COHORT B: Former Smokers - Participants receive no intervention for 26 weeks, then cross-over to cohort A. Participants undergo bronchoscopy biopsy and blood sample collection at screening, at week 26, and at 13 weeks after cross-over to Cohort A. COHORT C: Current Smokers - Participants receive metformin extended release (ER) orally (PO) once daily (QD) for 26 weeks in the absence of unacceptable toxicity. Participants undergo bronchoscopy biopsy and blood sample collection at screening, and week 13. After completion of study treatment, participants are followed up at weeks 30-32 (Cohorts A and C) and weeks 56-58 (Cohort B).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
50
Undergo biopsy
Undergo blood sample collection
Undergo bronchoscopy
Given PO
Ancillary studies
Rocky Mountain Regional VA Medical Center
Aurora, Colorado, United States
Roswell Park Cancer Institute
Buffalo, New York, United States
BC Cancer Research Centre
Vancouver, British Columbia, Canada
University of British Columbia Hospital
Vancouver, British Columbia, Canada
PD-1 expression of pulmonary regulatory T cells (Tregs) before and after metformin extended release (ER) treatment
Change from pre- to post-metformin extended release (ER) treatment in cell surface PD-1 expression levels of pulmonary (BAL) Tregs, measured as mean fluorescent intensity (MFI). Changes in MFI due to metformin ER treatment among all n = 40 subjects will be used for the primary analysis.
Time frame: Pre- to post-treatment
Estimated PD-1 expression of pulmonary Tregs change in cohort B during the wait period (6 months with no treatment)
This is the estimate of change in MFI following the 6-month wait period among n = 20 subjects randomized to the wait-list arm. This will confirm the stability of the PD-1 expression of pulmonary Tregs over time.
Time frame: Randomization to week 26
Circulating immune cells
Circulating immune cell composition between blood samples collected pre- and post-metformin ER treatment to assess the effect of metformin ER on circulating immune cells and to identify potential biomarkers of metformin ER response.
Time frame: Pre- to post-treatment
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