Metformin Addition to Chemotherapy in Stage IV Non-Small Cell Lung Cancer: an Open Label Randomized Controlled Study

Purpose: To evaluate effects of metformin on clinical outcome of non-diabetic patients with stage IV NSCLC.Materials and
Methods: A prospective, randomized, open-label, controlled pilot study was conducted on patientswith stage IV NSCLC with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0-2,excluding patients with diabetes and lactic acidosis. Thirty chemo-naïve, non-diabetic patients with stage IVNSCLC were enrolled. Fifteen patients received intravenous gemcitabine/cisplatin regimen alone (arm B) whilefifteen patients received the same regimen plus daily oral metformin 500mg (arm A). The effect of metformin onchemotherapy-response rates, survival, and adverse events in these patients was evaluated.
Results: Objectiveresponse rate (ORR) and median overall survival (OS) in arms A and B were 46.7% versus 13.3% respectively,p=0.109 and 12 months versus 6.5 months, respectively, p=0.119. Median progression free survival (PFS) inarms A and B was 5.5 months versus 5 months, p=0.062. No significant increase in toxicity was observed in armA versus arm B. Percentage of patients who experienced nausea was significantly lower in arm A versus armB, at 26.7% versus 66.7% respectively, p=0.028.
Conclusions: Metformin administration reduced occurrenceof chemotherapy induced-nausea. Non-statistically significant improvements in the ORR or OS were observed.Metformin had no effect on PFS.