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

To evaluate effects of metformin on clinical outcome of non-diabetic patients with stage IV NSCLC.

A prospective, randomized, open-label, controlled pilot study was conducted on patients with 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-naive, non-diabetic patients with stage IV NSCLC were enrolled. Fifteen patients received intravenous gemcitabine/cisplatin regimen alone (arm B) while fifteen patients received the same regimen plus daily oral metformin 500 mg (arm A). The effect of metformin on chemotherapy-response rates, survival, and adverse events in these patients was evaluated.

Objective response 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) in arms A and B was 5.5 months versus 5 months, p=0.062. No significant increase in toxicity was observed in arm A versus arm B. Percentage of patients who experienced nausea was significantly lower in arm A versus arm B, at 26.7% versus 66.7% respectively, p=0.028.

Metformin administration reduced occurrence of chemotherapy induced-nausea. Non-statistically significant improvements in the ORR or OS were observed. Metformin had no effect on PFS.