Tsakiridis T, Pond GR, Wright J, et al. - This multicenter phase 2 randomized clinical trial (OCOG-ALMERA), in patients with unresected locally advanced non–small cell lung cancer (LA-NSCLC) who did not have diabetes, revealed worse treatment efficacy and increased toxic effects in relation to addition of metformin to chemoradiotherapy vs combined modality therapy alone, thus, metformin is not advised in LA-NSCLC patients who are candidates for chemoradiotherapy.

• A total of 54 patients with unresected LA-NSCLC who did not have diabetes were randomized (26 in experimental arm and 28 in control arm).

• Patients were randomly assigned to platinum-based chemotherapy, concurrent with chest radiotherapy, with or without consolidation chemotherapy or the same treatment plus metformin, 2000 mg/d, during chemoradiotherapy and afterward for up to 12 months.

• A failure event within 1 year (ie, locoregional disease progression, distant metastases, death, or withdrawal) occurred in 69.2% patients in the metformin arm vs 42.9% in the control arm.

• In the metformin and control arms, 1-year progression-free survival rates were 34.8% and 63.0%, respectively, (hazard ratio, 2.42) and overall survival rates were 47.4% and 85.2%, respectively (hazard ratio, 3.80).

• At least 1 grade 3 or higher adverse event was experienced by more patients in the experimental arm vs control arm (53.8% vs 25.0%).