Linagliptin for patients aged 70 years or older with type 2 diabetes inadequately controlled with common antidiabetes treatments: a randomised, double-blind, placebo-controlled trial

Background: A substantial proportion of patients with type 2 diabetes are elderly (≥65 years) but this group has been largely excluded from clinical studies of glucose-lowering drugs. We aimed to assess the effectiveness of linagliptin, a dipeptidyl peptidase-4 inhibitor, in elderly patients with type 2 diabetes.

Methods: In this randomised, double-blind, parallel-group, multinational phase 3 study, patients aged 70 years or older with type 2 diabetes, glycated haemoglobin A1c (HbA1c) of 7·0% or more, receiving metformin, sulfonylureas, or basal insulin, or combinations of these drugs, were randomised (by computer-generated randomisation sequence, concealed with a voice-response system, stratified by HbA1c level [<8·5% vs ≥8·5%] and insulin use [yes vs no], block size four) in a 2:1 ratio to once-daily oral treatment with linagliptin 5 mg or matching placebo for 24 weeks. Investigators and participants were masked to assignment throughout the study. The primary endpoint was change in HbA1c from baseline to week 24. This trial is registered with ClinicalTrials.gov, number NCT01084005.

Findings: 241 community-living outpatients were randomised (162 linagliptin, 79 placebo). Mean age was 74·9 years (SD 4·3). Mean HbA1c was 7·8% (SD 0·8). At week 24, placebo-adjusted mean change in HbA1c with linagliptin was -0·64% (95% CI -0·81 to -0·48, p<0·0001). Overall safety and tolerability were much the same between the linagliptin and placebo groups; 75·9% of patients in both groups had an adverse event (linagliptin n=123, placebo n=60). No deaths occurred. Serious adverse events occurred in 8·6% (14) of patients in the linagliptin group and 6·3% (five) patients in the placebo group; none were deemed related to study drug. Hypoglycaemia was the most common adverse event in both groups, but did not differ between groups (24·1% [39] in the linagliptin group, 16·5% [13] in the placebo group; odds ratio 1·58, 95% CI 0·78-3·78, p=0·2083).

Interpretation: In elderly patients with type 2 diabetes linagliptin was efficacious in lowering glucose with a safety profile similar to placebo. These findings could inform treatment decisions for achieving individualised glycaemic goals with minimal risk in this important population of patients.

Funding: Boehringer Ingelheim.