Comparison of the efficacy and safety of once-daily insulin degludec/insulin aspart (IDegAsp) and long-acting second-generation basal insulin (insulin degludec and insulin glargine 300 units/mL) in insulin-naïve Japanese adults with type 2 diabetes: a pilot, randomized, controlled study.

To examine the efficacy and safety of once-daily insulin degludec/insulin aspart (IDegAsp) or once-daily second-generation basal insulin analogs (insulin degludec and insulin glargine 300 units/mL) in insulin-naive Japanese adults with type 2 diabetes in routine clinical practice. A 12-week multicenter open-label, randomized, pilot study was performed in 52 subjects with type 2 diabetes treated with oral antidiabetic drugs (OADs). Subjects were randomized to once-daily IDegAsp (n= 26) or basal insulin (n- 26). The primary endpoint was percent change in HbA1c from baseline to week 12. Furthermore, it was analyzed post hoc in subgroups stratified by baseline HbA1c. During a follow-up period, percent change in HbA1c was not significantly different between the two groups (p= 0.161). Daily insulin doses and frequency of overall hypoglycemia were also similar in the two groups. In post hoc analyses, once-daily basal insulin was more effective than IDegAsp in subjects with HbA1c more than or equal to 8.5% (p < 0.05); however, in subjects with HbA1c less than 8.5%, once-daily IDegAsp showed a significant improvement in percent change in HbA1c at week 12, compared with basal insulin (p < 0.01). Although there was no apparent difference in the HbA1c-lowering effects between two groups, when compared in subjects with HbA1c less than 8.5%, once-daily IDegAsp showed a significant effect in comparison with once-daily basal insulin. These findings suggest that the baseline HbA1c level might provide the important information for choosing IDegAsp or basal insulin in patients insufficiently controlled with OADs.