Effectiveness and safety of insulin glargine 300 unit/mL in Japanese type 2 diabetes mellitus patients: a 12-month post-marketing surveillance study (X-STAR study).

Background: With limited real-world insulin glargine 300 unit/mL (Gla-300) data available, we assessed the effectiveness and safety of Gla-300 in the Japanese type 2 diabetes mellitus (T2DM) population.
Research Design and Methods: X-STAR was a prospective, observational, 12-month post-marketing study of Gla-300 from 2015 to 2018. T2DM patients received Gla-300 as the first insulin (insulin-naïve) or after treatment with another type of insulin (insulin-experienced).
Results: We identified 1,227 insulin-naïve and 3,394 insulin-experienced patients. Insulin-naïve group increased the Gla-300 starting dose by 2.80 U/day during 12 months (7.49 to 10.29 U/day). Mean HbA1c reduced by 1.99% (9.82 to 7.83%), and 28.4% showed HbA1c < 7.0%. Insulin-experienced group had a baseline insulin dose of 14.86 U/day, which increased by 0.73 U/day. Mean HbA1c reduced by 0.18% (7.99 to 7.81%), and 24.6% showed HbA1c < 7.0%. Adverse drug reactions occurred in 3.42% (insulin-naïve) and 4.45% (insulin-experienced); symptomatic hypoglycemia (2.93% and 3.86%, respectively) was the most common in both groups.
Conclusions: Gla-300, in clinical practice, provides an effective and safe therapy as HbA1c was reduced/maintained in insulin-naïve/experienced Japanese T2DM patients without new safety signal. This study provides insights into the current Japanese clinical practices where insulin use is delayed and conservative despite relatively low HbA1c achievement.