We thank Dr. Perfetti [1] for his letter to the editor. We appreciate his concern that readers may be unclear as to which insulin glargine formulation is the reference product and we wish to confirm that the reference insulin glargine in the studies reviewed is indeed insulin glargine 100 U/mL (Lantus® [2, 3]). We will clarify this point in our article by specifying in the abstract and in the introduction that subcutaneous once-daily LY2963016 insulin glargine 100 U/mL (Abasaglar®/Basaglar® [4, 5]) has been approved as a biosimilar in the EU and as a follow-on biologic in the USA to reference insulin glargine 100 U/mL (Lantus®).