Abstract
Insulin replacement therapy is the standard of care for patients with type 1 and advanced type 2 diabetes mellitus. Porcine and bovine pancreatic tissue was the source of the hormone for many years, followed by semisynthetic human insulin obtained by modification of animal insulin. With the development of recombinant DNA technology, recombinant (biosynthetic) human insulin became available in large amounts by biosynthesis in microorganisms (Escherichia coli, yeast) providing reliable supplies of the hormone worldwide at affordable costs. The purity and pharmaceutical quality of recombinant human insulin was demonstrated to be superior to animal and semisynthetic insulin and patients with diabetes could be safely and effectively transferred from animal or semisynthetic human insulin to recombinant human insulin with no change expected in insulin dose. The decision for change remains a clinical objective, follow-up after any change of insulin product is recommended to confirm clinical efficacy. This review provides a summary and retrospective assessment of early clinical studies with recombinant insulins (Insuman®, Humulin®, Novolin®).