Genetically engineered insulin: five years of experience.

Genetically engineered insulin is the first application of recombinant DNA technology which has gone into industrial production and wide clinical use. Four years after the first clinical trials, it appears that there are only minor pharmacokinetic differences from purified pork insulin; in particular, a faster subcutaneous absorption for both regular and NPH forms. The hypoglycaemic potency of genetically engineered insulin is identical to that of purified pork insulin but a weaker effect on counterregulatory hormones has been reported. However, the main advantage of biosynthetic human insulin is its species specificity, which reduces its immunogenicity. Convincing results were obtained in patients suffering from insulin-produced adverse reactions such as insulin resistance or allergy, although biosynthetic human insulin does have some immunological properties and crossreacts with beef or pork insulin antibodies.