[Lys(B28), Pro(B29)]-Human Insulin: A Rapidly Absorbed Analogue of Human Insulin

[Lys(B28, Pro(B29)]-human insulin (LYSPRO) is an insulin analogue in which the natural amino acid sequence of the B-chain at positions 28 and 29 is inverted. These changes result in an insulin molecule with a greatly reduced capacity for self-association in solution. These clinical studies were designed to compare LYSPRO with human Regular insulin after subcutaneous injection in humans. We wanted to evaluate the effect of adding zinc to LYSPRO on its pharmacokinetics and pharmacodynamics. In addition, we compared the pharmacokinetics and pharmacodynamics of LYSPRO and human Regular insulin after subcutaneous injection to those of human Regular insulin given intravenously. Thus, we compared four treatments: solutions of zinc-free LYSPRO given subcutaneously (A), zinc-containing LYSPRO given subcutaneously (B), human Regular insulin given subcutaneously (C), and human Regular insulin given intravenously (D). We gave a 10-U dose of each treatment to 10 healthy (nondiabetic) men during glucose clamps. Serum insulin concentrations peaked more than two times higher (maximum serum insulin level [C_max], 698 vs. 308 pM, A vs. C) and in < half the time (time to Cmax [T_max], 42 vs. 101 min, A vs. C) after subcutaneous injection of zinc-free LYSPRO. At the same time, the glucose infusion rate peaked in about half the time (time to maximum glucose infusion rate [TR_max], 99 vs. 179 min, A vs. C) and was slightly but not significantly higher (maximum glucose infusion rate [R_max], 3.1 vs. 2.2 mmol/min, A vs. C) than that of human Regular insulin. Although the addition of zinc retarded the absorption of LYSPRO slightly (C_max, 550 vs. 698 pM, B vs. A), zinc-containing LYSPRO retained its distinct profile (T_max 53 vs. 42 min, B vs. A). LYSPRO displays faster pharmacodynamic action than human Regular insulin when injected subcutaneously