INS and type 2 diabetes mellitus: The PREserVing Beta-cell Function in Type 2 Diabetes with Exenatide And InsuLin (PREVAIL) Trial was an open-label, parallel-arm, randomized controlled trial that was designed to evaluate the metabolic effects of three insulin-based therapies (glargine alone, glargine + lispro, glargine + exenatide) early in the course of T2DM.