Jennifer Mathews: Having Type 2 diabetes is no walk in the park for John Sullivan. John Sullivan: It's my health. I want to live. It can be a death sentence without discipline. Jennifer Mathews: To stay one step ahead of his disease, John enrolled in a clinical trial. John Sullivan: I hopes that the drug brings - helps me maintain a low blood sugar. Jennifer Mathews: The medication John is receiving belongs to a new class of drugs called DPP4 inhibitors. Dr. Richard Pratley says, they stop the breakdown of the hormone GLP-1. Dr. Richard Pratley: By inhibiting the breakdown of GLP-1, we actually have more of the active hormone around, and this helps to control blood glucose levels. Jennifer Mathews: A study on one of the drugs showed hemoglobin A1c levels dropped more than 1%. A1c levels are a measure of blood sugar control, and research shows every 1% drop means a 35% lower risk of diabetes related complications. Dr. Richard Pratley: It's a very significant improvement in glucose. Jennifer Mathews: Dr. Pratley says, "What's exciting about these new drugs is that they may actually change the course of the disease by making insulin-producing cells healthier." John's daughter Mariah helps him stay focused on his health. The new drug also helps. John Sullivan: I want to remain healthy. I'm 52-years-old, and I have - our youngest is five-and-a-half years old. Jennifer Mathews: And that's enough motivation to keep his blood sugar in check, even if he does have to pay his health by the mouthful. This is Jennifer Mathews reporting.