In this episode of The Deep Dive, we explore the full lifecycle of sitagliptin, the first oral DPP-4 inhibitor to revolutionize type 2 diabetes management. Starting with its scientific origins in the 1990s, the episode traces how researchers discovered the role of incretin hormones and developed sitagliptin to preserve their glucose-lowering effects. Listeners will learn how sitagliptin works selectively to boost insulin secretion and suppress glucagon—without causing significant hypoglycemia when used alone. We break down its pharmacokinetics, renal clearance pathways, and critical dose adjustments for patients with impaired kidney function. The conversation also unpacks clinical applications, real-world efficacy, weight neutrality, and how the drug performs in combination with metformin or insulin therapies.

Beyond the clinic, the episode delves into how sitagliptin is manufactured, its asymmetric hydrogenation synthesis, and how Merck scaled it into a global blockbuster under the Januvia and Janumet brands. We examine its regulatory approval history, long-term safety signals—including concerns over pancreatitis and rare skin reactions—and Merck’s strategic use of salt form patents to extend exclusivity in the U.S. until 2026. Global market dynamics are unpacked, with generics gaining traction in Europe and Asia while the U.S. market still holds due to delayed competition. Sitagliptin's cultural and economic footprint is also discussed—from adherence advantages to its role in shaping treatment guidelines and access initiatives. With newer classes like GLP-1 agonists and SGLT2 inhibitors emerging, the episode closes by asking: what will be the future place of sitagliptin in a rapidly evolving diabetes landscape?