XP21279 + carbidopa

XP21279 + carbidopa is an investigational oral combination therapy developed for the treatment of Parkinson's disease. XP21279 is a prodrug of levodopa (L-DOPA), designed to be actively transported throughout the gastrointestinal tract via high-capacity nutrient transporters and then rapidly converted into levodopa by endogenous enzymes. This design aims to improve absorption, provide sustained release, and reduce fluctuations in plasma L-DOPA levels compared to standard formulations. Carbidopa is included as a peripheral decarboxylase inhibitor, preventing premature conversion of levodopa outside the brain and thereby increasing its availability in the central nervous system while reducing side effects such as nausea. The combination was under development by XenoPort (later Arbor Pharmaceuticals) and reached phase 2 clinical trials for Parkinson's disease before development was discontinued due to conflicting trial results[2][3][4][5][6].

Other names

Levodopa prodrug + carbidopa