XP20925

XP20925 is an orally bioavailable small molecule prodrug of R-baclofen (arbaclofen) developed by XenoPort. It was engineered using XenoPort's proprietary Transported Prodrug technology, which designs molecules to be recognized by high-capacity nutrient transporters in the gastrointestinal tract, specifically the monocarboxylate transporter 1 (MCT1). This approach was intended to improve the pharmacokinetic profile of R-baclofen by providing more consistent absorption and allowing for sustained-release delivery. Once absorbed, XP20925 is converted into R-baclofen, a selective agonist of the gamma-aminobutyric acid type B (GABA-B) receptor. By activating these receptors in the spinal cord, the drug inhibits the release of excitatory neurotransmitters, thereby reducing muscle spasticity. XP20925 was primarily investigated as a backup candidate to XP19986 (arbaclofen placarbil) for the treatment of spasticity associated with multiple sclerosis and spinal cord injury, but development was ultimately discontinued.

Other names

R-baclofen prodrug