XL-510

XL-510 is a PAS polymer developed by XL-protein as a biodegradable alternative to polyethylene glycol (PEG) for the modification of biopharmaceuticals, a technology known as PASylation. The substance consists of genetically encoded, conformationally disordered sequences of the amino acids Proline, Alanine, and Serine (PAS). When fused or conjugated to therapeutic proteins or peptides, XL-510 increases the hydrodynamic volume of the molecule, which significantly reduces renal clearance and extends the plasma half-life. Unlike synthetic PEG, PAS polymers are biodegradable and generally non-immunogenic, potentially avoiding the formation of anti-drug antibodies that can compromise treatment efficacy. XL-510 serves as a foundational component for various drug candidates in XL-protein's pipeline, aimed at improving the pharmacokinetic profiles of cytokines, enzymes, and antibody fragments.

Other names

PAS substancePEG substitute (PAS)PAS polymer