Pegloticase, approved for refractory gout, differs from recombinant uricase (rasburicase) in its clinical utility due to its PK modification. This modification is:
- A Pegylation (attachment of polyethylene glycol chains) prolonging half-life from <1 hour to ~2 weeks and reducing immunogenicity ✓
- B Conjugation with methotrexate enabling co-administration with DMARDs
- C Lipid encapsulation in liposomes reducing infusion reactions
- D Site-directed mutagenesis creating a recombinant uricase more specific for human urate
Explanation
Uricase (urate oxidase) converts uric acid to allantoin (a more water-soluble metabolite), dramatically lowering serum urate. Rasburicase (recombinant fungal uricase) has a very short half-life and is highly immunogenic in humans (who lack uricase). Pegloticase attaches multiple polyethylene glycol (PEG) chains to the uricase protein, extending the circulating half-life to approximately 2 weeks, allowing biweekly IV infusions for chronic gout management. PEGylation also shields the protein from immune recognition, reducing anti-drug antibody formation, though loss of efficacy (infusion reactions) is monitored via serum urate levels before each dose.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.