ENZYME THERAPY OF XERODERMA-PIGMENTOSUM - SAFETY AND EFFICACY TESTINGOF T4N5 LIPOSOME LOTION CONTAINING A PROKARYOTIC DNA-REPAIR ENZYME

Xeroderma pigmentosum (XP) is a rare genetic disease in which patients are defective in DNA repair and are extremely sensitive to solar UV r adiation exposure. A new treatment approach was tested,in these patien ts, in which a prokaryotic DNA repair enzyme specific for UV-induced D NA damage was delivered into the skin by means of topically applied li posomes to supplement the deficient activity. Acute and chronic safety testing in both mice and humans showed neither adverse reactions nor significant changes in serum chemistry or in skin histology. The skin of XP patients treated with the DNA repair liposomes had fewer cyclobu tylpyrimidine dimers in DNA and showed less erythema than did control sites. The results encourage further clinical testing of this new enzy me therapy approach.