PLATELET GROWTH FACTOR (TPO): THE NEXT EPO? GENENTECH, ZYMOGENETICS

PLATELET GROWTH FACTOR (TPO): THE NEXT EPO? GENENTECH, ZYMOGENETICS have separately isolated and cloned a protein that stimulates the growth of platelets. The companies' early research on the compound, believed to be thrombopoietin, is reported in the June 16 issue of Nature. Novo Nordisk subsidiary ZymoGenetics, in collaboration with University of Washington researchers, reported that in mice, platelet levels (but not hematocrit or white blood cell levels) were elevated fourfold on the fifth day following treatment with the company's purified protein.