the present invention relates to a novel antineoplastic agent , designated imic having the following characteristics : is present in the retentate of dialyzed skim milk ; is non - dialyzable ; has general properties of pyrimidines ; is bound to a protein in the proteose - peptone fration of milk ; is soluble in water ; is insoluble in organic solvents ; is stable in acid ; is not bound or retained by a c 18 or c 8 reverse phase hplc columns ; is not retained by a c 18 or silica gel sep . pak ; has λ maximum absorbance at 208 nm and 278 nm in neutral ad acidic solution and in a basic solution at 223 and 290 nm ; provides peaks with a retention time of 7 . 52 minutes upon fractionation by hflc on a biorad aminex resin column with 0 . 05 nh 2 so 4 as the mobile phase and with a flow rate of 0 . 7 ml / minute ; provides peaks with a retention time of 9 . 9 minutes upon fractionation on an hplc biorad ag 50 mx - 8 resin column with 0 . 035n formic acid as the mobil phase and a flow rate of 4 ml / minutes . inhibits cholesterolgenesis by inhibiting mevalonate incorporation into cholesterol along the cholesterol biosynthetic pathway . imic can be employed in compositions of pharmaceutically acceptable dosages and , specifically , in a method of treating neoplastic disorders in mammals .