X0201 42004-01-20 0000874015 ISIS PHARMACEUTICALS INC ISIS 0000897667 CROOKE STANLEY T 2292 FARADAY AVENUE CARLSBAD CA 92008 1100Chairman, President, CEOCommon Stock2004-01-202004-01-204S080007.50D951741DCommon Stock2004-01-212004-01-214S070008.0229D944741DCommon Stock2004-01-222004-01-224S05008.19D944241DCommon Stock1050Iby wifeThe sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 10-6-03.B. Lynne Parshall, by Power of Attorney2004-01-22