Sense from antisense

Acceptance of antisense oligonucleotides as therapies has been slow in coming, with skeptics doubting the method's true mechanism of action as well as awaiting a proof-of-principle from the clinic. Isis Pharmaceuticals Inc. last week presented data from its previously disclosed Phase III trial of fomivirsen in cytomegalovirus (CMV) retinitis in AIDS (see BioCentury, Jan. 26), which it said adds to its collection of clinical and preclinical data validating both the antisense mechanism and the overall approach.

The theory behind antisense is simple: the oligonucleotides block the