 The drug was withdrawn because while there was a high unmet need for drugs to treat CMV when the drug was initially discovered and developed due to the CMV arising in people with AIDS, the development of HAART dramatically reduced the number of cases of CMV.It is an antisense oligonucleotide -- a synthetic 21 member oligonucleotide with phosphorothioate linkages (which are resistant to degradation by nucleases) and has the sequence