Complex sentence: Fomivirsen (brand name Vitravene) is an antisense antiviral drug that was used in the treatment of cytomegalovirus retinitis (CMV) in immunocompromised patients, including those with AIDS.
Split into simpler sentences: Fomivirsen (brand name Vitravene) is an antiviral drug. It is used in the treatment of cytomegalovirus retinitis (CMV) in immunocompromised patients, including those with AIDS.