Branched chimeric compounds, and methods of use thereof

A pharmaceutical composition comprising (i) a pharmaceutically acceptable excipient and (ii) a branched chimeric compound of formula (I):

• [D-L1-L2-(PEG)-L3]x-F (I)
• wherein:
• D is a linear chimeric compound;
• L1 is a first linker comprising an alkylthio group;
• L2 is a second linker comprising a succinimide group;
• L3 is a third linker comprising an amide group;
• PEG is of the formula —(OCH2CH2)n—, where n is an integer from 2 to 80;
• x is an integer from 3 to 300;
• and
• F is a branched copolymer of sucrose and epichlorohydrin having a molecular weight of about 100,000 to about 700,000 daltons and is connected to L3 via an ether group;
• and
• wherein the linear chimeric compound of D comprises three nucleic acid moieties and two hexaethylene glycol (HEG) spacers as 5′-TCGGCGC-3′-HEG-5′-AACGTTC-3′-HEG-5′-TCGGCGC-3′ (SEQ ID NO:2), wherein the linear chimeric compound contains less than 50 nucleotides, and wherein one or more linkages between the nucleotides, between the nucleotides and the HEG spacers and between the 3′-terminal nucleotide and L1 are phosphorothioate ester linkages.