Multi-arm targeting anti-cancer conjugate

A multi-branched drug conjugate having the following structural formula (I) or a pharmaceutically acceptable salt thereof:

• R is an organic core, POLY is a polymer, L is a multivalent linker, T is a targeting molecule, D is an active agent, and q is any integer between 3 and 8, wherein L is
• a symbol “*” represents an attachment point of the multivalent linker L and the targeting molecule T, “#” represents an attachment point of the multivalent linker L and the active agent D, and “%” represents an attachment point of the multivalent linker L and POLY, wherein l is any integer between 2 and 20, and m and n are any integer between 0 and 10 respectively;
• T is an RGD peptide containing a sequence of “arginine-glycine-aspartic acid”, tLyp-1, Lyp-1, RPARPAR, Angiopep2, or GE11;
• D is a camptothecin-based drug as represented by formula (II):
• wherein R1 to R5 are selected from the following groups independently from each other:
• hydrogen, halogen, acyl, alkyl, substituted alkyl, alkoxy, substituted alkoxy, alkenyl, alkynyl, cycloalkyl, hydroxyl, cyano, nitro, azido, amido, hydrazine, amine group, substituted amine group, hydroxycarbonyl, alkoxycarbonyl, alkoxycarbonyloxy, carbamoyloxy, arylsulfonyloxy, and alkylsulfonyloxy;
• R6 is H or OR8;
• R8 is alkyl, alkenyl, cycloalkyl, halogenated alkyl, or hydroxyalkyl;
• and R7 is hydroxyl.