US Patent 9089614 Hydrophilic self-immolative linkers and conjugates thereof

The present disclosure provides compounds with a hydrophilic self-immolative linker, which is cleavable under appropriate conditions and incorporates a hydrophilic group to provide better solubility of the compound. The compounds of the present disclosure comprise a drug moiety, a targeting moiety capable of targeting a selected cell population, and a linker which contains an acyl unit, an optional spacer unit for providing distance between the drug moiety and the targeting moiety, a peptide linker which can be cleavable under appropriate conditions, a hydrophilic self-immolative linker, and an optional second self-immolative spacer or cyclization self-elimination linker.