There were two key developments beyond the state of the art in this project:
1) first, we developed the first on-demand activable bioorthogonal reaction. This means, we can trigger the reactivity to allow a super fast reaction (complete within 9 seconds) that does not interfere with endogenous cellular processes
2) secondly, and in our search for the best linker+payload, we ended up developing a new self-immolative linker strategy for the protection of ortho-quinone payloads. Importantly, we showed for the first time that a C–C bond may be cleaved in vivo through a 1,6-elimination reaction.
Chemistry is at the center of our research. While the bioorthogonal chemistry provided insight into the internalisation and intracellular trafficking of a relevant receptor overexpressed in cancer cells, the second allows for specific intracellular releaase of a drug once the complex antibody/receptor is internalised. This combination led to the construction of conjugates which we showed to be safe and highly efficacious in relevant models of leukemia.