Cancer is the lead cause of death worldwide, accounting for 10 million deaths in 2020, or 1 in 6 deaths. While current therapies have significantly advanced in the last decade, they suffer from severe limitations such as resistance, lack of selectivity and life-threatening side effects. Herein we present three novel strategies of targeting prostate cancer, breast cancer and leukaemia.

1. The development of a novel class of hybrid compounds designed through covalently linking enzalutamide and EPI-001 through triazole-PEG linkers is reported. The compounds are accessed in 6 synthetic steps performed in parallel for the 5 final target compounds. The compounds display a 50-fold improvement in the cell killing potency compared to the gold standards of therapy, enzalutamide and EPI-001 (LC₅₀ EPI = 85 μM, LC₅₀ Enza = 65 μM, LC₅₀ hybrid = 1.6 μM). The best in line compound was proven to exhibit its toxicity exclusively through AR mediated pathways, yielding the first-in-class hybrid AR inhibitor.

2. We report the design, computational validation and synthesis of a proposed lysine targeting allosteric CK2 inhibitor. The challenging synthetic steps towards the peptidomimetic electrophile are presented, along with the biological characterisation of the final target molecule. Protein mass spectrometry and tandem mass spectrometry studies indicate that the electrophile does not target Lys158, as intended, but that instead it forms a transient, water unstable, covalent bond with the protein.

3. We developed a novel class of lysine targeting covalent inhibitors, targeting the PH domain of BTK, a previously unreported targeting strategy. 3 families of analogues were rapidly constructed using an efficient 4 step synthetic strategy, yielding 23 analogues and 14 co-crystal structures with the BTK PH domain. The high percentage of crystal structures represents a success rate of 61%, which validates the fragment elaboration strategy, whereby all fragments covalently label Lys12. The binding selectivity was validated by protein mass spectrometry and differential scanning fluorimetry, whereby all analogues induce expected responses with the WT BTK, but fail to induce a response with the loss of function mutant R28C, as expected. A 6-fold improvement in binding affinity from the parent compound was achieved through a hit-to-lead optimisation campaign (160 μM to 30 μM).