Discovery of a Novel Mutant-Selective Epidermal Growth Factor Receptor Inhibitor Using an <i>In Silico</i> Enabled Drug Discovery Platform

Despite the success of first, second, and third generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) for non-small cell lung cancer with classical EGFR mutations (L858R or Exon 19 deletions), disease progression occurs due to the acquisition of T790M and C797S resistance. Herein, we report a physics-based computationally driven lead identification approach that identified structurally unique imidazo[3.2-<i>b</i>]pyrazoles as reversible and wild-type-sparing EGFR TKIs of classical mutations bearing both T790M and C797S. During profiling of imidazo[3.2-<i>b</i>]pyrazoles, we elucidated the bioactivation mechanism causing CYP3A4/5 time-dependent inhibition (TDI) and found key modifications to mitigate the TDI. Compound <b>31</b> inhibited EGFR L858R/T790M/C797S in biochemical assays with a <i>K</i>_i = 2.1 nM and EGFR del19/T790M/C797S in a Ba/F3 cellular assay with an IC₅₀ = 56.9 nM. The deuterated analogue of <b>31</b> (<b>38</b>) demonstrated dose-dependent tumor growth inhibition in a Ba/F3 EGFR del19/T790M/C797S CDX model by 47% at 50 mg/kg BID and 92% at 100 mg/kg BID.