Potent and selective Bruton's tyrosine kinase inhibitors: Discovery of GDC-0834.Young, W.B., Barbosa, J., Blomgren, P., Bremer, M.C., Crawford, J.J., Dambach, D., Gallion, S., Hymowitz, S.G., Kropf, J.E., Lee, S.H., Liu, L., Lubach, J.W., Macaluso, J., Maciejewski, P., Maurer, B., Mitchell, S.A., Ortwine, D.F., Di Paolo, J., Reif, K., Scheerens, H., Schmitt, A., Sowell, C.G., Wang, X., Wong, H., Xiong, J.M., Xu, J., Zhao, Z., Currie, K.S.
(2015) Bioorg.Med.Chem.Lett. 25: 1333-1337
- PubMed: 25701252
- DOI: 10.1016/j.bmcl.2015.01.032
- PubMed Abstract:
SAR studies focused on improving the pharmacokinetic (PK) properties of the previously reported potent and selective Btk inhibitor CGI-1746 (1) resulted in the clinical candidate GDC-0834 (2), which retained the potency and selectivity of CGI-1746, b ...
SAR studies focused on improving the pharmacokinetic (PK) properties of the previously reported potent and selective Btk inhibitor CGI-1746 (1) resulted in the clinical candidate GDC-0834 (2), which retained the potency and selectivity of CGI-1746, but with much improved PK in preclinical animal models. Structure based design efforts drove this work as modifications to 1 were investigated at both the solvent exposed region as well as 'H3 binding pocket'. However, in vitro metabolic evaluation of 2 revealed a non CYP-mediated metabolic process that was more prevalent in human than preclinical species (mouse, rat, dog, cyno), leading to a high-level of uncertainly in predicting human pharmacokinetics. Due to its promising potency, selectivity, and preclinical efficacy, a single dose IND was filed and 2 was taken in to a single dose phase I trial in healthy volunteers to quickly evaluate the human pharmacokinetics. In human, 2 was found to be highly labile at the exo-cyclic amide bond that links the tetrahydrobenzothiophene moiety to the central aniline ring, resulting in insufficient parent drug exposure. This information informed the back-up program and discovery of improved inhibitors.
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