Discovery of novel triazolo[4,3-b]pyridazin-3-yl-quinoline derivatives as PIM inhibitors
Sonia Martínez-González, Sonsoles Rodríguez-Arístegui, Cristina Ana Gómez de la Oliva, Ana Isabel Hernández, Esther González Cantalapiedra, Carmen Varela, Ana Belén García, Obdulia Rabal, Julen Oyarzabal, James R Bischoff, Javier Klett, María Isabel Albarrán, Antonio Cebriá, Nuria Ajenjo, Beatriz García-Serelde, Elena Gómez-Casero, Manuel Cuadrado-Urbano, David Cebrián, Carmen Blanco-Aparicio, Joaquín Pastor
PIM kinase family (PIM-1, PIM-2 and PIM-3) is an appealing target for the discovery and development of selective inhibitors, useful in various disease conditions in which these proteins are highly expressed, such as cancer. The significant effort put, in the recent years, towards the development of small molecules exhibiting inhibitory activity against this protein family has ended up with several molecules entering clinical trials.
As part of our ongoing exploration for potential drug candidates that exhibit affinity towards this protein family, we have generated a novel chemical series of triazolo[4,3-b]pyridazine based tricycles by applying a scaffold hopping strategy over our previously reported potent pan-PIM inhibitor ETP-47453 (compound 2). The structure-activity relationship studies presented herein demonstrate a rather selective PIM-1/PIM-3 biochemical profile for this novel series of tricycles, although pan-PIM and PIM-1 inhibitors have also been identified.
Selected examples show significant inhibition of the phosphorylation of BAD protein in a cell-based assay. Moreover, optimized and highly selective compounds, such as 42, did not show significant hERG inhibition at 20 μM concentration, and proved its antiproliferative activity and utility in combination with particular antitumoral agents in several tumor cell lines.
CITATION Eur J Med Chem. 2019 Apr 15;168:87-109. doi: 10.1016/j.ejmech.2019.02.022. Epub 2019 Feb 19.