Phenyl Dihydrouracil: An Alternative Cereblon Binder for PROTAC Design

Thalidomide and its analogues are frequently used in PROTAC design. However, they are known to be inherently unstable, undergoing hydrolysis even in commonly utilized cell culture media. We recently reported that phenyl glutarimide (PG)-based PROTACs displayed improved chemical stability and, consequently, improved protein degradation efficacy and cellular potency. Our optimization efforts, aiming to further improve the chemical stability and eliminate the racemization-prone chiral center in PG, led us to the development of phenyl dihydrouracil (PD)-based PROTACs. Here we describe the design and synthesis of LCK-directing PD-PROTACs and compare their physicochemical and pharmacological properties to those of the corresponding IMiD and PG analogues

Structure Guided Optimization, in Vitro Activity, and in Vivo Activity of Pan-PIM Kinase Inhibitors

Proviral insertion of Moloney virus (PIM) 1, 2, and 3 kinases are serine/threonine kinases that normally function in survival and proliferation of hematopoietic cells. As high expression of PIM1, 2, and 3 is frequently observed in many human malignancies, including multiple myeloma, non-Hodgkins lymphoma, and myeloid leukemias, there is interest in determining whether selective PIM inhibition can improve outcomes of these human cancers. Herein, we describe our efforts toward this goal. The structure guided optimization of a singleton high throughput screening hit in which the potency against all three PIM isoforms was increased >10,000-fold to yield compounds with pan PIM <i>K</i>_is < 10 pM, nanomolar cellular potency, and in vivo activity in an acute myeloid leukemia Pim-dependent tumor model is described

Identification of <i>N</i>‑(4-((1<i>R</i>,3<i>S</i>,5<i>S</i>)‑3-Amino-5-methylcyclohexyl)pyridin-3-yl)-6-(2,6-difluorophenyl)-5-fluoropicolinamide (PIM447), a Potent and Selective Proviral Insertion Site of Moloney Murine Leukemia (PIM) 1, 2, and 3 Kinase Inhibitor in Clinical Trials for Hematological Malignancies

Pan proviral insertion site of Moloney murine leukemia (PIM) 1, 2, and 3 kinase inhibitors have recently begun to be tested in humans to assess whether pan PIM kinase inhibition may provide benefit to cancer patients. Herein, the synthesis, in vitro activity, in vivo activity in an acute myeloid leukemia xenograft model, and preclinical profile of the potent and selective pan PIM kinase inhibitor compound <b>8</b> (PIM447) are described. Starting from the reported aminopiperidyl pan PIM kinase inhibitor compound <b>3</b>, a strategy to improve the microsomal stability was pursued resulting in the identification of potent aminocyclohexyl pan PIM inhibitors with high metabolic stability. From this aminocyclohexyl series, compound <b>8</b> entered the clinic in 2012 in multiple myeloma patients and is currently in several phase 1 trials of cancer patients with hematological malignancies