A novel series of N-aryl-N'-pyrimidin-4-yl ureas has been optimized to afford potent and selective inhibitors of the fibroblast growth factor receptor tyrosine kinases 1, 2, and 3 by rationally designing the substitution pattern of the aryl ring. On the basis of its in vitro profile, compound 1h (NVP-BGJ398) was selected for in vivo evaluation and showed significant antitumor activity in RT112 bladder cancer xenografts models overexpressing wild-type FGFR3. These results support the potential therapeutic use of 1h as a new anticancer agent.
As a result of our efforts to discover novel p53:MDM2 protein-protein interaction inhibitors useful for treating cancer, the potent and selective MDM2 inhibitor NVP-CGM097 (1) with an excellent in vivo profile was selected as a clinical candidate and is currently in phase 1 clinical development. This article provides an overview of the discovery of this new clinical p53:MDM2 inhibitor. The following aspects are addressed: mechanism of action, scientific rationale, binding mode, medicinal chemistry, pharmacokinetic and pharmacodynamic properties, and in vivo pharmacology/toxicology in preclinical species.
Permeability and oral bioavailability of macrocyclic peptides still represent difficult challenges in drug discovery. Despite the recognized potential of macrocyclic peptides as therapeutics, their use is still restricted to extracellular targets and intravenous administration. Indeed, macrocyclic peptides generally suffer from limited proteolytic stability, high clearance, and poor membrane permeability, and this leads to the absence of systemic exposure after oral administration. To overcome these limitations, we started to investigate the development of a general cyclic decapeptide scaffold that possesses ideal features for cell permeability and oral exposure. On the basis of a rigid hairpin structure, the scaffold design aimed to decrease the overall polarity of the compound, thereby limiting the energetic cost of NH desolvation and the entropy penalty during cell penetration. The results of this study also demonstrate the importance of rigidity for the β-turn design regarding clearance. To stabilize the scaffold in the desired β-hairpin conformation, the introduction of d-proline at the i+1 turn position proved to be beneficial for both permeability and clearance. As a result, cyclopeptide decamers with unprecedented high values for oral bioavailability and exposure are reported herein. NMR spectroscopy conformation and dynamic analysis confirmed, for selected examples, the rigidity of the scaffold and the presence of transannular hydrogen bonds in polar and apolar environments. Furthermore, we showed, for one compound, that its transition from a polar environment to an apolar one was accompanied by an increased molecular motion, revealing an entropy contribution to membrane permeation.
FGF19 signaling through
the FGFR4/β-klotho receptor complex
has been shown to be a key driver of growth and survival in a subset
of hepatocellular carcinomas, making selective FGFR4 inhibition an
attractive treatment opportunity. A kinome-wide sequence alignment
highlighted a poorly conserved cysteine residue within the FGFR4 ATP-binding
site at position 552, two positions beyond the gate-keeper residue.
Several strategies for targeting this cysteine to identify FGFR4 selective
inhibitor starting points are summarized which made use of both rational
and unbiased screening approaches. The optimization of a 2-formylquinoline
amide hit series is described in which the aldehyde makes a hemithioacetal
reversible-covalent interaction with cysteine 552. Key challenges
addressed during the optimization are improving the FGFR4 potency,
metabolic stability, and solubility leading ultimately to the highly
selective first-in-class clinical candidate roblitinib.
We previously reported the design of several cyclic decapeptides based on a generic scaffold that achieved favorable oral bioavailability and exposure. With the goal to further investigate the potential of this approach, we describe herein the effect of mono- and difunctionalization of this scaffold. A series of cyclic decapeptides were therefore subjected to a range of in vitro assays and pharmacokinetic (PK) studies to investigate whether the introduction of polar or charged groups could be tolerated by the "engineered" scaffold while maintaining good PK profiles. Whereas the introduction of charged amino acids proved-besides maintaining low clearance-to conceal the inherent PK properties of the scaffold, the introduction of polar amino acids (i.e., threonine and pyridyl alanine) led to several cyclic decapeptides exhibiting excellent PK profiles together with a solubility that was significantly improved relative to that of previously reported cyclic decapeptides.
The IL approach was instrumental for tuning physico-chemical API properties, while avoiding the inherent need for structural changes as required for prodrugs.
Recently, a variety of studies concerned with the permeability and oral bioavailability of cyclic peptides have been reported. In particular, strategies aiming at modifying peptides to maintain or to enhance solubility while enabling permeability constitute a significant challenge, but are of high interest to ensure a smooth drug discovery process. Current methodologies include N-methylation, matching of hydrogen bonding acceptors and donors across the macrocycle, and additional masking of polarity. In this study, we investigate further the pivotal effects of shielding on permeability and studied the metabolism of the corresponding peptides in more detail by comparing peptide concentrations in the portal versus the jugular vein in rats. Interestingly, minor changes in one particular side chain impacts both permeability and liver metabolism.Graphical Abstract
Electronic supplementary materialThe online version of this article (doi:10.1007/s10989-017-9590-8) contains supplementary material, which is available to authorized users.
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