FMS-like tyrosine kinase 3 inhibitors: a patent review

Novel spiroindoline quinazolinedione derivatives as anticancer agents and potential FLT3 kinase inhibitors

Despite considerable recent progress in therapeutic strategies, cancer still remains one of the leading causes of death. Molecularly targeted therapies, in particular those focused on blocking receptor tyrosine kinases have produced promising outcomes in recent years. In this study, a new series of spiro[indoline-3,2'-quinazoline]-2,4'(3'H)-dione derivatives (5a-5l) were synthesized and evaluated as potential kinase inhibitors with anticancereffects. The anti-proliferative activity was measured by MTT assay, while the cell cycle was studied using flow cytometry. Moreover, kinase inhibition profiles of the most promising compounds were assessed against a panel of 25 oncogenic kinases. Compounds 5f,5g,5i, and 5jshowed anti-proliferative effect against EBC-1, A549, and HT-29 solid tumor models in addition to leukemia cell line K562. In particular, compound 5f, bearing 4-methylphenyl pendant on the isatin ring displayed considerable potency with IC₅₀ values of 2.4 to 13.4 μM against cancer cells. The most potent derivatives also altered the distribution of cells in different phases of cell cycle and increased the sub-G1 phase cells in K562 cells. Moreover, kinase inhibition assays identified FLT3 kinase was as the primary targetof these derivatives. Compound 5f at 25 μM concentration showed inhibitory activities of 55% and 62% against wild-type FLT3 and its mutant, D835Y, respectively. Finally, the docking and simulation studies revealed the important interactions of compound 5f with wild type and mutant FLT3. The results of this study showed that some novel spiroindoline quinazolinedione compounds could be potential candidates for further development as novel targeted anticancer agents.

The synthesis review of the approved tyrosine kinase inhibitors for anticancer therapy in 2015-2020

In the 21st century, cancer is the major public health problem worldwide. Based on the important roles of protein tyrosine kinase, the accelerated hunt for potent small-molecule tyrosine kinase inhibitors has led to the success of 30 newly inhibitors in this family for the cancer therapy in last five years. In this review, we updated their synthesis methods, and compared the original research routes with the optimized routes for each PTK inhibitor against different target, in order to make an outlook on the future synthesis of potential PTK inhibitors for anticancer therapy.

An update of new small-molecule anticancer drugs approved from 2015 to 2020

A high incidence of cancer has given rise to the development of more anti-tumor drugs. From 2015 to 2020, fifty-six new small-molecule anticancer drugs, divided into ten categories according to their anti-tumor target activities, have been approved. These include TKIs (30 drugs), MAPK inhibitors (3 drugs), CDK inhibitors (3 drugs), PARP inhibitors (3 drugs), PI3K inhibitors (3 drugs), SMO receptor antagonists (2 drugs), AR antagonists (2 drugs), SSTR inhibitors (2 drugs), IDH inhibitors (2 drugs) and others (6 drugs). Among them, PTK inhibitors (30/56) have led to a paradigm shift in cancer treatment with less toxicity and more potency. Each of their structures, approval statuses, applications, SAR analyses, and original research synthesis routes have been summarized, giving us a more comprehensive map for further efforts to design more specific targeted agents for reducing cancer in the future. We believe this review will help further research of potential antitumor agents in clinical usage.

Computational prediction of formulation strategies for beyond-rule-of-5 compounds

The physicochemical properties of some contemporary drug candidates are moving towards higher molecular weight, and coincidentally also higher lipophilicity in the quest for biological selectivity and specificity. These physicochemical properties move the compounds towards beyond rule-of-5 (B-r-o-5) chemical space and often result in lower water solubility. For such B-r-o-5 compounds non-traditional delivery strategies (i.e. those other than conventional tablet and capsule formulations) typically are required to achieve adequate exposure after oral administration. In this review, we present the current status of computational tools for prediction of intestinal drug absorption, models for prediction of the most suitable formulation strategies for B-r-o-5 compounds and models to obtain an enhanced understanding of the interplay between drug, formulation and physiological environment. In silico models are able to identify the likely molecular basis for low solubility in physiologically relevant fluids such as gastric and intestinal fluids. With this baseline information, a formulation scientist can, at an early stage, evaluate different orally administered, enabling formulation strategies. Recent computational models have emerged that predict glass-forming ability and crystallisation tendency and therefore the potential utility of amorphous solid dispersion formulations. Further, computational models of loading capacity in lipids, and therefore the potential for formulation as a lipid-based formulation, are now available. Whilst such tools are useful for rapid identification of suitable formulation strategies, they do not reveal drug localisation and molecular interaction patterns between drug and excipients. For the latter, Molecular Dynamics simulations provide an insight into the interplay between drug, formulation and intestinal fluid. These different computational approaches are reviewed. Additionally, we analyse the molecular requirements of different targets, since these can provide an early signal that enabling formulation strategies will be required. Based on the analysis we conclude that computational biopharmaceutical profiling can be used to identify where non-conventional gateways, such as prediction of 'formulate-ability' during lead optimisation and early development stages, are important and may ultimately increase the number of orally tractable contemporary targets.