Weihua Wan

CEP-28122, a Highly Potent and Selective Orally Active Inhibitor of Anaplastic Lymphoma Kinase with Antitumor Activity in Experimental Models of Human Cancers

Anaplastic lymphoma kinase (ALK) is constitutively activated in a number of human cancer types due to chromosomal translocations, point mutations, and gene amplification and has emerged as an excellent molecular target for cancer therapy. Here we report the identification and preclinical characterization of CEP-28122, a highly potent and selective orally active ALK inhibitor. CEP-28122 is a potent inhibitor of recombinant ALK activity and cellular ALK tyrosine phosphorylation. It induced concentration-dependent growth inhibition/cytotoxicity of ALK-positive anaplastic large-cell lymphoma (ALCL), non-small cell lung cancer (NSCLC), and neuroblastoma cells, and displayed dose-dependent inhibition of ALK tyrosine phosphorylation in tumor xenografts in mice, with substantial target inhibition (>90%) for more than 12 hours following single oral dosing at 30 mg/kg. Dose-dependent antitumor activity was observed in ALK-positive ALCL, NSCLC, and neuroblastoma tumor xenografts in mice administered CEP-28122 orally, with complete/near complete tumor regressions observed following treatment at doses of 30 mg/kg twice daily or higher. Treatment of mice bearing Sup-M2 tumor xenografts for 4 weeks and primary human ALCL tumor grafts for 2 weeks at 55 or 100 mg/kg twice daily led to sustained tumor regression in all mice, with no tumor reemergence for more than 60 days postcessation of treatment. Conversely, CEP-28122 displayed marginal antitumor activity against ALK-negative human tumor xenografts under the same dosing regimens. Administration of CEP-28122 was well tolerated in mice and rats. In summary, CEP-28122 is a highly potent and selective orally active ALK inhibitor with a favorable pharmaceutical and pharmacokinetic profile and robust and selective pharmacologic efficacy against ALK-positive human cancer cells and tumor xenograft models in mice. Mol Cancer Ther; 11(3); 670–9. ©2011 AACR.

Discovery of a Potent Inhibitor of Anaplastic Lymphoma Kinase with in Vivo Antitumor Activity

A series of novel 7-amino-1,3,4,5-tetrahydrobenzo[b]azepin-2-one derivatives within the diaminopyrimidine class of kinase inhibitors were identified that target anaplastic lymphoma kinase (ALK). These inhibitors are potent against ALK in an isolated enzyme assay and inhibit autophosphorylation of the oncogenic fusion protein NPM-ALK in anaplastic large cell lymphoma (ALCL) cell lines. The lead inhibitor 15, which incorporates a bicyclo[2.2.1]hept-5-ene ring system in place of an aryl moiety, activates the pro-apoptotic caspases (3 and 7) and displays selective cytotoxicity against ALK-positive ALCL cells. Furthermore, 15 provides more than 40-fold selectivity against the structurally related insulin receptor, is orally bioavailable in multiple species, and displays in vivo antitumor efficacy when dosed orally in ALK-positive ALCL tumor xenografts in Scid mice.

2,7-disubstituted-pyrrolo[2,1-f][1,2,4]triazines: new variant of an old template and application to the discovery of anaplastic lymphoma kinase (ALK) inhibitors with in vivo antitumor activity.

A novel 2,7-disubstituted-pyrrolo[2,1-f][1,2,4]triazine scaffold has been designed as a new kinase inhibitor platform mimicking the bioactive conformation of the well-known diaminopyrimidine motif. The design, synthesis, and validation of this new pyrrolo[2,1-f][1,2,4]triazine scaffold will be described for inhibitors of anaplastic lymphoma kinase (ALK). Importantly, incorporation of appropriate potency and selectivity determinants has led to the discovery of several advanced leads that were orally efficacious in animal models of anaplastic large cell lymphoma (ALCL). A lead inhibitor (30) displaying superior efficacy was identified and in depth in vitro/in vivo characterization will be presented.

Novel 2,3,4,5-tetrahydro-benzo[d]azepine derivatives of 2,4-diaminopyrimidine, selective and orally bioavailable ALK inhibitors with antitumor efficacy in ALCL mouse models.

The synthesis and biological evaluation of potent and selective anaplastic lymphoma kinase (ALK) inhibitors from a novel class of 2,4-diaminopyrimidines, incorporating 2,3,4,5-tetrahydro-benzo[d]azepine fragments, is described. An orally bioavailable analogue (18) that displayed antitumor efficacy in ALCL xenograft models in mice was identified and extensively profiled.

Discovery of an Orally Efficacious Inhibitor of Anaplastic Lymphoma Kinase

Anaplastic lymphoma kinase (ALK) is a promising therapeutic target for the treatment of cancer, supported by considerable favorable preclinical and clinical activities over the past several years and culminating in the recent FDA approval of the ALK inhibitor crizotinib. Through a series of targeted modifications on an ALK inhibitor diaminopyrimidine scaffold, our research group has driven improvements in ALK potency, kinase selectivity, and overall pharmaceutical properties. Optimization of this scaffold has led to the identification of a potent and efficacious inhibitor of ALK, 25b. A striking feature of 25b over previously described ALK inhibitors is its >600-fold selectivity over insulin receptor (IR), a closely related kinase family member. Most importantly, 25b exhibited dose proportional escalation in rat compared to compound 3 which suffered dose limiting absorption preventing further advancement. Compound 25b exhibited significant in vivo antitumor efficacy when dosed orally in an ALK-positive ALCL tumor xenograft model in SCID mice, warranting further assessment in advanced preclinical models.

Strategies to Mitigate the Bioactivation of 2-Anilino-7-Aryl-Pyrrolo[2,1-f][1,2,4]triazines: Identification of Orally Bioavailable, Efficacious ALK Inhibitors

Chemical strategies to mitigate cytochrome P450-mediated bioactivation of novel 2,7-disubstituted pyrrolo[2,1-f][1,2,4]triazine ALK inhibitors are described along with synthesis and biological activity. Piperidine-derived analogues showing minimal microsomal reactive metabolite formation were discovered. Potent, selective, and metabolically stable ALK inhibitors from this class were identified, and an orally bioavailable compound (32) with antitumor efficacy in ALK-driven xenografts in mouse models was extensively characterized.

Methanesulfonamido-cyclohexylamine derivatives of 2,4-diaminopyrimidine as potent ALK inhibitors

The incorporation of R,R-1,2-diaminocyclohexane at C4 in a series of 2,4-diaminopyrimidines led to a number of ALK inhibitors in which optimized activity was achieved by conversion of the 2-amino group into a methanesulfonamide. Tumor growth inhibition was observed when an orally bioavailable analog was evaluated in a Karpas-299 tumor xenograft mouse model.

Discovery of Clinical Candidate CEP-37440, a Selective Inhibitor of Focal Adhesion Kinase (FAK) and Anaplastic Lymphoma Kinase (ALK)

Analogues structurally related to anaplastic lymphoma kinase (ALK) inhibitor 1 were optimized for metabolic stability. The results from this endeavor not only led to improved metabolic stability, pharmacokinetic parameters, and in vitro activity against clinically derived resistance mutations but also led to the incorporation of activity for focal adhesion kinase (FAK). FAK activation, via amplification and/or overexpression, is characteristic of multiple invasive solid tumors and metastasis. The discovery of the clinical stage, dual FAK/ALK inhibitor 27b, including details surrounding SAR, in vitro/in vivo pharmacology, and pharmacokinetics, is reported herein.

Design of 7-amino-6-chloro-3H-imidazo[4,5-b]pyridine scaffold from 5-chloro-2,4-diaminopyrimidine pharmacophore: identification of potent inhibitors of anaplastic lymphoma kinase

A series of potent anaplastic lymphoma kinase (ALK) inhibitors based on a 7-amino-6-chloro-3H-imidazo[4,5-b]pyridine scaffold were identified through rational design from a 5-chloro-2,4-diaminopyrimidine pharmacophore, maintaining key binding elements, favourable lipophilic interactions and orienting the side chains into favoured trajectories. Importantly, potency and selectivity determinants from the parent series were directly applicable to the new scaffold. This highly focused strategy led to the identification of several lead inhibitors that displayed potent activity in enzyme and cellular assays as well as pronounced oral bioavailability.

Piperidine-3,4-diol and piperidine-3-ol derivatives of pyrrolo[2,1-f][1,2,4]triazine as inhibitors of anaplastic lymphoma kinase.

The diastereoselective synthesis and biological activity of piperidine-3,4-diol and piperidine-3-ol-derived pyrrolotriazine inhibitors of anaplastic lymphoma kinase (ALK) are described. Although piperidine-3,4-diol and piperidine-3-ol derivatives showed comparable in vitro ALK activity, the latter subset of inhibitors demonstrated improved physiochemical and pharmacokinetic properties. Furthermore, the stereochemistry of the C3 and C4 centers had a marked impact on the in vivo inhibition of ALK autophosphorylation. Thus, trans-4-aryl-piperidine-3-ols (22) were more potent than the cis diastereomers (20).