Kinase experiment:

Enzyme activities of Aurora A/TPX2 and Aurora B/INCENP complexes are assayed at room temperature in buffer containing serially diluted TAK-901, and the product is quantified using IMAP detection reagents. Aurora A/TPX2 (2 nM) is assayed with 100 nM FL-Kemptide and 1 mM ATP. Aurora B/INCENP (0.8 nM) is assayed with 100 nM 5-carboxy-fluorescein-GRTGRRNSI-NH2 (FL-PKAtide) and 10 mM ATP. For time-dependent inhibition, Aurora B/INCENP is incubated with TAK-901 for 1 hour at room temperature followed by addition of 150 mM ATP to initiate the reaction[1].

Cell experiment:

Cells are plated in 96-well microtiter plates and incubated with serial dilutions of TAK-901 for 72 hours. Cell proliferation is determined by ELISA analysis of bromodeoxyuridine (BrdUrd) incorporation into DNA. IMR-90 immortalized lung fibroblasts are seeded in 96-well microtiter plates and cultured for 3 to 4 days until confluent. Cells are then incubated with serial dilutions of TAK-901 for 72 hours. The MTS assay is conducted[1].

Animal experiment:

Mice: Tumor-bearing mice or rats are treated intravenously twice daily (b.i.d.) with either vehicle or TAK-901 on 2 consecutive days per week or every other day for 2 or 3 cycles. The antitumor activity of TAK-901 in human tumor and leukemia xenograft models are monitored[1]. Nude rats bearing A2780 tumors averaging 250 to 500 mg receive an intravenous dose of TAK-901. Plasma samples are collected by terminal cardiac puncture under CO2 anesthesia. Tumors are dissected and snap-frozen at -80℃[1].

IC50: 0.0017, 0.021 for Aurora-B/INCENP and Aurora-A/TPX2, respectively

Protein kinases Aurora A, B, and C play crucial roles during mitosis and cell division, are frequently elevated in cancer, and represent attractive targets for therapeutic intervention. TAK-901 is a novel, multitargeted Aurora B kinase inhibitor derived from a novel azacarboline kinase hinge-binder chemotype.

In vitro: TAK-901 exhibited time-dependent, tight-binding inhibition of Aurora B, but not Aurora A. Consistently, TAK-901 suppressed cellular histone H3 phosphorylation and induced polyploidy. In various human cancer cell lines, TAK-901 inhibited cell proliferation with effective concentration values from 40 to 500 nmol/L. TAK-901 potently inhibited only a few kinases other than Aurora B in intact cells, including FLT3 and FGFR2 [1].

In vivo: In rodent xenografts, TAK-901 exhibited potent activity against multiple human solid tumor types, and complete regression was found in the ovarian cancer A2780 model. In vivo biomarker studies showed that TAK-901 induced PD responses consistent with Aurora B inhibition and correlating with retention of TAK-901 in tumor tissue. [2].

Clinical trials: An open-label, dose escalation, phase I study has been conducted to identify the MTD and PK profile of TAK-901 in adult patients with advanced solid tumors or lymphoma.

Reference:
[1] Farrell P, Shi L, Matuszkiewicz J, Balakrishna D, Hoshino T, Zhang L, Elliott S, Fabrey R, Lee B, Halkowycz P, Sang B, Ishino S, Nomura T, Teratani M, Ohta Y, Grimshaw C, Paraselli B, Satou T, de Jong R.   Biological characterization of TAK-901, an investigational, novel, multitargeted Aurora B kinase inhibitor. Mol Cancer Ther. 2013;12(4):460-70.