AZD8055

Pediatr Blood Cancer,2012 Feb;58(2):191-9.

Initial testing (stage 1) of the mTOR kinase inhibitor AZD8055 by the pediatric preclinical testing program.[Pubmed: 21337679]

AZD8055 is a small molecule ATP-competitive inhibitor of the serine/threonine kinase mTOR that regulates cap-dependent translation through the mTORC1 complex and Akt activation through the mTORC2 complex.
METHODS AND RESULTS:
Procedures AZD8055 was tested against the PPTP in vitro panel at concentrations ranging from 1.0 nM to 10 µM and against the PPTP in vivo panels at a dose of 20 mg/kg administered orally daily x 7 for 4 weeks. In vitro the median relative IC(50) for AZD8055 against the PPTP cell lines was 24.7 nM. Relative I/O values >0% (consistent with a cytostatic effect) were observed in 8 cell lines and 15 cell lines showed Relative I/O values ranging from -4.7 to -92.2% (consistent with varying degrees of cytotoxic activity). In vivo AZD8055 induced significant differences in EFS distribution compared to controls in 23 of 36 (64%) evaluable solid tumor xenografts, and 1 of 6 evaluable ALL xenografts. Intermediate activity for the time to event activity measure (EFS T/C >2) was observed in 5 of 32 (16%) solid tumor xenografts evaluable. The best response was stable disease. PD2 (progressive disease with growth delay) was observed in 20 of 36 (55.6%) evaluable solid tumor xenografts. AZD8055 significantly inhibited 4E-BP1, S6, and Akt phosphorylation following day 1 and day 4 dosing, but suppression of mTORC1 or mTORC2 signaling did not predict tumor sensitivity.
CONCLUSIONS:
AZD8055 demonstrated broad activity in vitro, but at the dose and schedule studied demonstrated limited activity in vivo against the PPTP solid tumor and ALL panels.

Br J Cancer,2011 Mar 29;104(7):1116-25.

Effect of PI3K- and mTOR-specific inhibitors on spontaneous B-cell follicular lymphomas in PTEN/LKB1-deficient mice[Pubmed: 21407213]

The PI3K-mTOR (phosphoinositide 3-kinase-mammalian target of rapamycin kinase) pathway is activated in the majority of tumours, and there is interest in assessing whether inhibitors of PI3K or mTOR kinase have efficacy in treating cancer. Here, we define the effectiveness of specific mTOR (AZD8055) and PI3K (GDC-0941) inhibitors, currently in clinical trials, in treating spontaneous B-cell follicular lymphoma that develops in PTEN(+/-)LKB1(+/hypo) mice.
METHODS AND RESULTS:
The PTEN(+/-)LKB1(+/hypo) mice were administered AZD8055 or GDC-0941, and the volumes of B-cell follicular lymphoma were measured by MRI. Tumour samples were analysed by immunohistochemistry, immunoblot and flow cytometry. The AZD8055 or GDC-0941 induced ∼40% reduction in tumour volume within 2 weeks, accompanied by ablation of phosphorylation of AKT, S6K and SGK (serum and glucocorticoid protein kinase) protein kinases. The drugs reduced tumour cell proliferation, promoted apoptosis and suppressed centroblast population. The AZD8055 or GDC-0941 treatment beyond 3 weeks caused a moderate additional decrease in tumour volume, reaching ∼50% of the initial volume after 6 weeks of treatment. Tumours grew back at an increased rate and displayed similar high grade and diffuse morphology as the control untreated tumours upon cessation of drug treatment.
CONCLUSIONS:
These results define the effects that newly designed and specific mTOR and PI3K inhibitors have on a spontaneous tumour model, which may be more representative than xenograft models frequently employed to assess effectiveness of kinase inhibitors. Our data suggest that mTOR and PI3K inhibitors would benefit treatment of cancers in which the PI3K pathway is inappropriately activated; however, when administered alone, may not cause complete regression of such tumours.

Leukemia,2012 Jun;26(6):1195-202.

The dual mTORC1 and mTORC2 inhibitor AZD8055 has anti-tumor activity in acute myeloid leukemia[Pubmed: 22143671]

The serine/threonine kinase mammalian target of rapamycin (mTOR) is crucial for cell growth and proliferation, and is constitutively activated in primary acute myeloid leukemia (AML) cells, therefore representing a major target for drug development in this disease.
METHODS AND RESULTS:
We show here that the specific mTOR kinase inhibitor AZD8055 blocked mTORC1 and mTORC2 signaling in AML. Particularly, AZD8055 fully inhibited multisite eIF4E-binding protein 1 phosphorylation, subsequently blocking protein translation, which was in contrast to the effects of rapamycin. In addition, the mTORC1-dependent PI3K/Akt feedback activation was fully abrogated in AZD8055-treated AML cells. Significantly, AZD8055 decreased AML blast cell proliferation and cell cycle progression, reduced the clonogenic growth of leukemic progenitors and induced caspase-dependent apoptosis in leukemic cells but not in normal immature CD34+ cells. Interestingly, AZD8055 strongly induced autophagy, which may be either protective or cell death inducing, depending on concentration. Finally, AZD8055 markedly increased the survival of AML transplanted mice through a significant reduction of tumor growth, without apparent toxicity.
CONCLUSIONS:
Our current results strongly suggest that AZD8055 should be tested in AML patients in clinical trials.

Cancer Res,2010 Jan 1;70(1):288-98.

AZD8055 is a potent, selective, and orally bioavailable ATP-competitive mammalian target of rapamycin kinase inhibitor with in vitro and in vivo antitumor activity.[Pubmed: 20028854]

Cell lines:U87MG, A549 and H838 cells
Concentrations: 1 nM - 1 μM
Incubation Time: 72 to 96 hours
Method:
Cells are exposed to AZD8055 for 72 to 96 hours and stained for cell nuclei (0.03 mg/mL Hoechst 33342) and acidic vesicles (1 μg/mL acridine orange). Images are captured at 450 and 536 nm on an ArrayScan II platform, and the percentage of acidic vesicles and the number of cells are quantified. For LC3 assessment, cells are exposed to e64d/pepstatin (10 μg/mL) for 30 to 90 min before incubation with AZD8055. Cells are lysed on ice and analyzed by immunoblotting.

Cancer Res,2010 Jan 1;70(1):288-98.

AZD8055 is a potent, selective, and orally bioavailable ATP-competitive mammalian target of rapamycin kinase inhibitor with in vitro and in vivo antitumor activity.[Pubmed: 20028854]

Animal Models: U87MG, BT474c, A549, Calu-3, LoVo, SW620, PC3 and MES-SA U87-MG and A549 are established in pathogen-free, female nude mice (nu/nu:Alpk)
Formulation: 2.5-20 mg/kg
Administration: Oral gavage once or twice daily