cp-724714 and Breast-Neoplasms

CP-724,714 is an orally available, small molecule, potent HER-2 tyrosine kinase inhibitor under development for the treatment of advanced HER2-overexpressing cancers. In this study, the influence of baseline clinical characteristics and pathophysiological variables on the pharmacokinetics (PK) of CP-724,714, and the correlation between PK exposure and safety were examined in patients treated in the First-in-Human trial. PK and safety were also simulated for a Phase 2 trial at the recommended Phase 2 dose (RP2D) to assess if the simulated PK exposures of CP-724,714 covered the preclinically predicted efficacious concentrations, and if the predicted incidence of hepatic toxicities (>or=CTC grade 3) was acceptable.. Patients (n = 30) with advanced malignant HER2 positive solid tumors were enrolled in this open label dose-escalation study, and treated with daily oral dosing of CP-724,714 in 21-day cycles at the following dose levels: 250 mg QD, 250 mg BID, 400 mg BID, and 250 mg TID. PK parameter values were estimated using noncompartmental techniques. PK exposure parameters were correlated with the baseline pathophysiological variables, clinical characteristics, and safety. The simulations of PK exposures and the incidence of >or=grade 3 liver toxicity at the recommended Phase 2 dose were performed by nonparametric bootstrap (n = 1,000).. C (max) and AUC increased in an approximate dose proportional manner. The terminal t (1/2) was approximately 4.5 h, and was constant across the dose range from 250 to 400 mg. There was some accumulation with BID and TID dosing with a mean AUC accumulation ratio approximately 1.2-1.5, consistent with the t (1/2). Inter-patient variability in PK parameters was 31-65%, resulting in a considerable overlap of systemic exposure parameters (C (max) and AUC) at higher doses (i.e., 250 mg TID and 400 mg BID), as expected for the narrow dose range. Significant correlations were observed for body size and oral clearance (CL/F) (r = 0.574, P = 0.001) and oral steady-state volume of distribution (V (dss)/F) (r = 0.669, P = 0.0001). The most frequently encountered toxicities were elevated ALT and AST, hyperbilirubinemia, rash, asthenia, and nausea/vomiting (N/V). The steady-state AUC0-24 h was significantly correlated with the elevation of total bilirubin (r = 0.670, P = 0.001), ALT (r = 0.548, P = 0.002), and AST (r = 0.461, P = 0.010). The simulation of the Phase 2 trial at 250 mg BID predicted that the 95% confidence interval of the simulated mean concentrations of CP-724,714 were above the preclinically predicted efficacious concentrations throughout the majority of the dosing interval. The probability for >or=33% incidence of grade 3 or greater elevations of liver function test (LFT) was low (1.1%).. CP-724,714 demonstrates linear single-dose and multiple-dose PK. Both CL/F and V (dss)/F correlate with body size. Elevations of ALT, AST, and total bilirubin positively correlate with the steady-state AUC0-24 h. The Phase 2 trial simulation suggests that CP-724,714 will be well tolerated and that PK exposures will exceed the preclinically predicted efficacious level at the recommended Phase 2 dose (250 mg BID), supporting further evaluation of CP-724,714 in the Phase 2 trial.

Topics: Adult; Aged; Algorithms; Antineoplastic Agents; Area Under Curve; Breast Neoplasms; Chemical and Drug Induced Liver Injury; Chromatography, Liquid; Dose-Response Relationship, Drug; Enzyme Inhibitors; Female; Half-Life; Humans; Liver Function Tests; Middle Aged; Neoplasm Metastasis; Neoplasms; Protein-Tyrosine Kinases; Quinazolines; Receptor, ErbB-2; Tandem Mass Spectrometry

LASP-1 was identified as a protein following mass spectrometric analysis of phosphoproteins consequent to signaling by ErbB2 in SKOV-3 cells. It has been previously identified as an oncogene and is located on chromosomal arm 17q 0.76 Mb centromeric to ErbB2. It is expressed in serous ovarian cancer cell lines as a 40 kDa protein. In SKOV-3 cells, it was phosphorylated and was inhibited by Lapatinib and CP7274714. LASP-1 co-immunoprecipitated with ErbB2 in SKOV-3 cells, suggesting a direct interaction. This interaction and phosphorylation were independent of the kinase activity of ErbB2. Moreover, the binding of LASP-1 to ErbB2 was independent of the tyrosine phosphorylation of LASP-1. LASP-1 was neither expressed on the surface epithelium of the normal ovary nor in the fallopian tube. It was expressed in 28% of ovarian tumours (n = 101) that did not significantly correlate with other clinical factors. In tumours from patients with invasive ductal carcinoma of the breast who had ErbB2 amplification (3+), LASP-1 was expressed in 3/20 (P < 0.001). Analysis of the expression of an independent dataset of ovarian and breast tumours from TCGA showed the significant co-occurrence of ErbB2 and LASP-1 (P < 0.01). These results suggest that LASP-1 and ErbB2 interaction could be important in the pathogenesis of ovarian cancer.

Topics: Adaptor Proteins, Signal Transducing; Adult; Breast Neoplasms; Carcinoma, Ductal, Breast; Carcinoma, Ovarian Epithelial; Cell Line, Tumor; Cohort Studies; Cytoskeletal Proteins; Female; HEK293 Cells; Humans; Lapatinib; LIM Domain Proteins; Middle Aged; Ovarian Neoplasms; Phosphorylation; Plasmids; Protein Kinase Inhibitors; Quinazolines; Receptor, ErbB-2; Signal Transduction; Transfection

Though incidence of PI3K oncogenic mutation is prominent in breast cancer (20-30%), pharmacological targeting of this signaling pathway alone has failed to provide meaningful clinical benefit. To better understand and address this problem, we conducted genome-wide analysis to study the association of mutant PI3K with other gene amplification events. One of the most significant copy number gain events associated with PIK3CA mutation was the region within chromosome 17 containing HER2. To investigate the oncogenic effect and cell signaling regulation of co-occurring PIK3CA-H1047R and or HER2 gene, we generated cell models ectopically expressing mutant PIK3CA, HER2 or both genetic alterations. We observed that cells with both genetic alterations demonstrate increased aggressiveness and invasive capabilities than cells with either genetic change alone. Furthermore, we found that the combination of the HER2 inhibitor (CP-724714) and pan PI3K inhibitor (LY294002) is more potent than either inhibitor alone in terms of inhibition of cell proliferation and colony formation. Significantly, four cell signaling pathways were found in common for cells with HER2, mutant PIK3CA and cells with both genetic alterations through an Affymetric microarray analysis. Moreover, the cells with both genetic alterations acquired more significant replication stress as shown by enriched signaling pathways of cell cycle checkpoint control and DNA damage response signaling. Our study suggests co-occurrence of oncogenic HER2 and mutant PIK3CA cooperatively drives breast cancer progression. The cells with both genetic alterations obtain additional features of replication stress which could open new opportunity for cancer diagnostics and treatment.

Topics: Breast Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Chromones; Chromosomes, Human, Pair 17; Class I Phosphatidylinositol 3-Kinases; DNA Replication; Female; Gene Amplification; Genome-Wide Association Study; Humans; Mammary Glands, Human; Morpholines; Mutation; Quinazolines; Receptor, ErbB-2; Signal Transduction

Consensus virtual screening models were generated and validated utilizing a set of known human epidermal growth factor receptor-2 (HER2) inhibitors and modeled HER2 active and inactive state structures. The virtual screening models were successfully employed to discover a set of structurally diverse compounds with growth inhibitory activity against HER2-overexpressing SKBR3 breast cancer cell line. A search of a 3D database containing 350000 small-molecules using the consensus models retrieved 531 potential hits. Of the 531 hits, 57 were selected for testing in SKBR3 cells on the basis of structural novelty and desirable drug-like properties. Seven compounds inhibited growth of SKBR3 cells with IC50 values <10 microM. These lead compounds have desirable physicochemical properties and are excellent candidates for further optimization.

Topics: Amino Acid Sequence; Aniline Compounds; Antineoplastic Agents; Binding Sites; Breast Neoplasms; Catalytic Domain; Cell Line, Tumor; Drug Screening Assays, Antitumor; Female; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, 3-Ring; Humans; Ligands; Models, Molecular; Molecular Sequence Data; Piperazines; Pyrimidines; Quantitative Structure-Activity Relationship; Quinazolines; Quinolines; Receptor, ErbB-2; Small Molecule Libraries

Amplification and overexpression of erbB2 (Her-2/neu) proto-oncogene has been linked to human malignancies including tumors of the breast, ovary, and stomach. It has been implicated in tumor growth, sensitivity to standard chemotherapy, prognosis of patients, and disease-free survival. Although the clinical use of trastuzumab (Herceptin) has prolonged the survival of breast cancer patients with erbB2-overexpressing tumors, there is an urgent need for more potent and orally bioavailable small-molecule inhibitors. CP-724,714 is a potent inhibitor of erbB2 receptor autophosphorylation in intact cells and is currently undergoing phase I clinical trials. Here, we describe the effects of CP-724,714 in vitro and in vivo in human breast cancer models. CP-724,714 is selective for inhibiting growth of HER2-driven cell lines. In addition, we show that it induces G1 cell cycle block in erbB2-overexpressing BT-474 human breast carcinoma cells and inhibits erbB2 autophosphorylation in xenografts when administered p.o. to athymic mice. It induces a marked reduction of extracellular signal-regulated kinase and Akt phosphorylation, tumor cell apoptosis, and release of caspase-3. P.o. administration (q.d. or b.i.d.) of CP-724,714 inhibits the growth of erbB2-overexpressing tumors in athymic mice without overt adverse effects.

Topics: Animals; Apoptosis; Breast Neoplasms; Cell Cycle; Cell Growth Processes; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Mice; Mice, Nude; NIH 3T3 Cells; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Mas; Proto-Oncogene Proteins c-akt; Quinazolines; Receptor, ErbB-2; Xenograft Model Antitumor Assays