Exposure-response (E-R) analysis to facilitate phase III (P3) dose selection for AMG 479 (A479) in combination with gemcitabine (G) to treat metastatic pancreatic cancer (mPC)

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Background: A479 is an investigational, fully human monoclonal antibody against IGF1R. In a phase II study, 125 pts with mPC were randomized 1:1:1 to A479, placebo (P), or conatumumab in combination with G. Addition of A479 (12 mg/kg IV, Q2W) to G (1000 mg/m2) showed evidence of improved OS and PFS (Kindler, JCO 2010:28 abstr 4035). An E-R analysis was done to inform P3 dose selection for A479.

Methods: A population PK model of A479 was constructed using data from multiple studies. An E-R analysis was performed with pts from the A479+G and P+G arms (∼40 pts/arm). The effect of estimated steady-state area under the curve (AUCss) on OS and PFS was evaluated with a Cox proportional hazard model. Effects of potential confounding factors on OS- AUCss and PFS-AUCss associations were assessed by multivariate analysis. Exposure-safety data were analyzed with descriptive statistics and linear regression. P3 doses for A479 were explored with Monte Carlo simulations using population PK and parametric survival models.

Results: There was a positive association between OS or PFS and higher AUCss in the A479+G arm (P<0.001, <0.001) that remained even when data from the A479+G and P+G arms were combined (P=0.033, 0.022). Pts with AUCss ≥ median (19.2 mg·h/μL) had longer median OS and PFS (16.0, 7.6 months) than pts with AUCss < median (4.7, 1.9 months). OS-AUCss and PFS-AUCss associations were significant after adjusting for potential confounding factors. Sensitivity E-R analyses were done to confirm the modeling results. The incidence of most adverse events was similar between the AUCss < and ≥ median groups, although the incidence of grade ≥3 hyperglycemia, neutropenia, and thrombocytopenia trended higher in pts with AUCss ≥ median. Population PK indicated 1.7-fold higher clearance of A479 in mPC than non-mPC pts. No G-A479 PK interactions were identified. PK simulations showed similar AUCss of A479 in mPC pts at 20 mg/kg and in non-mPC pts at 12 mg/kg. Simulations projected improved OS and PFS with 20 mg/kg vs 12 mg/kg A479.

Conclusions: Increased exposure to A479 is associated with improved clinical outcomes in mPC. This supports the evaluation of 20 mg/kg A479 in P3.

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Transcription factors BmPOUM2 and BmβFTZ-F1 are involved in regulation of the expression of the wing cuticle protein gene BmWCP4 in the silkworm, Bombyx mori

In Bombyx mori, the wing cuticle protein gene BmWCP4 is expressed specifically in the epidermis at the onset and mid-stage of pupation and is responsible for the formation of the pupal cuticle during the larval-pupal metamorphosis. The gene consists of four exons and three introns and is present as a single copy in the genome. Its expression was up-regulated by 20-hydroxyecdysone (20E) and the 20E-induced expression was suppressed by juvenile hormone (JH) III. The upstream regulatory sequence region of the BmWCP4 gene was cloned and the regulatory elements responsible for 20E induction were identified. Two cis-regulatory elements (CREs) bound by the transcription factors BmPOUM2 and BmβFTZ-F1 were identified that mediated 20E-regulated expression of this gene. An electrophoretic mobility shift assay detected two nuclear proteins isolated from the epidermis and the BmN cell line that specifically bound to the POU and βFTZ-F1 CREs, respectively. BmPOUM2 recombinant protein explicitly bound to the POU CRE. Developmental and 20E-induced expression of the BmWCP4, BmPOUM2 and BmβFTZ-F1 genes showed that BmPOUM2 and BmβFTZ-F1 were initially expressed, followed by BmWCP4. These data suggest that the 20E-induced expression of BmWCP4 is mediated by the transcription factors BmPOUM2 and BmβFTZ-F1 binding to their CREs in the regulatory sequence region of the BmWCP4 gene.

Proteomic analysis of human serum for finding pathogenic factors and potential biomarkers in preeclampsia

OBJECTIVE(S)

To apply a novel proteomic method to discover potential pathogenic factors and biomarkers of preeclampsia.

STUDY DESIGN

Sera from five patients complicated with preeclampsia and five healthy pregnant controls were separately pooled. Each pool was treated with peptide ligand library beads (PLLBs) to remove high abundance proteins by affinity and thus enrich low abundance proteins. The proteins from the eluate were analyzed by a combination of 1D Gel-LC-MS/MS. Protein expression levels were quantified using spectral counts and the extracted ion current.

RESULTS

1172 unique proteins in preeclampsia and 1149 in healthy controls were identified in the present study. 51 proteins were differentially expressed between preeclampsia and healthy pregnant women including chorionic somatommammptropin hormone (CSH) and fibulin-1. 31 proteins identified were up-regulated and 20 were down-regulated.

CONCLUSIONS

The results demonstrate that peptide ligand library combining with 1D gel-LC-MS/MS analysis is an efficient method to identify differentially expressed proteins in sera and two biological processes of complement and coagulation activations and lipid metabolism were involved in the pathogenesis of preeclampsia.

Haplotype-dependent HLA susceptibility to nasopharyngeal carcinoma in a Southern Chinese population

We have conducted a comprehensive case-control study of a nasopharyngeal carcinoma (NPC) population cohort from Guangxi Province of Southern China, a region with one of the highest NPC incidences on record. A total of 1407 individuals including NPC patients, healthy controls, and their adult children were examined for the human leukocyte antigen (HLA) association, which is so far the largest NPC cohort reported for such studies. Stratified analysis performed in this study clearly demonstrated that while NPC protection is associated with independent HLA alleles, most NPC susceptibility is strictly associated with HLA haplotypes. Our study also detected for the first time that A(*)0206, a unique A2 subtype to South and Southeast Asia is also associated with a high risk for NPC. HLA-A(*)0206, HLA-B(*)3802 alleles plus the A(*)0207-B(*)4601 and A(*)3303-B(*)5801 haplotypes conferred high risk for NPC showing a combined odds ratio (OR) of 2.6 (P<0.0001). HLA alleles that associate with low risk for NPC include HLA-A(*)1101, B(*)27, and B(*)55 with a combined OR of 0.42 (P<0.0001). The overall high frequency of NPC-susceptible HLA factors in the Guangxi population is likely to have contributed to the high-NPC incidence in this region.

Mir-30 reduction maintains self-renewal and inhibits apoptosis in breast tumor-initiating cells

Accumulating evidence indicates that a sub-population of cancer cells with stem-like properties, termed tumor-initiating cells (T-ICs), exist in many different kinds of malignancies, which have a pivotal role in tumorigenesis, tumor progression, metastasis and post-treatment relapse. However, how the stem-like properties of T-ICs are regulated remains obscure. Our previous study showed that reduction of let-7 microRNA (miRNA) in breast tumor-initiating cells (BT-ICs) contributes to the maintenance of their self-renewal capacity and undifferentiated status. In this study we show the effect of mir-30 reduction on the stem-like features of BT-ICs. Similar to let-7, mir-30 is reduced in BT-ICs, and the protein level of Ubc9 (ubiquitin-conjugating enzyme 9) and ITGB3 (integrin beta3), the target genes of mir-30, is markedly upregulated. Enforced constitutive expression of mir-30 in BT-ICs inhibits their self-renewal capacity by reducing Ubc9, and induces apoptosis through silencing ITGB3. On the contrary, blocking the miRNA with a specific antisense oligonucleotide (ASO) in differentiated breast cancer cells revived their self-renewal capacity. Furthermore, ectopic expression of mir-30 in BT-IC xenografts reduces tumorigenesis and lung metastasis in nonobese diabetic/severe combined immunodeficient mice, whereas blocking mir-30 expression enhances tumorigenesis and metastasis. Together, our data suggest mir-30 as one of the important miRNAs in regulating the stem-like features of T-ICs.

Synthesis and optical properties of vertically aligned ZnO nanorods

ZnO nanorods were grown on an n-type silicon (111) substrate with the assistance of Au catalyst by chemical vapor deposition (CVD). The ZnO nanorods were about 200 nm diameter with uniform lengths of about 1.2 microm. The ZnO nanorods exhibited [0001] orientation. ZnO nanorods grow in dense arrays perpendicular to the (111)-plane of silicon due to [0001]ZnO perpendicular [111]Si, [2110]ZnO perpendicular [110]Si, [1210]ZnO perpendicular [101]Si and [1120]ZnO perpendicular [011]Si epitaxy. Room-temperature photoluminescence (PL) measurements show three near band-edge emission peak at 377, 379, 389 nm. These peaks are attributed to exciton transitions. Analysis indicates that the band gap of ZnO nanorods is 3.301 eV and exciton binding energy is 0.114 eV.

Pim-3 protects against hepatic failure in D-galactosamine (D-GalN)-sensitized rats

BACKGROUND

Fulminant hepatic failure (FHF) has a high mortality resulted from massive hepatic apoptosis and haemorrhage necrosis; it is required to develop a valid therapy directed towards hepatocyte protection and regeneration. Pim-3, a hepatic growth stimulator, belongs to the serine/threonine kinase Pim-family that has been implicated in gp130-mediated induction of cell proliferation, protection from apoptosis downstream of Signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor-A-dependent vasculogenesis and angiogenesis, thus is suggested to possibly play a role in the tissue repair of FHF.

MATERIALS AND METHODS

Male Wistar rats received simultaneous intraperitoneal injections of lipopolysaccharide (LPS) (100 microg kg(-1)) and D-galactosamine (D-GalN) (600 mg kg(-1)). One day prior to LPS/D-GalN administration, naked plasmid or Ringer's solution was injected via tail vein by hydrodynamics-based procedure.

RESULTS

Exogenous Pim-3 gene protected against LPS/D-GalN-induced lethality with survival rate of more than 80% and improved the hepatic pathomorphism. The fractions of hepatic apoptotic-positive cells and the levels of caspase-3 activity were markedly lower in Pim-3-pretreated rats. Furthermore, exogenous Pim-3 significantly inhibited expression of tumour necrosis factor-alpha and interleukin-1beta in the liver, declined p53 and inducible nitric oxide synthase mRNAs levels, but elevated levels of Bcl-2 protein, an anti-apoptosis member of Bcl-2 family, in the liver. Exogenous Pim-3, however, showed little effect on expression of Bax, a pro-apoptosis member of Bcl-2 family.

CONCLUSIONS

Pim-3 gene could protect rats from FHF by inhibiting liver apoptosis and improving inflammatory response of liver tissues, which could be associated with inhibiting expression of inflammatory mediators and promoting expression of anti-apoptosis protein Bcl-2.

Examination of the MSX1 gene in patients with Parkinson's disease

BACKGROUND

Several genetic variants in transcription factor genes have been reported to be associated with Parkinson's disease (PD). The muscle segment homeobox drosophila homolog of 1 gene (MSX1) is a major upstream regulator of the dopaminergic neuronal subtype specification.

AIMS OF THE STUDY

To determine whether genetic variation in the coding region of the MSX1 gene plays a role in the etiology of PD.

METHODS

We searched for genetic variations in the coding region of the MSX1 gene in 202 patients with PD and 200 normal controls by PCR-single-strand conformation polymorphism (PCR-SSCP) and sequencing.

RESULTS

No mutation in the MSX1 gene was identified in our cohort.

CONCLUSIONS

Mutations in the coding region of the MSX1 gene play little or no role in the development of PD.

Analysis of biomarkers during early phase clinical development of AMG 479, an investigational fully human monoclonal antibody antagonist of type 1 insulin-like growth factor receptor (IGF-1R)

3545

Background: AMG 479 showed anti-tumor activity in a phase 1 (P1) and phase 1b (P1b) trial (Tolcher, J Clin Oncol. 2007;25:3002; Sarantopoulos, J Clin Oncol. 2008;26:3583). We sought to identify predictive markers of response to AMG 479 in these trials by analyzing pharmacodynamic (PD) markers in serum, and expression and mutations of regulators of the IGF-1R pathway in tumors. Methods: Patients (pts) had advanced solid tumors and received AMG 479 (1–20 mg/kg Q2W) in the P1 trial or AMG 479 (6 or 12 mg/kg Q2W) + panitumumab (6 mg/kg Q2W) or gemcitabine (1,000 mg/m2 QW) in the P1b trial. Serum levels of IGF-1 and IGFBP-3 were measured pre dose on Day -1 and post dose at various time points. In the P1 trial, we examined relationships between tumor response (by RECIST) and: 1) levels of IGF-1 and IGFBP-3 (at baseline or PD change from baseline); 2) somatic mutations in key genes (including K-ras, and PTEN) of the IGF-1R pathway (in archival tumors); and 3) expression of PTEN (measured by immunohistochemistry in archival tumors). Results: Serum IGF-1 and IGFBP-3 increased in a concentration-dependent manner between 1 and 12 mg/kg AMG 479, with an apparent plateau between 12 and 20 mg/kg AMG 479. Baseline and PD changes in IGF-1 and IGFBP-3 were not substantially different in pts with a tumor response compared with those without a tumor response. A partial response to AMG 479 was observed in a pt with an activating K-ras mutation. No responses have been observed in tumors that lack expression of PTEN. Conclusions: The PD results suggest near complete biochemical coverage at 12-mg/kg AMG 479. Our hypothesis-generating analyses suggest that: 1) pre and postdose levels of IGF-1 and IGFBP-3 do not predict response to single-agent AMG 479; 2) activating K-ras mutations do not appear to preclude responsiveness to single-agent AMG 479 (in contrast to EGFR inhibitors); 3) expression and mutations of regulators of the PI3K/Akt pathway downstream of IGF-1R activation may be useful in predicting response to AMG 479.

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Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.