Several angiogenesis inhibitors targeting the vascular endothelial growth factor (VEGF) signaling pathway have been approved for cancer treatment. However, VEGF inhibitors alone were shown to promote tumor invasion and metastasis by increasing intratumoral hypoxia in some preclinical and clinical studies. Emerging reports suggest that Delta-like ligand 4 (Dll4) is a promising target of angiogenesis inhibition to augment the effects of VEGF inhibitors. To evaluate the effects of simultaneous blockade against VEGF and Dll4, we developed a bispecific antibody, HD105, targeting VEGF and Dll4. The HD105 bispecific antibody, which is composed of an anti-VEGF antibody (bevacizumab-similar) backbone C-terminally linked with a Dll4-targeting single-chain variable fragment, showed potent binding affinities against VEGF (KD: 1.3 nM) and Dll4 (KD: 30 nM). In addition, the HD105 bispecific antibody competitively inhibited the binding of ligands to their receptors, i.e., VEGF to VEGFR2 (EC50: 2.84 ± 0.41 nM) and Dll4 to Notch1 (EC50: 1.14 ± 0.06 nM). Using in vitro cell-based assays, we found that HD105 effectively blocked both the VEGF/VEGFR2 and Dll4/Notch1 signaling pathways in endothelial cells, resulting in a conspicuous inhibition of endothelial cell proliferation and sprouting. HD105 also suppressed Dll4-induced Notch1-dependent activation of the luciferase gene. In vivo xenograft studies demonstrated that HD105 more efficiently inhibited the tumor progression of human A549 lung and SCH gastric cancers than an anti-VEGF antibody or anti-Dll4 antibody alone. In conclusion, HD105 may be a novel therapeutic bispecific antibody for cancer treatment.

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SAR405838 is a potent and specific MDM2 inhibitor currently being evaluated in Phase I clinical trials for the treatment of human cancer. Using the SJSA-1 osteosarcoma cell line which harbors an amplified MDM2 gene and wild-type p53, we have investigated the acquired resistance mechanisms both in vitro and in vivo to SAR405838. Treatment of SJSA-1 cells with SAR405838 in vitro leads to dose-dependent cell growth inhibition, cell cycle arrest and robust apoptosis. However, prolonged treatment of SJSA-1 cells in vitro with SAR405838 results in profound acquired resistance to the drug. Analysis of in vitro-derived resistant cell lines showed that p53 is mutated in the DNA binding domain and can no longer be activated by SAR405838. Treatment of the parental SJSA-1 xenograft tumors with SAR405838 in mice yields rapid tumor regression but the tumors eventually regrow. Culturing the regrown tumors established a number of sublines, which showed only modest (3-5 times) loss of sensitivity to SAR405838 in vitro. Sequencing of the p53 showed that it retains its wild-type status in these in vivo sublines, with the exception of one subline, which harbors a single heterozygous C176F p53 mutation. Using xenograft models of two in vivo derived sublines, which has either wild-type p53 or p53 containing a single heterozygous C176F mutation, we showed that while SAR405838 effectively achieves partial tumor regression in these models, it no longer induces complete tumor regression and tumors resume growth once the treatment is stopped. Harvesting and culturing tumors obtained from a prolonged treatment with SAR405838 in mice established additional in vivo sublines, which all contain a single heterozygous C176F mutation with no additional p53 mutation detected. Interestingly, SAR405838 can still effectively activate p53 in all sublines containing a single heterozygous C176F mutation, with a moderately reduced potency as compared to that in the parental cell line. Consistently, SAR405838 is 3-5 times less effective in all the in vivo derived sublines containing a single heterozygous C176F p53 mutation than in the SJSA-1 parental cell line in assays of cell growth and apoptosis. Computational modeling suggested that a p53 tetramer containing two wild-type p53 molecules and two C176F mutated molecules can maintain the structural stability and interactions with DNA by formation of additional hydrophobic and cation-π interactions which compensate for the loss of sulphur-zinc coordination. Our data thus show that SJSA-1 tumor cells acquire very different levels of resistance in vitro and in vivo to the MDM2 inhibitor SAR405838. Our present study may have a significant implication for the investigation of resistant mechanisms for other classes of anticancer drugs.

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The treatment of chronic myeloid leukemia (CML) has improved considerably since the introduction of the tyrosine kinase inhibitor (TKI) imatinib in 2001 and the approval of second-generation TKIs (dasatinib and nilotinib) beginning in 2006.The objective of this study was to explore treatment patterns of TKI therapy (adherence, duration, and switching) among patients with CML in the United States, following the availability of second-generation TKIs.
This study used US health plan claims data from January 1, 2007, through December 31, 2011. Patients were required to be aged ≥18 years, have a prescription fill for a TKI, and a diagnosis of CML. Duration of TKI use was determined based on a gap in TKI coverage of ≥180 consecutive days after TKI initiation or switch to another TKI within the 180-day window. To account for censoring due to disenrollment from the health plan or end of the study period, median treatment duration was projected by using the Kaplan-Meier estimator.
We identified 695 patients who started TKI treatment and had a CML diagnosis during the study time frame. The mean age of patients was 55 years, and 58% of patients were male. The most common first-line TKI was imatinib (82%), with dasatinib and nilotinib use equally distributed (9%). Among the 148 (21.3%) patients who initiated a second-line TKI, the majority had switched from imatinib to dasatinib or nilotinib (86%). The median duration of first-line TKI use was 39.8 months and second-line TKI use was 22.4 months. Median duration of treatment for first-line (P = 0.4342) and second-line (P = 0.1792) treatment did not differ significantly according to TKI. Mean adherence (ie, proportion of days covered) during the first line of therapy was 0.90.
For the US patients studied, we found that imatinib was used more frequently than other TKIs in the first-line setting, but there was an increased use of second-generation TKIs in the first-line setting over time (9% in 2008 vs 43% in 2011 were nilotinib or dasatinib users). Only about one fifth of patients switched to a second-line TKI during the period of data collection.
Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

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The objective was to obtain a standardized evaluation of available specific and generic breast cancer health-related quality-of-life instruments.
We carried out systematic literature reviews in the PubMed and EMBASE databases to identify manuscripts which contained information regarding either the development process or metric properties of health-related quality-of-life instruments used among breast cancer patients. Each instrument was evaluated independently by two researchers, and occasionally a third one, using the Evaluating Measures of Patient-Reported Outcomes (EMPRO) tool. An overall score and seven attribute-specific EMPRO scores were calculated (range 0-100, worst to best): concept and measurement model, reliability, validity, responsiveness, interpretability, burden, and alternative forms.
FACT-B was the instrument with the best global performance, obtaining an overall EMPRO score of 79.27. It was also the most accurate instrument on the Concept and Measurement Model, Reliability, and Interpretability attributes. Four more instruments scored over 50 points on the overall score, which summarizes the five attribute-specific scores: EORTC BR-23, IBCSG, WHO-QOL BREF, and SF-36. An overall score of at least 50 points implies that the use of these instruments could be recommended for assessing health-related quality of life in breast cancer patients.
The FACT-B scored the highest on overall on our EMPRO evaluation of instruments measuring health-related quality of life among breast cancer patients. However, depending on the purpose of the study, several instruments (EORTC BR-23, IBCSG, SF-36, and WHO-QOL BREF) have shown good performance in some of the specific individual dimensions included in the EMPRO.

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Biosimilars are designed to be highly similar to approved or licensed (reference) biologics and are evaluated based on the totality of evidence from extensive analytical, nonclinical and clinical studies. As part of the stepwise approach recommended by regulatory agencies, the first step in the clinical evaluation of biosimilarity is to conduct a pharmacokinetics similarity study in which the potential biosimilar is compared with the reference product. In the context of biosimilar development, a pharmacokinetics similarity study is not necessarily designed for a comparative assessment of safety. Development of PF-05280014, a potential biosimilar to trastuzumab, illustrates how a numerical imbalance in an adverse event in a small pharmacokinetics study can raise questions on safety that may require additional clinical trials.

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