Search

PURPOSE This phase Ib study evaluated the safety and efficacy of paclitaxel plus navicixizumab, a bispecific antiangiogenic antibody to vascular endothelial growth factor and delta-like ligand 4, against platinum-resistant ovarian cancer. PATIENTS AND METHODS This open-label, nonrandomized, dose-escalation and -expansion study included 44 patients with previously treated, recurrent, platinum-resistant grade 2/3 ovarian cancer. Treatment was intravenous navicixizumab (3 mg/kg or 4 mg/kg once every 2 weeks) plus paclitaxel (80 mg/m2 intravenously on days 0, 7, and 14 of 28-day cycles). The primary and secondary objectives were to evaluate the safety and efficacy of navicixizumab plus paclitaxel. An RNA-based diagnostic panel was retrospectively used to test the hypothesis that tumors with high angiogenesis or immune-suppressed tumor microenvironment (TME) subtypes (biomarker-positive) are more likely to respond to navicixizumab than those with immune-active/-desert TME subtypes (biomarker-negative). RNA expression was analyzed in available pretreatment tumor tissue to classify 33 patients' TME subtypes, and TME panel findings were correlated with tumor response. RESULTS The dose-escalation cohorts enrolled patients at navicixizumab doses of 3 mg/kg once every 2 weeks (n = 3) and 4 mg/kg once every 2 weeks (n = 2); 3 mg/kg was selected for expansion (n = 39). No dose-limiting toxicities occurred. The most common grade 3/4 treatment-related adverse events were hypertension (40.9%), neutropenia (6.8%), and thrombocytopenia (4.5%). Pulmonary hypertension occurred in 18.2% (grade 1-2). The overall objective response rate was 43.2% (95% CI, 28.3 to 59.0): 33.3% (95% CI, 17.3 to 52.8) in patients previously treated with bevacizumab, 64.3% (95% CI, 35.1 to 87.2) in bevacizumab-naive patients, and 62% (95% CI, 31.6 to 86.1) in biomarker-positive patients. The median duration of response was 6 months (95% CI, 5.4 months to not estimable). CONCLUSION Navicixizumab plus paclitaxel demonstrated promising clinical activity in bevacizumab-treated and -naive patients with platinum-resistant ovarian cancer, with manageable toxicity.

Purpose: Although chemotherapy is standard of care for metastatic colorectal cancer (mCRC), immunotherapy has no role in microsatellite stable (MSS) mCRC, a “cold” tumor. PolyPEPI1018 is an off-the-shelf, multi-peptide vaccine derived from 7 tumor-associated antigens (TAA) frequently expressed in mCRC. This study assessed PolyPEPI1018 combined with first-line maintenance therapy in patients with MSS mCRC. Patients and Methods: Eleven patients with MSS mCRC received PolyPEPI1018 and Montanide ISA51VG adjuvant subcutaneously, combined with fluoropyrimidine/biologic following first-line induction with chemotherapy and a biologic (NCT03391232). In Part A of the study, 5 patients received a single dose; in Part B, 6 patients received up to three doses of PolyPEPI1018 every 12 weeks. The primary objective was safety; secondary objectives were preliminary efficacy, immunogenicity at peripheral and tumor level, and immune correlates. Results: PolyPEPI1018 vaccination was safe and well tolerated. No vaccine-related serious adverse event occurred. Eighty percent of patients had CD8+ T-cell responses against ≥3 TAAs. Increased density of tumor-infiltrating lymphocytes were detected post-treatment for 3 of 4 patients’ liver biopsies, combined with increased expression of immune-related gene signatures. Three patients had objective response according to RECISTv1.1, and 2 patients qualified for curative surgery. Longer median progression-free survival for patients receiving multiple doses compared with a single dose (12.5 vs. 4.6 months; P = 0.017) suggested a dose–efficacy correlation. The host HLA genotype predicted multi-antigen–specific T-cell responses (P = 0.01) indicative of clinical outcome. Conclusions: PolyPEPI1018 added to maintenance chemotherapy for patients with unresectable, MSS mCRC was safe and associated with specific immune responses and antitumor activity warranting further confirmation in a randomized, controlled setting.

Purpose: In the phase III DUO trial, duvelisib, an oral dual PI3K-δ,γ inhibitor, demonstrated significantly improved efficacy versus ofatumumab [median (m) progression-free survival (PFS), 13.3 vs. 9.9 months (HR, 0.52; P < 0.0001); overall response rate [ORR], 74% vs. 45% (P < 0.0001)], with a manageable safety profile in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). We report results from patients with progressive disease (PD) after ofatumumab who crossed over to duvelisib in the DUO trial. Patients and Methods: Patients with radiographically confirmed PD after ofatumumab received duvelisib 25 mg twice daily in 28-day cycles until PD, intolerance, death, or study withdrawal. The primary endpoint was ORR per investigator. Secondary endpoints included duration of response (DOR), PFS, and safety. Results: As of December 14, 2018, 90 ofatumumab-treated patients in the DUO trial prior to crossover had an ORR of 29%, mDOR of 10.4 months, and mPFS of 9.4 months. After crossover, 77% of patients (69/90) achieved a response, with an mDOR of 14.9 months and mPFS of 15.7 months. Patients with del(17p) and/or TP53 mutations had similar outcomes [ORR, 77% (20/26); mPFS, 14.7 months]. Notably, 73% of patients (47/64) with disease previously refractory to ofatumumab achieved a response. The most frequent any-grade/grade 3/4 treatment-emergent adverse events were diarrhea (47%/23%), neutropenia (26%/23%), pyrexia (24%/4%), cutaneous reactions (23%/4%), and thrombocytopenia (10%/6%). Conclusions: Duvelisib demonstrated high response rates with good durability and a manageable safety profile in patients with R/R CLL/SLL who progressed on ofatumumab, including patients with high-risk disease and disease previously refractory to ofatumumab.

Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements-only together can they realize the full potential of nanomedicines for patients.

Prostate cancer is the leading cause of cancer-related death in men in the United States. A major cause of drug resistance in prostate and other epithelial tumors may be due to the presence of a fraction of tumor cells that retain the ability to initiate tumors and hence are termed tumor-initiating cells (TIC) or cancer stem cells. Here, we report that darinaparsin, an organic derivative of arsenic trioxide, is cytotoxic to prostate cancer cell lines as well as fresh prostate cancer cells from patients at low micromolar concentrations, and importantly inhibits the TIC subpopulations. It also inhibits growth of the castrate-resistant Du145 prostate tumor propagated as xenograft in mice and inhibits the tumor-initiating potential of prostate cancer cells. Although the mechanism by which darinaparsin acts is not completely known, we show that it kills prostate cancer cells by blocking cells in the G2–M phase of the cell cycle and inhibits Hedgehog signaling by downregulating Gli-2 transcriptional activity. These data provide a rationale for evaluating darinaparsin in patients with castrate-resistant prostate cancer. Mol Cancer Ther; 14(1); 23–30. ©2014 AACR.

Introduction We conducted a phase II study of dual-agent monoclonal antibody therapy consisting of cetuximab and bevacizumab in combination with paclitaxel and carboplatin chemotherapy in non–small-cell lung cancer. Methods Patients with stage IIIB/IV nonsquamous non–small-cell lung cancer randomly received cetuximab (400 mg/m 2 initially, 250 mg/m 2 weekly thereafter) plus bevacizumab (15 mg/kg) for six cycles combined with paclitaxel (200 mg/m 2 ) and carboplatin (area under the curve 6) for either six cycles (six-cycle arm) or the first three cycles (three-cycle arm) (one cycle=3 weeks). The primary objective was progression-free survival (PFS), estimated separately for each treatment arm. Results In 121 patients, the median PFS was 6.05 months (95% confidence interval [CI]: 5.65, 7.03) in the six-cycle arm and 4.50 months (95% CI: 4.01, 5.42) in the three-cycle arm. Respective median overall survival times were 12.06 months (95% CI: 9.40, 19.25) and 11.63 months (95% CI: 6.64, 17.61). The tumor response rate was 51.7% (95% CI: 39.0%, 64.3%) and 44.3% (95% CI: 31.8%, 56.7%) in the six-cycle and three-cycle arms, respectively, with corresponding median response durations of 4.86 months (95% CI: 4.30, 7.16) and 3.94 months (95% CI: 2.92, 4.47). Quality of life was consistent across arms. Cetuximab-related grade 3/4 events in greater than 5% of patients (six-cycle arm, three-cycle arm) were dermatitis acneiform (6.9%; 8.6%) and fatigue (13.8%; 5.2%). Three patients died during the study from drug-related adverse events (one in the six-cycle arm and two in the three-cycle arm). Conclusions Both the regimens showed expected PFS and numerically comparable overall survival. Quality of life was similar in the two arms, and both the regimens were well tolerated.

Introduction: This phase I/II study evaluated the safety and antitumor effect of the combination of erlotinib with cixutumumab, a recombinant fully humanized anti-insulin-like growth factor-1 receptor IgG1 monoclonal antibody, in advanced non-small cell lung cancer (NSCLC). Methods: Patients with advanced NSCLC were treated in an initial safety-lead and drop-down cohorts using erlotinib 150 mg/d with cixutumumab 6 or 5 mg/kg on days 1, 8, 15, and 22 in 28-day cycles (cohorts 1 and 2). Emerging pharmacokinetic data led to an additional cohort (3 + 3 design) with cixutumumab at 15 mg/kg on day 1 in 21-day cycles (cohort 3). Results: Eighteen patients entered the study (6 at 6 mg/kg, 8 at 5 mg/kg, and 4 at 15 mg/kg), with median age of 65 years. Four of six patients at 6 mg/kg experienced dose-limiting toxicities (DLTs), whereas at 5 mg/kg, one of eight patients experienced DLT but three of eight patients still required a dose delay during cycle 1. At 15 mg/kg every 21 days, two of four patients experienced DLTs. In all cohorts, DLTs were either G3 rash or fatigue. Five patients had stable disease as best response and 14 patients had progressive disease. The median progression-free survival was 39 days (range 21–432+ days). Biomarkers analyses showed a trend toward better progression-free survival seen with higher free baseline insulin-like growth factor-1 levels as seen with other insulin-like growth factor-1R inhibitors. Conclusions: The combinations of cixutumumab at 6 mg/kg every 7 days and 15 mg/kg every 21 days and full-dose erlotinib are not tolerable in unselected patients with NSCLC, as measured by DLT. Cixutumumab at 5 mg/kg every 7 days was tolerable per DLT, but dose delays were common. Efficacy in unselected patients with NSCLC seems to be low.

Insulin-like growth factor type-1 receptor (IGF-1R) plays a central role in cell proliferation and survival and is overexpressed in many tumor types. Notably, IGF-1R – mediated signaling confers resistance to diverse cytotoxic, hormonal, and biologic agents, suggesting that therapies targeting IGF-1R may be effective against a broad range of human malignancies. Cixutumumab (IMC-A12; ImClone Systems) is a fully human immunoglobulin G1 (IgG1) monoclonal antibody that specifically inhibits IGF-1R signaling. Binding of cixutumumab to IGF-1R results in receptor internalization and degradation. Because cixutumumab is an IgG1 monoclonal antibody, it may induce additional cytotoxicity via immune effector mechanisms such as antibody-dependent cellular cytotoxicity. In preclinical studies, cixutumumab monotherapy resulted in growth inhibition of multiple experimental cancers. Moreover, cixutumumab safely enhanced the tumor growth inhibitory and cytotoxic effects of a broad range of chemotherapeutics, and modulated the action of agents that target hormone receptors and signal transduction, which may have implications for cancer therapy. Herein, we review published preclinical and clinical data for cixutumumab and provide a comprehensive overview of selected clinical studies.

The purpose of this study was to assess the efficacy and safety of bevacizumab plus cetuximab with or without gemcitabine in patients with advanced pancreatic adenocarcinoma. Patients with locally advanced or metastatic pancreatic adenocarcinoma, previously untreated, were randomized to bevacizumab (10 mg/kg q2w) plus cetuximab (400/250 mg/m(2) initial/weekly), either with (Arm A) or without (Arm B) gemcitabine (1000 mg/m(2) weekly × 3 of 4 weeks). Tumor assessments were performed q8w. Primary study endpoint was progression-free survival (PFS). Sixty-one patients were randomized to Arm A (n = 30) or Arm B (n = 31). Median treatment duration was 9 weeks in Arm A and 8 weeks in Arm B (range, 2.0-40.4). Patients in Arm A had median PFS and overall survival values of 3.55 months and 5.41 months, respectively, compared to 1.91 months and 4.17 months in Arm B. The study closed early due to lack of sufficient efficacy in both treatment arms. Although both regimens were well tolerated, patients treated with gemcitabine experienced more grade 3-4 toxicities, including proteinuria and thromboembolic events. The combination of cetuximab and bevacizumab did not result in promising activity with or without gemcitabine, suggesting that a strategy of dual EGFR/VEGF inhibition in pancreatic cancer does not warrant further development. To our knowledge, this is one of the first trials to evaluate a completely noncytotoxic regimen in the first-line treatment of advanced pancreatic cancer. (ClinicalTrials.gov number, NCT00326911).

The human vascular endothelial growth factor receptor-1 (VEGFR-1, or Flt-1) is widely expressed in normal and pathologic tissue and contributes to the pathogenesis of both neoplastic and inflammatory diseases. In human cancer, VEGFR-1 mediated signaling is responsible for both direct tumor activation and angiogenesis. VEGFR-1 mediated activation of nonmalignant supporting cells, particularly stromal, dendritic, hematopoietic cells, and macrophages, is also likely important for cancer pathogenesis. VEGFR-1 is also hypothesized to enable the development of cancer metastases by means of activation and premetastatic localization in distant organs of bone marrow-derived hematopoietic progenitor cells, which express VEGFR-1. IMC-18F1 is a fully human IgG1 antibody that binds to VEGFR-1 and has been associated with the inhibition of cancer growth in multiple in vitro and human tumor xenograft models. The preliminary results of phase 1 investigations have also indicated a favorable safety profile for IMC-18F1 at doses that confer antibody concentrations that are associated with relevant antitumor activity in preclinical models. Cancer 2010;116(4 suppl):1027–32. © 2010 American Cancer Society.

A large body of evidence suggests that the platelet-derived growth factor (PDGF) family and associated receptors are potential targets in oncology therapeutic development because of their critical roles in the proliferation and survival of various cancers and in the regulation and growth of the tumor stroma and blood vessels. Several small molecules that nonspecifically target the PDGF signaling axis are in current use or development as anticancer therapies. However, for the majority of these agents, PDGF and its receptors are neither the primary targets nor the principal mediators of anticancer activity. IMC-3G3, a fully human monoclonal antibody of the immunoglobulin G subclass 1, specifically binds to the human PDGF receptor alpha (PDGFRalpha) with high affinity and blocks PDGF ligand binding and PDGFRalpha activation. The results of preclinical studies and the frequent expression of PDGFRalpha in many types of cancer and in cancer-associated stroma support a rationale for the clinical development of IMC-3G3. Currently, IMC-3G3 is being evaluated in early clinical development for patients with several types of solid malignancies.

FMS-related tyrosine kinase receptor 3 (FLT3) is a class III receptor tyrosine kinase that holds considerable promise as a therapeutic target in hematologic malignancies. Current efforts directed toward the development of small-molecule tyrosine kinase inhibitors of FLT3 may be limited by off-target toxicities and the development of drug resistance. Target-specific antibodies could overcome these hurdles and provide additional mechanisms to enhance the antitumor efficacy of FLT3 inhibitors. IMC-EB10 is a novel antibody directed against FLT3. The binding of IMC-EB10 to FLT3 results in antiproliferative effects in vitro and in mouse models engrafted with human leukemia cells that harbor wild-type or constitutively activated FLT3. Future clinical trials will test these notions formally and will identify the most appropriate opportunities for this member of a new generation of antileukemic therapies.

Summary Background Previous results from our phase 3 randomised trial showed that adding cetuximab to primary radiotherapy increased overall survival in patients with locoregionally advanced squamous-cell carcinoma of the head and neck (LASCCHN) at 3 years. Here we report the 5-year survival data, and investigate the relation between cetuximabinduced rash and survival. Methods Patients with LASCCHN of the oropharynx, hypopharynx, or larynx with measurable disease were randomly allocated in a 1:1 ratio to receive either comprehensive head and neck radiotherapy alone for 6–7 weeks or radiotherapy plus weekly doses of cetuximab: 400 mg/m² initial dose, followed by seven weekly doses at 250 mg/m². Randomisation was done with an adaptive minimisation technique to balance assignments across stratifi cation factors of Karnofsky performance score, T stage, N stage, and radiation fractionation. The trial was un-blinded. The primary endpoint was locoregional control, with a secondary endpoint of survival. Following discussions with the US Food and Drug Administration, the dataset was locked, except for queries to the sites about overall survival, before our previous report in 2006, so that an independent review could be done. Analyses were done on an intention-to-treat basis. Following completion of treatment, patients underwent physical examination and radiographic imaging every 4 months for 2 years, and then every 6 months thereafter . The trial is registered at www.ClinicalTrials.gov , number NCT00004227. Findings Patients were randomly assigned to receive radiotherapy with (n=211) or without (n=213) cetuximab, and all patients were followed for survival. Updated median overall survival for patients treated with cetuximab and radiotherapy was 49·0 months (95% CI 32·8–69·5) versus 29·3 months (20·6–41·4) in the radiotherapy-alone group (hazard ratio [HR] 0·73, 95% CI 0·56–0·95; p=0·018). 5-year overall survival was 45·6% in the cetuximab-plus-radiotherapy group and 36·4% in the radiotherapy-alone group. Additionally, for the patients treated with cetuximab, overall survival was signifi cantly improved in those who experienced an acneiform rash of at least grade 2 severity compared with patients with no rash or grade 1 rash (HR 0·49, 0·34–0·72; p=0·002). Interpretation For patients with LASCCHN, cetuximab plus radiotherapy signifi cantly improves overall survival at 5 years compared with radiotherapy alone, confi rming cetuximab plus radiotherapy as an important treatment option in this group of patients. Cetuximab-treated patients with prominent cetuximab-induced rash (grade 2 or above) have better survival than patients with no or grade 1 rash.

Purpose: First-in-human phase I trial to determine the safety, pharmacokinetics, and antitumor activity of BIND-014, a novel, tumor prostate-specific membrane antigen (PSMA)–targeted nanoparticle, containing docetaxel. Experimental Design: Patients with advanced solid tumors received BIND-014 every three weeks (n = 28) or weekly (n = 27), with dose levels ranging from 3.5 to 75 mg/m2 and 15 to 45 mg/m2, respectively. Results: BIND-014 was generally well tolerated, with no unexpected toxicities. The most common drug-related toxicities (>20% of patients) on either schedule included neutropenia, fatigue, anemia, alopecia, and diarrhea. BIND-014 demonstrated a dose-linear pharmacokinetic profile, distinct from docetaxel, with prolonged persistence of docetaxel-encapsulated circulating nanoparticles. Of the 52 patients evaluable for response, one had a complete response (cervical cancer on the every three week schedule) and five had partial responses (ampullary adenocarcinoma, non–small cell lung, and prostate cancers on the every-three-week schedule, and breast and gastroesophageal cancers on the weekly schedule). Responses were noted in both PSMA-detectable and -undetectable tumors. Conclusions: BIND-014 was generally well tolerated, with predictable and manageable toxicity and a unique pharmacokinetic profile compared with conventional docetaxel. Clinical activity was noted in multiple tumor types. The recommended phase II dose of BIND-014 is 60 mg/m2 every three weeks or 40 mg/m2 weekly. Clin Cancer Res; 22(13); 3157–63. ©2016 AACR.

Purpose: This phase II trial evaluated the efficacy and safety of cixutumumab, a human anti–insulin-like growth factor receptor 1 (IGF-1R) monoclonal IgG1 antibody, and explored potential biomarkers in postmenopausal women with hormone receptor–positive breast cancer. Experimental Design: Patients with hormone receptor–positive breast cancer that progressed on antiestrogen therapy received (2:1 randomization) cixutumumab 10 mg/kg and the same antiestrogen (arm A) or cixutumumab alone (arm B) every 2 weeks (q2w). Primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS) and safety. Correlative analyses of IGF-1R, total insulin receptor (IR), and IR isoforms A (IR-A) and B (IR-B) expression in tumor tissue were explored. Results: Ninety-three patients were randomized (arm A, n = 62; arm B, n = 31). Median PFS was 2.0 and 3.1 months for arm A and arm B, respectively. Secondary efficacy measures were similar between the arms. Overall, cixutumumab was well tolerated. IGF-1R expression was not associated with clinical outcomes. Regardless of the treatment, lower IR-A, IR-B, and total IR mRNA expression in tumor tissue was significantly associated with longer PFS [IR-A: HR, 2.62 (P = 0.0062); IR-B: HR, 2.21 (P = 0.0202); and total IR: HR, 2.18 (P = 0.0230)] and OS [IR-A: HR, 2.94 (P = 0.0156); IR-B: HR, 2.69 (P = 0.0245); and total IR: HR, 2.72 (P = 0.0231)]. Conclusions: Cixutumumab (10 mg/kg) with or without antiestrogen q2w had an acceptable safety profile, but no significant clinical efficacy. Patients with low total IR, IR-A, and IR-B mRNA expression levels had significantly longer PFS and OS, independent of the treatment. The prognostic or predictive value of IR as a biomarker for IGF-1R–targeted therapies requires further validation. Clin Cancer Res; 22(2); 301–9. ©2015 AACR.

Radioactive ligands for the prostate-specific membrane antigen (PSMA) are under development for therapy of metastasized prostate cancer. Since PSMA expression is also found in the kidneys, renal tracer uptake can be dose-limiting. Because kidney kinetics differ from tumor kinetics, serial application of PSMA inhibitors such as 2-(phosphonomethyl)pentanedioic acid (PMPA) may improve the kidney-to-tumor ratio. In this study, we evaluated the effect of PMPA on the biodistribution of 2 promising PSMA ligands. Methods: Human prostate cancer xenografts (LNCaP) were transplanted subcutaneously into mice. After injection of 125I-MIP1095, a 16-h latency period was allowed for tracer clearance from the blood and renal calices. After baseline scintigraphy, PMPA was injected in doses of 0.2–50 mg/kg (n = 3 per dose, 5 controls), followed by scans at 2, 4, 6, and 24 h after PMPA injection. Kidney and tumor displacement was determined as a percentage of baseline. A shortened but similar design was used to evaluate the PSMA ligand MIP1404, which contains a chelate for 99mTc/rhenium. Results: PMPA injection 16 h after MIP1095 translated into a rapid and quantitative relevant displacement of renal activity. Tumor uptake was reduced to a significantly lesser extent in a dose-dependent manner. PMPA doses of 0.2–1 mg/kg appear optimal for sustaining nearly complete tumor uptake while simultaneously achieving near-total blocking of specific renal PSMA binding. The effect was successfully validated with the PSMA ligand MIP1404. Conclusion: PSMA-targeted radionuclide therapy can benefit from serial PMPA comedication by reducing off-target radiation to the kidneys. These data will be used for a first approximation in clinical translation, although in patients an optimization of the dose and time schedule may be necessary.

BACKGROUND We conducted a multinational, randomized study to compare radiotherapy alone with radiotherapy plus cetuximab, a monoclonal antibody against the epidermal growth factor receptor, in the treatment of locoregionally advanced squamous-cell carcinoma of the head and neck. METHODS Patients with locoregionally advanced head and neck cancer were randomly assigned to treatment with high-dose radiotherapy alone (213 patients) or high-dose radiotherapy plus weekly cetuximab (211 patients) at an initial dose of 400 mg per square meter of body-surface area, followed by 250 mg per square meter weekly for the duration of radiotherapy. The primary end point was the duration of control of locoregional disease; secondary end points were overall survival, progression-free survival, the response rate, and safety. RESULTS The median duration of locoregional control was 24.4 months among patients treated with cetuximab plus radiotherapy and 14.9 months among those given radiotherapy alone (hazard ratio for locoregional progression or death, 0.68; P = 0.005). With a median follow-up of 54.0 months, the median duration of overall survival was 49.0 months among patients treated with combined therapy and 29.3 months among those treated with radiotherapy alone (hazard ratio for death, 0.74; P = 0.03). Radiotherapy plus cetuximab significantly prolonged progression-free survival (hazard ratio for disease progression or death, 0.70; P = 0.006). With the exception of acneiform rash and infusion reactions, the incidence of grade 3 or greater toxic effects, including mucositis, did not differ significantly between the two groups. CONCLUSIONS Treatment of locoregionally advanced head and neck cancer with concomitant highdose radiotherapy plus cetuximab improves locoregional control and reduces mortality without increasing the common toxic effects associated with radiotherapy to the head and neck. (ClinicalTrials.gov number, NCT00004227.)

Fanconi anaemia (FA) is a genetic disease characterised by bone marrow failure with excess risk of myelogenous leukaemia and solid tumours. A widely accepted notion in FA research invokes a deficiency of response to DNA damage as the fundamental basis of the 'crosslinker sensitivity' observed in this disorder. However, such an isolated defect cannot readily account for the full cellular and clinical phenotype, which includes a number of other abnormalities, such as malformations, endocrinopathies, and typical skin spots. An extensive body of evidence pointing toward an involvement of oxidative stress in the FA phenotype includes the following: (i) In vitro and ex vivo abnormalities in a number of redox status endpoints; (ii) the functions of several FA proteins in protecting cells from oxidative stress; (iii) redox-related toxicity mechanisms of the xenobiotics evoking excess toxicity in FA cells. The clinical features in FA and the in vivo abnormalities of redox parameters are here reconsidered in view of the pleiotropic clinical phenotype and known biochemical and molecular links to an in vivo prooxidant state, which causes oxidative damage to biomolecules, resulting in an excessive number of acquired abnormalities that may overwhelm the cellular repair capacity rather than a primary deficiency in DNA repair. FA may thus represent a unique model disease in testing the integration between the acquisition of macromolecular damage as a result of oxidative stress and the ability of the mammalian cell to respond effectively to such damage.

Somatic mosaicism -- the presence of genetically distinct populations of somatic cells in a given organism -- is frequently masked, but it can also result in major phenotypic changes and reveal the expression of otherwise lethal genetic mutations. Mosaicism can be caused by DNA mutations, epigenetic alterations of DNA, chromosomal abnormalities and the spontaneous reversion of inherited mutations. In this review, we discuss the human disorders that result from somatic mosaicism, as well as the molecular genetic mechanisms by which they arise. Specifically, we emphasize the role of selection in the phenotypic manifestations of mosaicism.

Studies have previously described the feasibility of receptor-mediated protein transfer in a cell culture model of Fanconi anemia (FA) group C. This study explores the versatility of this approach by using an antibody single-chain fusion protein to correct the phenotypic defect in FA group F cells. A 68.5-kd chimeric protein (His-M195FANCF) was expressed, consisting of a His tag, a single-chain antibody to the myeloid antigen CD33, and the FANCF protein, as well as a 43-kd His-FANCF fusion protein lacking the antibody motif, inEscherichia coli. The nickel-agarose–purified His-M195FANCF protein bound specifically to the surface of HeLa cells transfected with CD33 and internalized through vesicular structures. The fusion protein, but not CD33, sorted to the nucleus, consistent with the known nuclear localization of FANCF. No similar binding or internalization was observed with His-FANCF. Pretreatment of the transfected cells with chloroquine abolished nuclear accumulation, but there was little change with brefeldin A, indicating a minimal if any role for the Golgi apparatus in mediating transport from endosomes to the cytosol and the nucleus. The intracellular half-life of His-M195FANCF was approximately 160 minutes. Treatment of CD33-transfected FA group F lymphoblastoid cells with 0.1 mg/mL His-M195FANCF conferred resistance to mitomycin C. No similar protection was noted in CD33− parental cells or CD33+ FA cells belonging to groups A and C. These results demonstrate that antibody-directed, receptor-mediated protein transfer is a versatile method for the delivery of biologically active proteins into hematopoietic cells.

Fanconi anemia (FA) is an autosomal recessive disorder manifested by chromosomal breakage, birth defects, and susceptibility to bone marrow failure and cancer. At least seven complementation groups have been identified, and the genes defective in four groups have been cloned. The most common subtype is complementation group A. Although the normal functions of the gene products defective in FA cells are not completely understood, a clue to the function of the FA group A gene product (FANCA) was provided by the detection of limited homology in the amino terminal region to a class of heme peroxidases. We evaluated this hypothesis by mutagenesis and functional complementation studies. We substituted alanine residues for the most conserved FANCA residues in the putative peroxidase domain and tested their effects on known biochemical and cellular functions of FANCA. While the substitution mutants were comparable to wild-type FANCA with regard to their stability, subcellular localization, and interaction with FANCG, only the Trp(183)-to-Ala substitution (W183A) abolished the ability of FANCA to complement the sensitivity of FA group A cells to mitomycin C. By contrast, TUNEL assays for apoptosis after exposure to H2O2 showed no differences between parental FA group A cells, cells complemented with wild-type FANCA, and cells complemented with the W183A of FANCA. Moreover, semiquantitative RT-PCR analysis for the expression of the peroxide-sensitive heme oxygenase gene showed appropriate induction after H2O2 exposure. Thus, W183A appears to be essential for the in vivo activity of FANCA in a manner independent of its interaction with FANCG. Moreover, neither wild-type FANCA nor the W183A mutation appears to alter the peroxide-induced apoptosisor peroxide-sensing ability of FA group A cells.

Despite the cloning of four disease-associated genes for Fanconi anemia (FA), the molecular pathogenesis of FA remains largely unknown. To study FA complementation group A using the mouse as a mode I system, we cloned and characterized the mouse homolog of the human FANCA cDNA, The mouse cDNA (Fanca) encodes a 161-kDa protein that shares 65% amino acid sequence identity with human FANCA. Fanca is located at the distal region of mouse chromosome 8 and has a ubiquitous pattern of expression in embryonic and adult tissues. Expression of the mouse DNA in human FA-A cells restores the cellular drug sensitivity to normal levels. Thus, the expression pattern, protein structure, chromosomal location, and function of FANCA are conserved in the mouse. We also isolated a novel zinc finger protein, Zfp276, which has five C2H2 domains. Interestingly, Zfp276 is situated in the Fanca locus, and the 3'UTR of its cDNA overlaps with the last four exons of Fanca in a tail-to-tail manner. Zfp276 is expressed in the same tissues as Fanca, but does not complement the mitomycin C (MMC)-sensitive phenotype of FA-A cells. The overlapping genomic organization between Zfp276 and Fanca may have relevance to the disease phenotype of FA. (C) 2000 Academic Press.

Fanconi anemia is a chromosomal breakage disorder with eight complementation groups (A–H), and three genes ( FANCA, FANCC, and FANCG ) have been identified. Initial investigations of the interaction between FANCA and FANCC, principally by co-immunoprecipitation, have proved controversial. We used the yeast two-hybrid assay to test for interactions of the FANCA, FANCC, and FANCG proteins. No activation of the reporter gene was observed in yeast co-expressing FANCA and FANCC as hybrid proteins, suggesting that FANCA does not directly interact with FANCC. However, a high level of activation was found when FANCA was co-expressed with FANCG, indicating strong, direct interaction between these proteins. Both FANCA and FANCG show weak but consistent interaction with themselves, suggesting that their function may involve dimerisation. The site of interaction of FANCG with FANCA was investigated by analysis of 12 mutant fragments of FANCG. Although both N- and C-terminal fragments did interact, binding to FANCA was drastically reduced, suggesting that more than one region of the FANCG protein is required for proper interaction with FANCA.

Mutations at the Werner helicase locus (WRN) are responsible for the Werner syndrome (WS). WS patients prematurely develop an aged appearance and various age-related disorders. We have generated transgenic mice expressing human WRN with a putative dominant-negative mutation (K577M-WRN). Primary tail fibroblast cultures from K577M-WRN mice showed three characteristics of WS cells: hypersensitivity to 4-nitroquinoline-1-oxide (4NQO), reduced replicative potential, and reduced expression of the endogenous WRN protein. These data suggest that K577M-WRN mice may provide a novel mouse model for the WS.

Werner syndrome is a human progeroid syndrome caused by mutations at the Werner helicase locus (WRN). Progeroid features and diseases associated with aging (including arteriosclerosis) do not become apparent until after puberty. We entertained two alternative hypotheses to explain the post-pubertal onset: 1) WRN expression is induced at the time of puberty, its earlier functions being satisfied by another member of that family of helicases; and 2) it is expressed at all ages, but the phenotype of deficiency becomes apparent only after puberty. We report initial experiments consistent with the second hypothesis. Steady-state levels of WRN mRNA in aortic tissues were determined by semiquantitative reverse transcription-polymerase chain reaction. WRN mRNA was detectable as early as 49 days of gestation (the earliest available material). There was no statistically significant change in these levels between fetal and adult tissues. The presence of the WRN protein in fetal aorta was confirmed by Western analysis. This rules out the possibility that Werner syndrome phenotypes manifest after the puberty because of peripubertal induction of WRN expression.

The Bloom (BLM) and Werner's (WRN) syndrome proteins may regulate recombination and DNA repair. Using a novel polyclonal antibody to human BLM, we detected the 170-kda BLM antigen in wild-type but not Bloom syndrome cells. BLM was localized to punctate nuclear structures. The level of BLM but not WRN was 3.6 fold-higher in G(1)/S-synchronized fibroblasts than in G(0)-synchronized fibroblasts. BLM-positive cells invariably expressed topoisomerase IIalpha, whereas topoisomerase IIbeta was expressed constitutively. Transfections of BLM deletion mutants demonstrated that the C-terminal domain of BLM mediated nuclear entry and the central helicase domain was necessary for producing the punctate pattern. By subcellular fractionation, BLM was found primarily in high-salt extracts of the nucleoplasm and the nuclear matrix and was enriched in G(1)/S-synchronized cells compared with G(0)-synchronized cells. There was no interaction between BLM and WRN or topoisomerases IIalpha and IIbeta in fibroblasts. These results demonstrate that BLM is targeted to specific nuclear structures and that its expression is enhanced during cell growth. The known nucleolar localization of WRN, its invariant expression during the cell cycle, and the lack of interaction between BLM and WRN suggest distinct roles for BLM and WRN in processes such as DNA repair and recombination.

About 80% of all cases of Fanconi anemia (FA) can be accounted for by complementation groups A and C. To understand the relationship between these groups, we analyzed the expression pattern of the mouse FA group-A gene (Fanca) during embryogenesis and compared it with the known pattern of the group-C gene (Fancc). Northern analysis of RNA from mouse embryos at embryonic days 7, 11, 15, and 17 showed a predominant 4.5 kb band in all stages. By in situ hybridization, Fanca transcripts were found in the whisker follicles, teeth, brain, retina, kidney, liver, and limbs. There was also stage-specific variation in Fanca expression, particularly within the developing whiskers and the brain. Some tissues known to express Fancc (eg, gut) failed to show Fancaexpression. These observations show that (1) Fanca is under both tissue- and stage-specific regulation in several tissues; (2) the expression pattern of Fanca is consistent with the phenotype of the human disease; and (3) Fanca expression is not necessarily coupled to that of Fancc. The presence of distinct tissue targets for FA genes suggests that some of the variability in the clinical phenotype can be attributed to the complementation group assignment.

Mutations at the Werner helicase locus (WRN) are responsible for the Werner syndrome (WS), a "caricature of aging." We have localized the Werner protein (WRNp) to the nucleoli of replicating mammalian cells, where its appearance is associated with transcriptional activity. A dramatic reduction of the nucleolar signal and of [3H]uridine incorporation occurred when cultures were made quiescent or were exposed to 4-nitroquinoline-1-oxide (4NQO), to which WS cells are particularly susceptible. Total cellular levels of WRNp, however, did not change, and virtually all WRNp was in the nuclear fractions, consistent with translocation to the nucleoplasm and/or masking of the epitopes. The 4NQO-induced altered state of WRNp was prevented by Na3VO4, but not by okadaic acid, suggesting that WRNp localization/function is partially regulated by kinases/phosphatases for Tyr substrates on WRNp or interacting proteins. The repression of rDNA transcription by 4NQO was not reversed by Na3VO4. We suggest that physiological states and genotoxic agents modulate the interaction of WRNp with rDNA, consistent with a role of WRNp in rDNA transcription.

Fanconi anemia (FA) consists of a group of at least five autosomal recessive disorders that share both clinical (e.g., birth defects and hematopoietic failure) and cellular (e.g., sensitivity to cross-linking agents and predisposition to apoptosis) features with each other. However, a common pathogenetic link among these groups has not been established. To identify genetic pathways that are altered in FA and characterize shared molecular defects, we used mRNA differential display to isolate genes that have altered expression patterns in FA cells. Here, we report that the expression of an interferon-inducible gene, MxA, is highly upregulated in cells of FA complementation groups A, B, C, and D, but it is suppressed in FA group C cells complemented with wild-type FAC cDNA as well as in non-FA cells. A posttranscriptional mechanism rather than transcriptional induction appears to account for MxA overexpression. Forced expression of MxA in Hep3B cells enhances their sensitivity to mitomycin C and induces apoptosis, similar to the FA phenotype. Thus, MxA is a downstream target of FAC and is the first genetic marker to be identified among multiple FA complementation groups. These data suggest that FA subtypes converge onto a final common pathway, which is intimately related to the interferon signaling mechanism. Constitutive activity of this pathway may explain a number of the phenotypic features of FA, particularly the pathogenesis of bone marrow failure.

The platelet-derived growth factor receptor (PDGFR) has an important role in tumorigenesis and tumor progression. Olaratumab (IMC-3G3) is a fully human monoclonal antibody that selectively binds human PDGFRα and blocks ligand binding. This phase I study assessed the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), pharmacokinetics, and preliminary antitumor activity of olaratumab in patients with advanced solid tumors.Patients were enrolled into five dose-escalating cohorts of 3-6 patients each. Olaratumab was administered intravenously weekly at 4, 8, or 16 mg/kg (cohorts 1-3) or once every other week at 15 or 20 mg/kg (cohorts 4-5), with 4 weeks/cycle.Nineteen patients were treated in five cohorts. There were no dose-limiting toxicities; the MTD was not identified with the doses studied. The most common olaratumab-related adverse events (AE) were fatigue and infusion reactions (10.5 % each). With the exception of 1 patient (20 mg/kg) experiencing two grade 3 drug-related AEs after the dose-limiting toxicity assessment period, all drug-related AEs were grade 1 or 2. The trough concentrations (C min) for 16 mg/kg weekly and 20 mg/kg biweekly were higher than 155 μg/mL, and the concentration found to be efficacious in preclinical xenograft models. Twelve patients (63.2 %) had a best response of stable disease [median duration of 3.9 months (95 % CI 2.3-8.7)].Olaratumab was well tolerated and showed preliminary antitumor activity. RP2Ds are 16 mg/kg weekly and 20 mg/kg biweekly. Phase II studies of olaratumab as monotherapy and in combination are ongoing in several tumor types.

Background Cixutumumab (IMC-A12), a fully human immunoglobulin G1 (IgG1) monoclonal antibody, exerts preclinical activity in several sarcoma models and may be effective for the treatment of these tumours. Methods In this open-label, multicentre, phase 2 study, patients with previously treated advanced or metastatic rhabdomyosarcoma, leiomyosarcoma, adipocytic sarcoma, synovial sarcoma or Ewing family of tumours received intravenous cixutumumab (10 mg/kg) for 1 h every other week until disease progression or discontinuation. The primary end-point was the progression-free survival rate (PFR), defined as stable disease or better at 12 weeks. In each tier of disease histology, Simon's optimum 2-stage design was applied (PFR at 12 weeks P0 = 20%, P1 = 40%, α = 0.10, β = 0.10). Stage 1 enrolled 17 patients in each disease group/tier, with at least four patients with stable disease or better required at 12 weeks to proceed to stage 2. Results A total of 113 patients were enrolled; all tiers except adipocytic sarcoma were closed after stage 1 due to futility. The 12-week PFR was 12% for rhabdomyosarcoma (n = 17), 14% for leiomyosarcoma (n = 22), 32% for adipocytic sarcoma (n = 37), 18% for synovial sarcoma (n = 17) and 11% for Ewing family of tumours (n = 18). Median progression-free survival (weeks) was 6.1 for rhabdomyosarcoma, 6.0 for leiomyosarcoma, 12.1 for adipocytic sarcoma, 6.4 for synovial sarcoma and 6.4 for Ewing family of tumours. Among all patients, the most frequent treatment-emergent adverse events (AEs) were nausea (26%), fatigue (23%), diarrhoea (23%) and hyperglycaemia (20%). Conclusions Patients with adipocytic sarcoma may benefit from treatment with cixutumumab. Cixutumumab treatment was well tolerated, with limited gastrointestinal AEs, fatigue and hyperglycaemia. © 2013 Elsevier Ltd. All rights reserved.

Despite significant advances in understanding of molecular pathobiology, the adoption of this knowledge and its application to drug development is sporadic. Consequently, the drug development process has remained intrinsically laborious and inefficient. Translational research seeks to improve this process by integrating scientific advances into well-defined clinical challenges and opportunities. The focus of this article is on cancer therapeutics, specifically, 2 biotechnology organizations' advances in oncology: (1) optimizing the safety and efficacy of a novel DNA cross-linking small molecule, palifosfamide, and (2) bringing synthetic biology into clinical practice using a controllable gene therapy strategy with intratumorally injected interleukin-12 DNA, a potent cytokine.

Background IMC-18F1 (icrucumab), a human monoclonal antibody against vascular endothelial growth factor receptor-1 (VEGFR-1), potently inhibits ligand-dependent phosphorylation of VEGFR-1 and downstream signaling, making icrucumab an attractive candidate for antitumor activity. Objectives The primary objective was to determine the safety profile and maximum tolerated dose of icrucumab in patients with advanced solid tumors that were previously unresponsive to standard therapy or for which no standard therapy was available. Methods In this open-label, dose-escalation, Phase 1 study, patients received icrucumab intravenously weekly at 2, 3, 6, and 12 mg/kg (Cohorts 1–4), every other week (q2w) at 15 mg/kg (Cohort 5), or every third week at 20 mg/kg (Cohort 6). Patients received icrucumab until evidence of progressive disease or other withdrawal criteria were met. Results Twenty-six patients received icrucumab. The most common adverse events were fatigue, nausea, peripheral edema, anemia, dyspnea, and vomiting. No dose-limiting toxicities (DLTs) were observed in Cohorts 1–5. Two DLTs were observed in Cohort 6 (anemia and hyponatremia), and enrollment was stopped. No patient demonstrated an immunogenic response. Overall, icrucumab exhibited nonlinear pharmacokinetics at doses >6 mg/kg. Six patients (23.1 %) achieved stable disease with median duration of 11.1 weeks (range = 10.3–18.7 weeks); tumor types were thyroid, melanoma, colorectal (3 patients), and small-cell lung cancers. Conclusions Icrucumab was safely administered weekly at doses of 2–12 mg/kg and q2w at a dose of 15 mg/kg with no DLTs. Based on achievement of stable disease, icrucumab has potential for antitumor activity against advanced solid tumors.

The authors report studies of a female with severe hemophilia A resulting from a complex de novo translocation of chromosomes X and 17 (46,X,t(X; 17)). Somatic cell hybrids containing the normal X, the der(X), or the der(17) were analyzed for coagulation factor VIII (F8C) sequences using Southern blots and polymerase chain reaction. The normal X, always late replicating, contains a normal F8C gene, whereas the der(X) has no F8C sequences. The der(17) chromosome containing Xq24-Xq28 carries a functional G6PD locus and a deleted F8C allele that lacks exons 1--15. Also, it lacks the DXYS64-X locus, situated between the F8C locus and the Xq telomere. These results indicate that a cryptic breakpoint within Xq28 deleted the 5[prime] end of F8C, but left the more proximal G6PD locus intact on the der(17)chromosome. As the deleted segment includes the 5[prime] half of F8C as well as the subtelomeric DXYS64 locus, F8C must be oriented on the chromosome with its 5[prime] region closest to the telomere. Therefore, the order of these loci is Xcen-G6PD-3[prime]F8C-5[prime]F8C-DXYS64-Xqtel. The analysis of somatic cell hybrids has elucidated the true nature of the F8C mutation in the pro-band, revealing a more complex rearrangement (three chromosomes involved) than that expected frommore » cytogenetic analysis, chromosome painting, and Southern blots. A 900-kb segment within Xq28 has been translocated to another autosome. Hemophilia A in this heterozygous female is due to the decapitation of the F8C gene on the der(17) and inactivation of the intact allele on the normal X. 27 refs., 5 figs., 1 tab.« less

The benefits of inhibiting vascular endothelial growth factor (VEGF) signaling in cancer patients are predominantly attributed to effects on tumor endothelial cells. Targeting non–endothelial stromal cells to further impact tumor cell growth and survival is being pursued through the inhibition of additional growth factor pathways important for the survival and/or proliferation of these cells. However, recent data suggest that VEGF receptor (VEGFR)–specific inhibitors may target lymphatic vessels and pericytes in addition to blood vessels. Here, in fact, we demonstrate that DC101 (40 mg/kg, thrice a week), an antibody specific to murine VEGFR2, significantly reduces all three of these stromal components in subcutaneous (SKRC-29) and orthotopic (786-O-LP) models of renal cell carcinoma (RCC) established in nu/nu athymic mice. Sunitinib (40 mg/kg, once daily), a receptor tyrosine kinase inhibitor of VEGFR2 and other growth factor receptors, also caused significant loss of tumor blood vessels in RCC models but had weaker effects than DC101 on pericytes and lymphatic vessels. In combination, sunitinib did not significantly add to the effects of DC101 on tumor blood vessels, lymphatic vessels, or pericytes. Nevertheless, sunitinib increased the effect of DC101 on tumor burden in the SKRC-29 model, perhaps related to its broader specificity. Our data have important implications for combination therapy design, supporting the conclusion that targeting VEGFR2 alone in RCC has the potential to have pleiotropic effects on tumor stroma.

Purpose: This study aimed to determine a maximum tolerated dose (MTD) and recommended dose for disease-directed studies of necitumumab (IMC-11F8), a fully human IgG1 monoclonal antibody directed at the epidermal growth factor receptor, and to characterize the safety profile, pharmacokinetics, preliminary antitumor activity, and immunogenicity of necitumumab. Experimental Design: Patients with advanced solid malignancies were treated with 100 to 1,000 mg (flat dosing) necitumumab followed by a 2-week pharmacokinetics sampling period, before beginning 6-week cycles of therapy. Results: Sixty patients received necitumumab weekly (29 patients) or every other week (31 patients). Two patients receiving 1,000 mg every 2 weeks experienced dose-limiting toxicities (DLT; grade 3 headache), accompanied by grade 3 nausea and vomiting in one patient. Occurring hours after the initial dose, these DLTs established 800 mg as the MTD. Mild dose-related skin toxicity was the most common drug-related toxicity (80%). One patient in each arm experienced grade 3 acneform rash, which responded to oral antibiotics and topical therapy. Toxicity was similar on both schedules. Necitumumab exhibited saturable elimination and nonlinear pharmacokinetics. At 800 mg (both arms), its half-life was approximately 7 days. All patients treated with ≥600 mg necitumumab achieved target trough concentrations (≥40 μg/mL). Antibodies against necitumumab were not detected. Partial response and stable disease were experienced by 2 and 16 patients, respectively. Conclusion: Well tolerated, necitumumab is associated with preliminary evidence of antitumor activity, and achieves biologically relevant concentrations throughout the dosing period. The recommended dose of necitumumab for further clinical development is 800 mg (flat dose) weekly or every 2 weeks based on the clinical setting. Clin Cancer Res; 16(6); 1915–23

Purpose To evaluate the safety, maximum-tolerated dose (MTD), pharmacokinetics (PKs), pharmacodynamics, and preliminary anticancer activity of ramucirumab (IMC-1121B), a fully human immunoglobulin G1 monoclonal antibody targeting the vascular endothelial growth factor receptor (VEGFR)-2. Patients and Methods Patients with advanced solid malignancies were treated once weekly with escalating doses of ramucirumab. Blood was sampled for PK studies throughout treatment. The effects of ramucirumab on circulating vascular endothelial growth factor-A (VEGF-A), soluble VEGFR-1 and VEGFR-2, tumor perfusion, and vascularity using dynamic contrast-enhanced magnetic resonance imaging were assessed. Results Thirty-seven patients were treated with 2 to 16 mg/kg of ramucirumab. After one patient each developed dose-limiting hypertension and deep venous thrombosis at 16 mg/kg, the next lower dose (13 mg/kg) was considered the MTD. Nausea, vomiting, headache, fatigue, and proteinuria were also noted. Four (15%) of 27 patients with measurable disease had a partial response (PR), and 11 (30%) of 37 patients had either a PR or stable disease lasting at least 6 months. PKs were characterized by dose-dependent elimination and nonlinear exposure consistent with saturable clearance. Mean trough concentrations exceeded biologically relevant target levels throughout treatment at all dose levels. Serum VEGF-A increased 1.5 to 3.5 times above pretreatment values and remained in this range throughout treatment at all dose levels. Tumor perfusion and vascularity decreased in 69% of evaluable patients. Conclusion Objective antitumor activity and antiangiogenic effects were observed over a wide range of dose levels, suggesting that ramucirumab may have a favorable therapeutic index in treating malignancies amenable to VEGFR-2 inhibition.

In this multinational, placebo-controlled, randomized phase III trial, Translational Research In Oncology (TRIO) will define the efficacy and safety of adding a novel antiangiogenic agent, IMC-1121B (ramucirumab), to standard first-line docetaxel chemotherapy for women with HER2-negative metastatic breast cancer. We will evaluate whether the addition of IMC-1121B prolongs progression-free survival and whether its use improves overall survival. Accrual is under way.

Purpose To determine antitumor activity of cetuximab monotherapy in patients with refractory metastatic colorectal carcinoma (mCRC) with lack of specific membrane immunostaining for the epidermal growth factor receptor (EGFR). Patients and methods Patients had immunohistochemical (IHC)-determined mCRC with absent EGFR immunostaining that progressed after receiving at least one standard, fluoropyrimidine-containing chemotherapeutic regimen. Absent EGFR immunostaining was defined as the IHC absence of specific membrane staining in ≥500 cancer cells examined in well-preserved tissue. The study was performed prior to results of studies linking cetuximab sensitivity to K-ras mutation status. Patients received 400 mg/m2 of intravenous (i.v.) cetuximab followed by once-weekly i.v. cetuximab 250 mg/m2 until disease progression or unacceptable toxicity. Patients were evaluated for objective response at least every 6 weeks. Kaplan-Meier estimates were calculated for duration of response, time to progression (TTP), and overall survival (OS). Results Seven (8.2%) of 85 mCRC patients whose tumors lacked EGFR immunostaining had major responses following cetuximab treatment. The median duration of response was 5.1 months. Median TTP and OS were 2.5 months and 10.0 months, respectively; the 1-year survival rate was 39.6%. The most frequently reported cetuximab-related adverse events were acneiform dermatitis, fatigue, headache, and dry skin. Conclusion Cetuximab monotherapy produces objective antitumor activity in patients with mCRC that does not express EGFR as determined by IHC. The activity and safety profiles of cetuximab monotherapy in mCRC lacking EGFR immunostaining are similar to previous observations in EGFR IHC-positive disease that was not selected based on K-ras mutation status.

Targeted monoclonal antibody therapy is an important strategy in cancer therapeutics. Among the most promising characteristics of therapeutic targets are those that modulate the growth and survival of malignant neoplasms and their sensitivity to anticancer therapies. The insulin-like growth factor-I receptor (IGF-IR) is overexpressed in many types of solid and hematopoietic malignancies, and has been implicated as a principal cause of heightened proliferative and survival signaling. IGF-IR has also been shown to confer resistance to cytotoxic, hormonal, and targeted therapies, suggesting that therapeutics targeting IGF-IR may be effective against a broad range of malignancies. IMC-A12 (ImClone Systems Incorporated), a fully human monoclonal IgG1 antibody that binds with high affinity to the IGF-IR, inhibits ligand-dependent receptor activation and downstream signaling. IMC-A12 also mediates robust internalization and degradation of the IGF-IR. In human tumor xenograft models, IGF-IR blockade by IMC-A12 results in rapid and profound growth inhibition of cancers of the breast, lung, colon, and pancreas, and many other neoplasms. Although promising single-agent activity has been observed, the most impressive effects of targeting the IGF-IR with IMC-A12 have been noted when this agent was combined with cytotoxic agents or other targeted therapeutics. The results with IMC-A12 to date suggest that it may be an effective therapeutic in a diverse array of oncologic indications.

Angiogenesis is a fundamental mechanism of cancer growth and invasion. Current translational approaches are using both small-molecule inhibitors and antibodies that modulate various steps of these processes, and several such compounds have already received regulatory approval for the therapy of specific indications in cancer. Among the many molecular targets involved in the control of angiogenesis, the vascular endothelial growth factor receptor-2 (VEGFR-2; or kinase insert domain-containing receptor) is attractive as shown in part by the efficacy of small-molecule inhibitors directed to this receptor. Two small-molecule inhibitors that target VEGFR-2 have recently been granted approval for the treatment of renal cell cancer and gastrointestinal stromal tumors. The development of antibodies that can selectively block VEGFR-2 could potentially result in improved potency or tolerability. Here, we discuss the role of VEGFR-2 in cancer and ongoing efforts to develop highly specific monoclonal antibodies for cancer therapy.

The authors of this Viewpoint argue there are no facile solutions to replace the painstaking, empirical effort required to identify the targets within 'addicted' tumors. Redundant pathways and our incomplete understanding of drug targets cast doubt on biomarker evidence unless reinforced by biological observations. Further integration of academia, industry and the regulatory organizations is required.

Condensin is a conserved 13S heteropentamer composed of two nonidentical structural maintenance of chromosome (SMC) family proteins, in Xenopus XCAP-C and XCAP-E, and three regulatory subunits, XCAP-D2, XCAP-G, and XCAP-H. Both biochemical and genetic analyses have demonstrated an essential role for the 13S condensin complex in mitotic chromosome condensation. Further, a potential requirement for condensin in completion of chromatid arm separation in early anaphase is demonstrated by the mutational phenotypes of the Drosophila homologues ofXCAP-H, barren and XCAP-C,DmSMC4. In this study we have investigated the expression and subcellular distribution of hCAP-H, the human homolog of XCAP-H, in order to better understand its cellular functions. Transcription of hCAP-H was restricted to proliferating cells with highest expression during the G2 phase of the cell cycle. In contrast, cellular hCAP-H protein levels were constant throughout the cell cycle. hCAP-H was found to be associated with mitotic chromosomes exhibiting a nonuniform but symmetric distribution along sister chromatids. The symmetry of hCAP-H association with sister chromatids suggests that there are sequence-dependent domains of condensin aggregation. During interphase hCAP-H, -C, and -E, have distinct punctate nucleolar localization, suggesting that condensin may associate with and modulate the conformation and function of rDNA. hCAP-H association with condensed chromatin was not observed in the early phase of chromosome condensation when histone H3 phosphorylation has already taken place. This finding is consistent with the hypothesis that histone H3 phosphorylation precedes condensin-mediated condensation.

The Fanconi anemia group C protein (FANCC) plays an important role in hematopoiesis by ensuring the survival of hematopoietic progenitor cells through an unknown mechanism. We investigated the function of FANCC by identifying FANCC-binding proteins in hematopoietic cells. Here we show that glutathione S-transferase P1-1 (GSTP1) interacts with FANCC, and that overexpression of both proteins in a myeloid progenitor cell line prevents apoptosis following factor deprivation. FANCC increases GSTP1 activity after the induction of apoptosis. GSTP1 is an enzyme that catalyzes the detoxification of xenobiotics and by-products of oxidative stress, and it is frequently upregulated in neoplastic cells. Although FANCC lacks homology with conventional disulfide reductases, it functions by preventing the formation of inactivating disulfide bonds within GSTP1 during apoptosis. The prevention of protein oxidation by FANCC reveals a novel mechanism of enzyme regulation during apoptosis and has implications for the treatment of degenerative diseases with thiol reducing agents.

Bloom syndrome is a disorder associated with genomic instability that causes affected people to be prone to cancer. Bloom cell lines show increased sister chromatid exchange, yet are proficient in the repair of various DNA lesions. The underlying cause of this disease are mutations in a gene encoding a RECQ DNA helicase. Using embryonic stem cell technology, we have generated viable Bloom mice that are prone to a wide variety of cancers. Cell lines from these mice show elevations in the rates of mitotic recombination. We demonstrate that the increased rate of loss of heterozygosity (LOH) resulting from mitotic recombination in vivo constitutes the underlying mechanism causing tumour susceptibility in these mice.

ABSTRACT: The X-linked form of the bone marrow failure syndrome Dyskeratosis congenita is caused by mutations in dyskerin, a 514 amino acid protein that is presumed to play a role in ribosome biogenesis. Here we report that dyskerin tagged with the human immunoglobulin epitope localizes to nuclei of transfected HeLa and COS-1 cells. A carboxyl-terminal domain consisting of amino acids 467–475 and encoding KKEKKKSKK is both necessary and sufficient to mediate nuclear entry. Immunoglobulin-tagged dyskerin did not interact with the Fanconi anemia group A protein, FANCA. These results suggest a nuclear role for dyskerin. Moreover, hematopoietic failure observed in both Dyskeratosis congenita and the most common type of Fanconi anemia is unlikely to have a common mechanism resulting from abnormal physical interactions between the respective gene products of these disorders.

Fanconi anemia (FA) is a genetically heterogeneous disorder characterized by bone marrow failure, birth defects, and chromosomal instability. Because FA cells are sensitive to mitomycin C (MMC), FA gene products could be involved in cellular defense mechanisms. The FANCA and FANCG proteins deficient in FA groups A and G interact directly with each other. We have localized the mutual interaction domains of these proteins to amino acids 18-29 of FANCA and to two noncontiguous carboxyl-terminal domains of FANCG encompassing amino acids 400-475 and 585-622. Site-directed mutagenesis of FANCA residues 18-29 revealed a novel arginine-rich interaction domain (RRRAWAELLAG). By alanine mutagenesis, Arg(1), Arg(2), and Leu(8) but not Arg(3), Trp(5), and Glu(7) appeared to be critical for binding to FANCG. Similar immunolocalization for FANCA and FANCG suggested that these proteins interact in vivo. Moreover, targeting of FANCA to the nucleus or the cytoplasm with nuclear localization and nuclear export signals, respectively, showed concordance between the localization patterns of FANCA and FANCG. The complementation function of FANCA was abolished by mutations in its FANCG-binding domain. Conversely, stable expression of FANCA mutants encoding intact FANCG interaction domains induced hypersensitivity to MMC in HeLa cells. These results demonstrate that FANCA-FANCG complexes are required for cellular resistance to MMC. Because the FANCC protein deficient in FA group C works within the cytoplasm, we suggest that FANCC and the FANCA-FANCG complexes suppress MMC cytotoxicity within distinct cellular compartments.

Fanconi anemia (FA) is a recessively inherited disease characterized at the cellular level by spontaneous chromosomal instability and specific hypersensitivity to cross-linking agents. FA is genetically heterogeneous, comprising at least eight complementation groups (A-H). We report that the protein encoded by the gene mutated in complementation group G (FANCG) localizes to the cytoplasm and nucleus of the cell and assembles in a molecular complex with the FANCA protein, both in vivo and in vitro . Endogenous FANCA/FANCG complex was detected in both non-FA cells and in FA cells from groups D and E. By contrast, no complex was detected in specific cell lines belonging to groups A and G, whereas reduced levels were found in cells from groups B, C, F, and H. Wild-type levels of FANCA/FANCG complex were restored upon correction of the cellular phenotype by transfection or cell fusion experiments, suggesting that this complex is of functional significance in the FA pathway. These results indicate that the cellular FA phenotype can be connected to three biochemical subtypes based on the levels of FANCA/FANCG complex. Disruption of the complex may provide an experimental strategy for chemosensitization of neoplastic cells.