P O Witteveen

University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

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Publications (53)179.56 Total impact

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    ABSTRACT: This study assessed the pharmacokinetics and safety of oral panobinostat and its metabolite BJB432 in patients with advanced solid tumors and normal to severely impaired renal function.
    Cancer Chemotherapy and Pharmacology 11/2014; · 2.80 Impact Factor
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    ABSTRACT: Optimal long-lasting treatment with sunitinib and sorafenib is limited by dose modifications (DMs) due to adverse events (AEs). These AEs may be underrecognized and their influence on health-related quality of life (HRQL) underestimated. Improved insight into the relationship between AEs and therapy decisions is needed. To improve decision making around managing symptoms and reduce DMs, this study was set up to explore the influence of patient-reported symptoms on therapy decisions. In this multicenter cohort study, patient characteristics, reasons for and different forms of used dose modifications, and AEs were prospectively obtained from cancer patients on sunitinib/sorafenib treatment. Used instruments to get insight into AEs were the patient-scored Utrecht Symptom Diary (USD) and the professional-scored Common Terminology Criteria for AEs version 3.0. Median total treatment duration in 42 patients was 16 weeks. Median time till dose modification was 10 weeks. DMs occurred mostly due to multiple mild AEs. By using the USD, a higher prevalence of most AEs was found compared to the literature. Sixty percent of the patients experienced a decreased HRQL due to multiple AEs. Because severe AEs due to sunitinib/sorafenib treatment seldom occur, it is more important to focus on treating and preventing multiple mild AEs with higher impact on HRQL, when trying to avoid dose modifications. Using patient self-reported measurement methods helps to early recognize symptoms and to differentiate among symptom intensities. This systematic approach might help to achieve the optimal dosing, which might improve PFS and OS.
    Supportive Care in Cancer 04/2014; · 2.09 Impact Factor
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    ABSTRACT: Intra-tumor heterogeneity is a hallmark of many cancers and may lead to therapy resistance or interfere with personalized treatment strategies. Here, we combined topographic mapping of somatic breakpoints and transcriptional profiling to probe intra-tumor heterogeneity of treatment-naïve stage IIIC/IV epithelial ovarian cancer. We observed that most substantial differences in genomic rearrangement landscapes occurred between metastases in the omentum and peritoneum versus tumor sites in the ovaries. Several cancer genes such as NF1, CDKN2A and FANCD2 were affected by lesion-specific breakpoints. Furthermore, the intra-tumor variability involved different mutational hallmarks including lesion-specific kataegis (local mutation shower coinciding with genomic breakpoints), rearrangement classes and coding mutations. In one extreme case, we identified two independent TP53 mutations in ovary tumors and omentum/peritoneum metastases, respectively. Examination of gene expression dynamics revealed upregulation of key cancer pathways including WNT, integrin, chemokine and hedgehog signalling in only subsets of tumor samples from the same patient. Finally, we took advantage of the multi-level tumor analysis to understand the effects of genomic breakpoints on qualitative and quantitative gene expression changes. We show that intra-tumor gene expression differences are caused by site-specific genomic alterations, including formation of in frame fusion genes. These data highlight the plasticity of ovarian cancer genomes, which may contribute to their strong capacity to adapt to changing environmental conditions and give rise to the high rate of recurrent disease following standard treatment regimes.
    Genome Research 11/2013; · 14.40 Impact Factor
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    ABSTRACT: PURPOSE: To evaluate dosimetric parameters and clinical outcome for cervical cancer patients treated with chemo-radiation and MR-image guided adaptive brachytherapy (MR-IGABT) using tandem-ovoid applicators for intracavitary or combined intracavitary/interstitial approaches. METHOD: This retrospective analysis includes 46 patients treated between 2006 and 2008. Dose-volume parameters D90 HR-CTV (high-risk clinical target volume) and D2cc OARs (organs at risk) were determined and converted into biologically equivalent doses in 2Gy fractions (EQD2). Clinical outcome parameters (local control (LC), progression free survival (PFS) and overall survival (OS)) were analysed actuarially and late morbidity crude rates were scored using CTCAEv3.0. RESULTS: Mean D90 HR-CTV was 84 (SD9) Gy EQD2 for HR-CTV volumes of mean 57 (SD37) cm(3) at time of first brachytherapy (BT). Median follow-up was 41 (range, 4-67)months. Three year LC, PFS, and OS rates were 93, 71, and 65%, respectively. Node negative patients had significantly higher 3-year survival rates compared to node positive ones (PFS 85 versus 53% (p=0.013), OS 77 versus 50% (p=0.032), respectively) with an even larger difference for patients with FIGO stages IB-IIB (PFS 87 versus 42% (p=0.002), OS 83 versus 46% (p=0.007), respectively). Late grade 3-4 mainly gastrointestinal or vaginal morbidity was observed in 4 patients (9.5%). No correlations were seen between morbidity and D2cc OAR values. CONCLUSION: (Chemo-) radiation and MR-IGABT with tandem-ovoid applicators result in high LC and promising survival rates with reasonable morbidity.
    Radiotherapy and Oncology 04/2013; · 4.52 Impact Factor
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    ABSTRACT: CP-4126 is a gemcitabine (2',2'-difluorodeoxycytidine; dFdC) 5' elaidic acid ester. The purpose of this dose-escalating study was to assess safety, pharmacokinetics (PK) and preliminary antitumor activity of the oral formulation and to determine the recommended dose (RD) for phase II studies. The study had a two-step design: a non-randomized dose-escalating step I with oral CP-4126 alone, followed by a randomized, cross-over step II that compared oral CP-4126 with dFdC i.v.. CP-4126 was given on days 1,8,15 in a 4-week schedule with increasing doses until the RD was established. 26 patients with different solid tumours were enrolled in step I at seven dose levels (100-3,000 mg/day). The most frequent drug-related AEs were fatigue and dysgeusia, the majority being grade 1-2. One patient experienced a dose limiting toxicity after one dose of CP-4126 at 1,300 mg/day (ASAT grade 3). PK of CP-4126 could not be determined. The metabolites dFdC and dFdU obeyed dose-dependent pharmacokinetics. Exposures to dFdC were about ten-fold lower compared to exposures after comparable doses of dFdC i.v.. Nine patients reached stable disease as best response, whereby in one patient with vaginal carcinoma a 25 % reduction of tumor volume was reached. This study demonstrates that CP-4126 can be safely administered orally to patients up to 3,000 mg/day in a d1,8,15 q4w schedule with a tolerable safety profile. CP-4126 acts as a prodrug for dFdC when given orally, but because of the poor absorption and the rapid pre-systemic metabolism the study was terminated early and no RD could be determined.
    Investigational New Drugs 01/2013; · 3.50 Impact Factor
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    ABSTRACT: Malignant ovarian germ cell tumor is a rare disease, but with current treatment strategies including surgery and platinum based chemotherapy survival is excellent. After treatment, intensive followup is indicated to encounter tumor relapse at an early stage. This case describes a 22-year-old female with a history of common variable immune deficiency (CVID) who underwent a resection of a large ovarian germ cell tumor followed by 4 cycles of cisplatin and etoposide resulting in clinical complete remission. During followup, she developed a mass at the umbilicus and ascites. Initially, the cytology of the ascites was interpreted as tumor positive, suspicious of relapse of the disease, but tumor markers remained negative. However, during laparoscopy it turned out to be a mature teratoma, which can develop after chemotherapy, the so called growing teratoma syndrome. In retrospect, the ascites was false positive. This case shows that current diagnostic tools are not sufficient to distinguish between vital tumor and mature teratoma and can be misleading. Tumor biopsy and/or laparoscopic inspection are therefore indicated.
    Case reports in obstetrics and gynecology. 01/2013; 2013:984524.
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    ABSTRACT: PURPOSE: The aim of this study was to determine the plasma pharmacokinetics of eribulin mesylate in patients with solid tumors with mild and moderate hepatic impairment. PATIENTS AND METHODS: A phase I, pharmacokinetic study was performed in patients with advanced solid tumors and normal hepatic function or Child-Pugh A (mild) or Child-Pugh B (moderate) hepatic impairment. Treatments were given on day 1 and 8 of a 21-day cycle and consisted of 1.4, 1.1 and 0.7 mg/m(2) eribulin mesylate, for normal hepatic function, Child-Pugh A and B hepatic impairment, respectively. Also safety and anti-tumor activity were determined. RESULTS: Hepatic impairment increased exposure to eribulin. In patients with Child-Pugh A (N = 7) and Child-Pugh B (N = 5), mean dose-normalized AUC(0-∞) was 1.75-fold (90 % confidence intervals (CI): 1.16-2.65) and 2.48-fold (90 % CI: 1.57-3.92) increased, respectively, compared with patients who have normal function (N = 6). The most frequently reported treatment-related events were alopecia (12/18) and fatigue (7/18) and these were observed across all groups. Nine patients (50 %) had stable disease as best response. CONCLUSIONS: A reduced dose of 1.1 and 0.7 mg/m(2) of eribulin mesylate is recommended for patients with Child-Pugh A or B hepatic impairment, respectively.
    Cancer Chemotherapy and Pharmacology 09/2012; · 2.80 Impact Factor
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    ABSTRACT: AIM: Eribulin mesylate is a non-taxane microtubule dynamics inhibitor that was recently approved for treatment of metastatic breast cancer. The aim of this study was to determine the effect of rifampicin, a CYP3A4 inducer, on the plasma pharmacokinetics of eribulin in patients with solid tumors. METHODS: An open-label, non-randomized phase I study. Patients received intravenous 1.4 mg/m(2) eribulin mesylate on day 1 and 15 and oral rifampicin 600 mg on days 9 to 20 of a 28-day cycle. Pharmacokinetic sampling for determination of eribulin plasma concentrations was performed up to 144 hours following administration. AUC (0-∞) and C (max) for eribulin exposure without or with co-administration of rifampicin were subjected to an analysis of variance (ANOVA) and corresponding 90% confidence intervals (CI) were calculated. Subsequently, patients were allowed to continue eribulin mesylate treatment with 1.4 mg/m(2) eribulin mesylate on days 1 and 8 of a 21-day cycle. Also the adverse event profile and anti-tumor activity were assessed. RESULTS: Fourteen patients were included and eleven patients were evaluable for pharmacokinetic analysis. Co-administration of rifampicin had no effect on single-dose exposure to eribulin (geometric least square means ratio: AUC (0-∞) =1.10 [90% CI 0.91 - 1.34] and C (max) = 0.97 [90% 0.81 - 1.17]). The most common treatment-related grade ≥ 3 adverse events were grade 3 neutropenia (4/14, 29%), leukopenia and fatigue (both 3/14, 21%) CONCLUSIONS: These results indicate that eribulin mesylate may be safely co-administered with compounds that are CYP3A4 inducers.
    British Journal of Clinical Pharmacology 07/2012; · 3.69 Impact Factor
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    ABSTRACT: This study evaluates intra- and interobserver variability of automatic diameter and volume measurements of colorectal liver metastases (CRLM) before and after chemotherapy and its influence on response classification. Pre-and post-chemotherapy CT-scans of 33 patients with 138 CRLM were evaluated. Two observers measured all metastases three times on pre-and post-chemotherapy CT-scans, using three different techniques: manual diameter (MD), automatic diameter (AD) and automatic volume (AV). RECIST 1.0 criteria were used to define response classification. For each technique, we assessed intra- and interobserver reliability by determining the intraclass correlation coefficient (α-level 0.05). Intra-observer agreement was estimated by the variance coefficient (%). For inter-observer agreement the relative measurement error (%) was calculated using Bland-Altman analysis. In addition, we compared agreement in response classification by calculating kappa-scores (κ) and estimating proportions of discordance between methods (%). Intra-observer variability was 6.05%, 4.28% and 12.72% for MD, AD and AV, respectively. Inter-observer variability was 4.23%, 2.02% and 14.86% for MD, AD and AV, respectively. Chemotherapy marginally affected these estimates. Agreement in response classification did not improve using AD or AV (MD κ=0.653, AD κ=0.548, AV κ=0.548) and substantial discordance between observers was observed with all three methods (MD 17.8%, AD 22.2%, AV 22.2%). Semi-automatic software allows repeatable and reproducible measurement of both diameter and volume measurements of CRLM, but does not reduce variability in response classification.
    European journal of radiology 01/2012; 81(10):2543-9. · 2.65 Impact Factor
  • European Journal of Cancer 09/2011; 47. · 5.06 Impact Factor
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    ABSTRACT: LY2334737 is an orally available prodrug of gemcitabine. The objective of this study was to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of daily administration of LY2334737 with or without erlotinib. Patients with advanced or metastatic cancer were treated with escalating doses of LY2334737 monotherapy or in combination with continuous daily administration of 100 mg erlotinib. LY2334737 was given once daily for 14 days of a 21-day cycle. The study was extended with a bioequivalence trial to investigate a novel LY2334737 drug formulation. A total of 65 patients were treated in this study. The MTD was 40 mg LY2334737. Fatigue was the most frequent DLT for LY2334737 monotherapy (4 patients) followed by elevated transaminase levels (2 patients), both observed at the 40- to 50-mg dose levels. Among the 10 patients in the combination arm, 2 had DLTs at the 40-mg dose level. These were fatigue and elevated liver enzyme levels. The most common adverse events were fatigue (n = 38), nausea (n = 27), vomiting (n = 24), diarrhea (n = 23), anorexia (n = 20), pyrexia (n = 18), and elevated transaminase levels (n = 14). The pharmacokinetics showed dose proportional increase in LY2334737 and gemcitabine exposure. The metabolite 2',2'-difluorodeoxyuridine accumulated with an accumulation index of 4.3 (coefficient of variation: 20%). In one patient, complete response in prostate-specific antigen was observed for 4 cycles, and stable disease was achieved in 22 patients overall. Pharmacokinetic analysis showed that the 2 investigated LY2334737 drug formulations were bioequivalent. LY2334737 displays linear pharmacokinetics and the MTD is 40 mg with or without daily administration of 100 mg erlotinib. Signs of antitumor activity warrant further development.
    Clinical Cancer Research 07/2011; 17(18):6071-82. · 7.84 Impact Factor
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    ABSTRACT: Blocking both receptor and ligand of the vascular endothelial growth factor (receptor) VEGF(R) pathway might be feasible and increase antitumor activity. This phase I study investigated telatinib, an oral tyrosine kinase inhibitor targeting VEGFR-2, combined with bevacizumab, in adults with solid tumors. Twenty-six patients were treated in successive cohorts with telatinib (twice-daily continuously, 450-900 mg) or bevacizumab (bi-weekly, starting dose 5 mg/kg). Safety, pharmacokinetics, endothelial (progenitor) cell (E(P)C)/growth factor kinetics and efficacy were assessed. Most frequent adverse events were pain, nausea, voice changes and fatigue. Five dose-limiting toxicities (DLTs) occurred: hypertension (cohort I and II), bowel perforation, lipase increase and atrial flutter (cohort III). Cumulative toxicity resulted in a bevacizumab dose reduction to 1 mg/kg (cohort III). Due to three DLTs (n = 14), this cohort represented the best-tolerated dose level. Bevacizumab effectively neutralized plasma VEGF even at 1 mg/kg. Twelve patients had stable disease (clinical benefit 46%). EPC and SDF-1α levels increased during monotherapy telatinib. Telatinib (450 mg b.i.d.) combined with bevacizumab (1 mg/kg bi-weekly) shows antitumor activity, but accumulating constitutional toxicity impedes long-term treatment of patients. Therefore, this combination will not be pursued in a phase II setting.
    Annals of Oncology 03/2011; 22(11):2508-15. · 7.38 Impact Factor
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    ABSTRACT: Anti-VEGF (vascular endothelial growth factor) therapy with the monoclonal antibody bevacizumab can cause gastrointestinal (GI) perforations. In recent years it became apparent that GI perforations also occur during treatment with antiangiogenic tyrosine kinase inhibitors (TKIs). It is of clinical importance to consider (vague) abdominal complaints during antiangiogenic treatment as a sign of a GI perforation. To illustrate this serious complication, we report four cases of antiangiogenic treatment related GI perforations. In three cases this was due to antiangiogenic TKI treatment. Reported risk factors of GI perforations due to bevacizumab include the presence of a primary tumor in situ and recent history of endoscopy or abdominal radiotherapy. Pathology assessments of surgical removal of the perforated intestinal part reveal that perforations are predominantly seen at the tumor or anastomotic site, in case of carcinomatosis or diverticulitis or when GI obstruction or an intra-abdominal abscess is present. Whether the same risk factors may be involved in antiangiogenic TKI related GI perforations is unknown. The underlying mechanisms responsible for GI perforation during antiangiogenic treatment is unknown, but disturbance of host cell homeostasis of immune cells as well as platelet-endothelial cell interactions may play an important role. In conclusion, while clinical awareness that antiangiogenic treatment can cause GI perforations is critical for current medical practice, it is also very important to get more insight in its underlying mechanisms so that this life-threatening complication may be prevented in the near future.
    Angiogenesis 12/2010; 14(2):135-41. · 4.41 Impact Factor
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    ABSTRACT: Ovarian cancer overexpresses ET-1, and in vitro studies have shown that ET-1 confers resistance to anthracycline-containing chemotherapy. Atrasentan has been developed as an oral selective endothelin-A receptor antagonist. The objective of the study was to investigate the feasibility and toxicity of adding increasing doses of atrasentan (to a maximum of 10 mg/d) and liposomal doxorubicin in patients with progressive ovarian cancer, refractory for platinum and paclitaxel. Patients with platinum-resistant ovarian cancer were treated with pegylated liposomal doxorubicin (PLD) 50 mg/m(2) on day 1 (and repeated every 4 weeks) in combination with escalating doses of atrasentan once daily. The starting dose was 2.5 mg and escalated in cohorts of three patients from 5 to 10 mg. Twenty-six patients (mean age = 60 years, range = 42-74 years) were treated at the three dose levels. Atrasentan could be safely administered in combination at a dose of 10 mg. All patients were evaluable for toxicity, and 19 patients, included in the phase 2 period, were evaluable for response. Adverse events included nausea, vomiting, mucositis, skin toxicity, and rhinitis. Clinical cardiac toxicity, intensively monitored, was not observed, although two patients had a decrease in cardiac ejection fraction. Three objective responses were observed and another six patients had stable disease with a median time to progression of 14 weeks and an overall survival of 13.1 months. The addition of atrasentan to standard dose PLD in platinum-resistant ovarian cancer is feasible with some suggestion of prolonged survival.
    Neoplasia (New York, N.Y.) 11/2010; 12(11):941-5. · 5.48 Impact Factor
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    ABSTRACT: To determine, for each of two dosing schedules, the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of AZD1152, an Aurora B kinase inhibitor, and to evaluate its safety, biologic activity and pharmacokinetics (PK). Patients with advanced solid malignancies were treated with escalating doses (100-650 mg) of AZD1152, administered as a 2-h infusion every 7 days (A) or 14 days (B). Adverse events (AEs), PK variables and tumor response were assessed. Fifty-nine patients were treated; 19 in schedule A and 40 in schedule B. The MTDs were 200 and 450 mg, respectively. Neutropenia (with/without fever) was the most frequent AE and DLT in each schedule. Common Terminology Criteria of Adverse Events version 3.0 grade ≥3 neutropenia and leukopenia occurred in 58% and 11% of patients, respectively, in schedule A and 43% and 20%, respectively, in schedule B. No objective tumor responses were observed at any dose or schedule, although stable disease, as defined by RECIST, was achieved in 15 patients (25%) overall. Systemic exposure to AZD1152-hQPA (active drug) was observed by 1 h into the infusion and exhibited linear PK. AZD1152 was generally well tolerated with neutropenia being the most frequently reported AE and DLT. Exposure to AZD1152-hQPA, the active drug of AZD1152, was linear.
    Annals of Oncology 10/2010; 22(2):431-7. · 7.38 Impact Factor
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    ABSTRACT: In preclinical models recruitment of bone-marrow derived (endothelial) progenitor cells (BD(E)PCs) contributes to tumor growth and metastasis formation. Here we investigated whether these (E)PCs and mobilizing cytokines are released after partial hepatectomy or radiofrequency ablation (RFA) for liver tumors. In addition, we tested whether G-CSF could play a role in EPC mobilization in mice and in human volunteers. Patients undergoing partial hepatectomy or RFA showed an instantaneous release of EPCs following laparotomy and mobilization of the liver. Elevated EPC levels were maintained during the entire procedure, but dropped to near-baseline levels 4 h after completion of the procedure. Plasma G-CSF levels showed a 5-10-fold increase after the procedure and low-dose G-CSF administration to mice or healthy volunteers was sufficient to induce an immediate release of EPCs. Surgery also caused an increase in the plasma levels of VEGF, but not SDF-1alpha. Before, during and after liver surgery plasma and mononuclear cells were collected from 12 patients undergoing partial hepatectomy or RFA. To explore the role of G-CSF C57Bl/6 mice and 20 human volunteers received G-CSF (0.3, 3 or 300microg). In all individuals, (E)PC numbers were determined by flow cytometry at predefined timepoints shortly after therapy. Plasma levels of G-CSF, VEGF and SDF-1alpha were measured by ELISA. Compliant with previous published data concerning VDA and chemotherapy treatment, liver surgery induces an instantaneous release of EPCs, conceivably in response to elevated G-CSF levels. This suggests the value of exploring therapeutic avenues to prevent this process.
    Cancer biology & therapy 05/2010; 9(9):743-8. · 3.29 Impact Factor
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    ABSTRACT: We studied the safety and tolerability of telatinib, an orally available, small-molecule tyrosine kinase inhibitor of the vascular endothelial growth factor receptor (VEGFR-2/VEGFR-3), platelet-derived growth factor receptor beta, and c-Kit in combination with capecitabine and irinotecan. Telatinib twice daily continuously, irinotecan once every 3 weeks, and capecitabine oral twice daily on day 1 to 14 were administered in cycles of 21 days in escalating doses in successive cohorts. Toxicity was evaluated to conform to the Common Terminology Criteria for Adverse Events version 3.0. Pharmacokinetic and (circulating) endothelial (progenitor) cell measurements were done. Tumor efficacy was evaluated using the Response Evaluation Criteria in Solid Tumors. Twenty-three patients were included in this phase I trial. Most frequently (>25%) reported adverse events of any grade were vomiting, nausea, fatigue, diarrhea, alopecia, and hand-foot syndrome. A silent myocardial infarction and two cases of decreased left ventricular ejection fraction were reported; both were reversible. Cardiac monitoring of the subsequent patients did not reveal other abnormalities. The study was terminated when the recommended single agent phase II doses of telatinib (900 mg twice daily) and capecitabine/irinotecan was reached. Pharmacokinetic profiles showed no clinically relevant changes upon coadministration of the three drugs. (Circulating) endothelial (progenitor) cell levels stabilized during treatment. Five of 23 patients had partial remission and 9 of 23 patients showed stable disease. Continuous administration of 900 mg telatinib twice daily can be safely combined with irinotecan (180 mg/m(2)) and capecitabine (1,000 mg/m(2) twice daily, day 1-14) and is the recommended schedule for further phase II studies. Tumor shrinkage and disease stabilization was observed. Cardiac toxicity needs further investigation in following studies.
    Clinical Cancer Research 03/2010; 16(7):2187-97. · 7.84 Impact Factor
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    ABSTRACT: Cediranib is a highly potent inhibitor of vascular endothelial growth factor receptor (VEGFR) signalling. Preclinical and clinical data suggest that inhibition of the VEGFR and epidermal growth factor receptor (EGFR) pathways may be synergistic. Combination treatment with cediranib and gefitinib, an EGFR signalling inhibitor, was evaluated in patients with advanced solid tumours. Ninety patients received treatment in this four-part, open-label study (NCT00502060). The patients received once-daily oral doses of cediranib (20-45mg) and gefitinib 250mg (part A1; n=16) or 500mg (part B1; n=44). A cohort expansion phase investigated the potential pharmacokinetic interaction of cediranib 30mg with gefitinib 250mg (part A2; n=15) or 500mg (part B2; n=15). The primary objective was to assess the safety and tolerability of cediranib with gefitinib. Secondary assessments included pharmacokinetics, efficacy and pharmacodynamics. Combination treatment was generally well tolerated; the protocol-defined maximum-tolerated dose of cediranib was 30mg/day with gefitinib 250mg/day (part A1) and cediranib 45mg/day was the maximum dose investigated with gefitinib 500mg/day (part B1). The most common adverse events were diarrhoea (84 [93%]), anorexia (63 [70%]) and fatigue (60 [67%]). Cediranib pharmacokinetic parameters were not substantially different when given alone or in combination with gefitinib. Gefitinib pharmacokinetic parameters were similar to those seen previously with gefitinib monotherapy. Efficacy results included eight (9%) confirmed partial responses (6 renal; 1 lung; 1 osteosarcoma) and 38 (42%) patients with stable disease. Pharmacodynamic assessments demonstrated changes in levels of VEGF and soluble VEGFR-2 following treatment. Combination treatment was generally well tolerated and showed encouraging antitumour activity in patients with advanced solid tumours. These results merit further exploration.
    European journal of cancer (Oxford, England: 1990) 03/2010; 46(5):901-11. · 4.12 Impact Factor
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    ABSTRACT: This study aimed to determine a maximum tolerated dose (MTD) and recommended dose for disease-directed studies of necitumumab (IMC-11F8), a fully human IgG(1) monoclonal antibody directed at the epidermal growth factor receptor, and to characterize the safety profile, pharmacokinetics, preliminary antitumor activity, and immunogenicity of necitumumab. 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. 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 >or=600 mg necitumumab achieved target trough concentrations (>or=40 microg/mL). Antibodies against necitumumab were not detected. Partial response and stable disease were experienced by 2 and 16 patients, respectively. 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.
    Clinical Cancer Research 03/2010; 16(6):1915-23. · 7.84 Impact Factor
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    ABSTRACT: PTK/ZK is a small-molecule inhibitor of all three vascular endothelial growth factor (VEGF) receptors, platelet-derived growth factor receptor, colony-stimulating factor 1 receptor, and cytokine stem cell factor receptor. Cetuximab is a monoclonal antibody against epidermal growth factor (EGF) receptor. Combining inhibition of VEGF and EGF signaling might act additive or synergistically. In phase 1 design, patients with advanced solid tumors were treated with PTK/ZK daily (cohort 1, 750 mg once daily; cohort 2, 1250 mg once daily; cohort 3, 250 mg [morning] and 500 mg [evening]; and cohort 4, 500 mg [morning] and 750 mg [evening]) in combination with cetuximab 250 mg/m(2) weekly in cycles of 28 days in cohorts of three patients. Toxicity was evaluated conform the Common Terminology Criteria for Adverse Events classification 3.0. Pharmacokinetics and pharmacodynamics consisting of circulating endothelial (progenitor) cell (CE[P]C) analysis by flow cytometry were performed. Safety and tolerability was evaluated in 16 patients. The most frequently reported adverse events were acne, dry skin, fatigue, nausea, dizziness, vomiting, headache, and diarrhea. One dose-limiting toxicity occurred in cohort 3 consisting of a grade 3 transaminitis. Pharmacokinetic analysis revealed no significant changes in PTK/ZK exposure on coadministration with cetuximab and in bioavailability at equivalent total daily doses. Biomarker analysis showed no significant change in the number of CE(P)Cs during treatment. One of 14 evaluable patients showed a partial response for at least 11.5 months, and 7 patients (50%) stable disease for at least 2 months. This study shows that the combination of PTK/ZK and cetuximab is well tolerated with only slightly overlapping toxicity profiles and has antitumor activity.
    Neoplasia (New York, N.Y.) 02/2010; 12(2):206-13. · 5.48 Impact Factor

Publication Stats

375 Citations
179.56 Total Impact Points


  • 1995–2014
    • University Medical Center Utrecht
      • Julius Center for Health Sciences and Primary Care
      Utrecht, Utrecht, Netherlands
  • 2007–2012
    • Netherlands Cancer Institute
      • Department of Medical Oncology
      Amsterdamo, North Holland, Netherlands
  • 2010
    • Universiteit Utrecht
      • Department of Pharmaceutical Sciences
      Utrecht, Provincie Utrecht, Netherlands
    • St. Antonius Ziekenhuis
      Nieuwegen, Utrecht, Netherlands