Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Dionysis Papadatos-Pastos is active.

Publication


Featured researches published by Dionysis Papadatos-Pastos.


Radiology | 2012

Advanced Solid Tumors Treated with Cediranib: Comparison of Dynamic Contrast-enhanced MR Imaging and CT as Markers of Vascular Activity

Christina Messiou; Matthew R. Orton; Joo Ern Ang; David J. Collins; Veronica A. Morgan; Dorothy Mears; Isabel Castellano; Dionysis Papadatos-Pastos; Andre Brunetto; Nina Tunariu; Helen Mann; Jean Tessier; Helen Young; Dana Ghiorghiu; Sarah Marley; Stan B. Kaye; Johann De-Bono; Martin O. Leach; Nandita M. deSouza

PURPOSE To assess baseline reproducibility and compare performance of dynamic contrast material-enhanced (DCE) magnetic resonance (MR) imaging versus DCE computed tomographic (CT) measures of early vascular response in the same patients treated with cediranib (30 or 45 mg daily). MATERIALS AND METHODS After institutional review board approval, written informed consent was obtained from 29 patients with advanced solid tumors who had lesions 3 cm or larger and in whom simultaneous imaging of an adjacent artery was possible. Two baseline DCE MR acquisitions and two baseline DCE CT acquisitions 7 days or fewer apart (within 14 days of starting treatment) and two posttreatment acquisitions with each modality at day 7 and 28 (±3 days) were obtained. Nonmodeled and modeled parameters were derived (measured arterial input function [AIF] for CT, population-based AIF for MR imaging; temporal sampling rate of 0.5 second for CT, 3-6 seconds for MR imaging). Baseline variability was assessed by using intra- and intersubject analysis of variance and Bland-Altman analysis; a paired t test assessed change from baseline to after treatment. RESULTS The most reproducible parameters were DCE MR imaging enhancement fraction (baseline intrapatient coefficient of variation [CV]=8.6%), volume transfer constant (CV=13.9%), and integrated area under the contrast agent uptake curve at 60 seconds (CV=15.5%) and DCE CT positive enhancement integral (CV=16.0%). Blood plasma volume was highly variable and the only parameter with CV greater than 30%. Average reductions (percentage change) from baseline were consistently observed for all DCE MR imaging and DCE CT parameters at day 7 and 28 for both starting-dose groups (45 and 30 mg), except for DCE CT mean transit time. Percentage change from baseline for parameters reflecting blood flow and permeability were comparable, and reductions from baseline at day 7 were maintained at day 28. CONCLUSION DCE MR imaging and DCE CT can depict vascular response to antiangiogenic agents with response evident at day 7. Improved reproducibility with MR imaging favors its use in trials with small patient numbers.


Clinical Cancer Research | 2012

A Phase I Pharmacokinetic and Pharmacodynamic Study of CHR-3996, an Oral Class I Selective Histone Deacetylase Inhibitor in Refractory Solid Tumors

Udai Banerji; L. van Doorn; Dionysis Papadatos-Pastos; Rebecca Kristeleit; P. Debnam; M. Tall; Adam Stewart; Florence I. Raynaud; Michelle D. Garrett; M. Toal; L. Hooftman; J. S. De Bono; Jaap Verweij; F. Eskens

Purpose: This clinical trial investigated the safety, tolerability, pharmacokinetic (PK), and pharmacodynamic (PD) profile of CHR-3996, a selective class I histone deacetylase inhibitor. Patients and Methods: CHR-3996 was administered orally once a day. This phase I trial used a 3+3 dose-escalation design. PK profiles were analyzed by liquid chromatography–tandem mass spectroscopic methods and PD studies were conducted using ELISA studying histone H3 acetylation in peripheral blood mononuclear cells. Results: Thirty-nine patients were treated at dose levels of 5 mg (n = 3), 10 mg (n = 4), 20 mg (n = 3), 40 mg (n = 10), 80 mg (n = 10), 120 mg (n = 4), and 160 mg (n = 5) administered orally once daily. The dose-limiting toxicities seen were thrombocytopenia (160 mg), fatigue (80 and 120 mg), plasma creatinine elevation (80 and 120 mg), and atrial fibrillation (40 mg). The area under the curve was proportional to the administered dose and a maximal plasma concentration of 259 ng/mL at a dose of 40 mg exceeded the concentrations required for antitumor efficacy in preclinical models. Target inhibition measured by quantification of histone acetylation was shown at doses of 10 mg/d and was maximal at 40 mg. A partial response was seen in one patient with metastatic acinar pancreatic carcinoma. Conclusions: Taking the toxicity and PK/PD profile into consideration, the recommended phase II dose (RP2D) is 40 mg/d. At this dose, CHR-3996 has a favorable toxicologic, PK, and PD profile. CHR-3996 has shown preliminary clinical activity and should be evaluated in further clinical trials. Clin Cancer Res; 18(9); 2687–94. ©2012 AACR.


Clinical Cancer Research | 2011

Baseline Circulating Tumor Cell Counts Significantly Enhance a Prognostic Score for Patients Participating in Phase I Oncology Trials

David Olmos; Richard D. Baird; Timothy A. Yap; Christophe Massard; Lorna Pope; Shahneen Sandhu; Gerhardt Attard; Juliet P. Dukes; Dionysis Papadatos-Pastos; Philippa Grainger; Stan B. Kaye; Johann S. de Bono

Background: High circulating tumor cell (CTC) counts are associated with poor prognosis in several cancers. Enrollment of patients on phase I oncology trials requires a careful assessment of the potential risks and benefits. Many patients enrolled on such trials using established eligibility criteria have a short life expectancy and are less likely to benefit from trial participation. We hypothesized that the incorporation of CTC counts might improve patient selection for phase I trials. Methods: This retrospective analysis evaluated patients who had baseline CTCs enumerated prior to their starting on a phase I trial. CTCs were enumerated using the CellSearch System. Results: Between January 2006 and December 2009 a total of 128 patients enrolled in phase I trials had CTC counts evaluated. Higher CTC counts as a continuous variable independently correlated with risk of death in this patient population (P = 0.006). A multivariate point-based risk model was generated using CTCs as a dichotomous variable (≥3 or <3), and incorporated other established prognostic factors, including albumin <35 g/L, lactate dehydrogenase greater than upper limit of normal, and >2 metastatic sites. Comparison of receiver operating characteristic curves demonstrated that the addition of baseline CTC counts improved the performance of the prospectively validated Royal Marsden Hospital phase I prognostic score, which now identifies three risk groups (P < 0.0001): good prognosis [score 0–1, median overall survival (OS) 63.7 weeks], intermediate prognosis (score 2–3, median OS 37.3 weeks), and poor prognosis (score 4, median OS 13.4 weeks). Conclusion: CTC enumeration improved the performance of a validated prognostic score to help select patients for phase I oncology trials. Clin Cancer Res; 17(15); 5188–96. ©2011 AACR.


Oncologist | 2011

Revisiting the Role of Antiandrogen Strategies in Ovarian Cancer

Dionysis Papadatos-Pastos; Konstantin J. Dedes; Johann S. de Bono; Stanley B. Kaye

Androgen receptors are frequently expressed in epithelial ovarian cancer (EOC). Their role in the development of EOC is not fully understood. In the present review we first discuss the epidemiological data linking a hyperandrogen state to a higher risk for ovarian cancer, second describe in vitro studies of the role of androgens in influencing the growth of EOC, and finally review the completed clinical trials with compounds that exploit the androgen axis in patients with ovarian cancer. The therapeutic approaches that inhibit androgen signaling have so far produced only modest response rates. In the light of new data regarding the role of androgen stimulation in the evolution of EOC and the emergence of new compounds used for the treatment of other hormone-driven malignancies, such as prostate and breast cancer, we provide suggestions for new studies of antiandrogen therapeutics in the treatment of EOC. A specific example is the new agent abiraterone. In addition, we propose a panel of molecules that could be assessed as potential biomarkers that may aid patient selection for this approach in the future.


Journal of Neuro-oncology | 2011

Revisiting the role of molecular targeted therapies in patients with brain metastases

Dionysis Papadatos-Pastos; Udai Banerji

Brain metastases (BM) are treated with surgical resection when feasible. Unfortunately this occurs only in a small subset of patients. The optimal treatment for patients with intracranial metastases non amenable to surgical resection has not been identified. Radiotherapy improves symptom control and survival but long-term local control has been poor. Conventional chemotherapies have generally produced disappointing results possibly due to their limited ability to penetrate the blood brain barrier. Therefore, newer treatments are required for patients with unresectable BM. Targeted therapies such as bevacizumab, erlotinib, gefitinib, sunitinib and sorafenib, are all licensed and have demonstrated improved survival in patients with metastatic disease. In this review we will present current data on targeted therapies that have been approved for the treatment of malignant tumours and we discuss the evidence of their use in patients with BM.


British Journal of Cancer | 2010

A retrospective analysis of clinical outcome of patients with chemo-refractory metastatic breast cancer treated in a single institution phase I unit

Andre T. Brunetto; Debashis Sarker; Dionysis Papadatos-Pastos; Rudolf S. N. Fehrmann; Stan B. Kaye; Stephen R. D. Johnston; M. Allen; J. S. De Bono; Charles Swanton

Background and methods:Novel approaches to treat chemo-refractory metastatic breast cancer (MBC) are currently under investigation. This retrospective series reviews the outcome of 70 MBC patients who have participated in 30 phase I trials at the Royal Marsden Hospital from 2002 to 2009.Results:The median treatment lines before phase I trial entry for MBC was 5 (range: 1–12 lines). The overall response rate was 11.4% (95% CI: 4.0–18.9%) and the clinical benefit rate at 4 months was 20% (95% CI: 10.6–29.3). The median time to progression was 7.0 weeks (95% CI: 6.4–7.5) and median overall survival was 8.7 months (95% CI: 7.6–9.8) from start of first phase I treatment. No patients discontinued trial because of treatment-related toxicities. Abnormal lactate dehydrogenase, serum albumin <35 mg  per 100 ml, ⩾5 previous treatment lines, liver metastases and Eastern Cooperative Group performance status ⩾2 at study entry were significantly associated with poor overall survival in multivariate analysis.Conclusion:This retrospective analysis provides evidence that patients with MBC tolerate phase I clinical trials and a significant proportion of patients with chemo-refractory disease, particularly those with triple-negative or Her2-positive breast cancer, may benefit from treatment.


Cancer Research | 2016

Abstract CT012: Phase 1 trial of first-in-class ATR inhibitor VX-970 in combination with cisplatin (Cis) in patients (pts) with advanced solid tumors (NCT02157792):

Geoffrey I. Shapiro; Robert Wesolowski; Mark R. Middleton; Craig Devoe; Anastasia Constantinidou; Dionysis Papadatos-Pastos; Marjorie Fricano; Yanqiong Zhang; Sharon Karan; John Pollard; Marina Penney; Mohammed Asmal; F. Gary Renshaw; Scott Z. Fields; Timothy A. Yap

Background: ATR is a regulator of the cellular response to replication stress, where it signals DNA damage repair through the homologous recombination pathway. Many cancer cells depend on ATR to survive DNA damage. VX-970 is a potent, selective inhibitor of ATR with marked preclinical anticancer activity in combination with DNA-damaging chemotherapy in preclinical models. Methods: Pts received intravenous VX-970 in combination with Cis using a 3+3 dose escalation design. Cis was administered on day 1 and VX-970 on days 2 and 9 in 21-day cycles. Results: 28 pts were treated (12 M/16 F); median age 62.5 yrs (range 28-79 yrs) and ECOG PS 0-1. Primary tumors were colorectal (n = 5), breast (n = 4), ovarian (n = 3), pancreatic (n = 2), and other cancers (n = 14). Non-DLT grade 3-4 treatment-related adverse events occurred in 11 pts, including nausea, cytopenias, hypotension, hypoalbuminemia, hypokalemia, elevated LFTs, and drug hypersensitivity. Maximum tolerated combination dose was not reached; dose escalation was stopped because pharmacokinetic (PK) exposures of VX-970 at 140 mg/m2 exceeded levels previously shown in preclinical models to result in robust target engagement and tumor regression in combination with Cis. There was no effect of Cis on VX-970 PK. Terminal elimination half-life was ?16h and PK was proportional across the dose range. Among pts who received VX-970 at 140 mg/m2 with Cis, preliminary results showed RECIST partial responses in 4 pts: 3 platinum-resistant/refractory (mesothelioma, ovarian and TNBC) and 1 ongoing unconfirmed response in a pt in which platinum sensitivity is currently unknown (neuroendocrine prostate cancer). Conclusions: The recommended phase 2 dose is VX-970 140 mg/m2 and Cis 75 mg/m2 with RECIST antitumor responses observed including platinum-refractory/resistant pts. Combination studies involving pts with biomarker-defined NSCLC (gemcitabine) and TNBC (platinum) are ongoing. Citation Format: Geoffrey Shapiro, Robert Wesolowski, Mark Middleton, Craig Devoe, Anastasia Constantinidou, Dionysis Papadatos-Pastos, Marjorie Fricano, Yanqiong Zhang, Sharon Karan, John Pollard, Marina Penney, Mohammed Asmal, F. Gary Renshaw, Scott Z. Fields, Timothy A. Yap. Phase 1 trial of first-in-class ATR inhibitor VX-970 in combination with cisplatin (Cis) in patients (pts) with advanced solid tumors (NCT02157792). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT012.


Molecular Cancer Therapeutics | 2015

Abstract PR14: Phase I trial of first-in-class ataxia telangiectasia-mutated and Rad3-related (ATR) inhibitor VX-970 as monotherapy (mono) or in combination with carboplatin (CP) in advanced cancer patients (pts) with preliminary evidence of target modulation and antitumor activity

Timothy A. Yap; Maria Jose de Miguel Luken; Brent O'Carrigan; Desam Roda; Dionysis Papadatos-Pastos; David Lorente; Nina Tunariu; Raquel Perez Lopez; Sasha Gayle; Ruth Riisnaes; Ines Figueiredo; Susana Miranda; Suzanne Carreira; Fang Yang; Sharon Karan; Marina Penney; John Pollard; L. Rhoda Molife; Udai Banerji; Mohammed Asmal; Scott Z. Fields; Johann S. de Bono

Background: ATR mediates the homologous recombination DNA repair pathway and cellular response to replication stress. VX-970 is a potent and selective inhibitor of ATR (Ki Methods: Pts with advanced solid tumors enrolled in 2 sequential parts. Part A: pts received IV VX-970 mono weekly in single-pt cohorts, with 3+3 cohorts initiated if grade (G) ≥2 VX-970-related adverse events (AEs) were observed. Part B: pts received CP on day 1 and VX-970 on days 2 and 9 of a 21-day cycle in a 3+3 dose-escalation design. Paired VX-970 tumor biopsies were obtained in selected CP treated pts pre- and post-VX-970, and pS345 Chk1 levels assessed by IHC. Results: 25 pts were treated; M/F 10/15; median age 67 yr (range 49-76 yr); ECOG PS 0/1: 11/14. In Part A, 11 pts (colorectal [CRC; n = 2]; mesothelioma [n = 2]; other [n = 7]; median prior lines of therapy = 3) received VX-970 at 60 mg/m2 (n = 1), 120 mg/m2 (n = 2), 240 mg/m2 (n = 1) and 480 mg/m2 (n = 7). In Part B, 14 pts (CRC [n = 6]; ovarian [n = 2]; other [n = 6]; median prior lines of therapy = 3) received VX-970 240 mg/m2 + CP AUC5 (n = 3; dose level 1 [DL1]), VX-970 120 mg/m2 + CP AUC5 (n = 3; DL2), VX-970 120 mg/m2 + CP AUC4 (n = 3; DL3) and VX-970 90 mg/m2 + CP AUC5 (n = 5; DL4). In Part A, no dose-limiting toxicities (DLT) or drug-related G3-4 AEs were seen. In Part B, 2 pts had DLT: G4 neutropenia and fever (n = 1; DL1) and G3 hypersensitivity (n = 1; DL2). Non-DLT G3-4 AEs were neutropenia (n = 4; DL1-2) and thrombocytopenia (n = 1; DL2) requiring dose delays. No G3-4 AEs were seen at DL3-4. RP2D cohort expansion is ongoing at DL4. VX-970 displayed linear AUC and Cmax at all DLs; median half-life was 16h with no accumulation. Based on preclinical models, efficacious exposures were achieved. When combined with CP, DL1 and DL2 showed similar VX-970 exposure, suggesting no apparent drug interactions. Decreased Chk1 phosphorylation was seen in 2/2 paired tumor biopsies (74% at DL4; 94% at DL2). An advanced CRC pt (serosal disease and abdominal lymphadenopathy; 3 prior lines of chemotherapy) with complete ATM loss by IHC achieved RECIST complete response to VX-970 mono at 60 mg/m2 and remains on trial at 59+ wks. RECIST stable disease (SD) was seen with VX-970 mono in 4 pts (median duration of SD = 11 wks [11-17.4 wks]) and VX-970 + CP in 7 pts, who were still ongoing (duration of SD = 5+ to 20+ wks), including several pts who had progressed on prior platinum therapy. Conclusion: VX-970 is well tolerated as monotherapy and in combination with CP, with preliminary evidence of target modulation and antitumor activity. VX-970 will be further explored in early phase II studies; in multiple tumor types, including triple-negative breast cancer and non-small cell lung cancer; and in patients with DDR aberrations. Citation Format: Timothy A. Yap, Maria J. de Miguel Luken, Brent O9Carrigan, Desam Roda, Dionysis Papadatos-Pastos, David Lorente, Nina Tunariu, Raquel Perez Lopez, Sasha Gayle, Ruth Riisnaes, Ines Figueiredo, Susana Miranda, Suzanne Carreira, Fang Yang, Sharon Karan, Marina Penney, John Pollard, L. Rhoda Molife, Udai Banerji, Mohammed Asmal, Scott Z. Fields, Johann S. de Bono. Phase I trial of first-in-class ataxia telangiectasia-mutated and Rad3-related (ATR) inhibitor VX-970 as monotherapy (mono) or in combination with carboplatin (CP) in advanced cancer patients (pts) with preliminary evidence of target modulation and antitumor activity. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr PR14.


Oncology | 2011

Outcomes of patients with metastatic melanoma treated with molecularly targeted agents in phase I clinical trials.

Montserrat Blanco Codesido; Andre T. Brunetto; Sophia Frentzas; Victor Moreno Garcia; Dionysis Papadatos-Pastos; Joanna Vitfell Pedersen; Leonardo Trani; M. Puglisi; L. Rhoda Molife; Udai Banerji

Introduction: First-line treatment options utilizing chemotherapy and cytokine-based treatments for patients with metastatic melanoma (MM) are unsatisfactory. We analyzed the clinical outcomes of patients with MM treated in phase I trials of novel agents. We hypothesized that patients included in phase I clinical trials did not have worse outcomes than with the chemotherapy and cytokine-based first-line treatment. Methods: Data of patients with MM treated at The Drug Development Unit between 2004 and 2010 were collected. The response rate (RR) and time to progression (TTP) for first-line therapy were compared to those of phase I trial therapy. Patients acted as their own controls for statistical analyses. Results: Sixty-five patients were treated in 31 phase I trials. First-line treatment included dacarbazine or temozolomide in 58 (89%) cases and interferon-α in 5 patients (8%) and cisplatin-based treatment in 2 patients (3%). There was no significant difference in either the RR (11 vs. 14%, p = 0.87) or TTP (90 vs. 53 days, p = 0.15) in patients treated with first-line treatment versus phase I treatment, respectively. Conclusion: Phase I clinical trials of molecularly targeted agents show clinical activity that is not dissimilar to that of treatment with existing chemotherapy and cytokine-based treatment.


British Journal of Cancer | 2018

Target-based therapeutic matching of phase I trials in patients with metastatic breast cancer in a tertiary referral centre

Brent O’Carrigan; Joline Si Jing Lim; Awais Jalil; Samuel John Harris; Dionysis Papadatos-Pastos; Udai Banerji; Juanita Lopez; Johann S. de Bono; Timothy A. Yap

BackgroundGreater understanding of the molecular classification of breast cancer has permitted the development of rational drug design strategies. In a phase I clinical trial setting, molecular profiling with next-generation sequencing of individual tumour samples has been employed to guide treatment.MethodsWe conducted a retrospective evaluation of clinical outcomes of patients with metastatic breast cancer (MBC) treated in phase I clinical trials at our institution to assess the benefit of molecularly matched compared to non-matched treatments.ResultsA total of 97 consecutive patients with MBC were enrolled onto ≥1 trial between 2009 and 2015. Fourteen patients participated in multiple trials, and a total of 113 trial encounters were reviewed in this retrospective study. Eighty-three percent of patients with molecular data available were able to participate in trials matched to molecular aberrations. Patients who were treated on matched studies had improved clinical benefit (RR: 1.80, p = 0.005), progression-free (HR: 0.52, p = 0.003) and overall survival (HR: 0.54, p < 0.001). Treatment was well tolerated with low rates of treatment discontinuation for toxicity (8% overall) that did not differ between groups. No toxicity-related deaths were observed.ConclusionsMolecular profiling for MBC patients in a phase I setting is feasible and aids therapeutic decisions with improved patient outcomes.

Collaboration


Dive into the Dionysis Papadatos-Pastos's collaboration.

Top Co-Authors

Avatar

Udai Banerji

Institute of Cancer Research

View shared research outputs
Top Co-Authors

Avatar

Timothy A. Yap

University of Texas MD Anderson Cancer Center

View shared research outputs
Top Co-Authors

Avatar

Johann S. de Bono

The Royal Marsden NHS Foundation Trust

View shared research outputs
Top Co-Authors

Avatar

Andre T. Brunetto

The Royal Marsden NHS Foundation Trust

View shared research outputs
Top Co-Authors

Avatar

J. S. De Bono

Institute of Cancer Research

View shared research outputs
Top Co-Authors

Avatar

L. Rhoda Molife

The Royal Marsden NHS Foundation Trust

View shared research outputs
Top Co-Authors

Avatar

Stan B. Kaye

The Royal Marsden NHS Foundation Trust

View shared research outputs
Top Co-Authors

Avatar

Awais Jalil

Institute of Cancer Research

View shared research outputs
Top Co-Authors

Avatar

David Olmos

Institute of Cancer Research

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge