Obrador, Gregorio
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Obrador, Gregorio
Official Name
Tomás Obrador Vera, Gregorio
Alternative Name
gobrador
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ORCID
Scopus Author ID
6602806471
Researcher ID
B-3054-2011

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Regional Variation of Erythropoiesis-Stimulating Agent Hyporesponsiveness in the Global Daprodustat Dialysis Study (ASCEND-D)

2023 , Macdougall, Iain C. , Meadowcroft, Amy M. , Blackorby, Allison , Cizman, Borut , Cobitz, Alexander R. , Godoy, Sergio , Jha, Vivekanand , Johansen, Kirsten L. , McMahon, Gearoid , Obrador, Gregorio , Wong, Muh Geot , Singh, Ajay K.

Introduction: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) affects 10-15% of the chronic dialysis population. We explored baseline characteristics and predictors of ESA hyporesponsiveness in a global randomized cardiovascular outcomes study comparing an investigational hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI), daprodustat, with conventional ESA treatment. Methods: ASCEND-D (NCT02879305) recruited 2,964 chronic dialysis patients receiving ESA treatment (standardized to weekly intravenous [IV] epoetin) who were iron replete at baseline. The primary ESA hyporesponsiveness definition was an ESA Resistance Index (ERI, ESA units/kg/week/hemoglobin g/L) ≥2 or IV standardized ESA dose ≥450 units/kg/week. Predictors of ESA hyporesponsiveness were determined using a multivariable regression model. Alternative hyporesponder definitions were explored. The Author(s). Published by S. Karger AG, Basel.

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Study design and baseline characteristics of patients on dialysis in the ASCEND-D trial

2021 , Singh, Ajay K. , Blackorby, Allison , Cizman, Borut , Carroll, Kevin , Cobitz, Alexander R. , Davies, Rich , Jha, Vivekanand , Johansen, Kirsten L. , Lopes, Renato D. , Kler, Lata , Macdougall, Iain C. , McMurray, John J. V. , Meadowcroft, Amy M. , Obrador, Gregorio , Perkovic, Vlado , Solomon, Scott , Wanner, Christoph , Waikar, Sushrut S. , Wheeler, David C. , Wiecek, Andrzej

Background: The Anemia Studies in chronic kidney disease (CKD): Erythropoiesis via a Novel prolyl hydroxylase inhibitor Daprodustat-Dialysis (ASCEND-D) trial will test the hypothesis that daprodustat is noninferior to comparator epoetin alfa or darbepoetin alfa for two co-primary endpoints: hemoglobin (Hb) efficacy and cardiovascular (CV) safety. Methods: We report the trial design, key demographic, clinical and laboratory findings, and baseline therapies of 2964 patients randomized in the open-label (sponsor-blinded) active-controlled, parallel-group, randomized ASCEND-D clinical trial. We also compare baseline characteristics of ASCEND-D patients with patients who are on dialysis (CKD G5D) enrolled in other large CV outcome trials (CVOTs) and in the most relevant registries. © The Author(s) 2021. Published by Oxford University Press on behalf of the ERA-EDTA.

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Associations of Haemoglobin Values and Rate of Changes With MACE in the ASCEND-ND Randomised Clinical Trial

2022 , Singh, Ajay K. , Macdougall, Iain C. , Johansen, Kirsten , Jha, Vivekanand , Correa-Rotter, Ricardo , Del Vecchio, Lucia , Cases Amenos, Aleix , Robertson, Michele , Mallett, Steve , Bailey, Christine K. , Cobitz, Alexander , Obrador, Gregorio

Background and aims: Rapid changes in haemoglobin (Hb) following treatment with erythropoiesis-stimulating agents (ESAs) in patients with anaemia of chronic kidney disease (CKD) have been suggested to be associated with adverse outcomes [1–3]. This exploratory post-hoc analysis was performed to investigate the association between absolute Hb values or Hb changes over a 4-week period and the occurrence of first adjudicated major adverse cardiovascular event (MACE) in CKD patients not on dialysis who were treated with either daprodustat or darbepoetin. Method: ASCEND-ND was an event driven, cardiovascular outcomes trial conducted in over 30 countries that randomized 3872 CKD patients not on dialysis with baseline Hb of 8–10 g/dL if not on a prior ESA, or 8–11 g/dL if receiving an ESA, to receive either oral, once-daily daprodustat (1937 patients) or subcutaneous darbepoetin (1935 patients). Available doses were daprodustat 1–24 mg once-daily and darbepoetin 20–400 µg total 4-weekly dose. The study was recently reported to have met the co-primary endpoints of non-inferiority for first occurrence of adjudicated MACE and mean Hb change from baseline to weeks 28 through 52 [4]. MACE was a composite of death from any cause, non-fatal myocardial infarction or non-fatal stroke, and events were adjudicated by an independent clinical events committee blinded to treatment assignment. In this exploratory post-hoc analysis, we examined the associations of post-randomization absolute Hb values and Hb changes categorized into quintiles (see Table 1) with first adjudicated MACE. Each patient's time in the study, prior to a first MACE or end of follow-up, was divided into distinct 4-week intervals, with each interval associated with a particular post-randomization Hb value and rate of change. Separately for each treatment group, these 4-week periods were grouped according to quintiles of Hb values, and MACE rates were calculated for each quintile. This analysis was repeated using quintiles derived from Hb rate of decrease and increase. MACEs that occurred prior to Week 4, the first scheduled post-randomization Hb collection, were not included in the analysis. Copyright © Oxford University Press

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The ASCEND-ND trial: study design and participant characteristics

2021 , Perkovic, Vlado , Blackorby, Allison , Cizman, Borut , Carroll, Kevin , Cobitz, Alexander R. , Davies, Rich , DiMino, Tara L. , Jha, Vivekanand , Johansen, Kirsten L. , Lopes, Renato D. , Kler, Lata , Macdougall, Iain C. , McMurray, John J. V. , Meadowcroft, Amy M. , Obrador, Gregorio , Solomon, Scott , Taft, Lin , Wanner, Christoph , Waikar, Sushrut S. , Wheeler, David C. , Wiecek, Andrzej , Singh, Ajay K.

Background: Anaemia is common in chronic kidney disease (CKD) and assessment of the risks and benefits of new therapies is important. Methods: The Anaemia Study in CKD: Erythropoiesis via a Novel prolyl hydroxylase inhibitor Daprodustat-Non-Dialysis (ASCEND-ND) trial includes adult patients with CKD Stages 3-5, not using erythropoiesis-stimulating agents (ESAs) with screening haemoglobin (Hb) 8-10 g/dL or receiving ESAs with screening Hb of 8-12 g/dL. Participants were randomized to daprodustat or darbepoetin alfa (1:1) in an open-label trial (steering committee- and sponsor-blinded), with blinded endpoint assessment. The co-primary endpoints are mean change in Hb between baseline and evaluation period (average over Weeks 28-52) and time to first adjudicated major adverse cardiovascular (CV) event. Baseline characteristics were compared with those of participants in similar anaemia trials. © The Author(s) 2021. Published by Oxford University Press on behalf of the ERA.

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Kidney disease: Improving global outcomes (KDIGO) anemia work group. KDIGO clinical practice guideline for anemia in chronic kidney disease

2012 , McMurray, John J. V. , Parfrey, Patrick S. , Adamson, John W. , Aljama, Pedro , Berns, Jeffrey S. , Bohlius, Julia , Drüeke, Tilman B. , Finkelstein, Fredric O. , Fishbane, Steven , Ganz, Tomas , Macdougall, Iain C. , McDonald, Ruth A. , McMahon, Lawrence P. , Obrador, Gregorio , Strippoli, Giovanni F. M . , Weiss, Günter , Wiecek, Andrzej

The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline for Anemia in Chronic Kidney Disease aims to provide guidance on diagnosis, evaluation, management and treatment for all CKD patients (non-dialysis, dialysis, kidney transplant recipients and children) at risk of or with anemia. Guideline development followed an explicit process of evidence review and appraisal. The guideline contains chapters addressing diagnosis and evaluation of anemia in CKD and the use of various therapeutic agents (iron, ESAs and other agents) and red cell transfusion as means of treatment. Treatment approaches are addressed in each chapter and guideline recommendations are based on systematic reviews of relevant trials. Appraisal of the quality of the evidence and the strength of recommendations followed the GRADE approach. Ongoing areas of controversies and limitations of the evidence are discussed and additional suggestions are also provided for future research.

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How important is transfusion avoidance in 2013?

2013 , Macdougall, Iain C. , Obrador, Gregorio

Prior to the advent of recombinant erythropoietin in the late-1980s, blood transfusions were the mainstay of anaemia management in patients with end-stage renal failure, many of whom required “top-up” transfusions every 2 to 4 weeks to relieve the debilitating symptoms of severe anaemia. Erythropoietin therapy, however, allowed for the first time, such patients to achieve a sustained correction of anaemia, and there was a dramatic fall in both the use of red cell transfusions in dialysis units, as well as the associated transfusional iron overload prevalent in dialysis patients. Avoidance of blood transfusions improved access to, and outcomes of, kidney transplantation, due to reduced HLA sensitization. In recent years, however, there have been safety concerns regarding the use of erythropoiesis-stimulating agents (ESAs), and there are signs that the use of blood transfusions is once again increasing. The aim of this review is to reassess how important transfusion avoidance is in 2013, and whether we should still have the same concerns about HLA sensitization that we had 20 years ago. ©Nephrology Dialysis Transplantation.

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Daprodustat for the Treatment of Anemia in Patients Undergoing Dialysis

2021 , Singh, Ajay K. , Carroll, Kevin , Perkovic, Vlado , Solomon, Scott , Jha, Vivekanand , Johansen, Kirsten L. , Lopes, Renato D. , Macdougall, Iain C. , Obrador, Gregorio , Waikar, Sushrut S. , Wanner, Christoph , Wheeler, David C. , Wiecek, Andrzej , Blackorby, Allison , Cizman, Borut , Cobitz, Alexander R. , Davies, Rich , Dole, Jo , Kler, Lata , Meadowcroft, Amy M. , Zhu, Xinyi , McMurray, John J. V.

Background: Among patients with chronic kidney disease (CKD), the use of recombinant human erythropoietin and its derivatives for the treatment of anemia has been linked to a possibly increased risk of stroke, myocardial infarction, and other adverse events. Several trials have suggested that hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors (PHIs) are as effective as erythropoiesis-stimulating agents (ESAs) in increasing hemoglobin levels. Methods: In this randomized, open-label, phase 3 trial, we assigned patients with CKD who were undergoing dialysis and who had a hemoglobin level of 8.0 to 11.5 g per deciliter to receive an oral HIF-PHI (daprodustat) or an injectable ESA (epoetin alfa if they were receiving hemodialysis or darbepoetin alfa if they were receiving peritoneal dialysis). The two primary outcomes were the mean change in the hemoglobin level from baseline to weeks 28 through 52 (noninferiority margin, −0.75 g per deciliter) and the first occurrence of a major adverse cardiovascular event (a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke), with a noninferiority margin of 1.25. Copyright © Massachusetts Medical Society.

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Daprodustat for the Treatment of Anemia in Patients Not Undergoing Dialysis

2021 , Singh, Ajay K. , Carroll, Kevin , McMurray, John J. V. , Solomon, Scott , Jha, Vivekanand , Johansen, Kirsten L. , Lopes, Renato D. , Macdougall, Iain C. , Obrador, Gregorio , Waikar, Sushrut S. , Wanner, Christoph , Wheeler, David C. , Więcek, Andrzej , Blackorby, Allison , Cizman, Borut , Cobitz, Alexander R. , Davies, Rich , DiMino, Tara L. , Kler, Lata , Meadowcroft, Amy M. , Taft, Lin , Perkovic, Vlado

Background: Daprodustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor. In patients with chronic kidney disease (CKD) who are not undergoing dialysis, the efficacy and safety of daprodustat, as compared with the conventional erythropoiesis-stimulating agent darbepoetin alfa, are unknown. Methods: In this randomized, open-label, phase 3 trial with blinded adjudication of cardiovascular outcomes, we compared daprodustat with darbepoetin alfa for the treatment of anemia in patients with CKD who were not undergoing dialysis. The primary outcomes were the mean change in the hemoglobin level from baseline to weeks 28 through 52 and the first occurrence of a major adverse cardiovascular event (MACE; a composite of death from any cause, nonfatal myocardial infarction, or nonfatal stroke). Copyright © 2021 Massachusetts Medical Society.

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The ASCEND-NHQ randomized trial found positive effects of daprodustat on hemoglobin and quality of life in patients with non-dialysis chronic kidney disease

2023 , Johansen, Kirsten L. , Cobitz, Alexander R. , Singh, Ajay K. , Macdougall, Iain C. , Lopes, Renato D. , Obrador, Gregorio , Kovesdy, Csaba P. , Israni, Rubeen , Jha, Vivekanand , Okoro, Tony , Sprys, Mike , Jolly, Shivinder , Lindsay, Alistair C. , Bhatt, Purav , Refoios Camejo, Rodrigo , Keeley, Tom , Cizman, Borut , Wheeler, David C.

The ASCEND-NHQ trial evaluated the effects of daprodustat on hemoglobin and the Medical Outcomes Study 36-item Short Form Survey (SF-36) Vitality score (fatigue) in a multicenter, randomized, double-blind, placebo-controlled trial. Adults with chronic kidney disease (CKD) stages 3-5, hemoglobin 8.5-10.0 g/dl, transferrin saturation 15% or more, and ferritin 50 ng/ml or more without recent erythropoiesis-stimulating agent use were randomized (1:1) to oral daprodustat or placebo to achieve and maintain target hemoglobin of 11-12 g/dl over 28 weeks. The primary endpoint was the mean change in hemoglobin between baseline and the evaluation period (Weeks 24-28). Principal secondary endpoints were proportion of participants with a 1 g/dl or more increase in hemoglobin and mean change in the Vitality score between baseline and Week 28. Outcome superiority was tested (1-sided alpha level of 0.025). Overall, 614 participants with non-dialysis-dependent CKD were randomized. The adjusted mean change in hemoglobin from baseline to the evaluation period was greater with daprodustat (1.58 vs 0.19 g/dl). The adjusted mean treatment difference (AMD) was significant at 1.40 g/dl (95% confidence interval 1.23, 1.56). A significantly greater proportion of participants receiving daprodustat showed a 1 g/dl or greater increase in hemoglobin from baseline (77% vs 18%). The mean SF-36 Vitality score increased by 7.3 and 1.9 points with daprodustat and placebo, respectively; a clinically and statistically significant 5.4 point Week 28 AMD increase. Adverse event rates were similar (69% vs 71%); relative risk 0.98, (95% confidence interval 0.88, 1.09). Thus, in participants with CKD stages 3-5, daprodustat resulted in a significant increase in hemoglobin and improvement in fatigue without an increase in the overall frequency of adverse events. Copyright © 2023 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

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Effect of Red Cell Transfusions on Future Kidney Transplantation

2013 , Obrador, Gregorio , Macdougall, Iain C.

Red cell transfusions, erythropoiesis-stimulating agents (ESAs), and intravenous iron therapy all have a place in the treatment of anemia associated with CKD. Their relative merits and uses are subject to many clinical and nonclinical factors. New concerns associated with the use of ESA therapy make it likely that the use of blood transfusions will increase, refueling previous debates about their associated risks. Data on whether red cell transfusions increase sensitization to HLA antigens, rendering subsequent transplantation more problematic, are mainly derived from older literature. Older data suggested that women were more at risk of HLA sensitization than men, particularly those with previous multiple pregnancies, although recent U.S. Renal Data System data have challenged this. HLA sensitization prolongs the waiting time for transplantation and reduces graft survival. Leukocyte depletion of red cells does not appear to reduce the risk of HLA sensitization. This review summarizes much of the data on these issues, as well as highlighting the need for further research on the potential risks for blood transfusion in patients with CKD. © Clinical Journal of the American Society of Nephrology

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