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Young G, Callaghan MU, Balasa V, Soni A, Ahuja S, Roberts JC, Simpson ML, Kizilocak H, Frick A, Mokdad AG, Xing S, Caicedo J. Effects of PK-guided prophylaxis on clinical outcomes and FVIII consumption for patients with moderate to severe Haemophilia A. Haemophilia 2023; 29:1234-1242. [PMID: 37553998 DOI: 10.1111/hae.14826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 08/10/2023]
Abstract
INTRODUCTION In recent years, there has been increased focus on individualizing treatment for persons with hemophilia including pharmacokinetic-guided (PK) dosing. AIMS In this retrospective study clinical outcomes before and after PK-guided prophylaxis were examined. MATERIALS AND METHODS Eight Haemophilia Treatment Centres from the United States participated in the study and included 132 patients classified into two cohorts: those undergoing a PK-assessment for product switch (switchers) or to optimize treatment (non-switchers). Subset analyses for the two most common products and patients with dosing per prescription label were included for annual bleeding rates (ABR), mean weekly consumption outcomes, and annualized cost of prophylaxis. RESULTS The most common products before and after index date were octocog alfa, rurioctocog alfa pegol, and efmoroctocog alfa. Seventy-four (56%) patients were identified as switchers and 58 (44%) patients were classified as non-switchers. The majority of patients (78.0%) experienced either a decrease in ABR post-index or maintained 0 ABR during pre- and post-index time periods, with similar proportions identified in both switchers (77.0%) and non-switchers (79.3%) populations. Non-switchers were identified as having no significant change in cost of therapy, while switchers experienced increased cost of therapy driven by higher price of extended half-life products. Within subset analyses, patients receiving rurioctocog alfa pegol and efmoroctocog alfa had mean ABR under 1 after index date. CONCLUSION PK-guided prophylaxis has the potential to improve clinical outcomes without increase in cost of therapy for patients maintaining product and can aid in maintaining effective protection against bleeds in those switching product.
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Affiliation(s)
- Guy Young
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | | | - Vinod Balasa
- Hemotology/Oncology, Valley Children's Healthcare, Madera, California, USA
| | - Amit Soni
- Center for Inherited Blood Disorders, Orange, California, USA
| | - Sanjay Ahuja
- UH Rainbow Babies and Children's Hospital, Cleveland, Ohio, USA
| | | | | | - Hande Kizilocak
- Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, California, USA
| | | | - Ali G Mokdad
- Takeda Pharmaceuticals U.S.A, 95 Hayden Ave, Cambridge, Massachusetts, USA
| | - Shan Xing
- Takeda Pharmaceuticals U.S.A, 95 Hayden Ave, Cambridge, Massachusetts, USA
| | - Jorge Caicedo
- Takeda Pharmaceuticals U.S.A, 95 Hayden Ave, Cambridge, Massachusetts, USA
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Kizilocak H, Guerrera MF, Young G. Neutralizing antidrug antibody to emicizumab in patients with severe hemophilia A: Case report of a first noninhibitor patient and review of the literature. Res Pract Thromb Haemost 2023; 7:102194. [PMID: 37732158 PMCID: PMC10507376 DOI: 10.1016/j.rpth.2023.102194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/07/2023] [Accepted: 08/19/2023] [Indexed: 09/22/2023] Open
Abstract
Background Hemophilia A (HA) is a genetic bleeding disorder characterized by the deficiency of the coagulation protein factor (F) VIII (FVIII). The development of neutralizing antidrug antibodies (ADAs) to factor concentrates (inhibitors) created an unmet need for novel therapies. The first agent to address this need is emicizumab. Key Clinical Question Can emicizumab ADA occur in patients with HA without FVIII inhibitors? Clinical Approach A new case (the first in a noninhibitor patient) presented with unexpected and excessive bleeding and a prolonged activated partial thromboplastin time. The patient was evaluated by assessing FVIII levels, and the previously published modified version of the Bethesda assay was used to determine the level of ADA to emicizumab. Conclusion Although emicizumab is very effective and has minimal immunogenicity, ADAs, albeit rare, can still occur. There have been 4 previously published anti-emicizumab ADA cases with severe HA with inhibitors, and herein, we describe 1 new case with severe HA without inhibitors.
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Affiliation(s)
- Hande Kizilocak
- Children’s Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, CA, USA
| | | | - Guy Young
- Children’s Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, CA, USA
- University of Southern California, Keck School of Medicine, Los Angeles, CA, USA
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3
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Kizilocak H, Marquez-Casas E, Malvar J, Young G. Safety of FEIBA and emicizumab (SAFE): Dose escalation study evaluating the safety of in vivo administration of activated prothrombin complex concentrate in haemophilia A patients on emicizumab. Haemophilia 2023; 29:100-105. [PMID: 36287631 DOI: 10.1111/hae.14684] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/03/2022] [Accepted: 10/12/2022] [Indexed: 01/25/2023]
Abstract
INTRODUCTION Emicizumab is a humanized bispecific monoclonal antibody licensed for patients with severe haemophilia A. Breakthrough bleeding still occurs in patients on emicizumab and can be managed with recombinant factor VIIa (rFVIIa) or activated prothrombin complex concentrate (aPCC). Thrombotic events were reported when patients on emicizumab received concomitant aPCC at relatively high doses. We studied the effect of infusing various doses of aPCC to patients on emicizumab. MATERIAL AND METHODS Nine patients with severe haemophilia A with inhibitors who are on emicizumab were recruited to participate. Patients were infused with varying doses of aPCC in vivo. Samples were tested with thrombin generation (TG) assay. RESULTS In the current in vivo arm of the study four out of nine patients reached the highest dose, 75 U/kg of aPCC and six out of nine patients were actually eligible for the highest dose. In the previous in vitro arm of the study seven out of eight patients reached the normal plasma with spiking aPCC at a very low concentration equivalent to 5 U/kg. CONCLUSION The in vitro portion of the study demonstrated that clinically relevant concentrations of aPCC resulted in excessive TG, however, in vivo administration of aPCC to the same patients demonstrated that most of the patients had normal TG at the approved doses of aPCC. In the management of breakthrough bleeding clinicians should heed the boxed warning for concomitant use of emicizumab and aPCC, however, should also be aware that low doses of aPCC may not result in sufficient TG.
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Affiliation(s)
- Hande Kizilocak
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA
| | - Elizabeth Marquez-Casas
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA
| | - Jemily Malvar
- Children's Hospital Los Angeles, Cancer and Blood Disease Institute, Los Angeles, California, USA
| | - Guy Young
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA.,University of Southern California, Keck School of Medicine, Los Angeles, California, USA
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Karaman S, Kebudi R, Kizilocak H, Karakas Z, Demirag B, Evim MS, Yarali N, Kaya Z, Karagun BS, Aydogdu S, Caliskan U, Ayhan AC, Bahadir A, Cakir B, Guner BT, Albayrak C, Karapinar DY, Kazanci EG, Unal E, Turkkan E, Akici F, Bor O, Vural S, Yilmaz S, Apak H, Baytan B, Tahta NM, Güzelkucuk Z, Kocak U, Antmen B, Tokgöz H, Fisgin T, Özdemir N, Gunes AM, Vergin C, Unuvar A, Ozbek N, Tugcu D, Bay SB, Tanyildiz HG, Celkan T. Central Nervous System Fungal Infections in Children With Leukemia and Undergoing Hematopoietic Stem Cell Transplantation: A Retrospective Multicenter Study. J Pediatr Hematol Oncol 2022; 44:e1039-e1045. [PMID: 36036521 DOI: 10.1097/mph.0000000000002499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 05/04/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Central nervous system fungal infections (CNSFI) are seen in patients with hematologic malignancies and have high morbidity and mortality. Because of their rarity, there is limited data on CNSFI in children with no established treatment protocols or guidelines. MATERIALS AND METHODS In this multicenter retrospective study, 51 pediatric patients with leukemia, 6 of whom had undergone bone marrow transplantation, with proven or probable CNSFI were evaluated. Fungal infections were defined as proven or probable based on European Organisation for Research and Treatment of Cancer criteria. Proven CNSFI was diagnosed by appropriate central nervous system (CNS) imaging or tissue sample findings in combination with positive microbiological results of cerebrospinal fluid. A positive culture, microscopic evidence of hyphae, a positive result of the galactomannan assays are defined as positive microbiological evidence. Probable CNSFI was defined as appropriate CNS imaging findings together with proven or probable invasive fungal infections at another focus without CNS when there is no other explanatory condition. Data was collected by using the questionnaire form (Supplemental Digital Content 1, http://links.lww.com/JPHO/A541 ). RESULTS Seventeen patients had proven, 34 patients had probable CNSFI. Headaches and seizures were the most common clinical findings. The median time between the onset of fever and diagnosis was 5 days. The most common fungal agent identified was Aspergillus . Sixteen patients received single-agent, 35 received combination antifungal therapy. Surgery was performed in 23 patients. Twenty-two patients (43%) died, 29 of the CNSFI episodes recovered with a 20% neurological sequelae. CONCLUSION CNSFIs should be considered in the differential diagnosis in patients with leukemia and refractory/recurrent fever, headache, neurologicalocular symptoms, and a radiologic-serological evaluation should be performed immediately. Early diagnosis and prompt management, both medical and surgical, are essential for improving clinical outcomes.
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Affiliation(s)
- Serap Karaman
- Division of Pediatric Hematology-Oncology, Istanbul Faculty of Medicine, Istanbul University
| | - Rejin Kebudi
- Division of Pediatric Hematology-Oncology, Istanbul University Oncology Institute
| | - Hande Kizilocak
- Division of Pediatric Hematology-Oncology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa
| | - Zeynep Karakas
- Division of Pediatric Hematology-Oncology, Istanbul Faculty of Medicine, Istanbul University
| | - Bengu Demirag
- Division of Pediatric Hematology-Oncology, University of Health Sciences Dr. Behcet Uz Children's Hospital
| | - Melike S Evim
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Uludağ University
| | - Nese Yarali
- Division of Pediatric Hematology-Oncology, University of Health Sciences, Ankara Child Health and Diseases Hematology Oncology Training and Research Hospital
| | - Zuhre Kaya
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Gazi University, Ankara
| | - Barbaros S Karagun
- Division of Pediatric Hematology-Oncology, Acibadem Adana Hospital, Adana
| | - Selime Aydogdu
- Division of Pediatric Hematology-Oncology, Altinbas University Bahcelievler Medical Park Hospital
| | - Umran Caliskan
- Division of Pediatric Hematology-Oncology, Meram University Faculty of Medicine, Konya
| | - Aylin C Ayhan
- Division of Pediatric Hematology-Oncology, Medeniyet University, Faculty of Medicine
| | - Aysenur Bahadir
- Division of Pediatric Hematology-Oncology, Karadeniz Technical University, Faculty of Medicine, Trabzon
| | - Betul Cakir
- Division of Pediatric Hematology-Oncology, Bezmiâlem Vakif University
| | - Burcak T Guner
- Division of Pediatric Hematology-Oncology, Izmir University of Health Sciences Tepecik Training and Research Hospital
| | - Canan Albayrak
- Division of Pediatric Hematology-Oncology, Ondokuz Mayis University, Faculty of Medicine, Samsun
| | - Deniz Y Karapinar
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Ege University
| | - Elif G Kazanci
- Division of Pediatric Hematology-Oncology, Health Sciences University Bursa High Specialist Training and Research Hospital, Bursa
| | - Ekrem Unal
- Division of Pediatric Hematology-Oncology, Erciyes University Faculty of Medicine, Kayseri
| | - Emine Turkkan
- Division of Pediatric Hematology-Oncology, University of Health Sciences, Okmeydani Training and Research Hospital
| | - Ferhan Akici
- Division of Pediatric Hematology-Oncology, University of Health Science Kanuni Sultan Süleyman Research and Training Hospital
| | - Ozcan Bor
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Eskişehir Osmangazi University, Eskişehir, Turkey
| | - Sema Vural
- Division of Pediatric Hematology-Oncology, Health Sciences University Istanbul Sariyer Hamidiye Etfal Health Practice and Research Center, Istanbul
| | - Sebnem Yilmaz
- Division of Pediatric Hematology-Oncology, Dokuz Eylul University Faculty of Medicine, Izmir
| | - Hilmi Apak
- Division of Pediatric Hematology-Oncology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa
| | - Birol Baytan
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Uludağ University
| | - Neryal M Tahta
- Division of Pediatric Hematology-Oncology, University of Health Sciences Dr. Behcet Uz Children's Hospital
| | - Zeliha Güzelkucuk
- Division of Pediatric Hematology-Oncology, University of Health Sciences, Ankara Child Health and Diseases Hematology Oncology Training and Research Hospital
| | - Ulker Kocak
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Gazi University, Ankara
| | - Bulent Antmen
- Division of Pediatric Hematology-Oncology, Acibadem Adana Hospital, Adana
| | - Huseyin Tokgöz
- Division of Pediatric Hematology-Oncology, Meram University Faculty of Medicine, Konya
| | - Tunc Fisgin
- Division of Pediatric Hematology-Oncology, Altinbas University Bahcelievler Medical Park Hospital
| | - Nihal Özdemir
- Division of Pediatric Hematology-Oncology, University of Health Science Kanuni Sultan Süleyman Research and Training Hospital
| | - Adalet M Gunes
- Division of Pediatric Hematology-Oncology, Faculty of Medicine, Uludağ University
| | - Canan Vergin
- Division of Pediatric Hematology-Oncology, University of Health Sciences Dr. Behcet Uz Children's Hospital
| | - Aysegul Unuvar
- Division of Pediatric Hematology-Oncology, Istanbul Faculty of Medicine, Istanbul University
| | - Namik Ozbek
- Division of Pediatric Hematology-Oncology, University of Health Sciences, Ankara Child Health and Diseases Hematology Oncology Training and Research Hospital
| | - Deniz Tugcu
- Division of Pediatric Hematology-Oncology, Istanbul Faculty of Medicine, Istanbul University
| | - Sema B Bay
- Division of Pediatric Hematology-Oncology, Istanbul University Oncology Institute
| | - Hikmet G Tanyildiz
- Division of Pediatric Hematology-Oncology, Istanbul Faculty of Medicine, Istanbul University
| | - Tiraje Celkan
- Division of Pediatric Hematology-Oncology, Cerrahpasa Faculty of Medicine, Istanbul University-Cerrahpasa
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Carmona R, Kizilocak H, Marquez-Casas E, Vasquez S, Ji L, Ko RH, Young G, Jaffray J. Markers of hypercoagulability in children with newly diagnosed acute lymphoblastic leukemia. Pediatr Blood Cancer 2022; 69:e29522. [PMID: 34963026 DOI: 10.1002/pbc.29522] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 10/13/2021] [Accepted: 11/23/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND Venous thromboembolism (VTE) is a known complication for children with acute lymphoblastic leukemia (ALL). The aim of this study was to identify laboratory biomarkers that predict which children with ALL are at risk for VTE during induction chemotherapy. MATERIALS AND METHODS Newly diagnosed ALL patients admitted to Children's Hospital Los Angeles with a central venous catheter (CVC) were eligible to participate. Participants' blood samples (complete blood count [CBC], quantitative D-dimer, prothrombin fragment 1.2 [PTF 1.2], and thrombin-antithrombin complexes [TAT]) were collected at day 0 (baseline/prior to induction), day 7 (±2 days), day 14 (±2 days), day 21 (±2 days), and day 28 (±2 days) of induction chemotherapy or until participants presented with a symptomatic VTE. RESULTS Seventy-five participants aged 1-21 years were enrolled and included in the final analysis. Twenty-six (35%) of the 75 participants were diagnosed with a CVC-associated VTE (22 asymptomatic and four symptomatic). There was a statistically significant difference between VTE and non-VTE participants for D-dimer (odds ratio [OR] 1.61, 95% confidence interval [CI]: 1.59-1.64), TAT (OR 1.34, 95% CI: 1.32-1.38), and PTF 1.2 (OR 1.31, 95% CI: 1.25-1.37) at all time points. Participants >10 years had a significantly higher risk of developing a VTE compared to participants <4 years (p = .007). CONCLUSION Older children with ALL as well as those with an elevated TAT, PTF 1.2, or D-dimer showed an increased risk of VTE, which may hold potential for predicting VTE in future studies.
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Affiliation(s)
- Roxana Carmona
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Hande Kizilocak
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Elizabeth Marquez-Casas
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Siobhan Vasquez
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA
| | - Lingyun Ji
- Division of Biostatistics, Department of Preventive Medicine, University of Southern California, Los Angeles, California, USA
| | - Richard H Ko
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA.,Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Guy Young
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA.,Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Julie Jaffray
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California, USA.,Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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Kizilocak H, Young G. Emerging drugs for hemophilia A: insights into phase II and III clinical trials. Expert Opin Emerg Drugs 2021; 26:337-350. [PMID: 34601977 DOI: 10.1080/14728214.2021.1988073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Hemophilia is a lifelong, genetic-bleeding disorder, which inadequately treated results in permanent joint damage. It is characterized by spontaneous and trauma-related bleeding episodes. In the last 50 years, treatment has seen dramatic improvements which have improved the quality of life of persons with hemophilia. AREAS COVERED This review will provide a summary of current pharmacological approaches for hemophilia A as well as discuss novel agents which are either approved recently or in phase II-III clinical trials, plasma-derived and recombinant factor VIII (FVIII) products, extended half-life FVIII products, bypassing agents and non-replacement therapies. EXPERT OPINION Novel therapies are already changing the way that hemophilia A is managed, and as more new therapies get approved, there will be a revolution in the management of this serious condition. Clinicians will have both the opportunities as well as the challenges of incorporating such new technologies into clinical practice.
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Affiliation(s)
- Hande Kizilocak
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Cancer and Blood Disease Institute, Los Angeles, CA, USA
| | - Guy Young
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Cancer and Blood Disease Institute, Los Angeles, CA, USA.,Department of Hematology and Oncology, University of Southern California, Keck School of Medicine, Los Angeles, CA, USA
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7
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Kizilocak H, Marquez-Casas E, Malvar J, Carmona R, Young G. Determining the approximate factor VIII level of patients with severe haemophilia A on emicizumab using in vivo global haemostasis assays. Haemophilia 2021; 27:730-735. [PMID: 34115433 DOI: 10.1111/hae.14359] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/14/2021] [Accepted: 06/01/2021] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Emicizumab is a recombinant, humanized bispecific monoclonal antibody that mimics the function of factor VIII (FVIII) which results in a significant reduction in the annualized bleeding rate in patients with haemophilia A (HA), however, the degree with which emicizumab corrects the coagulation defect remains unclear. The objective of this study was to predict the approximate FVIII level in severe haemophilia A patients with inhibitors on emicizumab using global haemostasis assays. MATERIALS AND METHODS Patients with moderate and mild HA in the non-bleeding state and healthy controls had FVIII levels and thrombin generation assessed. Linear regression was utilized to model the FVIII levels as a function of the thrombin generation assay parameters and to make a calibration curve of FVIII levels versus peak thrombin and endogenous thrombin potential. Patients with severe haemophilia A with inhibitors on emicizumab had thrombin generation performed in the same manner and their peak thrombin and endogenous thrombin potential results were placed on the calibration curve to calculate their FVIII Equivalency of Emicizumab by Thrombin Generation (F8EmT). RESULTS All patients with severe HA with inhibitors on emicizumab had F8EmT >10%, suggesting they had been converted to a mild haemophilia phenotype. The patient's weight was inversely correlated to their F8EmT. CONCLUSION The results from this study suggest that the F8EmT in patients with severe HA on emicizumab falls within the range of mild haemophilia which is consistent with the data noted in the emicizumab clinical trials and in vivo studies in animals.
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Affiliation(s)
- Hande Kizilocak
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA
| | - Elizabeth Marquez-Casas
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA
| | - Jemily Malvar
- Children's Hospital Los Angeles, Cancer and Blood Disease Institute, Los Angeles, California, USA
| | - Roxana Carmona
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA
| | - Guy Young
- Children's Hospital Los Angeles, Hemostasis and Thrombosis Center, Los Angeles, California, USA.,Children's Hospital Los Angeles, Cancer and Blood Disease Institute, Los Angeles, California, USA.,Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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8
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Kizilocak H, Marquez-Casas E, Phei Wee C, Malvar J, Carmona R, Young G. Comparison of bypassing agents in patients on emicizumab using global hemostasis assays. Haemophilia 2020; 27:164-172. [PMID: 33245833 DOI: 10.1111/hae.14213] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/23/2020] [Accepted: 11/09/2020] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Emicizumab is a humanized bispecific monoclonal antibody licensed for patients with severe haemophilia A with and without inhibitors. Management of breakthrough bleeding in patients with inhibitors on emicizumab involves episodic treatment with bypassing agents (BPA), activated prothrombin complex concentrate (aPCC) or recombinant activated factor VII (rFVIIa). Thrombotic events and thrombotic microangiopathy were reported when patients on emicizumab received concomitant aPCC at relatively high doses yet such events were not reported with rFVIIa. We studied the effect of spiking various concentrations of BPA on plasma taken from patients on emicizumab. MATERIAL AND METHODS Eleven patients with severe haemophilia A with inhibitors who are on emicizumab were recruited to participate. Blood samples drawn from patients were spiked in vitro with varying concentrations of aPCC and rFVIIa. All samples were tested utilizing global haemostasis assays, thromboelastography and thrombin generation assay. RESULTS Thrombin generation increased with higher concentrations of spiked BPA with a normalized endogenous thrombin potential at a concentration of 0.05 IU/ml and 4 mcg/ml for aPCC and rFVIIa, respectively. Concentrations of aPCC in the range of licensed dosing led to excessive thrombin generation. Thromboelastography was not sufficiently sensitive. CONCLUSION Due to the known thrombotic complications when emicizumab is used in conjunction with aPCC, there has been a large-scale abandonment of the use of aPCC in patients on emicizumab. However, it is possible that aPCC can be used safely with emicizumab albeit with lower doses than are typically prescribed. It would be important to test this hypothesis in a clinical study.
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Affiliation(s)
- Hande Kizilocak
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | | | - Choo Phei Wee
- Saban Research Institute, Biostatistics Core, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Jemily Malvar
- Cancer and Blood Disease Institute, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Roxana Carmona
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Guy Young
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, CA, USA.,Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Harkins Druzgal C, Kizilocak H, Brown J, Sennett M, Young G. Neutralizing antidrug antibody to emicizumab in a patient with severe hemophilia A with inhibitors: New case with detailed laboratory evaluation. J Thromb Haemost 2020; 18:2205-2208. [PMID: 32544268 DOI: 10.1111/jth.14957] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/28/2020] [Accepted: 06/03/2020] [Indexed: 01/14/2023]
Abstract
Hemophilia A is an inherited bleeding disorder characterized by deficiency of the coagulation protein factor VIII. Development of clotting factor concentrates has resulted in an excellent prognosis for this historically fatal disease. However, neutralizing antidrug antibodies to factor concentrates can develop, complicating management and worsening the prognosis, and thus creating an unmet need for novel therapies. One such agent is emicizumab, a bispecific monoclonal antibody which mimics the function of factor VIII. Collectively across the HAVEN clinical trial program, the rate of antidrug antibodies with neutralizing potential was 0.75%. Since its licensure, there have been no further reports of such antibodies, despite its use in thousands of patients. In this report, we describe a patient with severe hemophilia A with inhibitors who developed a neutralizing antidrug antibody to emicizumab, for whom we performed extensive testing in the special coagulation laboratory.
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Affiliation(s)
- Colleen Harkins Druzgal
- Division of Hematology-Oncology, Department of Pediatrics, University of Virginia Health System, Charlottesville, VA, USA
| | - Hande Kizilocak
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Joshua Brown
- Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Margaret Sennett
- Division of Hematology-Oncology, Department of Pediatrics, University of Virginia Health System, Charlottesville, VA, USA
| | - Guy Young
- Division of Hematology-Oncology, Department of Pediatrics, University of Virginia Health System, Charlottesville, VA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Kizilocak H, Yukhtman CL, Marquez-Casas E, Lee J, Donkin J, Young G. Management of perioperative hemostasis in a severe hemophilia A patient with inhibitors on emicizumab using global hemostasis assays. Ther Adv Hematol 2019; 10:2040620719860025. [PMID: 31275538 PMCID: PMC6598318 DOI: 10.1177/2040620719860025] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 06/03/2019] [Indexed: 01/17/2023] Open
Abstract
Background: Patients with severe hemophilia A and inhibitors are at risk of bleeding during invasive procedures. The standard of care for preventing perioperative bleeding has been replacement therapy with FVIII concentrates or for patients with high-titer inhibitors, bypassing agents. However, there is no consensus on the appropriate management of surgery in patients receiving the novel agent emicizumab. The aim of this study was to demonstrate a case of a patient on emicizumab undergoing major surgery with bypassing agents with preoperative use of the thrombin generation assay (TGA) and thromboelastography (TEG). Methods: We report a patient with hemophilia A with inhibitors who had undergone a total knee replacement while on emicizumab combined with a bypassing agent. We utilized TEG and TGA to determine which bypassing agent to choose as well as to inform about the ideal dose. Results: We elected to use recombinant FVIIa as a bypassing agent for the surgery based upon the TGA results. Conclusion: The TGA can be utilized to support decision-making in patients on emicizumab undergoing major surgery to both predict efficacy and potentially minimize the risk of thrombotic events.
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Affiliation(s)
- Hande Kizilocak
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, 4650 Sunset Boulevard, Mail Stop #54, Los Angeles, CA 90027, USA
| | | | | | - Jeanie Lee
- Children's Hospital Los Angeles, Los Angeles, CA, USA
| | | | - Guy Young
- Children's Hospital Los Angeles, Los Angeles, CA, USA
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Kizilocak H, Young G. Diagnosis and treatment of hemophilia. Clin Adv Hematol Oncol 2019; 17:344-351. [PMID: 31437138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Hemophilia A and B are inherited bleeding disorders characterized by deficiency or dysfunction of coagulation protein factors VIII and IX, respectively. Recurrent joint and muscle bleeds are the major clinical manifestations. Replacement therapy with clotting factors, either at the time of bleeding or as part of a prophylactic regimen, is adapted to individual patient needs. The major complication of therapy is the development of neutralizing antibodies. In response, researchers have developed novel agents to both reduce the treatment burden and prevent bleeding regardless of the presence of inhibitors. Another new development, gene therapy, has the potential for a definitive cure. This review summarizes the pathophysiology, clinical presentation, diagnosis, and treatment of hemophilia, as well as information regarding neutralizing antibodies, immune tolerance induction, novel agents, and gene therapy.
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Affiliation(s)
- Hande Kizilocak
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, Los Angeles, California
| | - Guy Young
- Hemostasis and Thrombosis Center, Children's Hospital Los Angeles, and University of Southern California Keck School of Medicine, Los Angeles, California
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Kebudi R, Kizilocak H. Febrile Neutropenia in Children with Cancer: Approach to Diagnosis and Treatment. Curr Pediatr Rev 2018; 14:204-209. [PMID: 29737253 DOI: 10.2174/1573396314666180508121625] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 02/18/2018] [Accepted: 04/29/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND Febrile neutropenia is one of the major acute side effects of intensive treatment in pediatric cancer, necessitating prompt initiation of empirical broad-spectrum antibiotics. Patients may be classified as low or high risk according some risk factors (duration of neutropenia, depth of neutropenia, type of cancer, state of disease, bone marrow involvement, type of treatment, additional health problems). Initial evaluation of the febrile neutropenic child should include the history of the child, a detailed physical examination, blood culture (peripheral and catheter), urinalysis and culture, cultures of lesions. RESULT & CONCLUSION The standard of care in febrile neutropenic children is that they should be hospitalized, especially if high risk, and should be treated urgently with intravenous wide spectrum empiric antibiotics, the spectrum covering P. Aeruginosa. Empiric treatment should be modified according to culture results and clinical situation. Other options for low risk patients are starting with intravenous treatment and continuing with per oral treatment or giving per oral antibiotic treatment from the beginning.
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Affiliation(s)
- Rejin Kebudi
- Cerrahpasa Faculty of Medicine, Pediatric Hematology-Oncology, Istanbul University, Istanbul, Turkey.,Oncology Institute, Pediatric Hematology-Oncology, Istanbul University, Istanbul, Turkey
| | - Hande Kizilocak
- Cerrahpasa Faculty of Medicine, Pediatric Hematology-Oncology, Istanbul University, Istanbul, Turkey
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