New Trends In The New Trends In The Management Of Management Of
Bleeding DisordersBleeding DisordersGalila ZaherGalila Zaher
MRCPathMRCPathConsultant Hematologist Consultant Hematologist
KAUH KAUH
Congenital Bleeding Congenital Bleeding disordersdisorders
VWDVWD Hemophilia AHemophilia A Hemophilia BHemophilia B Other congenital factor deficiencyOther congenital factor deficiency Bernard Solier syndromeBernard Solier syndrome Glanzman’ThrombatheniaGlanzman’Thrombathenia Storage pool defectStorage pool defect
Acquired Bleeding DisordersAcquired Bleeding Disorders Coagulation Factor Coagulation Factor Liver DiseaseLiver Disease DICDIC Consumptions CoagulopathiesConsumptions Coagulopathies Vitamin K deficiencyVitamin K deficiency Platelets defectsPlatelets defects ITPITP Renal impairment Renal impairment Myelo-proliferate DisordersMyelo-proliferate Disorders
HemophiliaHemophilia
A = F VIII deficiencyA = F VIII deficiency B = F IX deficiencyB = F IX deficiency Affects one in 6000 malesAffects one in 6000 males A is 5 X > BA is 5 X > B Mild >5,Moderate 2 -5, severe < 2 %Mild >5,Moderate 2 -5, severe < 2 % Levels remain stable throughout lifeLevels remain stable throughout life Both HA & HB are X linkedBoth HA & HB are X linked
Clinical presentationClinical presentation
< 2 years: joint bleeds < 2 years: joint bleeds – RareRare– Only bruising or mouth bleeds are seenOnly bruising or mouth bleeds are seen– Head injuries are a major concernHead injuries are a major concern
> 2 years> 2 years– Joint and muscle bleeds become more Joint and muscle bleeds become more
commoncommon
Indication For ReplacementIndication For Replacement
All joint bleeds: Pain, All joint bleeds: Pain, swelling ,warmth or loss of swelling ,warmth or loss of movement .movement .
Muscle bleeds : severe pain or Muscle bleeds : severe pain or are in a dangerous locationare in a dangerous location
Bruises usually don’t need Bruises usually don’t need treatmenttreatment
Treatment Treatment
Keep weight off of jointKeep weight off of joint Ice packIce packFactor replacement - the sooner Factor replacement - the sooner
the betterthe betterAmicar or tranexamic acid : Amicar or tranexamic acid :
mouth bleedmouth bleed
Factor replacementFactor replacement
Derived from pooled human Derived from pooled human plasma plasma
Derived from pig (porcine) plasma Derived from pig (porcine) plasma Recombinant productsRecombinant products
Factor VIII (AHF)Factor VIII (AHF)
Mechanism of action Mechanism of action No tool to predict the efficacy No tool to predict the efficacy Allergic reactionsAllergic reactions Transient (short t ½) Transient (short t ½) Expensive.Expensive. Risk of transmission of infectionRisk of transmission of infection
Biotech Development of Biotech Development of Recombinant FactorsRecombinant Factors
Human FVII geneHuman FVII gene
BHK cellsBHK cells
Liver gene Liver gene librarylibrary
Single copySingle copyof gene isolatedof gene isolated
Expression ofExpression ofrF in culture mediumrF in culture medium
hFhFgenegene
hFhFGeneGene
ActivationActivationand Purification and Purification
®®
AmplificationAmplification
hF = human factor BHK = baby hamster BHK = baby hamster kidneykidney
Recombinant FactorsRecombinant Factors
Advantages Advantages :: Safe and stable source of the agentSafe and stable source of the agent When sources are scarce When sources are scarce
Problems :Problems : Contaminating proteins :Infectious or Contaminating proteins :Infectious or
immunogenic agentimmunogenic agent ExpensiveExpensive
Genetic StudyGenetic Study
Study the development of inhibitors. Study the development of inhibitors. Gene TransferGene Transfer
Sustained therapeutic production of Sustained therapeutic production of factors with No stimulation of an immune factors with No stimulation of an immune response . response .
The Tools of Genetic The Tools of Genetic EngineeringEngineering
DNA gene fragment of interest DNA gene fragment of interest EndonucleasesEndonucleases Plasmid Plasmid Ligase Ligase Host that is capable of accepting DNA Host that is capable of accepting DNA
Insertion into the genetic machinery Insertion into the genetic machinery Confirm that the gene is inserted.Confirm that the gene is inserted. Purify the protein of interestPurify the protein of interest
Gene Transfer Clinical TrialsGene Transfer Clinical Trials
5 trials approved in the States .5 trials approved in the States . Retroviral vectorRetroviral vector :B-domain deletion :B-domain deletion Non-viral approachNon-viral approach :reduction factor :reduction factor
use & spontaneous bleeding episodes.use & spontaneous bleeding episodes. Gutless adenovirusGutless adenovirus : eliminate : eliminate
immune response immune response
Results Of Clinical TrialsResults Of Clinical Trials
Long-term therapeutic expression Long-term therapeutic expression not achieved, but data are not achieved, but data are encouraging.encouraging.
Detectable factor levels observed. Detectable factor levels observed. The subjective : decreased bleeding . The subjective : decreased bleeding . No evidence of inhibitor.No evidence of inhibitor. Hepatic toxicity , thrombocytopenia.Hepatic toxicity , thrombocytopenia. Decline expression . Decline expression .
Shortcoming Of Treatment Shortcoming Of Treatment ModalitiesModalities
Short T Short T 1/21/2 CoastCoast Infections & ImmunologicInfections & Immunologic Hepatic toxicity ,low platelets Hepatic toxicity ,low platelets Decline expression. Decline expression. Owing to the shortcoming of treatment Owing to the shortcoming of treatment
Modalities prompted the need for anew Modalities prompted the need for anew hemostatic agent.hemostatic agent.
Initiation of HaemostasisInitiation of Haemostasis
X
XaVa
prothrombin
TF-bearing cell
platelet
activated platelet
VIIa
VIIaIX
IXa
VIIIa VaIXa
X X
Xa
prothrombin
thrombin
thrombin
IX
Fibrinogen
Fibrin
TF
TF
XIa
VIII/vWF VIIIa
V Va
XI XIa
TF–independent mechanism of rFVIIa TF–independent mechanism of rFVIIa enhanced hemostasisenhanced hemostasis
Rational Rational
Thrombin crucial role in haemostasis.Thrombin crucial role in haemostasis. Any agent that enhances the Any agent that enhances the
thrombin generation 'general thrombin generation 'general haemostatic agent'.haemostatic agent'.
rFVII enhances thrombin generation rFVII enhances thrombin generation on activated platelets on activated platelets
Compensates for lack of FVIII and Compensates for lack of FVIII and FIX. FIX.
Normalize fibrin clot permeability Normalize fibrin clot permeability
PharmacokineticPharmacokinetic tt½ :½ :2.7 h 2.7 h Inter-subject variability. Inter-subject variability. Rapid clearance in children > adults.Rapid clearance in children > adults. No readily available assays No readily available assays The haemostatic levels remains The haemostatic levels remains
uncertain.uncertain. Frequent bolus injections, IVI Frequent bolus injections, IVI
potential to minimize usage.potential to minimize usage.
Potential UsePotential Use
Increases thrombin generation on Increases thrombin generation on activated platelet activated platelet – Hemophilia (FVIII/FIX deficiency) Hemophilia (FVIII/FIX deficiency) – Acquired hemophilia.Acquired hemophilia.
– Platelet disorders qualitative and quantitativePlatelet disorders qualitative and quantitative – Diffuse bleeding triggered by surgery and Diffuse bleeding triggered by surgery and
trauma. trauma.
Impaired initial hemostasisImpaired initial hemostasis– FVII-deficiencyFVII-deficiency– Liver disease Liver disease – Oral anticoagulant therapy Oral anticoagulant therapy
Hemophilia with inhibitorsHemophilia with inhibitors
FDA Approved Feb 1999 FDA Approved Feb 1999 Bleeding during or prior to ITI therapy. Bleeding during or prior to ITI therapy. Control bleeding during surgery. Control bleeding during surgery. Safe and effective in 92% Safe and effective in 92% hemophilia hemophilia
research society registryresearch society registry Inhibitor titres are not boosted. Inhibitor titres are not boosted. Home treatment: mild-moderate episodes.Home treatment: mild-moderate episodes. Recommended dose 60-120 ug/kg q 2 -6 Recommended dose 60-120 ug/kg q 2 -6
h or IVI.h or IVI.
Acquired Hemophilia
Rare but potentially life-threatening condition mortality rate 20%.
Auto-antibodies against the deficient factor.
rFVIIa is effective in major bleeding Induces haemostasis independent of
the presence of FVIII or FIX. Well tolerated in these patients
Liver DiseaseLiver Disease Reduction in the synthesis of factors Reduction in the synthesis of factors
involved in coagulation and fibrinolysis.involved in coagulation and fibrinolysis. Moderate thrombocytopenia.Moderate thrombocytopenia. Upper gastrointestinal tract. Upper gastrointestinal tract. Vitamin K .Vitamin K . FFPFFP PCCs : thromboembolic complications.PCCs : thromboembolic complications.
rFVII &Liver DiseaserFVII &Liver Disease Acute hepatic trauma, liver biopsy, Acute hepatic trauma, liver biopsy,
chronic liver disease ,cirrhosis, and chronic liver disease ,cirrhosis, and liver transplantation.liver transplantation.
Experimental studies :seems to be Experimental studies :seems to be safe and effective. safe and effective.
No evidence of thrombosis . No evidence of thrombosis . Cirrhosis , achieved hemostasis in 74% Cirrhosis , achieved hemostasis in 74%
Jeffers et alJeffers et al
The Risk Of Thrombosis In The Risk Of Thrombosis In LIVER PatientsLIVER Patients
No evidence of dose relationshipNo evidence of dose relationship Many events have an alternative Many events have an alternative
aetiologyaetiology Few events within the first day after Few events within the first day after
dosingdosing No increase in events as compared No increase in events as compared
with background transplant with background transplant populationpopulation
Drug-Induced Drug-Induced CoagulopathyCoagulopathy
Oral anticoagulant treatment Oral anticoagulant treatment hemorrhage :0.6%/ m .hemorrhage :0.6%/ m .
Vitamin K, FFP or PCCs Vitamin K, FFP or PCCs rFVIIa in healthy volunteers :50% drop of rFVIIa in healthy volunteers :50% drop of
INR INR Girard et alGirard et al An open, multicenter pilot trial is An open, multicenter pilot trial is
underway to determine the efficacy underway to determine the efficacy FFondaparinux. normalized PT, aPTT, and ondaparinux. normalized PT, aPTT, and
TT. TT. Bijsterveld et alBijsterveld et al
Glanzmann’s Glanzmann’s ThrombastheniaThrombasthenia
Refractory to platelet transfusionRefractory to platelet transfusion Increases the initial thrombin generation, Increases the initial thrombin generation,
thereby compensating for defective platelet thereby compensating for defective platelet Effective in 60% during surgery . Effective in 60% during surgery . No adverse effects of rFVIIaNo adverse effects of rFVIIa International registry data :relatively safe International registry data :relatively safe
and effective when used in GT.and effective when used in GT.
Blood 1999; 94 (11): 3951-3953Blood 1999; 94 (11): 3951-3953
Thrombocytopenia Thrombocytopenia
Increased thrombin generation on Increased thrombin generation on activated platelets compensate for activated platelets compensate for the low platelet number.the low platelet number.
Reduction in bleeding time in 52.4% Reduction in bleeding time in 52.4% of 105 patients . of 105 patients .
Kristensen Kristensen et al et al
No major adverseNo major adverse
Surgical &Trauma patientsSurgical &Trauma patients
Effective and safe in the management of Effective and safe in the management of uncontrolled surgical in patients not uncontrolled surgical in patients not known to have inherited coagulopathy.known to have inherited coagulopathy.
Trauma :surgical intervention failed to Trauma :surgical intervention failed to stop life- threatening bleeding. stop life- threatening bleeding.
– Significant decrease to 2 packed RBC Significant decrease to 2 packed RBC
– Shortening of PT & aPTTShortening of PT & aPTT Adjunctive hemostatic treatmentAdjunctive hemostatic treatment Theoretical risk of TEDTheoretical risk of TED ,none observe ,none observedd
Building Strong Scientific Building Strong Scientific EvidenceEvidence
Clinical areaClinical area Status on project Status on project Liver transplantation Ph 2 study Upper GI bleeds Ph 2 study Liver resection Ph 2 study BMT Ph 2 study Reversal of OAC Ph 2 to be started Traumatology Ph 2 to be started
Questions more than Questions more than answersanswers
Optimal dosage.Optimal dosage. Dosing interval.Dosing interval. Adjunctive hemostatic treatment .Adjunctive hemostatic treatment . ‘‘General haemostatic agent.General haemostatic agent. Thromboembolic events .Thromboembolic events . Coat analysis studies.Coat analysis studies. Need for evidence-based guidelinesNeed for evidence-based guidelines
Local experienceLocal experience
Acquired Hemophilia Acquired Hemophilia Fresh PR bleeding Fresh PR bleeding FFP. Cryoppt,FVIII concFFP. Cryoppt,FVIII conc In preparation for molar root extract In preparation for molar root extract FVIII conc 100IU/KgFVIII conc 100IU/Kg rFVII 30IU rFVII 30IU Normal hemostasisNormal hemostasis Tranexamic acidTranexamic acid
Amount of thrombin formed in the Amount of thrombin formed in the initial burst is critical to assureinitial burst is critical to assure
1.1. assembly of a thick, strong assembly of a thick, strong fibrin plugfibrin plug
2.2. activation of FXIII to cross link activation of FXIII to cross link fibrinfibrin
3.3. activation of TAFI to makeactivation of TAFI to makefibrin plug resistant to fibrin plug resistant to fibrinolysisfibrinolysis
RNA repairRNA repair
Pre-messenger RNA (pre-mRNA) repair. Pre-messenger RNA (pre-mRNA) repair. splicing mechanisms to correct a portion splicing mechanisms to correct a portion
of the defective RNA. of the defective RNA. The advantage :large genes or genes that The advantage :large genes or genes that
contain large regulatory elements. contain large regulatory elements. Injection of a plasmid encoding a pre-Injection of a plasmid encoding a pre-
mRNAmRNA Useful for the treatment of autosomal Useful for the treatment of autosomal
dominant disorders.dominant disorders.
Inhibitors &Gene Transfer Inhibitors &Gene Transfer
InhibitorsInhibitors : :20% HA patients and 3% of HB 20% HA patients and 3% of HB patients.patients.
Antibodies inactivate the factor by Antibodies inactivate the factor by changing conformation.changing conformation.
Depends on type of genetic mutation. Depends on type of genetic mutation. A large deletion A large deletion incidence of inhibitor . incidence of inhibitor . Bleeding episodes are difficult to manage Bleeding episodes are difficult to manage