/
Current Trends in the Management of Hemophilia Current Trends in the Management of Hemophilia

Current Trends in the Management of Hemophilia - PowerPoint Presentation

phoebe-click
phoebe-click . @phoebe-click
Follow
489 views
Uploaded On 2016-10-29

Current Trends in the Management of Hemophilia - PPT Presentation

December 4 2015 Developed through a collaboration between Moderator 2 Maria Elisa Mancuso MD PhD Haematologist Angelo Bianchi Bonomi Hemophilia and Thrombosis Center Fondazione IRCCS Ca Granda Ospedale Maggiore Policlinico ID: 481863

submit questions 400 609 questions submit 609 400 text 1695 hemophilia factor fviii joint prophylaxis bleeds assay ehl risk

Share:

Link:

Embed:

Download Presentation from below link

Download Presentation The PPT/PDF document "Current Trends in the Management of Hemo..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.


Presentation Transcript

Slide1

Current Trends in the Management of Hemophilia

December 4, 2015

Developed through a

collaboration between:Slide2

Moderator2

Maria Elisa Mancuso, MD, PhD

Haematologist, Angelo Bianchi Bonomi Hemophilia and Thrombosis CenterFondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoDepartment of Pathophysiology and Transplantation

University of MilanMilan, Italy

To submit questions, please text them to 609-400-1695Slide3

Panelists3

Margaret V. Ragni, MD, MPH

Professor of MedicineDivision of Hematology/OncologyDirector

Hemophilia Center of Western PennsylvaniaUniversity of PittsburghPittsburgh, Pennsylvania

Craig M. Kessler, MDProfessor of Medicine and PathologyDirector, Division of CoagulationHemophilia and Thrombosis Comprehensive Care CenterGeorgetown University Medical CenterWashington, DCJohannes Oldenburg, MD, PhDProfessorInstitute of Experimental Haematology and Transfusion MedicineUniversity of BonnBonn, Germany

To submit questions, please text them to 609-400-1695Slide4

Directions

Submitting QuestionsTo submit questions to the panel, please email my.question.is1@gmail.com

OR text 609-400-1695Audience members can submit a question to the faculty at any time during the program. We may not be able to answer all due to time constraints.

Answering the Poll Questions With the Worldwide KeypadTo use the keypad, simply press the number that corresponds with the option you wish to choose.There is no enter button.

If you make a mistake, you can revote at any time during the polling period.At the end of the event please leave the keypads on your chair.4Slide5

Introduction

Maria Elisa Mancuso, MD, PhD

Haematologist,

Angelo Bianchi Bonomi Hemophilia and Thrombosis Center

Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico

Department of Pathophysiology and Transplantation

University of Milan

Milan, Italy

Developed through a

collaboration between:Slide6

Learning Objectives

Identify key data concerning advances in prophylaxis and the use of extended half-life factor replacement for hemophilia A and BEvaluate key clinical issues associated with advances in hemophilia care, including monitoring and genotyping

Determine best practice management strategies through the presentation and discussion of cases6To submit questions, please text them to 609-400-1695Slide7

EHL ProductsHow Far Are We?

EHL products promise a paradigm shift in treatment

Fewer infusions, longer and higher protection, increased adherence, and improved QoLTreatment individualization seems to be the key: not a standard regimen for allTreatment tailoring according to patient characteristics

7To submit questions, please text them to 609-400-1695Slide8

Margaret V. Ragni, MD, MPH

Overview of approved EHL productsImpact of EHL on prophylaxis

Longer half-life vs higher trough levelsManagement of the active adolescent8

EHL and ProphylaxisMoving From the Clinic to the Real WorldTo submit questions, please text them to 609-400-1695Slide9

Monitoring New Products

Rationale for monitoring: when and whoAdapt activity to half-life and vice versa

What is important for healthcare providersWhat is important for patientsAvailable assays and their interpretation9

To submit questions, please text them to 609-400-1695Slide10

Craig M. Kessler, MD

Rationale for monitoringConcept of extended half-life

Challenges to monitoringAvailable assaysDifferent monitoring for different patients10

Monitoring the Standard and New ProductsConundrums of Clinical Care

To submit questions, please text them to 609-400-1695Slide11

The Impact of Genes and Genetics

Hemophilia is a congenital disorder due to genetic mutationsGenotyping as a driver for interpreting clinical phenotype

Exploring the impact of genotype-phenotype on clinical practice and patient managementGenotyping for all?The role of genetic counseling

11To submit questions, please text them to 609-400-1695Slide12

Johannes Oldenburg, MD, PhD

What do we know about genotype-phenotype relationshipWhat can we do with genotyping?

Who is a candidate?The role of genetic counseling12

Genotyping and PhenotypingScientific and Practical ImplicationsTo submit questions, please text them to 609-400-1695Slide13

EHLs and Prophylaxis

Moving From the Clinic to the Real World

Margaret V. Ragni, MD, MPH

Professor of Medicine

Division of Hematology/OncologyDirectorHemophilia Center of Western PennsylvaniaUniversity of PittsburghPittsburgh, PennsylvaniaDeveloped through acollaboration between:Slide14

14

First case of hemophilia in US

1803

First whole blood transfusion

1840Queen Victoria -- hemophilia1843Deficiency of factor VIII, IX1930s

Plasma

1936

Cryoprecipitate

1964

Clotting factor: VII, IX, PCC

1960-80s

FIX,

FVIII genes cloned

1982-84

Liver transplant: cure

1985

Recombinant factor VIII, IX, VIIa

1992-99

Extended Half-Life VIII, IX

2010-15

Queen Victoria’s Family

Treatment Timeline

To submit questions, please text them to 609-400-1695Slide15

Introduction

Exciting time in clot factor management:Extended half-life proteins for hemophilia

Paradigm shift in treatment:Fewer infusionsLonger protection from bleedsImproved quality of lifeReduced immunogenicity

15To submit questions, please text them to 609-400-1695Slide16

Overview

FDA-approved EHL productsrFVIIIFc: Recombinant factor VIII-FC fusion protein

rFIXFc: Recombinant factor IX-Fc fusion proteinPEG-rFVIII: pegylated, full-length recombinant factor VIII Phase 3 pivotal studies

Mahlangu J, et al: rFVIIIFc fusionaPowell JS, et al: rFIXFc fusion

bCollins PW, et al: glycoPEGylated factor IX (N9-GP)c Konkle BA, et al: PEG-rFVIIIdSafety, efficacy, and pharmacokineticsImplementation in clinical settingCase discussion16a. Mahlangu J, et al. Blood

. 2014;123:317-325; b.

Powell JS, et al. N Engl J Med

. 2013;369:2313-2323;

c

. Collins PW, et al.

Blood

. 2014;124:3880-3886; d. Konkle BA, et al.

Blood

. 2015;126:1078-1085.Slide17

The Hemophilias

Defect Deficient, defective FVIII, FIXGenetics

X-linked DisorderClinicalBleeds into joint, musclesSeverity

Mild (> 5%) traumaticModerate (1-5%) traumaticSevere (< 1%) spontaneous, traumaticMorbidity

Spontaneous joint bleedsGoalPrevent bleeds by maintaining > 1% Half-LifeFVIII: 8-12 h; FIX: 12-24 h DosingFVIII: 3/wk; FIX: 2/wk17Prince AlexeiTo submit questions, please text them to 609-400-1695Slide18

Factor Level and Bleed RiskProphylaxis: FVIII, IX dosing to prevent spontaneous bleeds

18

Risk:

Spontaneous bleeds increase as time < 1% increases

Goal: Maintain factor > 1% to prevent spontaneous bleeds

Collins PW, et al.

J Thromb Haemost

.

 2009;7:413-420.

Predicted Bleeds per Year

Time With Factor VIII < 1 IU dL

-1

, h/wk

-1Slide19

Prophylaxis Landmark Study

Randomized Trial -- Hemophilia A age < 30 mo (N = 65)Aim --

To determine if prophylaxis (3,4/wk) prevents joint disease19

Prophylaxis

(N = 32)Standard Therapy(N = 33)P ValueNo joint damage (MRI), %

93

55

.002

No joint damage (X-ray), %

96

81

.10

Median no.

joint bleeds, no. patients/y

.20

4.35

< .001

Inhibitor formation, %

6.2

0

.24

Life-threatening

bleeds, %

0

9

.24

CVAD infections, %

91

76

.19

Conclusion:

Prophylaxis prevents joint damage and bleeds

Manco-Johnson MJ, et al.

N Engl J Med

. 2007;357:535-544.

To submit questions, please text them to 609-400-1695Slide20

Problems With ProphylaxisProphylaxis

Reduces joint bleedsa

Reduces joint damage by MRIStandard of care for severe hemophiliaProblemsRequires frequent injections: FVIII 3/wk; FIX 2/wkInvasive, costly: 50% of adults avoid prophylaxis

bPorts, access: most children receive ~1/wk dosec20

a. Manco-Johnson MJ, et al.

N Engl J Med

. 2007;357:535-544; b. Walsh CE, Valentino LA.

Haemophilia

. 2009;15:1014-1021;

c

. Ragni MV, et al.

Haemophilia

. 2012;18:63-68.Slide21

EHL FVIII and FIX ProteinsFc-IgG fusion proteins

rFIXFca

rFVIIIFcbAlbumin-fusion proteinsrFIX-FPcPegylated/glycoPEGylated proteinsN9-GP

dN8-GPeBAY 94-9027fPEG-rFVIII

g21a. Powell JS, et al. N Engl J Med. 2013;369:2313-2323; b. Mahlangu J, et al. Blood. 2014;123:317-325; c. Santagostino E, et al. ISTH 2015. Abstract OR347; d. Collins PW, et al. Blood. 2014;124:3880-3886; e. Tiede A, et al. J Thromb Haemost. 2013;11:670-678; f. Coyle TE, et al. J Thromb Haemost. 2014;12:488-496; g. Konkle BA, et al. Blood. 2015;126:1078-1085.Slide22

EHL Proteins22

Protein

Phase

Dose

(IU/kg)SubjectsABRResponse

Inhibitor

Half-life

Recombinant

FVIII EHL Proteins

rFVIIIFc

a

III

25-50

2/wk

N = 165

2.9

97.8%

0.0%

1.5-fold

(19

h)

N8-GP

b

III

50

q 4d

N = 175

1.3

95.5%

0.0%

1.5-fold

(18.3 h)

BAY 94-9027

c

III

25-60

1-2/wk

N

= 132

1.5

--

0.0%

1.4-fold

(18.7 h)

PEG-rFVIII

III

45

2/wk

N = 101

1.9

95.9%

0.0%

1.4-1.5-fold

Recombinant FIX EHL Proteins

rFIXFc

e

III

50-100

q 7-10d

N = 61

2.0

97.3%

0.0%

2.5-fold

(82 h)

rFIX-FP

f

III

50-75

q 7-14d

N = 63

--

98.6%

0.0%

> 5.0-fold

(105 h)

N9-GP

g

III

40

q wk

N = 29

1.0

100.0%

0.0%

2.5-fold

(93 h)

a.

Mahlangu J, et al.

Blood

. 2014;123:317-325; b.

Giangrande P, et al.

J

Thromb

Haemost

.

2015;13. Abstract OR212

; c.

Boggio LN, et al.

Blood.

2014;124. Abstract 1526

; d. Konkle BA, et al.

Blood

. 2015;126:1078-1085; e.

Powell JS, et al.

N Engl J Med

. 2013;369:2313-2323;

f

. Santagostino E, et al. ISTH 2015. Abstract OR347; g. Collins PW, et al.

Blood

. 2014;124:3880-3886. Slide23

EHLs: Clinical Trials Update

Phase 3 Clinical TrialsSafe, well tolerated

Improved t½, recovery; delayed clearanceNo inhibitor developmentNo allergic reactionsNo thrombosis

Efficacy comparable to rFVIII, rFIXSafety comparable to rFVIII, rFIX 23

To submit questions, please text them to 609-400-1695Slide24

EHL Dosing24

Republished with permission of the American Society of Hematology from

Mahlangu J, et al. Blood. 2014;123:317-325; permission conveyed through Copyright Clearance Center, Inc.; From Powell JS, et al.

N Engl J Med. 2013;369:2313-2323. Copyright © 2013 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society.

SHL: 25-25-50 U/kg TIW rFVIIIEHL: 25/65 U/kg BIW rFVIIIFcSHL: 75-100 U/kg BIW rFIXEHL: 75-100 U/kg 1/wk rFIXFc3%1%Slide25

EHL: Potential Implications

Longer duration factor level > 1% factorLess frequent infusions

Fewer ports, ED visitsFewer interruptions of school, workImproved QoL25

To submit questions, please text them to 609-400-1695Slide26

EHL Improves Half-life, AUC

A FVIII level > 1% was sustained in ~50% of adults receiving rFVIIIFc 50 U/kg q5d in phase 2 trial

Yet they had continued protection against bleeds Prolonged AUC (time spent > 1%) prevents bleeds26

Republished with permission of the American Society of Hematology from Mahlangu J, et al. Blood. 2014;123:317-325; permission conveyed through Copyright Clearance Center, Inc.Slide27

AUC: SHL vs EHL27

Mahdi AJ, et al.

Br J Haematol. 2015;169:768-776. 

Upper Panel:

SHL

Lower Panel:

EHL

For a once-weekly EHL protein to achieve a similar trough to an alternate-day SHL protein, the peak will need to be higher, with a longer time spent below a "critical level" and fewer peaks during the week

SHL = standard half-life; EHL = extended half-life

To submit questions, please text them to 609-400-1695Slide28

FVIII Trough and Prophylaxis

Prophylaxis StudyDose to achieve FVIII ≥ 1% differs by patient

Thus, individualized dosing may be more effectivePK-Guided Prophylaxis Study in 34 severe hemophilia A patientsIndividual dose to achieve trough 1% VIII determined

Individual trough to prevent bleeds determinedIndividual PK and bleeds for optimal prophylaxis modeled

Median FVIII at Bleed (N = 34)Joint Bleeds: 3.43 U/dL (0-42)Other Bleeds: 2.87 U/dL (0-11) Spontaneous: 2.71 U/dL (0-26)28Spotts G, et al. Blood. 2014;14. Abstract 689.To submit questions, please text them to 609-400-1695Slide29

FVIII Trough and Prophylaxis29

Spotts G, et al.

Blood. 2014;14. Abstract 689.Trough, %

Number

Bleed-Free, %≥ 115/3444

≥ 3

20/34

59

≥ 5

26/34

76

≥ 10

29/34

85

≥ 15

32/34

94

≥ 20

33/34

97

≥ 25

33/34

97

≥ 30

34/34

100

Minimally Effective Trough Target Trial

Findings:

76% predicted to be bleed-free at VIII

≥ 5%; and 94% at > 15%

Conclusion:

Individualized PK provides personalized prophylaxis regimen

To submit questions, please text them to 609-400-1695Slide30

Bleed type, frequency

Will EHLs delay onset and reduce type and frequency of bleed? Prophylaxis

Will EHLs simplify, encourage; at what dose and what trough?Chronic joint diseaseWill EHLs slow onset of joint disease, severity, surgery? Inhibitor formation

Will EHLs reduce inhibitor frequency, titer, or shorten ITI?30

What Is the Real-World Impact of EHLs?To submit questions, please text them to 609-400-1695Slide31

Prophylaxis, bleeds, joint disease

To demonstrate reduced ABR, infusion, time < 1%, improved joint preservation and lifestyleProspective data collection: PINK

LINK, QoL, PK, Cost-Effect Studies Inhibitor formation, toleranceTo demonstrate reduced immunogenicity, shorter and simpler immune tolerance induction

Prospective data collection: INHIBIT Study, HIRE Study31

Impact of Implementing EHLsTo submit questions, please text them to 609-400-1695Slide32

At HCWP, since 2014 FDA licensure: N=73 switched to EHL

32

Hemophilia A(N = 52)

Hemophilia B(N = 21)

Switched to rFVIIIFcSwitched to rFIXFcPTPs (2 doses/wk)< 1 y (N = 4) < 18 y (N = 33) rFVIIIFc ITI (N = 3)

PTPs

(1 dose/7-10/d)

Ragni

, M. unpublished data.

Impact of EHL: Local Experience

To submit questions, please text them to 609-400-1695Slide33

Prophylaxis

Initiate at 1st bleed once weeklyBreakthrough bleeds

Escalate to twice weeklyInhibitor prone-children Dose once weekly before bleedInhibitor patients

Initiate ITI as alternate day therapyPersonalized Rx Use trough to adjust dose to

> 1% Growth spurt Monitor q 3-6 months in children, adolescents Ongoing bleeds Discuss treatment duration, frequencySports Assess troughs and dose frequency 33 Impact of EHL: ConsiderationsTo submit questions, please text them to 609-400-1695Slide34

What Is Optimal Therapy?"Quotable Quotes" for consideration

The optimal trough is ~1% EHLs are for severe patients only

EHLs are for prophylaxis patients only EHLs should not be used in infants EHLs are not for inhibitor patients34

To submit questions, please text them to 609-400-1695Slide35

What Is Optimal Therapy?“Quotable Quotes” for consideration:

The optimal trough is ~1%EHLs are for severe patients only

EHLs are for prophylaxis patients only EHLs should not be used in infantsEHLs are not for inhibitor patients35

NOT NECESSARILY

NOT NECESSARILYNOT NECESSARILY

NOT NECESSARILYNOT NECESSARILY

To submit questions, please text them to 609-400-1695Slide36

EHL and Inhibitor FormationWhat Is the Evidence?

Fc contains Tregs that suppress immune responsea

Ig antibodies coupled to haptens induce Ag-specific tolerancebIn hem A mice, weekly rFVIIIFc reduces inhibitors (vs rFVIII)b EHL activate

, expand T regulatory epitopes, reduce immunogenicityFc Fusion proteinsc,d

Albumin Fc proteinse Pegylated proteinsf,gInhibitor formation: lower titer, more rapid toleranceh36a. Rath T, et al. Crit Rev Biotechnol. 2015;35:235-254; b. Lei TC, Scott DW. Blood. 2005;105:4865-4870; c. Borel Y. Immunol Rev. 1980;50:71-104. d. De Groot AS, et al. Blood. 2008;112:3303-3311; e. Basto AP, et al. Mol Immunol

. 2015;64:36-45; f. Chapman AP. Adv Drug Deliv Rev

. 2002;54:531-545. g. Hershfield MS. In Poly(ethylene glycol): chemistry and biological applications. 134-44. h. Malec LM, et al. ASH 2015. Abstract 3531.Slide37

Patient Management Issues

Is clinical or laboratory monitoring necessary to manage patients using long-lasting products?Is PK needed to determine optimal dose?

Are breakthrough bleeds sufficient monitoring?When should the prophylaxis dose be increased, decreased?37

To submit questions, please text them to 609-400-1695Slide38

Clinical Case: Presentation

Adolescent active in sports on prophylaxis15-year-old with moderately severe hemophilia B

Basketball practice twice/wk, game weekendsCurrent rFIX prophylaxis: 1-2/wk at nightRecent hip bleed, and recurrent ankle bleeds Growth spurt, next visit in 6 months

38To submit questions, please text them to 609-400-1695Slide39

How would you manage this patient’s prophylaxis?Remain on his regimen

Increase frequency of the current rFIX regimenSwitch to EHL every 7 days Switch to EHL every 10 days

39Clinical Case: QuestionsSlide40

Clinical Case: QuestionsWe decided to switch the patient to an EHL.

What starting dose would you use?75 U/kg once weekly

75 U/kg every 10 days100 U/kg once weekly100 U/kg every 10 days40Slide41

Clinical Case: Management

Adolescent active in sports on prophylaxis15-year-old with moderately severe hemophilia B

Basketball practice twice/wk, game weekendsCurrent rFIX prophylaxis: 1-2/wk at nightRecent hip bleed, and recurrent ankle bleeds Growth spurt, next visit in 6 months

41

75 U/kg/wk100 U/kg/wkPeak

1.01

--

U/mL

Trough

0.01

0.02

U/mL

Begun on rFIXFc 75 U/kg/wk:

Breakthrough BleedsSlide42

Conclusion: Personalized Approach

Sports

Invincibility with responsibility Transition issuesSelf-infusion, adjusted to practice, games One size does not fit all

Get peaks, troughsGrowth spurtGet frequent weights!

Infants/childrenOnce-weekly EHL prophy may be optimalRealistic expectationsAssess adherence, arthropathyAdherenceMay not improve with EHLChronic arthropathyMay not improve with EHL42To submit questions, please text them to 609-400-1695Slide43

Monitoring the Standard and New Factor Replacement Products

Conundrums of Clinical Care

Craig M. Kessler, MD

Professor of Medicine

and PathologyDirector, Division of CoagulationHemophilia and Thrombosis Comprehensive Care CenterGeorgetown University Medical CenterWashington, DCDeveloped through acollaboration between:Slide44

Presentation Overview

Rationale for monitoring: Understanding PKChallenges to monitoring

Available assaysCase study44

To submit questions, please text them to 609-400-1695Slide45

Hemophilia Clinical Trial Pipeline45

Hemophilia With Inhibitors

New Recombinants

BAX817 –

rFVIIaTransgenic rhFVIIaLonger-actingOBI-1 – rpFVIIICB813d – rVIIa analogueCSL689 – rVIIa:albumin fusionrVIIa:CTPHemophilia ALonger-actingrFVIII:Fc*BAY94-9027 – PEGylated rFVIIIBAY855 – PEGylated rFVIII*

CSL627 – SingleChain rFVIIINew Recombinants

simoctogog alfa – rFVIIIoctocog alfa sucrose plasma protein-free– rFVIII

GreenGene F - rFVIII

Hemophilia B

New Recombinants

IB1001 – rFIX

BAX326 – rFIX

*

Longer-acting

rFIX:Fc

*

CSL654 – rFIX:albumin fusion

Cross-Segment

Longer-acting

MC710 – pdFVIIa + pdFX

ACE910 – SC bispecific Ab

siRNA vs Antithrombin

* = ApprovedSlide46

Patients with mild/moderate hemophilia (ie, residual factor levels ≥ 1%) bleed less frequently and have less arthropathy

> 1% selected for existing economics and treatment protocol burden

Venous access and frequency of dosing 2-3X/wk for FVIIIAnimal models show that every single bleed matters and can cause irreversible damage when it occurs in the brain, solid organs, or joints1% trough level is too low to prevent all bleeds, particularly with active lifestyles or those with established joint damage

"FVIII/FIX levels of 1% limit the ability for full social integration equivalent to someone without a bleeding disorder. It is wholly insufficient to accommodate major or accidental trauma causing bleeding. The fear of traumatic injury remains a constant." 46

Skinner MW.

Haemophilia

. 2012;18:3-5.

Premise of Prophylaxis Therapy in Hemophilia

To submit questions, please text them to 609-400-1695Slide47

Peak range

May help prevent activity-related bleeds

a,bArea under the curveMay help prevent subclinical bleeding

aTrough

May help prevent spontaneous bleedinga,cUnderstanding the Curve47

Area under the curve

Peak following infusion

Trough

Time

Percent Factor Level

Infusion

Peak range

a. Collins PW, et al.

Haemophilia

. 2011;17:2-10; b. Collins PW.

Haemophilia

. 2012;18:131-135; c.

Collins PW, et al.

J Thromb Haemost

. 2009;7:413-420.Slide48

NHF has rated certain activities based on their perceived risk

48

Anderson A, et al.

Playing It Safe: Bleeding Disorders, Sports and Exercise. 2005.

1Safe1.5

Safe to Moderate risk

2

Moderate risk

2.5

Moderate to Dangerous risk

3

Dangerous

Risk Associated With Activity Is Highly Variable

To submit questions, please text them to 609-400-1695Slide49

Increased activity level is associated with an increased propensity to bleed

More factor is required to reduce the level of risk to the same as category 1There is still a high risk of bleeding at 100% factor level

49

Broderick CR, et al.

JAMA

. 2012;308:1452-1459. Copyright © 2012 American Medical Association. All rights reserved.

Category 2 vs Category 1 Activities Are Associated With Increased Risk of BleedingSlide50

Category 3 activity is associated with the highest propensity to bleed

Even more factor is required to reduce the level of risk to the same as category 1 There is still a risk of bleeding at 100% factor level

50

Broderick CR, et al.

JAMA

. 2012;308:1452-1459. Copyright © 2012 American Medical Association. All rights reserved.

Category 3 Activities Associated With

Highest

Risk of BleedingSlide51

Most patients experienced between 0-2 bleeds per year

Bleeding rate did not vary by the week of the year

Most bleeds occurred within 1 h of activity51

Bleed Window

Broderick CR, et al.

JAMA

. 2012;308:1452-1459. Copyright © 2012 American Medical Association. All rights reserved.

Data Highlight Transient Nature of Bleed RiskSlide52

Increased potential for collisions is associated with an increase in the risk of bleeding

Increasing factor levels can decrease the risk of bleeds

1% increase in factor = 2% decrease in riskMost bleeds associated with physical activity are apparent within an hourSuggests the need to have highest factor levels during the time of highest risk

52

Broderick CR, et al.

JAMA

. 2012;308:1452-1459.

Key Takeaway Lessons From Broderick 2012

To submit questions, please text them to 609-400-1695Slide53

US Joint Outcome Study53

Manco-Johnson MJ, et al.

N Engl J Med

. 2007;357:535-544.

Episodic

No routine infusions

Treatment of Acute Joint Bleed

40 U/kg immediately

20 U/kg at 24 & 72 h

20 U/kg alternate days until complete resolution of

pain and normal physical exam, up to 4 weeks

Prophylaxis

rFVIII 25 U/kg alternate days

Exit: Joint Outcome on

MRI & X-Ray at Age 6 y

Age < 30 months

FVIII ≤ 2%; no inhibitors

≤ 2 joint hemorrhages

Randomize

Study ProtocolSlide54

Primary Outcome54

Manco-Johnson MJ, et al.

N Engl J Med

. 2007;357:535-544.

Median number of joint bleeds

Prophylaxis vs Episodic arm:

0.2 vs 4.35/y

Prophylaxis → 83% relative risk reduction

Proportion of

Children With No Cartilage/Bone Changes

on MRI in the

6 Index Joints

at

Study Exit

20

0

80

100

Episodic -- 55%

Prophylaxis -- 93%

40

60

Number of Children, %

To submit questions, please text them to 609-400-1695Slide55

55

From Manco-Johnson M, et al. N

Engl

J Med. 2007;357:535-44. Copyright © 2007 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society.

MRI Score

10

9

8

7

6

5

4

1

0

0

5

10

15

20

Number of Clinically Evident Index-Joint Hemorrhages

2

3

25

Some joints with no hemorrhages had high MRI scores

Damaged

joints

Some joints with >10 hemorrhages had no bone/cartilage damage

Subclinical Bleeds by Joint Score in All PatientsSlide56

In a separate study:

Patients with hemophilia A or B (n=26) received prophylaxisJoints were asymptomatic

5/26 patients had a worsening of MRI findings without experiencing a joint bleedHigher MRI scores were correlated with higher rates of clinically asymptomatic ankle joints over a 10-year periodEarly morphologic changes in clinically asymptomatic ankles can be detected using MRI, despite adequate prophylaxis

56

Olivieri M, et al.

Haemophilia

. 2012;18:369-374.

Identification and Long-term Observation of Early Joint Damage by MRI

To submit questions, please text them to 609-400-1695Slide57

Correlation between the number of clinically evident hemarthroses and joint failure defined by MRI is weak, leading the investigators to suggest that:

"…chronic microhemorrhages into the joints or subchondral bone in young boys with hemophilia causes deterioration of joints without clinical evidence of hemarthroses and that prophylaxis prevents this subclinical process."

What is the effect on other body structures? Brain, kidney, etc57

Manco-Johnson MJ, et al.

N Engl J Med

. 2007;357:535-544.

Key Finding of the US Joint Outcome Study

To submit questions, please text them to 609-400-1695Slide58

A low factor level may not provide sufficient protection during activities

No correlation was found between bleeding frequency and trough FVIII levels (prospective randomized ESPRIT study)a

Patients may require a higher factor level during activitiesA personalized approach allows the physician to tailor patients’ regimens to their individual lifestyle

58

a. Gringeri A, et al.

J Thromb Haemost.

2011;9:700-710

.

A Personalized Approach May Benefit Active Individuals

With

Hemophilia

To submit questions, please text them to 609-400-1695Slide59

Half-life extended rFVIII/rFIX products could facilitate maintenance of desired trough levels during prophylaxis

Some patients may need higher trough levels because of frequent bleeding, presence of target joints, or higher physical activity

Pharmacokinetic profiles may be as individual as lifestyles AgeGenotypes

Clearance mechanismsVWF activity levelsThrombophilia factors

FVIII/FIX activities of at least 15-30% would allow for more "carefree" or "more normal" lifestyles; no monitoring would be necessary; no joint bleeds would be expectedBut at what cost to the individual and to society?59How Can We Reasonably Start to Achieve Higher Trough Levels?Slide60

PK responses to various clotting factor concentrates and the doses administered are patient dependent with inter-individual variance

Dosage of clotting factor replacement required to reach any predetermined plasma level can be optimized for each individual patient according to PK responses

Comparing PK characteristics between new and currently available concentrates is a mandatory regulatory prerequisite to establish bioequivalence before licensing60Pharmacokinetic Studies Why Perform Them?

To submit questions, please text them to 609-400-1695Slide61

Cumbersome and demanding (particularly in children)

Require long washout Crossover with existing licensed product

3 different lots for regulatory purposes and patients concerned about switching10 sampling points on the decay curveMay not reflect real-life conditions such as bleeding, surgery, or exercise

61Pharmacokinetic Studies Why NOT Perform Them?

To submit questions, please text them to 609-400-1695Slide62

Cmax of loading dose for on-demand treatment and for prompt pain relief

In vivo recovery is not a useful predictor for dose optimization for prophylaxisa

Half-life, AUC, and trough for maintenance therapy by repeated bolus administration or continuous infusion Which PK parameter takes into account dose, half-life, AUC, and trough expressing the total exposure of patient to the concentrate?Clearance, because it is the dose/AUC ratio

62

a. Björkman S, et al.

Haemophilia

. 2007;13:2-8.

C

max

Elimination Half-life

AUC

Trough

Which Is the Most Important PK Parameter to

Evaluate

the Efficacy of Replacement Therapy?

To submit questions, please text them to 609-400-1695Slide63

Individual PK can vary by agea

and withinb the patients themselvesIn pediatric and adult studies, t

1/2 has been shown to range from 6 to 25 hours for recombinant FVIIIc,d63

a. Turnheim K.

Exp Gerontol

. 2003;38:843-853; b. Collins PW, et al.

J Thromb Haemost

. 2010;8:269-275; c. Tarantino MD, et al.

Haemophilia

. 2004;10:428-437; d. Blanchette VS, et al.

J Thromb Haemost

. 2008;6:1319-1326.

Postinfusion

Time, h

Individual PK Can Influence When the Individual

Is

at RiskSlide64

The Cmax increased proportionally to the dose, but it was comparable between equal doses of rFVIII and rFVIIIFc

The total exposure (AUCINF

) also increased proportionally to the dose AUCINF of rFVIIIFc was 1.48- and 1.56-fold greater than that of rVIII at 25 IU/kg (P = .002) and 65 IU/kg (P < .001), respectively64

Republished with permission of the American Society of Hematology, from Powell JS, et al.

Blood

. 2012;119:3031-3037; permission conveyed through Copyright Clearance Center, Inc.

Time After Start of Infusion, h

Time After Start of Infusion, h

Plasma FVII Activity, IU/

dL

Plasma FVII Activity, IU/

dL

PK Profiles in Patients With Low Doses

and

High DosesSlide65

As the level of VWF increased, the CL of rFVIIIFc and of rFVIII decreased

As the level of VWF increased, the t1/2 of rFVIIIFc and of rFVIII increased

Fc moiety of rFVIIIFc does not alter the role of VWF in protecting FVIII from clearance65

VWF Antigen, %

VWF Antigen, %T1/2, hCL, mL/h/kgR2= 0.5415P = .0012R2= 0.5492P

= .0016

R2= 0.6403P

= .0003

R

2

= 0.7923

P

< .0001

Republished with permission of the American Society of Hematology, from Powell JS, et al.

Blood

. 2012;119:3031-3037; permission conveyed through Copyright Clearance Center, Inc.

VWF Ag Levels Influence CL and t1/2 of FVIII Activity

After

Infusion of

rFVIII

or

rFVIIIFc

Slide66

Important Conclusions

Adult terminal t1/2 approx 82 h, but initial decay is much faster

Error bars reflect individual variabilityIn the published trial, interval adjusted to keep trough > 1% in this study armThe slope varies on a log scale

66

From Powell JS, et al.

N

Engl

J Med

. 2013;369:2313-2323. Copyright © 2013 Massachusetts Medical Society. Reprinted with permission from Massachusetts Medical Society.

Duration of Factor IX Activity With Recombinant

Factor IX and rFIXFc at a Dose of 50 IU/kg

1 w = 168 h

Time Course of FIX Activity With Standard and

EHL

Factor ProteinsSlide67

67

Republished with permission of the American Society of Hematology, from

Negrier

C, et al.

Blood

. 2011;118:2695-2701; permission conveyed through Copyright Clearance Center, Inc..

The mean t

1/2

 of N9-GP was 93 h which was approximately 5 times longer compared with the patients' previous FIX product (

P

 < .001)

Time, h

FIX Activity, U/mL

Example of N9-GP vs Standard Factor IX ActivitySlide68

Facilitation of PK Monitoring

EMA, WHO, WFH recommend a PK study for every patient who starts a new clotting factor concentrate in order to optimize the patient-specific treatment regimens, taking into account inter-subject variability in drug dispositiona,b

If 10- or 12-point PK is too demanding, reduced 4- or 5-point timing may be used without losing significant informationcPK population models (for FVIII products): results from 3 clinical trials used Bayesian analysis for individual parameters (eg, age, BW, activity score, joint score, etc) Critical time points: 1 h and 9-12 h

68

a. Berntorp E, et al.

Haemophilia

. 2003;9:1-4; b. Shapiro AD, et al.

Haemophilia

. 2005;11:571-582; c. Morfini M, et al.

Haemophilia

. 2015;21:204-209

.Slide69

Requires large population Children and adults differ

Product specificRequires validation: UK and Canadian studies (NCT02528968 and NCT02061072) are under way to collect published and unpublished PK data on all products

Web application: 2-3 samples/patient; no washout used; 18 patientsaBased on physical activity, joint score, and PK parameters, through level chosen and most appropriate dosage for each patient calculated

69

a. Bello IF, et al. ASH 2015. Abstract 3534

.

Facilitation of PK Monitoring (cont)

To submit questions, please text them to 609-400-1695Slide70

The assay method definitely matters

Single stage (PTT-based assays) performance depends on the activating substance; preferred worldwide due to simplicity, automation, and cost control

Kaolin Silica Ellagic acid

27 APTT reagents, 16 FVIII-deficient plasmas; 15 ref plasmas commercially available, making a potential combination of 6480 different APTT assaysaChromogenic assay (probably more uniform)

Risk is at least twofold If the assay underreports true level, we might overtreat If the assay/drug combination doesn’t reflect 60 years of PTT history, we might be fooling ourselves to aim for 1% or any arbitrary levelShould industry create central labs? This will allow interlab comparisons 70

a. UK NEQAS for Blood Coagulation: Survey 203, Version 1. 2014.

Assays

Lab Differences

To submit questions, please text them to 609-400-1695Slide71

Product

Chromogenic/OSCA

Comments

B-Domain Truncated rFVIII (NovoEight)

~ 1Why different from ReFacto? Only slight difference in B-domain linker; tendency of OSCA to underestimate values at high levels and to overestimate values at low levels (NovoEight gp)25-100% variation with different OCSA reagents

Chromogenic testing only

B-domain deleted rFVIIIFc

1.27

OSCA slightly overestimated activity at low levels; no specific APTT reagent discrepancies

B-domain deleted rFVIII, pegylated --

(Bay94-9027)

Some silica OSCAs (little or no activity measured)

With ellagic acid OSCA saw analyser and reagent differences. Rectified by product standard; Chromogenic assay accurate

Pegylated

full-length

rFVIII

~1

All but 2 APTT reagents would be in range

Human-cl rhFVIII

~1

FVIII deficient plasma for APTT needs to have VWF

Sc rFVIII with truncated B-domain and covalent linkage between heavy and light chain

Discrepant between chromogenic and one-stage (more in line with ReFacto)

Use chromogenic assay

71

EMA. Workshop Report. 2014.

Characterization of New FVIII Products

Activity

Assay Assessment

To submit questions, please text them to 609-400-1695Slide72

Product

Chromogenic/OSCA

Comments

glycopegylated rFIX

OSCA with SynthAFax – correlates with chromogenic assaysPegylation affects activity in 1-stage assay, APTT reagent dependent; Chromogenic correlates with non-clinical/clinical efficacyrFIX-FcOSCA with ellagic acid reagent; underestimate with silica and kaolin

Chromogenic kits see lot to lot differences in 1 of kits; See variability in field study of post-infusion testing of spiked samples (0.05-0.8 IU/mL) with OSCA

rFIX –Albumin (rIX-FP)

~1

One-stage clotting assay used

Full-length rFIX

good agreement between one-stage and the 2 chromogenic assays

one-stage clotting activity of a rFIX product is dependent on the APTT reagent when the 4th IS for FIX concentrates is used as the reference. Chose silica type

72

EMA. Workshop Report. 2014.

Characterization of New FIX Products

Activity Assay Assessment

To submit questions, please text them to 609-400-1695Slide73

Measuring rFVIIIFc in the Lab73

Sommer JM, et al.

Haemophilia

. 2014;20:294-300.

To submit questions, please text them to 609-400-1695Slide74

74

Sommer JM, et al.

Haemophilia

. 2014;20:294-300.

Label Activity, IU mL

-1

Mean

Ratio CS

(n = 11 labs)/OS (n = 30 labs)

Mean CS/OS Ratio at Individual Labs

(n =

11*)

Range of CS/OS Ratios at Individual Labs

(n =

11*)

0.80

1.12

1.12

0.81-1.78

0.20

1.02

1.07

0.48-1.61

0.05

0.86

1.00

0.58-1.60

rFVIII

Label Activity, IU mL

-1

Mean

Ratio CS

(n = 11 labs)/OS (n = 30 labs)

Mean CS/OS Ratio at Individual Labs

(n =

11*)

Range of CS/OS Ratios at Individual Labs

(n =

11*)

0.87

1.26

1.27

0.87-2.18

0.22

1.26

1.37

0.59-2.63

0.054

1.04

1.24

0.65-2.08

rFVIIIFc

*Eleven of 30 participating laboratories performed both the one-stage and chromogenic substrate assays.

rFVIIIFc Chromogenic vs One-Stage Assays

To submit questions, please text them to 609-400-1695Slide75

32-year-old man with severe hemophilia B

He is undergoing on-demand treatment

He has 12 bleeds per year with mild arthropathy developing in his shoulderHe has to stock shelves in his warehouse job at the end of every month75

Clinical Case

PresentationTo submit questions, please text them to 609-400-1695Slide76

76

Time

Percent Factor Level

Infusion

For this activity, where on the curve would you want his factor level to be?

A

B

A

B

Clinical Case

QuestionsSlide77

77

How would you achieve this goal?On-demand at the end of the month

ProphylaxisPK testing to determine when to treatClinical Case

QuestionsSlide78

78

What product would you use? Standard half-life product

Extended half-life productClinical Case QuestionsSlide79

Discussion79

Individualized prophylaxis requires PK data and lifestyle considerations, age, etc

Each of the new products will continue to confound how we monitor factor activity levels for each new product in a number of patientsWe can overcome these issues by "overtreating" and always maintaining trough levels > 15%

The original economics of maintaining a 1-3% trough level may not be realistic as pts become more active Chromogenic assays may be the way to go, cost not withstanding; HTCs will need both assay techniques

To submit questions, please text them to 609-400-1695Slide80

Genotyping and Phenotyping: Scientific and Practical Implications

Johannes Oldenburg, MD, PhD

Professor

Institute of Experimental Haematology and Transfusion Medicine

University of Bonn

Bonn, Germany

Developed through a

collaboration between:Slide81

Why Mutation Analysis?

Genetic counselingGenotype -- Phenotype information

Degree of severity Inhibitor riska,bSeverity of bleeding, clinical coursec,d,e

Assay discrepanciesf,g81

a. Oldenburg J, Pavlova A. Haemophilia. 2006;12:15-22; b. Gouw SC, et al. Blood. 2012;119:2922-2934; c. Santagostino E, et al. J Thromb Haemost. 2010;8:737-743; d. Carcao MD, et al. Blood. 2013;121:3946-3952, S1; e. Pavlova A, Oldenburg J. Semin Thromb Hemost. 2013;39:702-710; f. Oldenburg J, Pavlova A. Hamostaseologie. 2010;30:207-211; g. Trossaërt M, et al. J Thromb Haemost. 2011;9:524-530.Slide82

82

26 exons

186 kb

FVIII-gene

Exon

26

14

22

1

cDNA

7 kb

Mature protein

NH

2

COOH

2332 aa

300 kDa

A1

A2

B

A3

C1

C2

Activated

protein

A1

A2

A3

C1

C2

Me

2+

Factor VIII

From Gene to Protein

To submit questions, please text them to 609-400-1695Slide83

Mutation Profile in Hemophilia A83

Severe

phenotype

Severe and

nonsevere

phenotype

Mutation Type

Absolute

(n = 850)

Relative, %

Intron 22 Inversion

302

35.7

Intron 1 Inversion

8

0.9

Stop Mutation

79

9.3

Small del/ins

86

10.2

Large Deletion

25

3.0

Splice Site

22

2.6

Missense Mutation

323

38.2

Oldenburg J, et al.

Haemophilia

.

 2006;12

Suppl

6:15-22.

To submit questions, please text them to 609-400-1695Slide84

84

Mechanism of the Intron 22 Inversion

Factor VIII

Factor VIII To submit questions, please text them to 609-400-1695Slide85

DNA extraction: high molecular weight genomic DNA (needed for intron 22 inversion analysis)

PCR amplification of fragments Inversion 22 inversion testing Intron 1 inversion is analyzed by PCR

Sequencing exons and flanking intronic regions (33 fragments) MLPA-testing (duplication screening in all samples with no mutation found)Time2 wk in the routine setting

Can speed it up to 2-3 d85

F8 Gene Analysis Stepwise ApproachTo submit questions, please text them to 609-400-1695Slide86

Testing Strategy86

Hemophilia A

Intron 1/22 inversions

Positive

Result

Sequencing the

F8

gene

Negative

Large

duplications

Positive

Result

Negative

Hemophilia B

Sequencing the

F9

gene

Result

Large

duplications

Positive

NegativeSlide87

Hemophilia Genotype/Phenotype87

Pavlova A, et al.

Semin Thromb Hemost. 2013;39:702-710.© Georg Thieme Verlag KG.

Environmental Factors

Hemophilia PhenotypeGeneticFactorsPatient DependentBehaviorBody habitus

First joint bleed

Non-patient Dependent

FVIII:C Lab Assays

Treatment

Factor VIII/IX Genotype

Co-inherited Genetic Variables

Severe

Nonsevere

Small del/ins in A stretch of FVIII

Non-conserved splice-site mutations

Missense mutations

Missense mutations with discrepancy between FVIII:C assays

FV Leiden

Thrombophilic gene mutations

Polymorphisms in FVII

Platelets function

Polymorphisms in inflammatory,

immunoregulatory

cytokines genesSlide88

88

Very large number of different gene defects

Majority of mutations are unique to the kindred

Intron 1/22 Inversions

Nonsense

Splice-site mutations

Small del/ins

Large deletions

Severe hemophilia

Missense mutations

Mild/moderate hemophilia

Sometimes: Severe hemophilia

The protein is formed but is functionally less active/inactive

No protein is formed

Genotype/Phenotype

Degree of SeveritySlide89

Characteristics of Patients With Severe Hemophilia Who Are Mild Bleeders

89

Santagostino E, et al. J Thromb Haemost. 2010;8:737-743.

Cases, Mild Bleeders

(n = 22)All Controls(n = 50)Median age, y (IQR)32 (27-43)

38 (30-44)

Hemophilia B, no (%)

7

(32)

4 (8)

Median age at first bleed,

mo

(IQR)

42 (12-75)

12 (12-24)

Median age at first joint bleed,

mo

(IQR)

84 (36-108)

24 (21-48)

Median number of bleeds/y (IQR)

0 (0-1)

20 (9.5-31.5)

Median factor consumption, IU kg

-1

y

-1

(IQR)

60 (37-158)

1957

(862-2238)

Median orthopedic joint score (range)

3 (0-7)

15 (9-24)

Median

Pettersson

score (range)

18 (9-25)

35 (25-46)

Median FVIII antigen, IU dL

-1

(IQR)

1.4 (< 0.5-3.5)

< 0.5 (< 0.5-0.7)

Median FIX antigen, IU dL

-1

(IQR)

9.9 (0.8-148)

< 0.5 (< 0.5-0.8)

Median ETP in PRP, n

m

x min (IQR)

850 (476-1145)

460 (137-830)

Null mutations, no. (%)

2/20 (10)

28/48 (58)

PTG20210A, no. (%)

1/21 (5)

2 (4)

FV

Leiden, no. (%)

0

3 (6)Slide90

Mutation Type and Inhibitor Prevalence 90

0

Prevalence of Inhibitors

100

7550

25

Schwaab R, et al.

Thromb Haemost.

1995;74:1402-1406;

Oldenburg J, Pavlova A.

Haemophilia

. 2006;12:15-22

.

Large

Deletions

41%

Nonsense

31%

Small

Deletions

16%

Intron 22/1

Inversions

21%/17%

Missense

5%

Splice site

3%

Single

Domain

25%

Multi

Domain

88%

Light

chain

40%

Heavy

chain

17%

Non A-Run

21%

A-Run

3%

C1-C2

10%

Non C1-C2

3%

Slide91

91

Eckhardt CL, et al.

Blood.

2013;122:1954-1962.

Heavy ChainLight ChainDistribution of F8 Missense Mutations Associated

With Inhibitor DevelopmentTo submit questions, please text them to 609-400-1695Slide92

Genotype/PhenotypeInhibitor Formation

92

High risk

NON-NULL MUTATIONSMissense mutations -- synthesis of an endogenous but functionally abnormal protein

Low riskNULL MUTATIONS Severe rearrangements in the F8 gene preclude the synthesis of the protein

To submit questions, please text them to 609-400-1695Slide93

Mutation Profile in Hemophilia B93

Giannelli F,

et al.

Nucleic Acids Res

. 1998;26:265-268.To submit questions, please text them to 609-400-1695Slide94

Hemophilia A: 25-30%Hemophilia B: 3-5

%Hemophilia A: 80% null mutation, 20% non-null mutations

Hemophilia B: 20% null mutations, 80% non-null mutationsThe proportion of null mutations (meaning absence of endogenous protein) determines the risk of inhibitor formation.

94Oldenburg J, Pavlova A.

Haemophilia. 2006;12:15-22. Gouw SC, et al. Blood. 2012;119:2922-2934.Epidemiology: Incidence InhibitorsHemophilia A vs Hemophilia BSlide95

The "Good" vs "Bad" Risk Patient

Factors Contributing to Low RiskGenetic Background

Negative family historyNon-severe hemophiliaWhite origin

Missense mutationIL10 134 negativeTNF alpha A2 negative

CTLA4-318 T positiveEnvironmentalEarly prophylaxisAbsence of danger signalsType of concentrate95

Factors Contributing to High Risk

Genetic Background

Positive family history

Severe hemophilia

African origin

Null mutation

IL10 134 positive

TNF alpha A2 positive

CTLA4-318 T negative

Environmental

Early event-based treatment

Intensive treatment

Continuous infusion

Danger signals

Type of concentrateSlide96

96

2.

Individualizing therapy regimen

1.

Determining the a priori risk of inhibitor formation (F8 gene analysis)Low inhibitor risk:"Classical therapy" depending on the bleeding Prophylaxis follows symptoms of bleeding

High inhibitor risk:

"

Early prophylaxis

"

low-dose FVIII exposure, before onset of bleeding, avoiding

"

danger

"

signals

 Prophylaxis at age 9-10 months, once-weekly 250 IU

Kurnik K, et al.

Haemophilia.

2010;16:256-262.

Perspective

Individualization of Therapy Regimens

To submit questions, please text them to 609-400-1695Slide97

Genotype/Phenotype Assay Discrepancies

97

Discrepancies 1/3 of cases with nonsevere hemophilia

or

FVIII:C one-stage > FVIII:C chromogenic

FVIII:C one-stage < FVIII:C chromogenic

NO consensus to which method most accurately represents the FVIII cofactor function in vivo and gives clinically relevant FVIII:C levels

Poulsen AL, et al.

Haemophilia.

2009;15:285-289.Slide98

Assay Discrepancy

Assay discrepancy is related to the geography of the point mutationIn the intersection between A-domains

FVIII:C chromogenic is lower than the one-stage assay. In some instances the phenotype may shift to moderate hemophilia A For example, at thrombin cleavage sites, converse assay discrepancy is foundFVIII:C chromogenic is near normal while the factor VIII:C by one-stage technique corresponds to mild hemophilia

98To submit questions, please text them to 609-400-1695Slide99

Assay DiscrepanciesChromogenic vs One-Stage Ratio

99

Factor

Chromogenic/One-Stage Ratio

Causes of DiscrepancyMissense mutations in F8Localized in the A1-A2-A3 domain interfaces

≤ 0.5

These mutations are associated with reduced stability of the

FVIIIa

heterodimer

Effect is minimized

in the one-stage assay and the prolonged incubation time of the first step of the chromogenic assay favors a higher rate of A2 dissociation leading to reduced FVIII activity

Located close to or within thrombin cleavage

sites, or FIX- or VWF-binding sites

≥ 2

These mutations affect thrombin activation or FVIII binding to

FIXa

or VWF

The one-stage assay is sensitive

to alterations in thrombin binding or cleavage of FVIII whereas the chromogenic assay is not

Peyvandi F, et al.

J Thromb Haemost

. In press.Slide100

Mutations are localized in the A1-A2-A3 domain interfaces

100

Pipe SW,

et al.

Blood. 2001;97:685-691; Yadegari H, et al. Haematologica. 2013;98:1315-1323. 

Literature

Bonn

Chromogenic Assay > One Stage AssaySlide101

Issues of Discrepant FVIII:C Assays101

Setting the cutoff level to define discrepancy

Which assay to use for defining degree of severity and for monitoring treatment?Understanding the mechanisms of discrepancy?Is there a relationship to the assay discrepancies in Bdel rFVIII concentrates/potency issue with one-stage/chromogenic assay?

To submit questions, please text them to 609-400-1695Slide102

New Products ChallengeAssays

ProblemsOne stage vs chromogenic

Potency determination and patient monitoringOptionsUse of chromogenic assayOne stage: use of ellagic acid-based APTT reagentsConcentrate specific reference standards

Conversion factorsGo with a product compatible for the local assay setup

102To submit questions, please text them to 609-400-1695Slide103

QuestionWhich mutation type indicates a low risk of inhibitor formation?

Nonsense mutationLarge deletionMissense mutation

Intron 22 Inversion103Slide104

Summary104

Genotyping has become standard in hemophilia A and B

Genotyping is nowadays mainly driven by the phenotype information less by genetic counselingGenotype is informing about Degree of severity, bleeding frequency

Risk of inhibitor formationFVIII assay discrepanciesGenetics may further be determinants for half-life, subsequent individual dosing, and manifestation of joint arthropathySlide105

Question and Answer Session Submitting Questions

To submit questions to the panel, please email my.question.is1@gmail.com OR

Text 609-400-1695ORUtilize the microphones in the center aisle105Slide106

CME CreditTo receive CME credit:

Complete the evaluation online at www.medscape.org/townhall/current-trends-in-hemophilia The URL will be accessible until December 18, 2015

106

Developed through a

collaboration between: