HBV quantitative sAg

assay: Ready for Prime

time?

yes

Robert G Gish MD

Professor Consultant, Stanford University

Medical Director: Hepatitis B Foundation

1

Relevant Disclosures

Consultant: Abbott, Genentech (Roche), Gilead

2

Refining Current Treatments:

Treatment Endpoints

Long-term suppression of HBV DNA

– Ideally by achievement of HBsAg seroconversion

HBeAg-positive

– Sustained HBeAg seroconversion

– If no HBeAg serconversion--> suppression of HBV DNA to low levels

HBeAg-negative

– Sustained low level HBV DNA

• On treatment if nucleosides

• Off treatment if peg-IFN

AASLD Guidelines 2009 EASL Guidelines 2012

APASL Guidelines 2012

Benefits of HBsAg Clearance

Hepatic decompensation

HCC

Survival

Levels of cccDNA

As close to cure as we can

expect to achieve in chronic

hepatitis B

Fattovich G, et al. Am J Gastro 1998; 93:896-900. Werle-Lapostolle B, et al. Gastroenterology 2004;

126(7):1750-1758. Perrillo R. Hepatology 2009; 49:1063-1065.

HBeAg-

positive

CHB

Biomarker Level PPV NPV Ref

Baseline

HBsAg 5,000

50,000

42%

77%

Piratvisuth,

HI 2011

HBeAg ≤ 31 PE

> 1300

54%

76%

Fried. Hepatology 2008

Week 12 HBsAg < 1500 55% Piratvisuth, HI 2011

Sonneveld, Hepatology

2011

No decline 97%

Vs.

82/71%

Sonneveld, Hepatology

2011

Piratvisuth, Hepatology

2011

>20,000 84% (93%) Piratvisuth, HI 2011

HBeAg < 10 53% Fried, Hepatology 2008

Week 24 HBsAg > 20,000 85% (95%, 100%)

HBeAg > 100 Fried, Hepatology 2008

HBsAg, HBeAg Levels for Prediction

of Anti-HBe Seroconversion

J Hepatology 2011;55:1121

1 IU/ml = 1-10 ng/ml HBsAg

= 2 x 108 subviral particles HBsAg

= 5 x 107 virions

What is a Significant Change?

• > 4 fold change

• > 1.0 log IU/ml

HBeAg-Positive

Chronic Hepatitis B

On-treatment HBsAg levels can predict:

PEG-IFN treatment response

Sonneveld et al. Hepatology 2013

Week HBV genotype HBsAg Rule N identified PPV response

Week 12 A (n=98) <1500 IU/mL 14 (14%) 86%

1500 - 20,000 42 (42%) 41%

>20,000 IU/mL 42 (42%) 17%

B (n=199) <1500 IU/mL 60 (30%) 42%

1500 - 20,000 101 (51%) 26%

>20,000 IU/mL 38 (19%) 8%

C (n=377) <1500 IU/mL 89 (24%) 42%

1500 - 20,000 221 (59%) 20%

>20,000 IU/mL 67 (18%) 2%

D (n=105) <1500 IU/mL 2 (2%) 0%

1500 - 20,000 28 (27%) 7%

>20,000 IU/mL 75 (71%) 4%

* Response = HBeAg loss + HBV DNA < 2,000 IU/mL

On-Treatment HBsAg Levels

Identify Good Responders*

Sonneveld et al. Hepatology 2013

Week HBV genotype HBsAg Rule N identified NPV response

Week 12 A (n=55) No decline* 13 (24%) 100%

B (n=120) >20,000 IU/mL 24 (20%) 92%

C (n=225) >20,000 IU/mL 45 (20%) 98%

D (n=54) No decline 33 (61%) 97%

Week 24 A (n=55) >20,000 IU/mL 24 (44%) 96%

B (n=122) >20,000 IU/mL 16 (13%) 100%

C (n=224) >20,000 IU/mL 27 (12%) 100%

D (n=53) >20,000 IU/mL 36 (68%) 100%

* HBsAg decline < 10%

On-Treatment HBsAg Levels

Identify Futility: Stopping Rules

HBeAg-Negative

Chronic Hepatitis B

On-treatment HBsAg levels

can provide:

Futility Rule

Rjickborst, J Hepatology 2012 * HBV DNA < 2,000 IU/mL and normal ALT

Validation cohorts (ph III / PegBeLiver)

(n = 160, genotype D = 91)

No

N = 84 (53%)

Yes

N = 76 (48%)

< 2 logs

N = 22 (14%)

2 logs

N = 62 (39%)

< 2 logs

N = 22 (14%)

2 logs

N = 54 (34%)

37% 45% 43% 5%

HBsAg decline

Week 12

HBV DNA decline

Week 12

SVR*

STOP

Combination of HBsAg and HBV DNA

to Predict SVR in HBeAg-Negative CHB

Predicting HBeAg Seroconversion (HBV DNA compared with quantitative HBeAg)

HBeAg level at Week 24 (Paul Ehrlich units)

HBeAg seroconversion Week 72

All patients

(n=263) > 100 52% NPV 96% 4% (3/72)

HBV DNA level at Week 24 (copies/mL)

All patients (n=263)

> 9.0 log10 21% NPV 86% 14% (8/59)

Fried MW, et al. Hepatology 2008;47:428-434.

NPV = negative predictive value.

Response Guided Therapy for Peg-

Interferon in the Treatment of Hepatitis B

Week 12 and 24 are the Key

HBeAg - Positive HBeAg - Negative

Week 12 – Define Possible Non-Responders Week 12 – Define Possible Non-Responders

Week 24 – Define the Level of Treatment Response Week 24 – Define the Level of Treatment Response

High: HBsAg < 1,500 IU/ml

Mid: HBsAg 1,500 to 20,000 IU/ml

Low: HBsAg > 20,000 IU/ml

High: HBsAg decline >10%

Low: HBsAg decline < 10%

Chan, HLY et al 2011. J Hepatol;55:1121

Criteria:

1) Absence of HBsAg decline OR

2) HBsAg > 20,000 IU/ml

Criteria:

1) Absence of HBsAg decline AND

2) HBV DNA reduction < 2 log

HBsAg decline can predict HBsAg loss on

tenofovir

N=266 patients treated with tenofovir (or adefovir-tenofovir) for 2 years

N=266 overall N=16 cleared HBsAg

0 12 24 36 48 60 72 84 96

0

-25000

-50000

-75000

-100000

-125000

-150000

Weeks of study

HB

sAg

(IU

/mL)

HBsAg levels during treatment

0 12 24 36 48 60 72 84 96

Weeks of study

HBV DNA levels during treatment 0

-2

-4

-6

-8

Ch

ange

fro

m b

ase

line

in H

BV

D

NA

lo

g 10

co

pie

s/m

L)

Heathcote et al. EASL and AASLD 2009

HBsAg Serum Levels Vary in the

Different Phases of HBV Infection

Combined single-point quantification of serum

HBsAg and HBV DNA levels

– Accurate diagnosis of the inactive carrier with

immune control

HBsAg quantification is a new, reliable

diagnostic tool

– Likely to improve (in conjunction with viral load)

the management of chronic HBV infection and

disease

Summary #1

HBsAg in Natural History

HBsAg is an old marker with new applications

HBsAg clearance is the closest to cure in CHB:

functional cure

HBsAg quantification provides additional clinical

guidance:

– Helps determine phase of infection

– The increasing access to quantification assay will foster

learning about how to use it to manage both carriers and

patients more effectively

Threshold levels can be set which predict for inactive

carrier status in HBeAg-negative patients

– Levels of 500 – 1000 should be evaluated further

After S Locarnini 2014

Summary #2

HBsAg Seroclearance as an Endpoint

HBsAg seroconversion is the hallmark of successful immunological control of HBV infection

– Associated with favourable long-term clinical outcomes including a lower incidence of cirrhosis and improved survival

– Can be induced by IFN-based therapy

– Less commonly achieved in patients treated with direct antiviral therapies, i.e. nucleos(t)ide analogues

Most patients have persistently normal ALT levels

Is usually associated with improvement of liver biochemistry

Most patients have undetectable serum HBV DNA with 6-12 months

Still harbour HBV DNA in the liver (cccDNA), but transcriptionally inactive

HCC still did develop in some patients, but only in those over 50 years of age

qHBsAg provides a great NPV:

– Can HBsAg quantification provide a predictive value?

Yuen, M-F. et al 2008. Gastroenterology;135:1192-1199 After S Locarnini 2014

Summary #3

HBsAg in Response Guided Therapy

On-treatment monitoring of HBsAg with or without

HBV DNA offers the prospect of response-guided,

individualized therapy in patients with CHB

– PEG-IFN

• On-treatment HBsAg decline is associated with sustained

immune control

– NAs

• HBsAg monitoring may help identify patients who are able to

stop treatment

HBsAg monitoring has the potential to guide

patient management in the future

After S Locarnini 2014

Start TDF during follow-up if prespecified safety criteria met

Study GS-US-174-0149 Design

Randomized, controlled, open-label study (N=740)

– Stratified by screening HBeAg status and HBV genotype

Inclusion criteria

– HBeAg+ and HBV DNA ≥20,000 IU/mL; HBeAg- and HBV DNA ≥2,000 IU/mL

– ALT >54 and ≤400 U/L (men); ALT >36 and ≤300 U/L (women)

– No bridging fibrosis or cirrhosis on liver biopsy or by transient elastography

0 48 120 72

TDF + PEG

TDF+PEG → TDF

24

n=186

n=184

n=185

n=185 PEG

16

TDF

Week

Primary endpoint: HBsAg loss

H Chan, EASL 2015

Results: HBsAg Loss Over Time (Week 72) P

atie

nts

w

ith

HB

sA

g L

oss,

Kapla

n-M

eie

r E

stim

ate

(%

)

0.10

0.09

0.08

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0.00

48 weeks

0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72

Week

0.15

0.14

0.13

0.12

0.11

72 weeks

TDF + PEG 16 wk →TDF 32 wk

TDF + PEG 48 wk 9.1%

0%

2.8%

2.8%

p=0.003

p<0.001

p=NS

p=NS PEG 48 wk

TDF 120 wk

7 patients had HBsAg seroreversion on or after Week 48 (4 [TDF + PEG 48 wk],

3 [TDF + PEG 16 wk →TDF 32 wk])

– 5/7 had ≤1 week of therapy after HBsAg loss H Chan, EASL 2015

On-Treatment Predictors of HBsAg Loss at

Week 72

Univariate

p-value

Multivariate

p-value

Hazard

Ratio*

HBsAg decrease >1 log10 IU/mL

by Week 12 <0.001 <0.001 17.8

HBsAg <100 IU/mL at Week 12 <0.001

HBsAg <1000 IU/mL at Week 12 <0.001

HBsAb >10 mIU/mL at Week 12 0.138 0.003 9.97

HBV DNA <15 IU/mL at Week 12 0.014 0.070 15.68

ALT >400 U/L (males) or >300 U/L

(females) during first 12 weeks <0.001 0.031 2.85

*Multivariate

H Chan, EASL 2015

Stopping TDF After Long-Term Virologic

Suppression in HBeAg-Negative CHB

36

FINITE CHB

Randomized

N=45

Withdrew consent

n=3

Week 48

TDF-Restart

n=3

Week 48

TDF-Stop

n=18

Week 48

TDF-Continue

n=21

TDF-Stop

n=21

TDF-Continue

n=21

86% of TDF-Stop subjects did not restart TDF by Week 48

Berg, EASL, 2015, O119

37

* TDF-Restart

-1 1 3 5

HBsAg (log10 reduction)

-1 1 3 5

HBsAg (log10 reduction)

TDF-Stop (n=21) TDF-Continue (n=20)

*

*

*

HBsAg Log10 Reduction: Median 0.283 Mean 0.773 HBsAg loss n=2

HBsAg Log10 Reduction: Median 0.088 Mean 0.109 HBsAg loss n=0

Week 48 HBsAg log10 Reduction (Individual Patients)

FINITE CHB

Stopping TDF was associated with a more profound decline in HBsAg levels compared to continuous TDF

HBsAg loss

HBsAg loss

Berg, EASL, 2015, O119

Immuno-Virologique

1Hôpital Saint Joseph, Marseilles, France,2INSERM UMR-S1136 Saint Antoine Paris,3

1Hôpital Saint Joseph, Marseilles, France,2INSERM UMR-S1136 Saint Antoine Paris,3

Titre document / Le 15 - 09 - 2013

38

EASL 2015 / April 22-26 - Vienna

HBsAg clearance after addition of 48 weeks of PEGIFN in HBeAg negative CHB patients on NUC therapy with undetectable HBV DNA for at least one year : Final results from ANRS-HB06 PEGAN study : a multicenter randomized controlled phase III trial.

Marc Bourlière1, Pascaline Rabiega2, Nathalie Ganne-Carrie3, Lawrence Serfaty4, Patrick Marcellin5, Noëlle Pouget2, Dominique Guyader6, Christophe Hezode7, Magali Picon8, Xavier Causse9, Vincent Leroy10, Jean Pierre Bronowicki11, Ghassan Riachi12, Isabelle Rosa13, Pierre Attali14, Jean Michel Molina15, Yannick Bacq16, Albert Tran17, Jean Didier Grangé18, Fabien Zoulim19, Hélène Fontaine20, Inga Bertucci21, Magali Bouvier-Alias22, Fabrice Carrat 2, Yves Benhamou 23 and the ANRS HB06 PEGAN Study Group.

1Hôpital Saint Joseph, Marseille, France,2INSERM UMR-S1136 Saint Antoine Paris,3Hôpital Jean Verdier, Bondy, 4 Hôpital Saint Antoine, Paris,5 Hôpital Beaujon , Clichy, 6Hôpital Pontchaillou, Rennes,7Hôpital Henri Mondor, Créteil, 8Centre Hospitalier du Pays d’Aix, Aix en provence, 9 Hôpital de la Source, Orléans, 10CHU Grenoble, 11Hôpital de Brabois, Nancy, 12Hôpital Charles Nicolle, Rouen, 13 CHIC Créteil , 14Hôpital Bicêtre, Le Kremlin Bicêtre, 15Hôpital Saint Louis Paris, 16Hôpital Trousseau, Tours, 17Hôpital de L’Archet, Nice, 18Hôpital Tenon, Paris, 19Hôpital Hotel Dieu Lyon, 20Hôpital Cochin, Paris, 21Inserm-ANRS, 22INSERM U635, 23Hôpital La Pitié Salpétrière, Paris.

Study Design

40

N=185 CHB patients

HBeAg negative

N=185 CHB patients

HBeAg negative

N=92 N=92 N=90* N=90*

W-6 W0 W48 W96 W144§

N=93 N=93

ran

do

miz

atio

n

* 1 patient withdrew consent and 1 patient excluded for major deviation inclusion criteria as pre-specified. § Visits W144 are ongoing.

Pti

mar

y e

nd

po

int PEGIFN α2a 180 µg/Wk

NUC treatment

Randomized, controlled, open-label study (N=185). Stratified by HBsAg titer (<2.25 log IU/ml or ≥2.25log IU/ml)

Key inclusion criteria HBeAg negative Undetectable HBV DNA with NUC for at least 1 year Stable NUC regimens for at least 3 months (no Telbivudine) No decompensated cirrhosis

Patients in the PEGIFN group were monitored monthly during the first 48 weeks, then every 3 months.

Treatment discontinuation was allowed if HBsAg loss was sustained for 24 weeks.

N=93 N=93

Bourliere EASL 2015

Efficacy : HBsAg loss and HBs seroconversion

45

All patients included, N (%) NUCs Alone PEGIFN + NUCs

P-Value

Randomization stratification Log10(IU/ml) < 2.25 ≥2.25 Total < 2.25 ≥2.25 Total

N=15 N=78 N=93 N=14 N=76 N=90

W48 Loss of HBsAg 0 (0) 0 (0) 0 (0) 3 (22) 4 (5) 7 (8) 0.0057

HBs seroconversion 0 (0) 0 (0) 0 (0) 2 (14) 2 (3) 4 (4) 0.0384

W96 Loss of HBsAg 2 (13) 1 (1) 3 (3) 4 (29) 3 (4) 7 (8) 0.1521

HBs seroconversion 0 (0) 1 (1) 1 (1) 3 (21) 3 (4) 6 (7) 0.0465

Patients Per Protocol, N(%)

NUCs Alone PEGIFN + NUCs

P-Value N=15 N=78 N=93 N=12 N=73 N=85

W48 Loss of HBsAg 0 (0) 0 (0) 0 (0) 3 (25) 4 (6) 7 (8) 0.0038

HBs seroconversion 0 (0) 0 (0) 0 (0) 2 (17) 2 (3) 4 (5) 0.0296

W96 Loss of HBsAg 2 (13) 1 (1) 3 (3) 4 (33) 3 (4) 7 (8) 0.1038

HBs seroconversion 0 (0) 1 (1) 1 (1) 3 (25) 3 (4) 6 (7) 0.0341

Patients Per Protocol full dose of PEGIFN, N (%)

NUCs Alone PEGIFN + NUCs

P-Value N=15 N=78 N=93 N=10 N=55 N=65

W48 Loss of HBsAg 0 (0) 0 (0) 0 (0) 3 (30) 4 (7) 7 (11) 0.0011

HBs seroconversion 0 (0) 0 (0) 0 (0) 2 (20) 2 (4) 4 (6) 0.0145

W96 Loss of HBsAg 2 (13) 1 (1) 3 (3) 4 (40) 3 (5) 7 (11) 0.0415

HBs seroconversion 0 (0) 1 (1) 1 (1) 3 (30) 3 (5) 6 (9) 0.0131

Bourliere EASL 2015

52

Univariate analysis

All patients included

N=7/90

Patients Per Protocol

N=7/85

Patients Per protocol full dose of PEGIFN N=7/65

OR IC 95% P-value OR IC 95% P-value OR IC 95% P-value

HBeAg at diagnosis (- vs +) 2.77 0.37 18.27 0.3865 2.80 0.37 18.62 0.3814 2.74 0.35 18.99 0.4137

HBsAg at randomization by decreasing unit (log10)

3.43 1.09 12.47 0.0339 3.60 1.11 13.64 0.0300 4.00 1.17 16.41 0.0240

Fibrosis (F3-F4 vs F0-F2) 2.49 0.39 18.25 0.4319 2.30 0.36 16.86 0.4971 2.92 0.44 22.20 0.3368

Previous PEGIFN treatment (yes vs no) 2.33 0.37 17,00 0.4804 2.23 0.35 16.31 0.5190 2.32 0.36 17.37 0.4998

Related to HBs seroconversion

Age, sex, origin, IL-28B profil, duration of undetectable HBV DNA from first undetectability and from latest undetectability were tested and were not significant.

Univariate analysis

All patients included

N=6/90

Patients Per Protocol

N=6/85

Patients Per protocol full dose of PEGIFN N=6/65

OR IC 95% P-value OR IC 95% P-value OR IC 95% P-value

HBeAg at diagnosis (- vs +) 3.74 0.46 30.64 0.2594 3.78 0.46 31.22 0.2555 3.71 0.44 31.77 0.2774

HBsAg at randomization by decreasing unit (log10)

3.50 1.02 14.29 0.0465 3.68 1.04 15.59 0.0419 4.03 1.09 18.22 0.0349

Fibrosis (F3-F4 vs F0-F2) 1.81 0.23 14.42 0.7611 1.67 0.21 13.33 0.8374 2.08 0.25 17.51 0.6498

Previous PEGIFN treatment (yes vs no) 3.55 0.48 41.37 0.2838 3.40 0.46 39.73 0.3096 3.54 0.47 42.28 0.2947

Related to HBsAg loss

Baseline predictive factors at W96 in PEGIFN group

Bourliere EASL 2015

W96 HBsAg loss according to HBsAg titer at inclusion

53

All patients included NUCs Alone

N=93 Trend test

PEGIFN + NUCs N=90

Trend test

HBsAg titer at W0 (log10 IU/ml), N <2 2/12

0.0038 2/8

0.0245 2-3 1/22 3/26 ≥3 0/59 2/56

Patients Per Protocol NUCs Alone

N=93 Trend test

PEGIFN + NUCs N=85

Trend test

<2 2/12 0.0038

2/7 0.0200 2-3 1/22 3/25

≥3 0/59 2/53

Patients Per Protocol full dose of PEGIFN

NUCs Alone N=93

Trend test

PEGIFN + NUCs N=65

Trend test

<2 2/12 0.0038

2/6 0.0150 2-3 1/22 3/16

≥3 0/59 2/43

HBsAg loss is associated with low baseline HBsAg titer.

HBsAg titer (log10IU/ml) NUCs Alone

N=93

PEGIFN+NUCs

N=65

< 2 log10 IU/ml 16% 33%

< 3 log10 IU/ml 8% 23%

> 3 log10 IU/ml 0% 4%

Bourliere EASL 2015

Conclusions of ANRS HB06 PEGAN

Addition of a 48 weeks of PEGIFN α2a to NUCs therapy in HBeAg negative CHB patients with undetectable HBV DNA for at least one year, results in higher rates of HBsAg loss and HBs seroconversion.

Low baseline qHBsAg levels increase HBsAg loss and HBs seroconversion at week 96.

However, acceptability of such regimen in patients treated with NUCs is poor and discontinuation due to adverse events occurred in 20% of the patients.

Therefore, this combination should be proposed in a selected HBeAg negative CHB patients population.

56 Bourliere EASL 2015

Variable HR IC 95% p

HBV DNA negative 2.37 1.34 – 4.19 0.03

HBsAg <1000 IU/ml 49.4 6.76 – 361.02 <0.001

Multivariate analysis:Factors associated with HBsAg clearance

HBV DNA

Positive

Cu

mu

lati

ve

p

rob

ab

ilit

y

Cu

mu

lati

ve

p

rob

ab

ilit

y

Negative

≥ 1000 IU/ml

< 1000 IU/ml

HBs Ag

González-Diéguez EASL 2015

Groups of patients with a significant different

probability of HBsAg loss at fifth year

Based on HBsAg

n= 151

HBV DNA positive

and

HBsAg >1000 IU/mll

HBV DNA negative

and

HBsAg <1000 IU/mll

HBV DNA negative

or

HBsAg <1000 IU/mll

n= 101

n= 45 P < 0.001

53.5%

27.2%

0%

Based on HBV-DNA and HBsAg

53 %

12.2 %

0% n= 160

HBsAg >

1.000 IU/ml

HBsAg < 100

IU/mll

HBsAg 100-

1000 IU/ml

n= 55

n= 79 P < 0.001

González-Diéguez EASL 2015

77 Liiu EASL 2015

Conclusions part II

Discovery of HBsAg has revolutionized the diagnosis and

management of HBV infection

A highly sensitive HBsAg test that is able to detect most surface

region mutant is important to avoid false negative results

HBsAg quantification – Combined with viral load, improve the

management of chronic HBV infection

Serum HBsAg quantification can provide additional information on the

transcriptional activity and amount of cccDNA inside the liver

Low HBsAg level can identify inactive carriers and predict lower risk

of HCC

On-treatment HBsAg quantification can predict response to peg-

interferon

Monitoring of serum HBsAg level can potentially time the cessation of

oral antiviral therapy

Over 3 Million qHBsAg assays are used worldwide each

year = Prime time is here !

Thank you to my sAg Gurus

Henry Chan

Harry Janssen

Steve Locarnini

Pietro Lampertico

Seng-Gee Lim and the post-

EASL Singapore Viral

Hepatitis Meeting

79