Mutazioni di HBV in corso di trattamento; quale approccio razionale?

Mutazioni di HBV in corso di trattamento; quale approccio razionale? Prevenire Interpretare Trattare Marco Lagget UODU Gastroenterologia ed Epatologia AOU San Giovanni Battista di Torino

Prevenire 1) Timing

Indication to Treatment is an Integrated Decision LIVER DISEASE STAGE HBVDNA LEVELS INDICATION TO TREATMENT PATIENT PROFILE PREVENTION OF HBV DRUGS RESISTANCE EASL 2009, Stresa 1-2

EASL Stresa 1

Preventire: 2) strategie terapeutiche Short-term: trattamento curativo IFN (S2)/ NUC (S3) Follow-up (mesi/anni) Risposta Durante il trattamento Anti-HBe+ HBV DNA < 2000 UI/ml ALT < UNL Portatore inattivo (PCI) Perdita HBsAg NUC (s) Long-term: trattamento soppressivo HBV DNA < 200 UI/ml Prtatore inattivo (PCI) Perdita HBsAg Anni

Prevenire: 3) scelta del farmaco Nucleoside analogue - Lamivudine - Entecavir - Telbivudine - Emtricitabine Trade name Company Dosage * 2007 ZEFFIX 100 mg/die 89 BARACLUDE 0.5mg/1mg/die 670 SEBIVO* 600 mg/die 693 EMTRIVA ^ 200 mg/die 266 Nucleotide analogue - Adefovir Dipivoxil HEPSERA 10 mg/die 705 - Tenofovir Disopr. Fum. VIREAD 300 mg/die 415 Nucleoside+nucleotide analogue - Emtricitabine + TRUVADA ^ 200 mg+ 713 Tenofovir Disopr. Fum. 300 mg/die ^ Drug approved for HIV *www.farmacieitaliane.it

HBeAg-Positive naive Patients 48 weeks HBe seroconversion Undetectable HBV DNA Normal ALT 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 30% 22% 12% 22% 26% 21% 25% 39% 21% 67% 60% 74% 39% 66% 48% 68% 77% 69% 0% PEG-IFN LAM ADV ETV LdT TDF PEG-IFN LAM ADV ETV LdT TDF PEG-IFN LAM ADV ETV LdT TDF EASL 2009

Dec. 2008 Mean HBV DNA: 8.64 (TNF) vs 8.88 (ADV) Logs Jan. 2009 Mean HBV DNA: 10.26 (ETV) vs 9.88 (ADV) Logs 76% 58%

Entecavir

( LAM ) HBeAg seroconversion: 31% (ETV) vs 26%

Entecavir Risposta in pazienti HBeAg+ ( anni (naïve, 5 ETV-022 HBeAg(+) ETV Long-term Cohort (ETV-022 ETV-901) Proportion of Patients (%) HBV DNA <300 copies/ml 100 80 60 40 20 Year 1 67% Year 1 55% Year 2 83% Year 3 89% Year 4 91% Year 5 94% 0 n = 236/354 80/146 116/140 116/131 98/108 88/94 a a 5 patients who remained on treatment at the Year 5 visit had missing PCR values (NC=M) Han, AASLD 2008

HBV DNA suppression HBeAg(+) ETV Long-term Cohort (ETV-022 ETV-901) 12 10 Mean HBV DNA (log 10 copies/ml) 8 6 4 2 300 copies/ml HBV DNA Suppression 0 0 Year 1 Year 2 Year 3 Year 4 Year 5 n = 146 146 140 131 108 94 a a 5 patients who remained on treatment at the Year 5 visit had missing PCR values (NC=M) Han, AASLD 2008

Resistance Analysis One (0.7%) of the 146 patients in this cohort had ETV resistance (Year 3). This patient also experienced virologic breakthrough Among the 47 patients who discontinued ETV prior to the Year 5 visit, 10 patients (7%) had HBV DNA 300 copies/ml at the last on-treatment measurement Genotypic analysis showed that none had evidence of genotypic ETVr Safety Good, no renal disfunction Han, AASLD 2008

Lactic acidosis (LA) and NUC

HBeAg-Negative naive Patients 48 weeks Undetectable HBV DNA Normal ALT 100% 90% 80% 70% 60% 50% 40% 63% 72% 51% 90% 92% 88% 38% 78% 77% 74% 72% 74% 30% 20% 10% 0% PEG-IFN LAM ADV ETV LdT TDF PEG-IFN LAM ADV ETV LdT TDF EASL 2009

3-yr ETV in HBeAg-negative Re-Treatment cohort Virological response ETV-027 ETV-901 Proportion of patients (%) HBV DNA <300 copies/ml 100 80 60 40 20 0 94% Off-treatment >60 days 93% 94% 95% 91% 83% 59% 4% EOD Baseline Wk 12 Wk 24 Wk 48 Wk 72 Wk 96 Wk 144 n= 93/99 4/99 56/95 79/95 84/90 72/77 67/74 54/57 EOD= end-of-dosing 10 patients who remained on treatment at the Week 144 of ETV-901 visit had missing PCR samples Shouval, AASLD 2008

Tenofovir

2:1 RCTs HBeAg + (176 pts-5 LAM exp) and (250 pts-43 LAM exp) TNF vs HBeAg + (90 pts-1 LAM exp) and (125 pts-23 LAM exp) ADV for 48 weeks HBV DNA negative (< 400 cps/ml/69 IU/mL) Assay: TaqMan cut-off 29 IU/mL HBeAg+ 76% TNF and 13% ADV HBeAg- 93% TNF and 63% ADV (P<0.001) Mean HBV DNA HBeAg+ 8.64 LOG Mean HBV DNA HBeAg- 6.86 LOG

Two Years Tenofovir Disoproxil Fumarate (TDF) Treatment and Adefovir Dipivoxil (ADV) (ITT) Switch Data in HBeAg+ (Heathcote J) and anti-hbe+ (Marcellin ( P Three years (HBeAg+ and anti-hbe+ ITT 81%; OTA 97%), Lee, AASLD 2009 D o u b l e B li n d Y e a r 1 O p e n - l a b e l Y e a r 2 Y e a r 8 RANDOMIZATION 2:1 T e n o f o v i r 3 0 0 m g A d e f o v i r 1 0 m g T e n o f o v i r 3 0 0 m g T e n o f o v i r 3 0 0 m g P r e - t r e a t m e n t L i v e r B i o p s y W e e k 4 8 L i v e r B i o p s y W e e k 7 2 * W e e k 9 6 W e e k 3 8 4 Patients With HBV DNA <400 copies/ml (95% CI) (ITT) Patients with HBV DNA <400 copies/ml (95% CI) (ITT) 100 TDF-TDF ADV-TDF Percentage (%) 100 90 80 70 60 50 40 30 20 10 0 n= n= Randomized Double Blind Open Label 0 8 16 24 32 40 48 56 64 72 80 88 96 Weeks in Study 176 174 170 172 171 168 164 165 90 89 88 88 90 89 87 86 78% 78% P=0.801 Percentage (%) 90 80 70 60 50 40 30 20 10 0 Randomized Double Blind 0 8 16 24 32 40 48 56 64 72 80 88 96 Weeks on Study Open Label TDF-TDF N= 250 245 243 248 247 242 243 234 ADV-TDF N= 125 125 124 120 123 123 122 122 91% P=0.672 89% 18% LAM Exp: 93% 96% Heathcote J, AASLD 2008 Marcellin, P, AASLD 2008

Resistance Surveillance Results No resistance up to 2 years of TDF mono-therapy No HBV pol/rt amino acid substitutions associated with TDF resistance were detected through 96 weeks of TDF monotherapy Safety Good, no renal disfunction

Prevenzione: 4) aderenza ai criteri di risposta Primary non-response Less than 1 log 10 IU/mL decrease in HBV DNA level from baseline at 3 months of therapy Virological response Partial virological response Virological breakthrough Undetectable HBV DNA by real-time PCR assay (<10-15 IU/mL) within 48 weeks of therapy Decrease of HBV DNA of more than 1 log 10 IU/mL but detectable HBV DNA by real-time PCR at 24 or 48 weeks of therapy (according to drug potency and genetic barrier to ( resistance Confirmed increase in HBV DNA level of more than 1 log 10 IU/mL compared to the nadir HBV resistance to NUCs Selection of HBV variants with amino acid substitutions that confer reduced ( NUC(s susceptibility to the administered EASL 2009

Partial virologic response to NUCs (%) and risk of resistance Resistance rate % LdT LAM 39% ADV 49% 40 35 30 25 20 15 10 5 0% 1% 6% 13% 7% 25% 20% 50 40 30 20 10 6% 0 <QL QL-3 log 3-4 log >4 log 0 <3 log >3 log HBV DNA at week 24 HBV DNA at week 48 Lai et al AASLD 2005 Hadziyannis et al, Gastroenterology 2006

Terapia di prima linea con analoghi nucleos(t)idici ( PVR ) Risposta virologica parziale 100 24 settimane 48 settimane * 16% 72w ^ 22% 72w * 6% 72w ^ 1-9 % 72w HBeAg+ HBeAg+ % PVR 50 0 56% Anti-HBe+ 87% Anti-HBe+ 69% 20% 29% 33*% 24^% 37% 10*% 8^% LDT LAM ADV ETV TNF

Prevenzione: 4) aderenza ai criteri di risposta Primary non-response Less than 1 log 10 IU/mL decrease in HBV DNA level from baseline at 3 months of therapy Virological response Partial virological response Virological breakthrough Undetectable HBV DNA by real-time PCR assay (<10-15 IU/mL) within 48 weeks of therapy Decrease of HBV DNA of more than 1 log 10 IU/mL but detectable HBV DNA by real-time PCR at 24 or 48 weeks of therapy (according to drug potency and genetic barrier to ( resistance Confirmed increase in HBV DNA level of more than 1 log 10 IU/mL compared to the nadir HBV resistance to NUCs Selection of HBV variants with amino acid substitutions that confer reduced ( NUC(s susceptibility to the administered EASL 2009

Cumulative Incidence of HBV Resistance in naive patients 100% 90% Year 1 Year 2 80% 70% 70% 67% Year 3 Year 4 Year 5 60% 50% 49% 40% 38% 30% 20% 24% 18% 29% 22% 10% 0% LAM 3% 0% 11% ADV 0.5% 1.2% 4% 0.2% 1.2% 1.2% 0% ETV LdT TDF EASL 2009

Long-Term Treatment with NUCs suppressive strategy Indicated in HBeAg-positive patients who achieve an HBe seroconversion did not HBeAg-negative patients The most potent drugs with the optimal resistance profile should be used as first-line monotherapies: Tenofovir Entecavir EASL 2009

Interpretare Keefee, J Vir Hep 2009 Marzano, 2007

Trattare la resistenza: Switch-to o Add-on

Add-on vs switch-to strategy ( 3y ) in 588 e-chb LAM-R patients 100 % Patients with HBV DNA < 3 log cp/ml 80 60 40 20 59% P<0.001 74% 0 ADV mono ADV+LAM Lampertico & Marzano, AASLD 2006

Add-on vs. switch-to strategy ( Logs in 42 LAM-R patients (HBV DNA > 5 % Patients with HBV DNA < 3 log cp/ml 100 80 60 40 20 0 38% ADV mono ( 21 ) P<0.05 81% ADV+LAM (21) Gaia & Marzano, J Hepatol 2008

Add-on versus switch-to ADV in ( resistance LAM-R HBeAg- CHB (ADV Patients with ADV-R (%) 40 35 30 25 20 15 10 5 0 A randomized controlled study 30% ADV mono (n=265) P<0.05 6% ADV+LAM (n=272) Lampertico & Marzano AASLD 2006

Lamivudine-Refractory Cohort (HBeAg+): Cumulative Probability of ETV Resistance Through 5 Years 100% ETVr = LVDr (M204V ± L180M) + T184, S202 and/or M250 substitutions ETVr + Virologic Breakthrough ( 1( 1 log increase from nadir) Cumulative Probability (%) 75% 50% 25% 0% Years 6 1 1 N=187 15 2 11 N=146 36 3 27 N=80 46 4 41 N=53 51 5 43 N=33 72/187 (39%) achieved HBV DNA < 300 c/ml; 3/72 (4%) had subsequent genotypic ETV resistance

Detection of Mutations Associated With Resistance to Nucleos(t)ide Analogues in Patients With HBV Infection During Treatment With Tenofovir P r o b a b ilit y o f A c h ie v in g H B V D N A le v e ls < 4 0 0 c o p ie s /m L w it h T e n o f o v ir M o n o t h e r a p y in H B V - m o n o in fe c t e d P a tie n t s A c c o r d in g t o t h e P r e s e n c e o f R e s is t a n t V a r ia n ts 1.0 0.8 P < 0.0 0 0 1 0.6 0.4 0.2 0.0 0 6 1 2 1 8 2 4 P a tie n ts u n d e r o b s e r v a tio n m o n th s W t L V D -R A D V -R 2 0 2 2 6 2 0 2 2 6 1 7 1 8 6 1 5 1 2 5 1 0 9 4 K a p la n -M e ie r A n a ly s is ; P < 0.0 0 0 1, lo g ra n k. W t: w ild ty p e ; L V D : la m iv u d in e ; A D V : a d e fo v ir d ip iv o x il Van Bommel, AASLD 2008

Add-on strategy 3-4 yrs ADV+LAM treatment in 145 LAM-R pts: virological response and ADV resistance Years of treatment (1) Virologicalresponse 1 2 3 4 (n=145) (n=112) (n=78) (n=39) HBV-DNA <35 cp/ml (2) 86 (61%) 78 (70%) 62 (79%) 32 (82%) Virologic breakthrough (3) 0 0 0 0 Genotypic ADV-R (4) 0 0 0 0 rta181t (5) 1 (0.7%) 1 (0.9%) 1 (1.3%) 0 (1) Median follow-up: 42 months (range 12-76) (2) TaqMan real time PCR assay, LLQ: 1.5 log copies/ml (3) > 1 log HBV-DNA compared to on treatment nadir, tested every 3 months (4) rtn236t and rta181v by INNOLiPA V2 assay (5) as a mixed viral population with rta181a Lampertico et al, Gastroenterology 2007

Early vs late treatment in LAM-R patients Cumulative virologic response by baseline viremia in 52 subjects 1,0 < 4 log HBV DNA %,8 4-5 log HBV DNA >5 log HBV DNA p<0,05 p< 0,0001,6,4,2 0,0 0 4 8 12 16 Months Uni and Multivariate analysis: Basal HBV DNA load ( p<0.001,rr3.8,ci 95% 1.7-8.6) and HBeAg+ (p<0.01, RR 3.6, CI 95% status 1.2-10.6) predicted VR. Basal ALT, age, sex, serum creatinine, stage of disease, therapeutic strategies: did not predict VR at univariate analysis. Gaia & Marzano, J Hepatol 2008

In vitro Tenofovir sensitivity of HBV populations from clinical specimens containing rta181t/v and or rt236t The presence of 50% of rta181t/v and/or N236T mutations did not have an impact of TNF susceptibility in an in vitro phenotypic assay ( 434 ) Kitrinos Km et al., AASLD 2009

Management of HBV Resistance Lamivudine resistance Add tenofovir Telbivudine resistance Add tenofovir* Entecavir resistance Adefovir resistance Tenofovir resistance** Add tenofovir* Switch to tenofovir and add a second drug If N236T, add lamivudine, entecavir* or telbivudine* or switch to Truvada If A181V/T, add entecavir* or switch to Truvada Do genotyping and phenotyping in an expert lab to determine the cross-resistance profile Add entecavir*, telbivudine*, lamivudine or switch to Truvada Nucleoside Nucleotide *the long-term safety of these combinations is unknown **not seen so far EASL 2009

2010 and more.challenge Partial Virological Response and Resistance Check for compliance Resistance surveillance and knowledge Patients receiving lamivudine, adefovir or telbivudine with a partial virological response at week 24: Either change to a more potent drug (tenofovir or ( entecavir Or add a more potent drug that does not share crossresistance Patients receiving tenofovir or entecavir with a partial virological response at week 48: Add the other drug in order to prevent resistance in the long term