1. 1 FDA Advisory Meeting Clinical Trial Design – Hepatitis B Treatment Anna S.F. Lok, M.D. University of Michigan Ann Arbor, M I

2. 2 TREATMENT OF CHRONIC HEPATITIS B Review of sentinel trials and meta- analysis of randomized controlled trials of Interferon (IFN) and Lamivudine (LAM) Clinical Practice Guidelines Issues for future clinical trials

3. 3 Goals of Antiviral Treatment of Chronic Hepatitis B 1. Sustained suppression of HBV replication Decrease in serum HBV DNA to <10 5 copies/ml HBeAg to anti-HBe seroconversion HBsAg to anti-HBs seroconversion 2. Remission of liver disease Normalization of serum ALT levels Decreased necroinflammation in liver 3. Improvement in clinical outcome Decreased risks of developing cirrhosis, liver failure and HCC Increased survival

4. 4 Review of Clinical Trials of IFN and Lamivudine Study population –HBeAg+ CHB –HBeAg- CHB –Decompensated cirrhosis Inclusion/exclusion criteria Treatment regimen Sample size End-points, response rates Ability of measurements of response to predict outcome

5. 5 Sentinel Clinical Trials of IFN and LAM in HBeAg + CHB IFN *LAM # ControlsNo R x Placebo No. of patients/arm10 – 10166 – 143 Sample SizeNot DiscussedPower for 1° end-point 1° End PointHBeAg & HBV DNA loss Decrease in HAI by >2 points HBV DNA Assay ------dot-blot/liquid hybridization * liquid hybridization #

6. 6 ‘Sentinel’ Clinical Trials of IFN and LAM in HBeAg- CHB IFN*LAM # Entry CriteriaHBV DNA+,  ALT ControlsSome trials1 trial Sample SizeNot discussed Duration of R x 3-24 months12 months - infinity 1° End PointNormal ALT, HBV DNA- HBV DNA Assay – dot blot/liquid hybridization * liquid hybridization, bDNA, hybrid capture, PCR #

7. 7 Meta-analysis of 24 RCTs of IFN in HBeAg+ CHB 855 IFN R x, 444 no R x Response Parameters Difference in Response Rate 95% CIP Value ALT normalization 26%18% - 34%<0.00001 Clearance of HBeAg 24%8%-29%<0.00001 Sustained loss of HBV DNA 23%18% - 29%<0.00001 Clearance of HBsAg 6%4% - 8%<0.00001 Craxi et al., J Hepatol (in press)

8. 8 Meta-analysis of 12 Studies of IFN Rx on Long-Term Outcome of HBeAg+ Adults # 765 IFN Rx, 1210 no R x * Mean FU 6·1 yr (2.1 – 8.9 yr) IFN (95% CI)No R x (95% CI) Loss of HBsAg11.4% (9.1 - 13.7)2.6% (1.8 - 3.4) Hepatic Decompensation 9.8% (7.7 - 12.1)13.3% (10.1 - 16.4) Development of HCC1.9% (0.8 - 3.0)3.2% (1.8 - 4.5) Liver Related Death4.9% (3.3 - 6.5) 8.7% (6.1 - 11.3) # Significant heterogeneity of results * Includes non-concurrent controls Craxi et al., J Hepatol (In press)

9. 9 IFN R x of HBeAg+ CHB PredIFN AloneControls + IFN5 MU1 MU No. of Patients4441 43 Loss of HBV DNA and HBeAg 16(36)15(37)7(17)3(7) Loss of HBV DNA only4(9)3(7)4(10)2(5) Loss of HBsAg5(11)5(12)1(2)0 ALT normal at Last FU19(43)18(44)11(27)8(19) Reactivation during FU1(2)0 0 Perrillo et al., NEJM 1990;323:295

10. 10 IFN Treatment of HBeAg - CHB Type of Study # Studies # Treated # Untreated Randomized 486 84 (IFN vs. no treatment) Randomized 2110  (comparing different IFN schedule) Randomized 345  (IFN vs. other active compound) Not Randomized 9 702  ALL 18943 84

11. 11 IFN Treatment of HBeAg - CHB Cumulative results of published studies 44 - 69 Alberti, NIH, HBV 2000 Meeting * HBV DNA by non-PCR assays 38 - 59 7 - 38 7 - 38

12. 12 IFN Rx of HBeAg - CHB: Histologic Response Author, Mean HAI Score Mean Fibrosis Score Year IFN Control IFN Control Lampertico, 1997 Baseline 10.39.3 2.1 2.2 } p=.001 End of Rx 5.39.3 1.8 2.0 Fattovich, 1992 Baseline 8.1 9.0 N/A N/A } p=.004 12 mon post-Rx 5.5 7.5 N/A N/A

13. 13 IFN R x of HBeAg- CHB 216 patients, FU median 7 yr 78 patients - median 5 months Rx 138 patients - median 12 months Rx 3 MU tiw Response End of R x 54% FU Yr. 144% of initial responders, 24% of all patients End of FU33% of initial responders, 18% of all patients Predictors of Response Duration of R x > 6 months Early response, within 4 months Manesis & Hadziyannis, Gastroenterology 2001;121:101

14. 14 Lamivudine R x of HBeAg+ CHB Placebo Lam x 52 wk IFN x 16 wk Lam x 24 wk +IFN x 16 wk HBeAg seroconversion at week 52 Lai et al., NEJM 1998 Dienstag et al., NEJM 1999 Schalm et al., Gut 2000 13

15. 15 Lamivudine R x of HBeAg+ CHB Histologic response at week 52 Placebo Lam x 52 wk IFN x 16 wk Lam x 24 wk. +IFN x 16 wk Dienstag et al., NEJM 1999 Schalm et al., Gut 2000 Lai et al., NEJM 1998 14

16. 16 Lamivudine Rx of HBeAg+ CHB Normal ALT at Week 52 LAM PLA LAM & IFN IFN

17. 17 Lamivudine R x of HBeAg+ CHB % of Patients Multi-center Asian Study

18. 18 Lamivudine R x of HBeAg- CHB Lamivudine Placebo 02452 Tassopoulos et al., Hepatology 1999; 29:889  HAI  2 points HBV DNA - (PCR) HBV DNA - (bDNA) ALT Normal At wk 24 HBV DNA - (bDNA) ALT Normal At wk 52

19. 19 Lamivudine Treatment (0-52 Weeks) Lamivudine R x of HBeAg- CHB HBV DNA (pg/mL) ALT (xULN) Normal ALT Tassopoulos et al., Hepatology 1999; 29:889

20. 20 Treatment of HBeAg - CHB Treatment On-Therapy Response Sustained Response IFN (3-6 MU tiw) 6 months60 – 90%10 – 15% > 12 months50 – 75%20 – 25% Lamivudine (100-150mg) 12 months65 – 80%~10% 24 months50 – 60%? > 36 months30 – 40%? Adefovir 12 months70%?

21. 21 Treatment of Decompensated Cirrhosis Measurements of Response –Viral suppression –Biochemical improvement –Decrease in CTP score (Alb, bil, PT, ascites, encephalopathy) –Decrease clinical complications + –Decrease need for transplant + –Decrease HCC ? –Improve survival +

22. 22 Lamivudine R x of Decompensated Cirrhosis 35 patients decomp cirrhosis 23 patients R X  6 months 22 patients  CTP score  2 points 20 patients alive at 19  2 months 3 with resistant mutants 5 deaths 7 OLT 1 no improvement  OLT 2 deaths; 1 SBP, 1 HCC Villeneuve et al., Hepatology 2000;31:207

23. 23 Clinical Practice Guidelines Who to treat What treatment When to stop treatment

24. 24 AASLD Practice Guidelines Current therapy has limited long-term efficacy Careful balance of benefits and risks before treatment is initiated –patients’ age –severity of liver disease –likelihood of response –potential adverse events Lok and McMahon, Hepatology 2001;34:1225

25. 25 + +<2x ULNBoth IFN and Lam low efficacy Observe + +>2x ULNIFN or Lam IFN NR or contraindications  Lam – +>2x ULNIFN or Lam Long-term R x required – –normalNo Rx required +/ – +cirrhosisCompensated: IFN low dose or Lam Decompensated: Lam, optimal timing unknown Transplant +/ – –cirrhosisCompensated: observe Decompensated: Transplant *HBV DNA in serum >10 5 copies/ml AASLD Practice Guidelines: Rx Strategies HBeAgHBV DNA* ALTTreatment Lok and McMahon, Hepatology 2001;34:1225

26. 26 Finite duration of R x More durable response Resistant mutants not reported Expensive Frequent side effects Long/indefinite duration of R x Resistant mutants Oral administration Negligible side effects Lower costs? Interferon Lamivudine Pros Cons Treatment of Chronic Hepatitis B

27. 27 AASLD Practice Guidelines Treatment Regimen - IFN Dose 5 MU QD or 10 MU tiw SC Duration e + CHB - 16 wk e – CHB - 12 months Lok and McMahon, Hepatology 2001;34:1225

28. 28 AASLD Practice Guidelines Treatment Regimen - Lamivudine Dose 100mg daily po HIV Coinfection – 150mg bid + other HIV R x Duration e+ CHB – 1yr... HBeAg seroconversion – Stop R x ? DNA suppression, HBeAg+ - Continue R x ? Breakthrough infection – continue R x if clinically stable? Stop R x if clinical deterioration e- CHB > 1yr, optimal duration? Lok and McMahon, Hepatology 2001;34:1225

29. 29 Issues for Future Clinical Trials Study population Entry criteria Treatment regimens Indications for assessing treatment response End-points for stopping treatment Durability of response after treatment withdrawal Short and long term safety and efficacy

30. 30 Issues for Future Clinical Trials Study population Adults with –e+ CHB (normal vs. elevated ALT) –e- CHB –decompensated cirrhosis Coinfection (HIV, HCV) Extrahepatic disease Patients on immunosuppressive/chemo R x Children

31. 31 Issues for Future Clinical Trials HBeAg+HBeAg- HBV DNA (copies/ml) > 10 5, 10 6 > 10 4, 10 5, 10 6 ALT (ULN)> 1.5, 2, 3, 5 Histology Required? HAI >? Fibrosis? Required? HAI >? Fibrosis? Entry Criteria

32. 32 Issues for Future Clinical Trials Treatment Regimens Study Design –Monotherapy – placebo vs. active control –Monotherapy vs. combination therapy Duration of R x –Finite duration – 1 or 2 years –Built in follow-up/follow-on durability of response long-term safety drug resistance additional response with extended R x

33. 33 Issues for Future Clinical Trials End-points for Treatment Response - Liver Histology Pros Direct assessment of liver disease – inflammation and fibrosis Cons Requires 2 biopsies Risks of complications Expensive Sampling error Intra and Inter observer variability Scores not linear Not applicable outside clinical trials Clinical significance of a 2-point decrease in HAI uncertain

34. 34 Issues for Future Clinical Trials End-points for treatment response HBeAg+ CHB HBeAg loss, + anti-HBe + Decreased HBV DNA level, <10 5 copies/ml + ALT normal HBeAg- CHB Decreased HBV DNA level, <10 3 copies/ml + ALT normal range Decompensated Cirrhosis Decreased HBV DNA level + CTP score decrease > 2 points and/or MELD score (INR, bil, Cr) decrease

35. 35 Issues for Future Clinical Trials Do proposed composite (virologic, serologic biochemical) end-points correlate with Histologic response Improved clinical outcome?

36. 36 Ability of Surrogate Markers to Predict Clinical Outcome Limited data Problems: 1.Prolonged natural course 2.Limited follow-up in prospective studies 3.Few RCTs, small sample size 4.Disease heterogeneity between treated and untreated controls (historical/non-concurrent) in retrospective studies

37. 37 IFN R x of HBeAg+ CHB Total HAI ScoreRanked Assessment* InitialFU Mon 6 Treated patients (90) HBeAg& HBV DNA Loss (30)8·0+36·2+318/9/3 HBV DNA Loss only (9)8·9+45·0+27/2 No Response (51)6·7+27·5+38/30/13 Controls (24)8·0+37·0+38/14/2 *Improved/same/worse Perrillo et al., NEJM 1990;323:295

38. 38 Impact of HBeAg Clearance on Long-Term Clinical Outcome 0 12 24 36 48 60 72 84 96 1.0 0.8 0.6 0.4 0.2 0.0 Month Proportion with complication free survival Niederau et al., NEJM 1996;334:1422-7 IFN No R x Clearance of HBeAg No Clearance of HBeAg

39. 39 20 40 100 80 60 0 01412108642 Percent Years IFN-SR (n=57) IFN-NR (n=152) Un-R x (n=195) Cumulative Transplant-Free Survival of Patients with HBeAg- Chronic Hepatitis Papatheodoridis et al., J Hepatol 2001; 34:306-313 IFN-SR vs IFN-NR p=0.03 IFN-SR vs Un-R x p=0.05

40. 40 Correlation Between Week 52 HBV DNA Levels and HBeAg Seroconversion in Lamivudine Trials NUCB 3009/NUCA 3010 PLA (n=120) LAM 100 (n=169) e-Sero Log 10 HBV DNA Levels Dienstag et al., NEJM 1999, Lai et al., NEJM 1998 Courtesy of GSK – L Condreay and S Gardner

41. 41 Correlation between Week 52 HBV DNA Levels and ALT Normalization Lamivudine Trials NUCB 3009/NUCA 3010 Log 10 HBV DNA Levels PLA (n=97) LAM 100 (n=124) ALT Normal Dienstag et al., NEJM 1999, Lai et al., NEJM 1998 Courtesy of GSK – L Condreay and S Gardner

42. 42 Correlation Between Week 52 HBV DNA Levels and Histologic Response Lamivudine Trials NUCB 3009/NUCA 3010 Log 10 HBV DNA Levels PLA (n=104) LAM 100 (n=150) Histologic Response Dienstag et al., NEJM 1999, Lai et al., NEJM 1998 Courtesy of GSK – L Condreay and S Gardner

43. 43 Correlation Between Week 48 HBeAg Seroconversion, HBV DNA, ALT and Histologic Response Adefovir Trial GS-437 (e+ CHB) HBeAg Seroconversion No HBeAg Seroconversion Log 10 HBV DNA Levels ADV 10mg Courtesy of J Fry, C Brosgart, Gillead

44. 44 Correlation Between Week 48 HBV DNA, ALT and Histologic Response Adefovir Trial GS-438 (e-CHB) ADV PLA Log 10 HBV DNA Levels Courtesy of J Fry, C. Brosgart, Gilead

45. 45 Issues for Future Clinical Trials Indications for stopping treatment Achievement of on-treatment response Maintenance of on-treatment response for defined duration Indications may vary depending on severity of underlying liver disease and immune status of host

46. 46 Correlation between Week 48 HBeAg loss, HBV DNA, ALT and Histologic Response ADV 10 mg HBeAg Loss No HBeAg Loss Log 10 HBV DNA Levels

47. 47 Treatment of Chronic Hepatitis B Role of IFN in Patients with Cirrhosis IFN vs Pred + IFN in CHB - US multi-center trial 98/150 (65%) had cirrhosis 1 treated and 1 control patient died of liver failure Perrillo et al., NEJM 1990 Low dose IFN in clinical cirrhosis Child’s classnResponseR x withdrawal A550 B1553 C604 Perrillo et al., Gastro 1995

48. 48 Effect of IFN on Survival and HCC Development Lin et al., Hepatology 1999;29:971 Survival HCC Treated group Control group P=0.018 Year of Follow-up 25 100 75 50 0 012108642 P=0.013 Cumulative Incidence (%)

49. 49 RCTs of IFN Treatment of HBeAg - CHB Author, IFN Dose,Number NumberFollow Year DurationTreated Untreated Up Hadziyannis, 5 MU/m 2,252512 mo. 1990 14-16 wks Fattovich, 5 MU/m 2,303012 mo. 1992 6 mo. Pastore, 5 MU/m 2,10 824 mo. 1992 6 mo. Lampertico, 6 MU/m 2,212122 mo. 1997 24 mo.

50. 50 IFN Treatment of HBeAg- Patients Hadziyannis S, et al., J Hepatology 1990; 11(Suppl 1):513 Fattovich G, Hepatology 1992; 15:584 Pastore G, J Hepatology 1992; 14;221 Lampertico p, Hepatology 1997; 26:1621

51. 51 Long-Term Follow-Up of HBeAg- Patients with End-of-Treatment Response to IFN Papatheodoridis et al., J Hepatol 2001; 34:306-313

52. 52 PLA Log 10 HBV DNA Levels Dienstag et al. Courtesy of L. Condreay and S. Gardner, GSK., NEJM 1999, Lai et al., NEJM 1998

53. 53 LAM Log 10 HBV DNA Levels Dienstag et al. Courtesy of L. Condreay and S. Gardner, GSK., NEJM 1999, Lai et al., NEJM 1998

54. 54 Log 10 HBV DNA Levels PLA

55. 55 LAM Log 10 HBV DNA Levels

56. 56 PLA Log 10 HBV DNA Levels

57. 57 LAM Log 10 HBV DNA Levels

58. 58 Correlation Between Week 48 HBeAg Seroconversion, HBV DNA, ALT and Histologic Response GS-437 (e+ CHB) Placebo HBeAg Seroconversion No HBeAg Seroconversion Log 10 HBV DNA Levels