Hepatitis C Virus Treatment-Related Anemia Is Associated With Higher Sustained Virologic Response Rate

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1 GASTROENTEROLOGY 2010;139: Hepatitis C Virus Treatment-Related Anemia Is Associated With Higher Sustained Virologic Response Rate MARK S. SULKOWSKI,* MITCHELL L. SHIFFMAN, NEZAM H. AFDHAL, K. RAJENDER REDDY, JONATHAN MCCONE, WILLIAM M. LEE, # STEVEN K. HERRINE,** STEPHEN A. HARRISON, F. FRED POORDAD, KENNETH KOURY, WEIPING DENG, STEPHANIE NOVIELLO, LISA D. PEDICONE, CLIFFORD A. BRASS, JANICE K. ALBRECHT, and JOHN G. MCHUTCHISON on behalf of the IDEAL Study Team *Johns Hopkins University School of Medicine, Baltimore, Maryland; Bon Secours Health System, Liver Institute of Virginia, Newport News, Virginia; Beth Israel Liver Center, Boston, Massachusetts; University of Pennsylvania Health System, Philadelphia, Pennsylvania; Mount Vernon Endoscopy Center, Alexandria, Virginia; # University of Texas Southwestern Medical Center, Dallas, Texas; **Thomas Jefferson University, Philadelphia, Pennsylvania; Brooke Army Medical Center, Fort Sam Houston, Texas; Cedars-Sinai Medical Center, Los Angeles, California; Schering-Plough Research Institute (now Merck & Co), Whitehouse Station, New Jersey; and Duke Clinical Research Institute, Durham, North Carolina BACKGROUND & AIMS: Hepatitis C virus (HCV) treatment is frequently complicated by anemia from ribavirin (RBV)-related hemolysis and peginterferon-alfa (PEG-IFN)- related bone marrow suppression. We investigated the relationships among treatment outcomes, anemia, and their management with RBV dose reduction and/or erythropoiesis-stimulating agents (ESAs). METHODS: We analyzed data from a trial conducted at 118 United States academic and community centers in treatment-naïve patients with HCV genotype 1. Patients were treated for as many as 48 weeks with 1 of 3 PEG-IFN/RBV regimens. ESAs were permitted for anemic patients (hemoglobin [Hb] 10 g/dl) after RBV dose reduction. Sustained virologic responses (SVR) were assessed based on decreases in Hb, anemia, and ESA use. RESULTS: While patients received treatment, 3023 had their Hb levels measured at least once. An SVR was associated with the magnitude of Hb decrease: 3 g/dl, 43.7%; 3 g/dl, 29.9% (P.001). Anemia occurred in 865 patients (28.6%); 449 of these (51.9%) used ESAs. In patients with early-onset anemia ( 8 weeks of treatment), ESAs were associated with higher SVR rate (45.0% vs 25.9%; P.001) and reduced discontinuation of treatment because of adverse events (12.6% vs 30.1%, P.001). ESAs did not affect SVR or discontinuation rates among patients with late-stage anemia. CONCLUSIONS: Among HCV genotype 1-infected patients treated with PEG-IFN/ RBV, anemia was associated with higher rates of SVR. The effect of ESAs varied by time to anemia; patients with early-onset anemia had higher rates of SVR with ESA use, whereas no effect was observed in those with late-onset anemia. Prospective trials are needed to assess the role of ESAs in HCV treatment. Keywords: Adverse Effects of Hepatitis Therapy; Clinical Trial; Liver Disease; Blood Disorders. Hepatitis C virus (HCV) chronically infects 180 million people worldwide and is a frequent cause of serious liver disease. 1 3 HCV treatment with peginterferon alfa-2b (PEG-IFN alfa-2b) or alfa-2a (PEG-IFN alfa- 2a) plus ribavirin (RBV) is recommended for persons at the greatest risk for liver disease progression. 3,4 Although effective, these regimens cause decreased hemoglobin (Hb) concentrations and anemia as a result of suppression of hematopoiesis because of PEG-IFN and hemolysis because of RBV. 5 8 Anemia has been observed in up to 30% of treated patients, often leading to symptoms (eg, fatigue), RBV dose reduction, and/or treatment discontinuation In some studies, RBV dose reduction has been linked to lower sustained virologic response (SVR) rates. Based on clinical trials demonstrating recovery of Hb levels, maintenance of RBV dosing, and improvement in symptoms, erythropoiesis-stimulating agents (ESAs) are used for the management of anemia in up to 15% of patients undergoing HCV treatment Despite the routine off-label use of ESAs for the management of anemia, the impact of ESAs on HCV treatment outcomes has not been defined. Furthermore, the US Food and Drug Administration has issued several Public Safety Advisories on potential adverse effects related to ESAs, including thrombovascular events, shortened time to tumor progression or recurrence, shortened survival time in patients with cancer, and pure red blood cell aplasia As such, considerable uncertainty exists regarding the role of adjuvant ESAs during HCV treatment. 3,18,25 The primary objective of this analysis was to evaluate the relationship of treatment-associated anemia, ESA use, and treatment outcomes in HCV genotype 1-infected patients treated with PEG-IFN/RBV in the Individualized Dosing Efficacy vs Flat Dosing to Assess OptimaL Pegylated Interferon Therapy (IDEAL) study. 26 Abbreviations used in this paper: AE, adverse event; EOT, end of treatment; ESA, erythropoiesis-stimulating agent; Hb, hemoglobin; HCV, hepatitis C virus; IDEAL, Individualized Dosing Efficacy vs Flat Dosing to Assess OptimaL Pegylated Interferon Therapy; PEG-IFN, peginterferon; RBV, ribavirin; SAE, serious adverse event; SAP, statistical analysis plan; SVR, sustained virologic response by the AGA Institute /$36.00 doi: /j.gastro

2 November 2010 ANEMIA, ESAS, AND HCV TREATMENT OUTCOMES 1603 Patients and Methods Patients Patients were enrolled from 118 academic and community centers in the United States. Eligible patients were 18 years old with compensated liver disease because of chronic HCV genotype 1 infection who had not been previously treated. Patients had an absolute neutrophil count 1500/mm 3, a platelet count 80,000/mm 3, and Hb 12 g/dl for females and 13 g/dl for males. Patients were excluded if they had human immunodeficiency virus or hepatitis B coinfection, any other cause of significant liver disease, poorly controlled diabetes, morbid obesity, severe depression or other psychiatric disorders, and/or active substance abuse. Patients underwent liver biopsy within 3 years prior to screening with review of biopsy slides by a pathologist at a central site. Study Design Patients received 1 of 3 treatment regimens: arm 1, PEG-IFN alfa-2b 1.5 g/kg/week (wk) (standard dose) or arm 2, PEG-IFN alfa-2b 1.0 g/kg/wk (low dose), both in combination with oral RBV dosed by body weight (40 65 kg, 800 mg/day; kg, 1000 mg/day; kg, 1200 mg/day; kg, 1400 mg/day); or arm 3, PEG-IFN alfa-2a 180 g/wk plus oral RBV mg/day dosed by body weight ( 75 kg, 1000 mg/ day; 75 kg, 1200 mg/day). HCV RNA levels were measured (screening visits 1 and 2 [baseline]; treatment weeks 2, 4, 12, 24, and 48; and follow-up weeks 4, 12, and 24) using the COBAS TaqMan assay (Roche Diagnostics, Indianapolis, IN), with a lower limit of quantitation at 27 IU/mL. Patients with an insufficient viral response at 12 weeks (detectable HCV RNA with 2-log 10 decrease in HCV RNA from baseline) or at 24 weeks (detectable HCV RNA) were considered to have treatment failure and discontinued therapy. Hb concentrations were assessed at screening visits 1 and 2 (baseline); treatment weeks 2, 4, 8, 12, 18, 24, 30, 36, 42, and 48; and follow-up weeks 4, 12, and 24. Non life-threatening adverse events (AEs) were managed by dose reduction of PEG-IFN and/or RBV. For patients receiving PEG-IFN alfa-2b, RBV dose reduction occurred in 2 steps: step 1 was reduction by either 200 mg (patients receiving mg/day) or 400 mg (patients receiving 1400 mg/day); step 2 was reduction by another 200 mg, if required. For patients receiving PEG- IFN alfa-2a, RBV was reduced to 600 mg/day based on the prescribing information. For all patients, RBV dose reduction was required for Hb 10 g/dl; treatment was permanently discontinued for 8.5 g/dl. In patients with Hb 10 g/dl, ESAs could be used at the discretion of the investigator after RBV dose reduction. ESAs were not provided by the study sponsor, and the use of supplemental iron, folic acid, and/or other adjuvant was not mandated. The RBV dose could be increased after resolution of the anemia (Hb 10 g/dl). The clinical study was approved by the Institutional Review Board or Ethics Committee at each participating center and was conducted in accordance with the provisions of the Declaration of Helsinki and Good Clinical Practice guidelines. End Points and Statistical Analyses Analyses are based on all randomized patients (all 3 treatment regimens combined) who received at least 1 dose of study medication and underwent Hb measurement at baseline and at least once during the treatment phase. Although the statistical analysis plan for the study stated that the relationship among change in Hb, the development of anemia, and the use of ESAs would be explored, the analyses were not prospectively specified. In addition, because the primary treatment regimen comparisons identified in the statistical analysis plan were not statistically significant, the results of any additional analyses could not be considered statistically significant based on the prespecified strategy for handling multiplicity. Consequently, the analyses presented are retrospective, and nominal (2-sided) P values are included to describe the results of these analyses. Patients were divided into 3 groups: those who never developed anemia, those who developed anemia but did not receive ESAs, and those who developed anemia and received ESAs. Because patients did or did not develop anemia after receiving their randomized treatment assignment (ie, anemia status is not a baseline characteristic) and investigators made the decision to use or not use ESAs for an individual patient, comparisons among these groups are not randomized comparisons. 2 Tests (for categorical variables) or t tests (for continuous variables) were used to make pair-wise comparisons of these groups with respect to baseline characteristics, virologic outcomes (end of treatment [EOT] response rates, SVR rates, and relapse rates), discontinuations, and AE rates. Patients who did not develop anemia were also compared with patients who did develop anemia (regardless of ESA use) with respect to virologic outcomes and discontinuation rates ( 2 tests). Similar comparisons were made between patients with and without a maximum absolute Hb decline 3 g/dl and between patients with and without a maximum relative Hb decline 21% (regardless of ESA use). Separate comparisons of ESA use vs no ESA use in anemic patients were made for patients who developed anemia early (by week 8) and for patients who developed anemia later (after week 8). In addition, because the comparisons of anemic patients who received or did not receive ESAs are not randomized comparisons and because there are baseline differences between the groups, logistic regression analyses were performed to compare SVR rates, controlling for potentially confounding factors. Two approaches were used: (1) control for all potentially confounding factors simultaneously to obtain an adjusted odds ratio for ESA vs no ESA use and (2) first use a stepwise procedure to select factors that are related to SVR (P.05 required for factors to enter and stay in the final model) and then

3 1604 SULKOWSKI ET AL GASTROENTEROLOGY Vol. 139, No. 5 Table 1. Characteristics According to Treatment-Related Anemia and Receipt of Erythropoiesis-Stimulating Agents No Anemia (A) n 2158 Anemia No ESA (B) n 416 Anemia ESA (C) n 449 P value a AvsB AvsC BvsC Male, n (%) 1451 (67) 157 (38) 197 (44) Race, n (%) White 1560 (72) 284 (68) 322 (72) African American/black 373 (17) 88 (21) 88 (20) Age, mean (SD), y 46.8 (7.9) 48.7 (8.2) 50.2 (7.6) Weight, mean (SD), kg 84.7 (16.1) 79.8 (16.9) 80.5 (15.9) HCV RNA 600,000 IU/mL, n (%) 1781 (83) 319 (77) 378 (84) Steatosis, n (%) b Absence 772 (36) 159 (38) 170 (38) Presence 1289 (60) 243 (58) 246 (55) METAVIR fibrosis score, n (%) b F0/1/ (85) 352 (85) 358 (80) F3/4 216 (10) 50 (12) 58 (13) Baseline Hb, mean (SD), g/dl 15.2 (1.2) 14.3 (1.1) 14.3 (1.2) Baseline Cr, mean (SD), mol/l 74.5 (14.1) 72.7 (13.5) 74.1 (15.1) Estimated Cr clearance, mean (SD), ml/min c (31.6) (30.8) (28.9) Treatment regimen, n (%) PEG-IFN alfa-2b 1.5/RBV 684 (32) 147 (35) 158 (35) PEG-IFN alfa-2a/rbv 727 (34) 148 (36) 158 (35) PEG-IFN alfa-2b 1.0/RBV 747 (35) 121 (29) 133 (30) Baseline RBV dose, mg/kg/day Mean (SD) 13.3 (1.4) 13.9 (1.8) 13.8 (1.7) Median (IQR) 13.1 ( ) 13.5 ( ) 13.5 ( ) Nadir Hb level, median (IQR), g/dl 11.5 ( ) 9.5 ( ) 9.4 ( ) Maximum Hb decline, median (IQR), g/dl 3.6 ( ) 4.9 ( ) 5.1 ( ) RBV dose reduction for adverse event 244 (11) 293 (70) 391 (87) during therapy, n (%) d Time to anemia, median (IQR), days 96.5 ( ) 58 (30 125).001 Time to Hb nadir, median (IQR), days 126 (57 219) 130 (68 215) 98 (54 170) NOTE. Roche COBAS TaqMan assay lower limit of quantitation, 27 IU/mL. Percentages are rounded up to the nearest whole number. HCV, hepatitis C virus; IQR, interquartile range (first to third quartiles); PEG-IFN, peginterferon alfa: RBV, ribavirin; SD, standard deviation. a P values are based on 2 tests for categorical variables, t tests, or Wilcoxon rank sum tests for continuous variables. b Data missing for 144 patients because of liver biopsy specimens deemed inadequate by the pathologist at the central site. c Using Cockcroft-Gault equation. d Excludes patients who discontinued treatment because of an adverse event. include the selected factors as covariates in a logistic regression of SVR on ESA use to obtain an adjusted odds ratio (selected factors listed are as follows: age, gender, race, body mass index, baseline viral load, fibrosis, steatosis, fasting glucose, alanine aminotransferase, hemoglobin, platelet count, ribavirin [mg/kg/day] assigned, genotype [1a, 1b], and body weight). Results Patient Characteristics Between March 2004 and June 2006, 3070 patients were randomized and treated; of these, 3023 patients had baseline and at least 1 Hb measurement during therapy. Anemia (Hb 10 g/dl) was observed in 865 (28.6%) patients, of whom, 449 (51.9%) were prescribed ESAs. Compared with patients without anemia, patients who had an Hb level 10 g/dl were more likely to be female, older, have lower body weight, lower baseline Hb level, and lower estimated creatinine clearance (Table 1). Although the median maximum Hb decline was higher and nadir Hb levels were lower in anemic patients than nonanemic patients, no difference in Hb decline was observed according to ESA use. However, ESA recipients were older, reached their nadir Hb level more rapidly, and were more likely to have a high baseline HCV RNA level ( 600,000 IU/mL) than patients who did not receive ESAs. Changes in Hb level, incidence of anemia, and ESA use were similar for patients treated with each of the 3 treatment regimens (data not shown). The median and mean RBV exposure (mg/kg/day) during the treatment period was lower in anemic patients; ESA use was not associated with higher RBV exposure (Supplementary Figure 1). In ESA recipients, the median (interquartile range) increase in Hb level from the nadir was 2.8 g/dl ( g/dl) compared with 1.4 g/dl ( g/dl) in anemic patients managed with dose reduction alone. Among patients with Hb levels 10 g/dl who had a subsequent Hb level on treatment, hemoglobin levels 12 g/dl occurred in 63.7% (279/438) of patients treated with ESAs compared with 16.8% (59/ 352) of those anemic patients managed without ESAs.

4 November 2010 ANEMIA, ESAS, AND HCV TREATMENT OUTCOMES 1605 Figure 1. A C: Virologic outcomes according to development of anemia, ESA use, and treatment assignment (n 3023). The median (interquartile range) length of ESA exposure during treatment was 120 days ( days). Hemoglobin Decline and Treatment Outcomes Virologic response rates (HCV RNA 27 IU/ ml) at EOT and end of follow-up (SVR) were significantly higher among patients who developed anemia (EOT, 65.5% [567/865]; SVR, 48.8% [422/865]) compared with those who did not (EOT, 52.9% [1142/ 2158]; SVR, 36.7% [793/2158]) (P.001) (Figure 1A C). Estimates of the differences in EOT response and SVR rates between anemic and nonanemic patients were as follows: EOT, 12.6% (95% confidence interval [CI]: 8.8% 16.4%; P.001); SVR, 12.0% (95% CI: 8.1% 15.9%; P.001). Lower nadir Hb level on treatment was associated with a higher probability of achieving SVR (Supplementary Figure 2). The treatment discontinuation rate because of virologic failure was lower among patients experiencing anemia (ESA use, 19%; no ESA use, 20%) compared with nonanemic patients (31%). Whereas the rates of EOT response and viral relapse were higher in patients treated with the PEG- IFN alfa-2a/rbv regimen, the SVR rate did not differ significantly between the 3 PEG-IFN/RBV treatment regimens according to anemia status (Figure 1A C). SVR rates also varied according to the maximum Hb decline during treatment, measured as the absolute Hb decline from baseline and as the relative decrease in Hb level from baseline (1 nadir Hb level/baseline Hb level 100) (Table 2; Supplementary Figure 3). SVR rates were significantly higher for patients with an absolute Hb decline 3 g/dl (43.7%, 984/2250) compared with those with maximum declines 3 g/dl (29.9%, 231/773) (Supplementary Figure 4). Estimates of the difference in SVR rates between patients with or without an absolute Hb decline 3 g/dl were as follows: 13.9% (95% CI: 10.1% 17.7%; P.001). Similarly, a small relative decline in Hb 21% was associated with a significantly lower SVR rate; estimate of the difference in SVR rate between patients with or without a relative Hb decline 21% was as follows: 15.3% (95% CI: 11.6% 19.2%; P.001). As shown in Table 3, the different strategies of 1-step (PEG-IFN alfa-2a) and 2-step dose reduction (PEG-IFN alfa-2b) had similar safety and virologic outcomes. Treatment discontinuation because of AE, incidence of SAE, and ESA use was similar for both strategies. Furthermore, there was no significant difference in the SVR rate for patients with RBV dose reduction according to strategy: PEG-IFN alfa-2a, 47.3% (all 1-step to 600 mg/day), and Table 2. End-of-Treatment Response, Relapse, and Sustained Virologic Response Rates According to Maximum Hemoglobin Decline During Therapy EOT response, % (n/n) Relapse, % (n/n) SVR, % (n/n) Maximum Hb decrease from baseline, g/dl a 1 10 (5/48) 67 (2/3) 2 (1/48) (66/196) 15 (9/59) 26 (50/196) (252/529) 23 (54/234) 34 (180/529) (467/793) 26 (113/439) 41 (329/793) (468/739) 26 (114/444) 45 (333/739) 5 63 (451/718) 28 (119/431) 45 (322/718) Relative Hb decrease from baseline, % b (305/754) 24 (67/282) 29 (216/754) (431/756) 26 (103/401) 40 (299/756) (488/755) 27 (128/467) 45 (342/755) (485/758) 25 (113/460) 47 (358/758) a Absolute decrease in Hb from baseline (baseline Hb nadir Hb). b Percentage maximum decrease from baseline Hb (1 nadir Hb/ baseline Hb) was used to stratify patients into quartiles: quartile 1 ( 21%), quartile 2 ( 21% 27%), quartile 3 ( 27% 33%), and quartile 4 ( 33%).

5 1606 SULKOWSKI ET AL GASTROENTEROLOGY Vol. 139, No. 5 Table 3. Efficacy and Safety Outcomes According to Treatment Regimen and Ribavirin Dose Reduction Strategy SVR, n/n (%) Relapse, n/n (%) a ESA use, n/n (%) Treatment emergent SAE, n/n (%) b Discontinuation of treatment because of AE, n/n (%) PEG-IFN alfa-2b 1.5 g/kg/week RBV 800 mg to 1400 mg/day No reduction 234/642 (36.4) 74/304 (24.3) 9/642 (1.4) 42/642 (6.5) 76/642 (11.8) Step 1 only c 95/199 (47.7) 33/128 (25.8) 93/199 (46.7) 11/199 (5.5) 22/199 (11.1) Steps 1 and 2 in 2 steps 52/94 (55.3) 11/62 (17.7) 48/94 (51.1) 8/94 (8.5) 10/94 (10.6) Steps 1 and 2 in 1 step 25/54 (46.3) 5/29 (17.2) 16/54 (29.6) 8/54 (14.8) 10/54 (18.5) All 406/989 (41.1) 123/523 (23.5) 166/989 (16.8) 69/989 (7.0) 118/989 (11.9) PEG-IFN alfa-2b 1.0 g/kg/week RBV 800 mg to 1400 mg/day No reduction 258/732 (35.2) 70/322 (21.7) 8/732 (1.1) 43/732 (5.9) 63/732 (8.6) Step 1 only c 78/165 (47.3) 17/95 (17.9) 84/165 (50.9) 13/165 (7.9) 20/165 (12.1) Steps 1 and 2 in 2 steps 37/66 (56.1) 5/42 (11.9) 37/66 (56.1) 9/66 (13.6) 8/66 (12.1) Steps 1 and 2 in 1 step 13/38 (34.2) 3/16 (18.8) 15/38 (39.5) 4/38 (10.5) 1/38 (2.6) All 386/1001 (38.6) 95/475 (20.0) 144/1001 (14.4) 69/1001 (6.9) 92/1001 (9.2) PEG-IFN alfa-2a 180 g/week RBV 1000 mg to 1200 mg/day No reduction 291/754 (38.6) 135/423 (31.9) 26/754 (3.4) 64/754 (8.5) 91/754 (12.1) Step 1 only d 132/279 (47.3) 58/189 (30.7) 146/279 (52.3) 31/279 (11.1) 43/279 (15.4) All 423/1033 (40.9) 193/612 (31.5) 172/1033 (16.7) 95/1033 (9.2) 134/1033 (13.0) NOTE. N 3023 patients. SVR, sustained virologic response; ESA, erythropoiesis-stimulating agents; SAE, serious adverse event; AE, adverse event; PEG-IFN, peginterferon alfa; RBV, ribavirin. a Relapse was defined as undetectable HCV RNA at the end of treatment and detectable during follow-up. b SAE during treatment phase. c For patients receiving PEG-IFN alfa-2b, RBV was reduced in 2 steps; step 1 was reduction by either 200 mg (patients receiving mg/day) or 400 mg (patients receiving 1400 mg/day); step 2 was reduction by another 200 mg, if required. d For patients receiving PEG-IFN alfa-2a, RBV was reduced to 600 mg/day for patients taking 1000 or 1200 mg/day. PEG-IFN 1.5 g/kg/wk, 49.6%, combined 1- and 2-step (1-step only, 47.7%; 1- and 2-step, 52.0%). For persons treated with PEG-IFN alfa-2b (1.5 g/kg/week) who underwent a 1-step (200 mg or 400 mg/day) RBV dose reduction, the relapse rate was 25.8% compared with 24.3% for those who did not have RBV dose reduction, representing an increase of 1.5%. For persons treated with PEG-IFN alfa-2a who underwent a larger 1-step (400 mg or 600 mg/day) RBV dose reduction, the relapse rate was 30.7% compared with 31.9% for those who did not have RBV dose reduction, representing a decrease of 1.2%. Thus, compared with the 2-step strategy for PEG-IFN alfa-2b, the 1-step strategy for PEG-IFN alfa-2a was not associated with lower SVR rate, higher relapse rate, or improved safety outcomes. ESA Use and Treatment Outcomes Anemic patients treated with ESAs had higher EOT response rates than patients who did not receive ESAs (ESA, 69.9%; no ESA, 60.8%), but only a small difference was observed in SVR rates (ESA, 49.7%; no ESA, 47.8%). The overall estimates of the differences in EOT response and SVR rates between anemic patients with or without ESA use were as follows: EOT, 9.1% (95% CI: 2.8% 15.4%; P.005), and SVR, 1.8% (95% CI: 4.8% to 8.5%; P.59). The relationship of ESA use and SVR varied according to the time of onset to the anemia (Table 4A; Supplementary Table 1; Supplementary Figure 5). For patients with early-onset anemia ( 8 weeks of treatment), ESA use was associated with a higher SVR rate (estimate of the difference in SVR rates between patients with early anemia with or without ESAs was 19.1% [95% CI: 9.5% 28.6%; P.001]). In patients with early-onset anemia, ESA use was associated with significantly less treatment discontinuation because of AEs, greater treatment duration, and proportion of intended medication doses delivered. For patients with late-onset anemia ( 8 weeks of treatment), no difference was detected between ESA users and nonusers for on-treatment RBV exposure, treatment discontinuation because of AEs, treatment duration, or SVR rate (Table 4A). In multivariate logistic regression analysis, ESA use was significantly associated with SVR in patients with early-onset (but not late-onset) anemia after adjusting for potential confounders (Table 4B). Anemia, ESAs, and Safety The proportions of patients who met the discontinuation criteria (Hb 8.5 g/dl) were low in all treatment arms: 2% to 4%. Among anemic patients, ESA use was associated with lower rates of discontinuation prior to treatment week 12 (ESA, 1%; no ESA, 8%) (Figure 2). SAEs occurred more frequently in anemic patients (12% 14%) compared with those who were

6 November 2010 ANEMIA, ESAS, AND HCV TREATMENT OUTCOMES 1607 Table 4A. SVR and Treatment Discontinuation Because of Adverse Event by Time to Onset of Anemia and Receipt of Erythropoiesis-Stimulating Agents Early-onset anemia ( week 8) Late-onset anemia ( week 8) No ESA (n 143) ESA (n 238) P value a No ESA (n 273) ESA (n 211) Week 12 cevr, % (n/n) b 29.4 (42/143) 40.8 (97/238) (151/273) 55.0 (116/211).94 Week 24 response, % (n/n) c 36.4 (52/143) 58.4 (139/238) (201/273) 73.5 (155/211).97 EOT response, % (n/n) d 36.4 (52/143) 61.3 (146/238) (201/273) 79.6 (168/211).12 SVR, % (n/n) 25.9 (37/143) 45.0 (107/238) (162/273) 54.9 (116/211).34 Discontinuation because of 30.1 (43/143) 12.6 (30/238) (30/273) 10.9 (23/211).98 adverse events, % (n/n) RBV received, mg/kg/day Mean (SD) (2.53) (2.22) (1.86) (1.68).91 Median (IQR) ( ) ( ) ( ) ( ).59 Treatment duration, days, 127 (92 335) 332 ( ) ( ) 336 ( ).98 median (IQR) Percentage of intended RBV doses delivered e Mean (SD) 42.7 (27.2) 63.9 (26.9) (21.8) 81.3 (19.5).04 Median (IQR) 32.7 ( ) 70.1 ( ) ( ) 89 ( ).06 Percentage of intended PEG- IFN doses delivered e Mean (SD) 53.1 (34.4) 71.4 (29.3) (23.5) 85.7 (20.7).04 Median (IQR) 37.5 ( ) 80.9 ( ) ( ) 97.2 ( ).23 P value a ESA, erythropoiesis-stimulating agent; cevr, complete early virologic response; EOT, end-of-treatment; SVR, sustained virologic response; SD, standard deviation; IQR, interquartile range. a P values are based on 2 tests for categorical variables and t tests or Wilcoxon rank-sum tests for continuous variables. b cevr, complete early virologic response is defined as undetectable HCV RNA at treatment week 12. c Week 24 response is defined as undetectable HCV RNA at treatment week 24. d EOT, end-of-treatment response is defined as undetectable HCV RNA at the end of treatment. e Percentage of intended doses delivered was calculated as follows: [number of doses received]/[number of doses that were intended by treatment assignment over the 48-week treatment course in the absence of early discontinuation and dose reduction] 100. Table 4B. Odds Ratios for ESA Effect on SVR, Controlling for Potentially Confounding Factors, by Time to Onset of Anemia Onset of anemia ESA use model Odds ratio (95% CI) P value Early ( 8 weeks) Unadjusted a 2.34 ( ).001 Model 1 b 3.52 ( ).001 Model 2 c 3.13 ( ).001 Late ( 8 weeks) Unadjusted a 0.84 ( ).34 Model 1 b 0.95 ( ).81 Model 2 c 0.92 ( ).70 All anemic patients Unadjusted a 1.08 ( ).59 Model 1 b 1.35 ( ).06 Model 2 c 1.29 ( ).10 a No control for potentially confounding factors. b Odds ratio adjusted for all potentially confounding factors (age, gender, race, body mass index, baseline viral load, fibrosis, steatosis, fasting glucose, alanine aminotransferase, hemoglobin, platelet count, ribavirin [mg/kg/day] assigned, genotype [1a, 1b], and body weight). c Odds ratio adjusted for factors related to outcome (stepwise variable selection procedure based on all anemic patients: race, baseline viral load, fibrosis, steatosis, fasting glucose, and body weight). not anemic (9%) (Table 5). The incidence of AEs related to the cardiovascular system and malignancy was low among all patients including those who received ESAs. Pure red blood cell aplasia was not observed. Thromboembolic events (n 9) including pulmonary embolus and deep venous thrombosis were observed in 8 patients; of these, 4 patients were receiving ESAs or within 2 weeks of its discontinuation. One or more risk factors for thromboemboli (overweight/obesity, 4 patients; tobacco use, 2; estrogen therapy, 2; prolonged immobility, 1) were noted in each of the ESA users. Among these patients, the maximum Hb level prior to the event ranged from 11.5 to 14.7 g/dl with an increase in Hb level after starting ESA of 1.8 to 4.8 g/dl. No deaths occurred in patients with thromboemboli; 5 achieved SVR. Among anemic patients, no deaths occurred in patients who used ESAs, whereas 4 deaths occurred in those who did not use ESAs including 1 patient with a 5-g/dL Hb decline who suffered a fatal myocardial infarction at treatment week 8.

7 1608 SULKOWSKI ET AL GASTROENTEROLOGY Vol. 139, No. 5 Figure 2. Cumulative incidence of HCV treatment discontinuation according to time to anemia ( 8 weeks or 8 weeks) and use of ESAs among all anemic patients (n 865). Discussion PEG-IFN plus RBV is the standard treatment for chronic HCV and will likely continue to be used in combination with direct-acting antiviral agents. 3,27 29 Anemia is a frequent complication of PEG-IFN/RBV therapy for which RBV dose reduction is the primary management strategy. However, because lower SVR rates have been reported in patients who undergo RBV dose reduction, many clinicians and patients prefer to avoid this strategy and instead use ESAs to improve anemiarelated symptoms while maintaining RBV dose. 11,30,31 Despite this routine practice, the safety and effectiveness of ESAs in this setting have not been established. As such, these findings from this large clinical trial have notable implications for the management of HCV treatmentrelated anemia. Anemia developed in 28% of patients, of whom, the majority underwent protocol-defined RBV dose reduction. Because of dose reduction, on-treatment RBV exposure was lower in anemic patients compared with nonanemic patients. Unexpectedly, the SVR rate was significantly higher in anemic patients independent of ESA use compared with nonanemic patients (difference, 12% for anemic patients). Importantly, 1-step RBV dose reduction by 400 or 600 mg/day used with PEG-IFN alfa-2a was not associated with lower SVR rate, higher relapse rate, or improved safety outcomes compared with the more gradual 2-step RBV dose reduction strategy used with PEG-IFN alfa-2b. Furthermore, patients who experienced only modest declines in Hb ( 3 g/dl or 21% of baseline Hb level) had significantly lower SVR rates compared with those with larger declines in Hb concentration. Together, these data do not support the hypothesis that RBV dose reduction as a consequence of anemia leads to decreased SVR rates; instead, the data suggest an alternative hypothesis: The magnitude of Hb loss is a pharmacodynamic marker of RBV exposure, correlating more closely with antiviral effect than the ingested RBV dose. Although this relationship could be the result of an impaired physiologic response to RBV in nonanemic patients, the drug exposure hypothesis is strengthened by other research demonstrating that higher plasma RBV concentrations (as early as day 1 and week 4) are associated with higher Hb decline and virologic response in IFN/RBV-treated patients Prospective research is needed to test the hypothesis that increasing the RBV dose in persons with an insufficient on-treatment Hb decline will increase SVR rates in HCV genotype 1-infected patients.

8 November 2010 ANEMIA, ESAS, AND HCV TREATMENT OUTCOMES 1609 Table 5. Safety and Tolerability of PEG-IFN/RBV According to Anemia Status and Receipt of ESAs No anemia (A) n 2158 a Anemia/No ESA (B) n 416 a Anemia/ESA (C) n 449 a AvsB P value b Death, n (%) 8 (0.4) c 4 (1) d Serious adverse events, n (%) 191 (9) 49 (12) 61 (14) Discontinuation because of adverse event, n (%) 218 (10) 73 (18) 53 (12) Clinically relevant adverse events, n (%) Fatigue 1383 (64) 279 (67) 334 (74) Anemia e 187 (9) 362 (87) 437 (97) Aplastic anemia f 0 0 1( 1) Dyspnea 420 (19) 119 (29) 147 (33) Hypertension 78 (4) 15 (4) 19 (4) Myocardial infarction 3 ( 1) 2 ( 1) 1 ( 1) Coronary artery disease 3 ( 1) 1 ( 1) 0 Angina pectoris 1 ( 1) 0 0 Pulmonary embolism and/or deep vein thrombosis 4 ( 1) 0 4 ( 1) Cardiac failure congestive 0 1 ( 1) 2 ( 1) Cerebrovascular accident ( 1) Cerebral haemorrhage 1 ( 1) 0 0 Cancer g 12 (1) 2 ( 1) 6 (1) BvsC a Anemia defined as hemoglobin 10 g/dl. b P value is based on 2-sided 2 test when n 5 for both groups. c Causes of death in patients in the no anemia group included suicide (n 3), acute methadone poisoning, fentanyl and ethanol toxicity, gastrointestinal hemorrhage, hepatocellular carcinoma, and unknown. d Causes of death in patients in the anemia/no ESA use group included gunshot wound, disseminated blastomycosis, metastatic pancreatic cancer, and myocardial infarction. e Anemia as reported by the investigator. f Aplastic anemia was not pure red cell aplasia. g Cancer is defined as MedDRA version 10.1 terms of basal cell carcinoma, bladder neoplasm, breast cancer, hepatic neoplasm malignant, lip neoplasm, lung neoplasm, malignant melanoma, malignant neoplasm of ampulla of Vater, neoplasm skin, neuroma, oropharyngeal cancer stage unspecified, ovarian adenoma, pancreatic carcinoma, thyroid neoplasm. In this study, the relationship of anemia and SVR is confounded by ESA use; 50% of anemic patients were prescribed ESAs. Previous studies reported that ESAs increased Hb levels and maintained RBV dose; surprisingly, in this study, ESAs led to correction of anemia, but on-treatment RBV exposure was not significantly increased with adjuvant ESAs compared with that of anemic patients not treated with ESAs. This discordant observation is likely explained by differences in the definition of RBV dose maintenance applied in this study compared with earlier studies. In the study by Afdhal et al, 88% of HCV-treated patients randomized to receive epoetin alfa maintained their RBV dose compared with 60% of those receiving sham injections. 12 Failure to maintain RBV dose included on-treatment dose reduction and HCV treatment discontinuation before study week 4 or because of anemia; in this study, on-treatment RBV exposure and HCV treatment discontinuation were considered as unique outcomes. Whereas on-treatment RBV exposure was similar, ESA use was associated with significantly lower treatment discontinuation rates in patients with early-onset anemia. In these patients, ESA use was associated with significantly higher SVR rates, largely through its effect on preventing treatment discontinuation. In contrast, ESA use in patients with late-onset anemia ( 8 weeks) was not associated with lower discontinuation or higher SVR rates. Because early treatment discontinuation precludes SVR for most genotype 1-infected patients, the differential effect of ESA use on SVR according to time to anemia is not unexpected. These data support the conceptual framework that HCV genotype 1-infected patients who have greater treatment effect (anemia) are more likely to achieve SVR than those with less RBV effect if anemia-related symptoms do not lead to treatment discontinuation. Within the context of this model, ESAs may prevent treatment discontinuation in patients who rapidly develop anemia; more importantly, these data suggest that patients with late-onset anemia are not likely to benefit from adjuvant ESAs, representing 56% of all anemic patients and 47% of those prescribed ESAs. Furthermore, on-treatment RBV dose reduction was not associated with lower SVR rates. Taken together, these data support the use of RBV dose reduction as the primary strategy for the management of anemia related to PEG-IFN/RBV therapy; importantly, ESAs should not be used solely to avoid RBV dose reduction in anemic patients. In other patient populations, ESAs have been linked to increased risk of serious cardiovascular events, tumor progression, thrombosis, and death. Additionally, pure red blood cell aplasia because of neutralizing antibodies to native erythropoietin has been reported during HCV treatment Many of those populations are at high

9 1610 SULKOWSKI ET AL GASTROENTEROLOGY Vol. 139, No. 5 risk for many of these events because of their underlying disease (eg, cancer, renal failure secondary to diabetes mellitus). In previous published studies, Shiffman et al and Costiniuk et al did not observe an increase in these events in patients treated with ESAs during HCV therapy. 16,36 Among patients exposed to ESAs (median duration, 120 days), this study did not detect a signal for ESA toxicity related to malignancy or cardiovascular events; however, 4 patients experienced thromboemboli during ESA use, of whom, each had one or more additional thrombosis risk factors. No deaths were observed in patients receiving ESAs; 4 deaths including 1 fatal myocardial infarction occurred in anemic patients who did not receive an ESA. The relatively small number of HCVinfected patients exposed to ESAs and nonrandomized nature of ESA use in this study does not permit a confident estimation of risk of these relatively uncommon adverse events; nonetheless, these data suggest that clinicians should attend to traditional thrombosis risk factors in patients prescribed ESAs. Prospective research is needed to define the safety and impact of ESAs on virologic treatment outcomes in patients treated with PEG- IFN/RBV. Furthermore, active and passive pharmacovigilance strategies should be employed to detect AEs, which may occur in HCV-infected patients who receive ESAs as part of routine medical care. In conclusion, among HCV genotype 1-infected patients treated with PEG-IFN/RBV, the magnitude of Hb decline is associated with the likelihood of SVR, and anemic patients were more likely to achieve SVR than those without anemia despite decreased RBV dosing following Hb decline. Furthermore, the virologic relapse rate was not increased in patients with RBV dose reduction, including those who followed the strategy of a single reduction to RBV dose of 600 mg per day. Accordingly, these data firmly underscore the recommendation for RBV dose reduction as the primary strategy for management of treatment-related anemia. Furthermore, ESA use was not associated with increased RBV exposure but did minimize treatment discontinuation in patients with early-onset anemia, leading to a higher SVR rate in this subset of patients. No benefit was observed with ESAs in those who first developed anemia after 8 weeks of HCV therapy. The safety of ESA use in this clinical setting remains incompletely defined, thus its use may be best limited to patients likely to benefit, namely those with early-onset anemia. Prospective, randomized controlled trials are needed to define the optimal role of adjuvant ESAs during HCV treatment regimens that include PEG- IFN/RBV. Supplementary Material Note: To access the supplementary material accompanying this article, visit the online version of Gastroenterology at and at doi: /j.gastro References 1. Armstrong GL, Wasley A, Simard EP, et al. The prevalence of hepatitis C virus infection in the United States, 1999 through Ann Intern Med 2006;144: Shepard CW, Finelli L, Alter M. Global epidemiology of hepatitis C virus infection. Lancet Infect Dis 2005;5: Ghany MG, Strader DB, Thomas DL, et al. Diagnosis, management, and treatment of hepatitis C: an update. Hepatology 2009; 49: National Institutes of Health Consensus Development Conference Statement: management of hepatitis C: June 10-12, Hepatology 2002;36:S3 S Sulkowski MS, Wasserman R, Brooks L, et al. Changes in haemoglobin during interferon -2b plus ribavirin combination therapy for chronic hepatitis C virus infection. J Viral Hepat 2004;11: De Franceschi L, Fattovich G, Turrini F, et al. Hemolytic anemia induced by ribavirin therapy in patients with chronic hepatitis C virus infection: role of membrane oxidative damage. Hepatology 2000;31: Canonico PG, Kastello MD, Spears CT, et al. Effects of ribavirin on red blood cells. Toxicol Appl Pharmacol 1984;74: Fried MW. Side effects of therapy of hepatitis C and their management. Hepatology 2002;36:S237 S Manns MP, McHutchison JG, Gordon SC, et al. Peginterferon alfa-2b plus ribavirin compared with interferon alfa-2b plus ribavirin for initial treatment of chronic hepatitis C: a randomised trial. Lancet 2001;358: Fried MW, Shiffman ML, Reddy KR, et al. Peginterferon alfa-2a plus ribavirin for chronic hepatitis C virus infection. N Engl J Med 2002;347: Shiffman ML, Di Bisceglie AM, Lindsay KL, et al. Peginterferon alfa-2a and ribavirin in patients with chronic hepatitis C who have failed prior treatment. Gastroenterology 2004;126: Afdhal NH, Dieterich DT, Pockros PJ, et al. Epoetin alfa maintains ribavirin dose in HCV-infected patients: a prospective, doubleblind, randomized controlled study. Gastroenterology 2004;126: Dieterich DT, Wasserman R, Brau N, et al. Once-weekly epoetin alfa improves anemia and facilitates maintenance of ribavirin dosing in hepatitis C virus-infected patients receiving ribavirin plus interferon alfa. Am J Gastroenterol 2003;98: Pockros PJ, Shiffman ML, Schiff ER, et al. Epoetin alfa improves quality of life in anemic HCV-infected patients receiving combination therapy. Hepatology 2004;40: Younossi ZM, Nader FH, Bai C, et al. A phase II dose finding study of darbepoetin and filgrastim for the management of anaemia and neutropenia in chronic hepatitis C treatment. J Viral Hepat 2008;15: Shiffman ML, Salvatore J, Hubbard S, et al. Treatment of chronic hepatitis C virus genotype 1 with peginterferon, ribavirin, and epoetin. Hepatology 2007;46: Thevenot T, Cadranel JF, Di Martino V, et al. A national French survey on the use of growth factors as adjuvant treatment of chronic hepatitis C. Hepatology 2007;45: Sherman M, Cohen L, Cooper MA, et al. Clinical recommendations for the use of recombinant human erythropoietin in patients with hepatitis C virus being treated with ribavirin. Can J Gastroenterol 2006;20: Del Rio RA, Post AB, Singer ME. Cost-effectiveness of hematologic growth factors for anemia occurring during hepatitis C combination therapy. Hepatology 2006;44: Backus LI, Boothroyd DB, Phillips BR, et al. Predictors of response of US veterans to treatment for the hepatitis C virus. Hepatology 2007;46:37 47.

10 November 2010 ANEMIA, ESAS, AND HCV TREATMENT OUTCOMES McKoy JM, Stonecash RE, Cournoyer D, et al. Epoetin-associated pure red cell aplasia: past, present, and future considerations. Transfusion 2008;48: Bohlius J, Schmidlin K, Brillant C, et al. Recombinant human erythropoiesis-stimulating agents and mortality in patients with cancer: a meta-analysis of randomised trials. Lancet 2009;373: Singh AK, Szczech L, Tang KL, et al. Correction of anemia with epoetin alfa in chronic kidney disease. N Engl J Med 2006;355: Stravitz RT, Chung H, Sterling RK, et al. Antibody-mediated pure red cell aplasia due to epoetin alfa during antiviral therapy of chronic hepatitis C. Am J Gastroenterol 2005;100: Yee HS, Currie SL, Darling JM, et al. Management and treatment of hepatitis C viral infection: recommendations from the Department of Veterans Affairs Hepatitis C Resource Center program and the National Hepatitis C Program office. Am J Gastroenterol 2006;101: McHutchison JG, Lawitz EJ, Shiffman ML, et al. Peginterferon alfa-2b or alfa-2a with ribavirin for treatment of hepatitis C infection. N Engl J Med 2009;361: McHutchison JG, Everson GT, Gordon SC, et al. Telaprevir with peginterferon and ribavirin for chronic HCV genotype 1 infection. N Engl J Med 2009;360: Mederacke I, Wedemeyer H, Manns MP. Boceprevir, an NS3 serine protease inhibitor of hepatitis C virus, for the treatment of HCV infection. Curr Opin Investig Drugs 2009;10: Sarrazin C, Rouzier R, Wagner F, et al. SCH , a novel hepatitis C virus pro-tease inhibitor, plus pegylated interferon -2b for genotype 1 nonresponders. Gastroenterology 2007; 132: Reddy KR, Shiffman ML, Morgan TR, et al. Impact of ribavirin dose reductions in hepatitis C virus genotype 1 patients completing peginterferon alfa-2a/ribavirin treatment. Clin Gastroenterol Hepatol 2007;5: Hiramatsu N, Oze T, Yakushijin T, et al. Ribavirin dose reduction raises relapse rate dose-dependently in genotype 1 patients with hepatitis C responding to pegylated interferon -2b plus ribavirin. J Viral Hepat 2009;16: Jen JF, Glue P, Gupta S, et al. Population pharmacokinetic and pharmacodynamic analysis of ribavirin in patients with chronic hepatitis C. Ther Drug Monit 2000;22: Dahari H, Markatou M, Zeremski M, et al. Early ribavirin pharmacokinetics, HCV RNA and alanine aminotransferase kinetics in HIV/HCV co-infected patients during treatment with pegylated interferon and ribavirin. J Hepatol 2007;47: Maynard M, Pradat P, Gagnieu MC, et al. Prediction of sustained virological response by ribavirin plasma concentration at week 4 of therapy in hepatitis C virus genotype 1 patients. Antivir Ther 2008;13: Loustaud-Ratti V, Alain S, Rousseau A, et al. Ribavirin exposure after the first dose is predictive of sustained virological response in chronic hepatitis C. Hepatology 2008;47: Costiniuk CT, Camacho F, Cooper CL. Erythropoiesis-stimulating agent use for anemia induced by interferon-ribavirin treatment in patients with hepatitis C virus infection is not associated with increased rates of cardiovascular disease, thrombosis, malignancy, or death. Clin Infect Dis 2008;47: Received January 14, Accepted July 30, Reprint requests Address requests for reprints to: Mark S. Sulkowski, MD, Johns Hopkins University School of Medicine, 600 North Wolfe St, 1830 Building, Suite 445, Baltimore, Maryland msulkowski@jhmi.edu; fax: (410) Acknowledgments The authors thank the study coordinators, nurses, and patients involved in the study and Michael Geffner, Richard Valanzola, Andrew Baczkowski, Navdeep Boparai, Karen Kelly, Misti Linaberry, Helen Nguyen, Peter Savino, Jianmin Long, and Rachael Steiner of Schering-Plough Research Institute for their contributions to the conduct of the study. The study sponsor played a major role in the study design, data collection, and analysis in conjunction with the academic principal investigators: Drs Sulkowski and McHutchison. The corresponding author had full access to all of the data and takes full responsibility for the veracity of the data and analysis. Conflicts of interest The authors disclose the following: J. G. McHutchison (consultant or advisor: Schering-Plough), M. L. Shiffman (consultant or advisor: Gilead, Roche, Schering-Plough, Vertex Pharmaceuticals, ZymoGenetics), J. McCone (consultant or advisor: Roche, Schering- Plough), M. S. Sulkowski (consultant or advisor: Roche, Schering- Plough), W. M. Lee (consultant or advisor: Gilead, Lilly, Novartis, Westat); J. G. McHutchison (lecture fees: Schering-Plough), J. McCone (lecture fees: Roche, Schering-Plough), W. M. Lee (lecture fees: Schering-Plough), M. S. Sulkowski (lecture fees: Roche, Schering-Plough), M. L. Shiffman (lecture fees: Gilead, Roche); F. F. Poordad (investigator: Bristol-Myers Squibb, Gilead, GlaxoSmithKline, Human Genome Sciences, Idenix, Intarcia, Intermune, Novartis, Roche, Schering-Plough, Valeant, Vertex, Wyeth); F. F. Poordad (speaker bureau: Gilead, Novartis, Schering-Plough, Valeant); S. Noviello is former employee and current consultant of Schering- Plough (now Merck & Co.); C. A. Brass, W. Deng, K. Koury, L. D. Pedicone, and J. K. Albrecht are employees of Schering-Plough (now Merck & Co.) and are stock holders in this entity. Funding Supported by Schering-Plough Research Institute (now Merck & Co) for the study and research. Grant support by Roche (to J.G.M., M.L.S., and M.S.S.), Schering-Plough (to J.G.M., M.L.S., J.M., and M.S.S.), Vertex Pharmaceuticals (to J.G.M., M.L.S., M.S.S., and W.M.L); Biolex (to M.L.S.), Bristol-Myers Squibb (to M.L.S. and W.M.L.), Coley Pharmaceuticals (to M.L.S.), Conatus Pharmaceuticals (to M.L.S.), Gilead (to M.L.S.), GlaxoSmithKline (to M.L.S. and W.M.L.), GlobeImmune (to M.L.S. and W.M.L.), Idenix (to M.L.S.), Johnson & Johnson (to M.L.S.), Pfizer (to M.L.S.), Pharmassett (to M.L.S.), Romark Laboratories (to M.L.S.), Tibotec (to M.L.S.), Valeant (to M.L.S.), Wyeth (to M.L.S.), ZymoGenetics) (to M.L.S.); Debio Pharmaceuticals (to M.S.S.), Duke University Medical Center (to M.S.S.), Peregrine Pharmaceuticals (to M.S.S.); Beckman (to W.M.L.) and GlobeImmune (to W.M.L.).

11 1611.e1 SULKOWSKI ET AL GASTROENTEROLOGY Vol. 139, No. 5 Appendix: 1. Additional members of the IDEAL study team In addition to the authors, the participants and members of this study group include the following: Abdullah Al-Osaimi, Bruce Bacon, Luis Balart, Michael Bennett, David Bernstein, Edmund Bini, Martin Black, Joseph Bloomer, Hector Bonilla, Terry Box, Thomas Boyer, Norbert Brau, Kimberly Brown, Robert Brown, Christine Bruno, William Cassidy, Raymond Chung, David Clain, Jeffrey Crippin, Douglas Dalke, Charles Davis, Gary Davis, Mitchell Davis, Franco Felizarta, Roberto Firpi-Morell, Steven Flamm, Jose Franco, Bradley Freilich, Joseph Galati, Greg Wayne Galler, Reem Ghalib, Alexandra Gibas, Eliot Godofsky, Fredric Gordon, John Gross, Jorge Herrera, Robert Herring, Ke-Qin Hu, Jonathan Israel, Ira Jacobson, Shobha Joshi, Mandana Khalili, Alan Kilby, John King, Paul King, Alvaro Koch, Edward Krawitt, Marcelo Kugelmas, Paul Kwo, Louis Lambiase, Eric Lawitz, Edward Lebovics, James Levin, Robert Levine, Steven Lidofsky, Michael Lucey, Mark Mailliard, Luis Marsano, Paul Martin, Thomas McGarrity, Dennis Mikolich, Timothy Morgan, Andrew Muir, Kevin Mullen, Santiago Munoz, Donald Nelson, Frederick Nunes, Anders Nyberg, Lisa Nyberg, Sangik Oh, Prashant Pandya, Mary Pat Pauly, Craig Peine, Robert Perrillo, Gary Poleynard, Anthony Post, John Poulos, David Pound, Mordechai Rabinovitz, Natarajan Ravendhran, Joanna Ready, Robert Reindollar, Adrian Reuben, Lorenzo Rossaro, Lawrence Rothman, Raymond Rubin, Vinod Rustgi, Michael Ryan, Eugene Schiff, Warren Schmidt, William Semon, Thomas Sepe, Kenneth Sherman, Maria Sjogren, Robert Sjogren, Coleman Smith, Lawrence Stein, Robert Strauss, Mark Swaim, Gyongnyi Szabo, Joseph Thurn, Myron Tong, John Vierling, George Wu, Rockford Yapp, Ziad Younes, Atif Zaman.