Multicenter, Double-Blind, Randomized Trial of Emricasan in Hepatitis C Treated Liver Transplant Recipients with Residual Fibrosis or Cirrhosis
Ethan W Weinberg EW1 Michael P. Curry2, Catherine T. Frenette3, Fredric G. Regenstein4, Eugene
R. Schiff5, Zachary D. Goodman6, James Mac Robinson7, Jean L. Chan7, Joanne C. Imperial7 and K.
Rajender Reddy1

(1) University of Pennsylvania, (2) Beth Israel Deaconess Medical Center, Boston, MA, (3) Scripps Clinic, (4) Tulane Medical Center, (5) University of Miami, (6) Inova Fairfax Hospital,
(7) Conatus Pharmaceuticals

Address Correspondence:
K. Rajender Reddy M.D Professor of Medicine University of Pennsylvania 2 Dulles, HUP
3400 Spruce Street
Philadelphia, PA 19104
E-mail [email protected]

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1002/LT.25934

Key words: Fibrosis and cirrhosis, Chronic Hepatitis C, Liver transplantation, Emricasan, POLT-Study
Abstract:

Background: Despite achieving sustained virologic response (SVR) to HCV therapy there remains a population of HCV patients post liver transplantation with advanced fibrosis or cirrhosis. Emricasan is an orally active, pan-caspase inhibitor which suppresses apoptosis and inflammation and therefore potentially decreases inflammation and fibrosis.
Aim: To determine the safety and efficacy of emricasan in reducing or preventing progression of hepatic fibrosis in post-transplant HCV recipients achieving SVR with anti-viral therapy, and assess changes from baseline in ALT and caspases 3/7.
Methods and Patients: Study IDN-6556-07 was a double-blind, randomized, placebo-controlled, multicenter study in liver transplant recipients with chronic HCV who had SVR but had residual HCV- related liver fibrosis or cirrhosis. Sixty-four subjects were randomized to receive 25 mg twice daily of emricasan or placebo in a 2:1 ratio for 24 months.
Results: 41 emricasan and 23 placebo subjects were randomized and 32 emricasan (78.0%) and 19 placebo (82.6%) subjects completed the study. There was no difference in the primary endpoint (Ishak F2-F5, improvement in fibrosis or stability; Ishak F6, improvement) between the emricasan (77.1%) and placebo groups (74.1%). Overall, there was no difference between the emricasan (54.5%) and placebo (60.7%) arms in the rate of fibrosis improvement alone. However, those in the pre-specified F3-5 subgroup had higher rates of stability or improvement in fibrosis in the emricasan group (95.2%) compared to placebo (54.6%);(P=0.01). ALT improved over the first 12 months of therapy with emricasan.
Conclusion: In liver transplant recipients with recurrent HCV who achieved SVR but had residual fibrosis, overall stability in Ishak fibrosis stage was similar between emricasan and placebo groups at 24 months (p=NS). However, there was improvement and/or stability in fibrosis stage in the pre- specified F3-F5 subgroup with emricasan vs. placebo (p=0.01), suggesting that patients with moderate fibrosis may further benefit with emricasan. Over 24 months, in combination with immunosuppression, tolerability and safety profiles were similar in both groups.

Introduction

Liver transplantation is a life-saving event for those with end-stage liver disease who are fortunate enough to receive one. However, close to thirty percent of liver-transplant recipients will experience graft loss or die within five years after transplant.1 Until 2015, Hepatitis C (HCV) was the leading cause for liver transplantation in the United States, but now remains the leading cause of repeat transplant.1,2 Direct acting antivirals (DAAs) have altered the landscape for HCV post-liver transplant, as the vast majority of patients achieve sustained virologic response (SVR) with the initial treatment regimen; those who fail the initial regimen can be treated with a salvage regimen.3–5 Despite achieving SVR, there remains a population of HCV patients post liver transplant with residual and advanced fibrosis who may progress to cirrhosis, thus remaining at risk of progression of liver disease and developing complications including HCC. One strategy would be attempting to regress fibrosis using an anti-fibrotic or anti-inflammatory drug, recognizing that there are no such approved therapies.
Emricasan is a pan-caspase inhibitor that was developed for its potential to reduce inflammation in the liver regardless of the etiology of the disease.6 Early studies with emricasan in HCV during the Peg-IFN era demonstrated reductions in ALT and AST without affecting HCV viral load.7,8 More recent clinical trials in NASH demonstrated that emricasan decreased ALT, caspase 3/7 activity and markers of apoptosis (cCK18).9–12 Emricasan has a favorable side-effect profile, with minimal attributable symptoms over placebo, even in end-stage liver disease.13 In addition, emricasan has few drug-drug interactions, making it an attractive option in patients with solid organ transplants, as they tend to be on numerous medications including long-term immunosuppressants. The POLT (Post Orthotopic Liver Transplant) study, a randomized, double-blind, placebo-controlled multi-centered trial, set out to evaluate the effect of emricasan in patients that had recurrent HCV after liver transplant that had subsequently achieved SVR but still had residual hepatic fibrosis post- SVR.
Methods

STUDY DESIGN

Study IDN-6556-07 was a double-blind, randomized, placebo-controlled, multicenter study involving subjects with chronic HCV who had undergone liver transplantation; developed HCV-related liver fibrosis or cirrhosis; achieved a sustained virologic response (SVR) following anti-HCV therapy; and still showed demonstrable fibrosis or cirrhosis on a liver biopsy obtained within 3 months of randomization. Approximately 60 subjects were to be randomized in a 2:1 ratio to receive 25 mg

twice daily of emricasan or placebo. Up to 15 subjects with an Ishak stage of F6 were permitted to be enrolled. The randomization schedule was generated using a validated randomization program and verified for accuracy using strict quality control procedures. Randomization numbers and study drug assignment were centrally coordinated through the study’s Interactive Web Randomization System (IWRS). The subjects were stratified based on the stage of fibrosis or cirrhosis at baseline: Ishak F2, Ishak F3 – F5, and Ishak F6. The primary objective of IDN-6556-07 was to assess the effect of emricasan on fibrosis or cirrhosis using the Ishak fibrosis stage, in subjects with HCV reinfection and liver fibrosis or cirrhosis following orthotopic liver transplantation for chronic HCV who subsequently achieved SVR following anti-HCV therapy. The secondary objectives of the study were to determine the effects of emricasan on necro-inflammatory sub-score of the modified Histological Activity Index, to determine the effects of emricasan on markers of mechanism of action and inflammation, and to assess the safety and tolerability of emricasan in subjects status post-orthotopic liver transplantation. The duration of each subject’s participation was approximately 26.5 months, consisting of a screening period (6-weeks), double-blind treatment period (24 months), and follow up visit (4 weeks).
STUDY PATIENTS

Patients with a history of orthotopic liver transplantation for HCV-induced liver disease that had achieved SVR with anti-viral HCV treatment within 18 months of randomization, and with liver fibrosis or cirrhosis on liver histology as read by a central histopathologist of Ishak F2 to F6 within three months of randomization. Patients were required to be on stable doses of immunosuppressant therapy for ≥ 3 months prior to randomization and have Hemoglobin ≥ 11 g/dL, platelet count ≥ 75 × 109/L and WBC ≥ 2.0 × 109/L. Key exclusion criteria were presence of another liver disease (NAFLD allowed), HIV, hepatocellular carcinoma (HCC) at entry, significant systemic or major illness other than liver disease, decompensated liver disease since liver transplantation, renal transplant or renal impairment with eGFR <30mL/min/1.73m2, or concurrent sirolimus use ( concern of a potential drug- drug interaction and anti-fibrotic effect). Pregnant and lactating women were excluded as well. Subjects were prohibited to take any potentially hepatotoxic medications for 30 days prior to and through the course of the study. Any drug known to cause fibrosis, with the exception of immunosuppressants, was prohibited for six-months prior to and through study enrollment.
OUTCOMES

Liver Histology

Liver biopsies were performed at screening, Month 12, and Month 24 for assessment of primary and

secondary efficacy endpoints. All liver biopsies taken during the study, regardless of the indication, (i.e., both protocol-defined and those performed for any clinical indications) were to be assessed at the local institution and also forwarded to the central histopathologist for assessment. In the event of any discrepancy between the local and central histopathology reports, the latter prevailed. The primary efficacy objective was based on the Ishak fibrosis scoring system.14 The Ishak modification of Knodell histological activity index (HAI) was assessed by liver biopsy. The four components of the Knodell HAI - interface hepatitis, confluent necrosis, parenchymal injury, and portal inflammation – were scored on a scale 0-4 or 0-6.15
Biomarkers
The following biomarkers were measured: ALT (reference range: males 10-40 U/L; females 10-33 U/L), AST (reference range: males 10-43 U/L); females 10-36 U/L), caspase 3/7 (reference range: 1429‐3908 relative light units), cCK18/M30 (reference range: ≤ 260 U/L), flCK18/M65 (reference range: ≤ 413 U/L), and Enhanced Liver Fibrosis (ELF) score (score reference range: ≤ 7.7; based on hyaluronic acid [reference range: 7.5-284.5 ng/mL], P3NP [reference range: 3-23.4 ng/mL], and TIMP-1 [reference range: 134-477.9 ng/mL]).
Safety Assessment

The following safety assessments were performed: adverse event assessment, medical history and physical examinations, vital sign measurements, liver and abdominal ultrasounds, 12-Lead ECG, and liver monitoring assessments. Laboratory assessments were performed at a central laboratory (PPD Laboratories, Highland Heights, KY, USA).
STATISTICAL ANALYSIS

Analyses were conducted using SASv9.3 or higher and pooled across all enrolling sites. Data were summarized descriptively with categorical variables. All disposition, demographics, and baseline summaries were based on the Full Analysis Set (FAS), which consisted of all randomized subjects who received at least one dose of study drug, representative of the intention-to-treat principle. Efficacy analyses were also based on the FAS. All safety analyses were based on the Safety Analysis Set (SAS), which consisted of all subjects who were randomized and received at least one dose of study drug according to the treatment actually received. As all subjects were treated as randomized, the FAS and SAS were identical. For purposes of laboratory summaries, baseline was to be defined as an average of all values observed up to and including Day 1. For purposes of

abnormality laboratory summaries and all other analyses, baseline was to be defined as the last observed value up to and including Day 1.
The response at Month 24 was the primary endpoint. All screening, month 12, and month 24 biopsy data were used in the primary analysis, irrespective of the defined protocol visit window. Responses, as defined below, at month 24 were summarized descriptively by treatment group, along with exact (Clopper-Pearson) 95% confidence intervals (CIs). The risk difference between groups was also to be provided with its 95% CI using the asymptotic method. The change from baseline in the Ishak fibrosis stage was to be derived for each subject and was to be used to classify subjects into one of the three following groups: 1) Improvement: defined as having a reduction from baseline of at least 1- point in the Ishak fibrosis stage. 2) Stable: defined as having no change from baseline in the Ishak fibrosis stage and 3) Worsening: defined as having an increase from baseline in the Ishak fibrosis
stage.

Subjects were to be classified as a responder or non-responder based on the above three groups. The definition of response was based on the following: For subjects with baseline Ishak fibrosis stage of F2-F5, achieving either improvement or remaining stable. For subjects with baseline Ishak fibrosis stage of F6, achieving improvement.
For the primary efficacy analysis based on the Month 24 biopsy, subjects missing the month 24 biopsy were to have their Ishak fibrosis stage imputed. Imputation of missing Ishak fibrosis stages was conducted using multiple imputation (MI). Imputed results were based on age, gender, baseline Ishak fibrosis stage, and the month 12 Ishak fibrosis stage. Imputations were based on at least 5 imputed datasets, depending on the percent of missing observations and were documented in the clinical study report. Within each imputed dataset, the change from baseline at month 24 was derived to allow categorization into response or no response. Multiple imputation was applied to the analysis of the primary endpoint in order to address a regulatory aspect that is required for studies that would have been planned for a new drug application (NDA) submission. This was done purely from the statistical regulatory expectation. All secondary analyses were conducted using the FAS. All secondary endpoints were summarized using observed cases. There were no imputations for missing data made for any of the secondary endpoints, except Ishak fibrosis stage at Month 12. Confidence intervals for multiple imputation results were calculated based on the methodology of Rubin and Schenker.16

Supportive testing of the difference in response rates was conducted using a Cochran- Mantel- Haenszel test. For each of the analyses, the testing was stratified separately by each of the following: 1) Baseline Ishak fibrosis stage strata (F2, F3-F5, F6) 2) Baseline Ishak fibrosis stage grouping A (F2-F3, F4-F6) and 3) Baseline Ishak fibrosis stage (F2, F3, F4, F5, F6).
Each multiple imputation p-value was calculated by combining the chi-square statistics across the imputed datasets.17 Response at Month 12 was summarized descriptively by treatment group, along with exact (Clopper-Pearson) 95% CIs. The risk difference between groups was also provided with its 95% CI using the asymptotic method. Multiple imputation was applied in the same manner as for the primary analysis. Changes from baseline for the Ishak fibrosis stage were summarized descriptively by treatment group using a shift table.
This study was conducted at multiple centers with the intent to randomize approximately 60 subjects in a 2:1 ratio to emricasan or placebo, respectively. The sample size determination for this study was based on the Phase 2b screening methodology.18 A placebo response rate of 30% was for this study based on a observational study reported by George et al, in which 29% of patients showed a response in fibrosis from a mean of 1.6 years following HCV-SVR.19 The expectation was to see at least a 15% difference between placebo and emricasan treatment groups, which was considered a clinically meaningful difference.
Results

Disposition

Of the 114 subjects screened, 64 met eligibility criteria and were subsequently randomized: 41 to emricasan and 23 to placebo (Figure1). Nine subjects (22.0%) in the emricasan arm and four subjects (17.4%) in the placebo arm discontinued the study prior to completion of the protocol (Figure 1). Of subjects who discontinued prematurely, three subjects in both the emricasan and placebo arms stopped due to adverse events (emricasan: acute renal failure, elevated creatinine, and hepatocellular carcinoma; placebo: pancreatitis, pancreatic cancer, and acute renal failure).
Baseline demographics and clinical characteristics

The median ages in both arms were 61 and 62 years old, more often male, about seven-years post liver transplant, treated with a DAA regimen, on tacrolimus, and had reached SVR about seven months prior to entering the trial (Table 1). There were no statistically significant differences at baseline among the emricasan and placebo groups in the Ishak Fibrosis stage, AST, ALT, Caspase

3/7, cCK18, and flCK18 levels (Table 1). The average ALT and AST at baseline were within the normal range (Table1).
Changes in fibrosis at 2 years

There was no difference in the primary endpoint (Ishak F2-F5, improvement in fibrosis or stability; Ishak F6, improvement) between the emricasan (77.1%) and placebo arms (74.1%), with both arms achieving response rates much higher than anticipated based a prior observational study reported by George et al from patients treated with interferon-based protocols (Table 2 and Figure 2a).19 Additionally, while there was no difference between the emricasan (54.5%) and placebo (60.7%) arms in the rate of fibrosis improvement alone, a higher percentage of patients in the placebo arm had worsening fibrosis after two years compared to the emricasan arm (Figure 2b).
Subjects in the pre-specified F3-5 subgroup had higher rates of stability or improvement in fibrosis in the emricasan arm (95.2%) compared to placebo (54.6%), while subjects in the F6 subgroup had higher rates of improvement in the placebo arm (100%) compared to the emricasan arm (0%). Among the F3-F5 placebo arm, 5/11 had worsening fibrosis on their month-24 liver biopsy (Figure 2c). The change in fibrosis score distribution from baseline through the end of the study did not differ between emricasan and placebo in the overall study population, with a similar percentage of subjects achieving minimal-to-no fibrosis (F0-F1) and moderate fibrosis (F2-F3) (Figure 2d). Neither the time from transplant nor the time from SVR had an effect on fibrosis regression at M24.

Changes in the Knodell Histologic Activity Index at 2 years

There were no differences in the inflammatory components (interface hepatitis, parenchymal injury, and portal inflammation) of the Knodell Histologic Activity Index (HAI) between emricasan and placebo after 24 months (Figure 3a-c). However, it is notable that the majority of patients with moderate to severe interface hepatitis (scores 2-4), whether receiving emricasan or placebo for 24 months, continued to show improvements in interface hepatitis from baseline (Figure 3d). Parenchymal injury and portal inflammation may be slower to improve, as the majority of patients enrolled had stable portal inflammation and parenchymal injury.

Pharmacodynamic activity

The therapeutic target was well-engaged in subjects receiving emricasan, as evidenced by a decrease in caspase 3/7 in the emricasan arm from D1 to month 12 compared to relatively stable caspase 3/7 levels in the placebo arm (Figure S1a). There were five fewer evaluable caspase 3/7 data-points for subjects in the emricasan arm at month 24 (n=32) compared to month 12 (n=37), while the placebo arm had only one fewer missing data point (month 12, n=20; month 24, n=19); these missing data-points may have contributed to the increase in the average caspase 3/7 levels in the emricasan group at month 24. While the ALT levels were normal at baseline in both the emricasan and placebo arms, there was a sustained decrease in ALT among the emricasan arm from D1 to month 12 (Figure S1b).

Assessment of safety

Emricasan was well-tolerated, overall. Treatment emergent adverse events (TEAE) occurred with similar frequency in both the emricasan (90.2%) and placebo (87.0%) arms (Table S1). Serious and severe TEAEs also occurred at similar rates between the emricasan (34.1; 31.7%) and placebo (30.4; 30.4%) groups. Common adverse effects – eg diarrhea, nausea, headache, and fatigue – occurred in similar frequencies among the emricasan and placebo arms; there was no characteristic emricasan-associated TEAE that would have unintentionally unblinded subjects in the emricasan arm (Table S2).
Infections and overall cancers occurred at similar rates in both emricasan and placebo arms (Table 3). Skin cancers are common among patients that have received a solid organ transplant, with an incidence over 1% per year.20 There was only one reported skin cancer (placebo) in the 24-month study. Ten patients in the emricasan arm and two patients in the placebo arm had HCC prior to transplant; there were two HCC occurrences in the emricasan group and no HCC occurrences in the placebo group. One HCC was deemed a recurrent HCC, occurring 4 years after the initial transplant for HCV cirrhosis with HCC; the baseline fibrosis stage in this patient was Ishak stage F2. The other HCC was deemed de novo, occurring 10 years after the initial transplant for HCV cirrhosis with HCC. The baseline, month 12, and month 24 liver biopsies in this patient demonstrated Ishak stage F3.
Discussion

HCV was the leading cause for liver transplantation in the United States annually throughout the interferon-era (1994-2013) and remains a leading cause of liver transplantation in the United

States.21,22 Prior to the introduction of DAAs, recurrent chronic HCV infection was unavoidable post- liver transplant, with the development of graft fibrosis in the majority of patients within two years of liver transplant and graft cirrhosis occurring in 20-30% of patients within five years of transplant.23,24 In the interferon era, nearly 40,000 liver transplants were performed for decompensated HCV cirrhosis, a majority of whom would develop post-liver transplant graft fibrosis or cirrhosis.1 While DAA therapy is highly-effective in curing HCV and reducing hepatic fibrosis, there remained an unmet need for medical therapies that reduce graft fibrosis post-liver transplant.
This study was a multi-centered, double-blinded randomized controlled trial evaluating the effect of emricasan, a pan-caspase inhibitor, on liver fibrosis post-SVR in patients with recurrent HCV after liver transplant. The primary endpoint of this study was stabilization or improvement in Ishak fibrosis stage on liver biopsy after 24 months of orally administered emricasan 25mg or placebo given twice daily. This was the first study to evaluate the course of liver fibrosis, and the impact of a potentially anti-fibrotic agent, in liver transplant patients who had HCV successfully eradicated but had residual fibrosis. A prior study in the interferon-era documented 25% of patients had improvement in fibrosis staging 24-weeks after completion of HCV therapy.25 A few single-center studies in the interferon era evaluated the long-term effects of SVR on liver fibrosis. George et al. found that among those with liver fibrosis Ishak stage ≥2, prior to HCV treatment, more than 80% had improvement in fibrosis score four years after SVR.19 D’Ambrosio et al. reported that 61% of patients in their cohort had cirrhosis regression five years after SVR from interferon-based therapies.26 Abdelmalek et al evaluated the effects of HCV SVR post-liver transplant with serial biopsies; 2 years after SVR, only 27% of patients had fibrosis regression, after 3-5 years, fibrosis regression occurred in 67% of patients.27 Roche et al found, on average, a small, non-significant decrease in both fibrosis and inflammatory histologic scores 2-3 years after SVR in 17 post-liver transplant patients.28 In this study, we observed high but similar rates of fibrosis regression in both the emricasan (54.5%) and placebo (60.7%) arms 24 months after baseline SVR-biopsy. This rapid rate of fibrosis regression after HCV SVR in the post-liver transplant setting has not been documented previously. While high and similar rates of fibrosis regression were noted in emricasan and placebo group after baseline SVR-liver biopsy, in a subset of patients with F3-F5 fibrosis, a greater fibrosis improvement in the emricasan arm was seen, suggesting that a sub-group of patients with moderate fibrosis may further benefit with an anti-fibrotic strategy. The median time for enrollment in this study was 7 months after SVR. It is possible that the post-SVR fibrosis regression had not yet reached steady state and that the placebo group improvement, overall may have been a

reason for not seeing a greater benefit in the study drug exposed group given the small sample size (Type II error).
Caspases are family of intracellular enzymes that are activated by cellular damage and lead to apoptosis of the cell. The relative amount of cellular damage and apoptotic effect of caspase activation can be quantified through measurement of cytokeratin-18 (CK18) by-products in the serum such as cCK18 (cleaved CK18) or flCK18 (full-length CK18).29 The long-term effects of constant caspase-mediated apoptosis in the liver has been hypothesized to contribute to fibrosis in chronic liver diseases. Inhibiting this pathway had led to decreases in serum markers of hepatic injury and inflammation in previous clinical trials for liver diseases.8,30,31 Emricasan engaged its biochemical target, as evidenced by the reduction in caspase 3/7 levels at day 14 and sustained through month
12. The improvement in ALT in the treatment group is quite intriguing and interesting. It has been argued that despite clearance of HCV, there might be ongoing subclinical inflammatory activity and thus it is conceivable that emricasan led to amelioration of this inflammation and subsequently fibrosis but in only those with moderate fibrosis.32
Emricasan was well-tolerated in the post-liver transplant patient population, with adverse events similar between emricasan and placebo arms. Overall incident cancer and infection rates were similar between emricasan and placebo. While there were two instances of HCC in the emricasan group and none in the placebo group, it is important to take into account that there were ten patients in the emricasan group who had HCC pre-transplant compared to two patients in the placebo group.
There are limitations to our study apart from the small sample size. The overall population of subjects had minimal evidence of elevated caspase activity at baseline, as measured by the executioner caspases-3/7, and the result of the executioner caspases on cCK18, making it unclear to what degree caspase activation may be important in the progression of liver disease in this patient population. Subjects had only a low level of active inflammation at baseline, as shown by the HAI activity scores, providing little room for more improvement. It was also difficult to estimate the degree of expected improvement in the placebo patients. Previous studies using paired biopsies in this patient population were limited, variable, and mainly from patients treated with interferon-based therapies; patients in these studies were also at variable times post-SVR.27,33–35 The population selected in the post-liver transplant state should have been those who had inflammatory activity leading to and perpetuating fibrosis. In contemporaneous studies, emricasan was shown to have

negligible effects on NASH in multiple cohorts – those with NASH, compensated NASH cirrhosis, and decompensated NASH cirrhosis. 9–12 Further, the influence on hemodynamic parameters of portal hypertension have been variable. 9,12 Based on the results of this study, emricasan may have a role in fibrosis regression in a subset of patients with persistent and moderate fibrosis after HCV SVR, but it does not appear to have global effects on the transplant population in the time-frame in which it was studied.

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35. Mauro E, Crespo G, Montironi C, et al. Portal pressure and liver stiffness measurements in the prediction of fibrosis regression after sustained virological response in recurrent hepatitis C. Hepatology. 2018;67(5):1683-1694.

Tables

Table 1

Emricasan 25 mg BID
(N=41) Placebo
(N=23) Total
(N=64)
Age (yr) 60.4 (8.05) 61.1 (6.09) 60.6 (7.36)

Gender – n (%)
Female 9 (22.0) 5 (21.7) 14 (21.9)
Male 32 (78.0) 18 (78.3) 50 (78.1)

Race – n (%)
Black or African American 7 (17.1) 2 (8.7) 9 (14.1)
White 30 (73.2) 20 (87.0) 50 (78.1)
More than one race 1 (2.4) 0 1 (1.6)
Unknown or Not Reported 3 (7.3) 1 (4.3) 4 (6.3)

Weight (lbs) 189.77 (33.688) 204.34 (23.631) 195.09 (31.017)
BMI (kg/m2) 28.10 (4.330) 30.51 (4.701) 28.98 (4.583)

Liver Transplantation
Years since transplant 7.21 (4.702) 6.96 (3.470) 7.12 (4.273)

Emricasan 25 mg BID
(N=41) Placebo
(N=23) Total
(N=64)

Source of transplant - n (%)
Living 0 1 (4.3) 1 (1.6)
Cadaveric 40 (97.6) 21 (91.3) 61 (95.3)
Unknown 1 (2.4) 1 (4.3) 2 (3.1)

Immunosuppressant therapy - n (%)
Tacrolimus 35 (85.4) 19 (82.6) 54 (84.4)
Cyclosporine 5 (12.2) 4 (17.4) 9 (14.1)
Glucocorticoids 0 1 (4.3) 1 (1.6)
Other 1 (2.4) 0 1 (1.6)

Time since SVRa (days) 242.6 (172.79) 281.8 (161.65) 256.7 (168.65)

Previous HCV Treatmentb - n (%)
Antiviral 33 (80.5) 19 (82.6) 52 (81.3)
Anitviral+Immunotherapy 8 (19.5) 4 (17.4) 12 (18.8)

Ishak fibrosis stage - n (%)
F0 0 0 0
F1 0 0 0
F2 9 (22.0) 6 (26.1) 15 (23.4)
F3 20 (48.8) 7 (30.4) 27 (42.2)
F4 5 (12.2) 5 (21.7) 10 (15.6)
F5 2 (4.9) 2 (8.7) 4 (6.3)
F6 5 (12.2) 3 (13.0) 8 (12.5)

ALT (U/L) 21.0 (10.85) 26.0 (19.54) 22.8 (14.67)
AST (U/L) 24.9 (9.32) 27.7 (11.55) 25.9 (10.20)
Platelet count (K/cu mm) 159.6 (56.94) 167.3 (74.24) 162.3 (63.12)
Total bilirubin (mg/dL) 0.600 (0.3392) 0.742 (0.4101) 0.652 (0.3699)
Albumin (g/dL) 4.46 (0.423) 4.39 (0.318) 4.43 (0.387)
INR 0.97 (0.086) 1.09 (0.546) 1.01 (0.333)

Emricasan 25 mg BID
(N=41) Placebo
(N=23) Total
(N=64)
Caspase 3/7 (raw RLU) 1873.6 (858.13) 1873.6 (858.13) 1873.6 (858.13)
cCK18/M30 (U/L) 252.9 (166.81) 294.6 (214.00) 267.7 (184.29)
flCK18/M65 (U/L) 374.8 (189.19) 485.9 (291.99) 414.2 (234.75)
ELF score 9.93 (0.933) 9.78 (0.980) 9.88 (0.945)
All values are Mean (standard deviation) unless otherwise noted

Table 2
Response a in Prespecified Subgroups (Observed)

Ishak Fibrosis Score at Baseline Emricasan Response Rate
% (n/N) Placebo Response Rate
% (n/N)
Difference (95% CI) Ad hoc p value
Overall Population 78.1 (25/32) 73.7 (14/19) 4.4 (-20.0, 28.9) 0.718b
F2 83.3 (5/6) 100 (5/5) -16.7 (-46.5, 13.2) 1.000 b
F3, F4, F5 95.2 (20/21) 54.6 (6/11) 40.7 (9.9, 71.5) 0.011 b
F6 0 (0/5) 100 (3/3) -100 (-100.0, -100.0) 0.018 b
This is the final version of the “response” table provided in the 04 April 2018 Press Release.
a Response: Baseline F2-F5: achieving either improvement or remaining stable; Baseline F6: achieving improvement (stable subjects were considered “non-responders.”)
bAdhoc p-values were calculated using a chi-square test for the overall population and a Fishers Exact Test for each subgroup.

Table 3

Treatment Emergent Adverse Events of Interest

Emricasan 25 mg BID
(N=41) Placebo
(N=23) Total
(N=64)
n (%) Events n (%) Events n (%) Events
Infections 4 (9.8) 6 1 (4.3) 2 5 (7.8) 8
Biliary tract infection bacterial 1 (2.4) 1 0 0 1 (1.6) 1
Enterobacter bacteraemia 1 (2.4) 1 0 0 1 (1.6) 1

Emricasan 25 mg BID
(N=41) Placebo
(N=23) Total
(N=64)
Gastroenteritis cryptosporidial 1 (2.4) 1 0 0 1 (1.6) 1
Gastroenteritis viral 1 (2.4) 1 0 0 1 (1.6) 1
Influenza 0 0 1 (4.3) 1 1 (1.6) 1
Pneumonia 1 (2.4) 1 0 0 1 (1.6) 1
Pneumonia mycoplasmal 1 (2.4) 1 0 0 1 (1.6) 1
Sepsis 0 0 1 (4.3) 1 1 (1.6) 1

Neoplasms benign, malignant and unspecified
(including cysts and polyps) 8 (19.5) 10 2 (8.7) 2 10 (15.6) 12
Basal cell carcinoma 3 (7.3) 4 0 0 3 (4.7) 4
Hepatocellular carcinoma* 2 (4.9) 2 0 0 2 (3.1) 2
Colon adenoma 1 (2.4) 1 0 0 1 (1.6) 1
Mycosis fungoides 1 (2.4) 1 0 0 1 (1.6) 1
Pancreatic carcinoma metastatic 0 0 1 (4.3) 1 1 (1.6) 1
Prostate cancer 1 (2.4) 1 0 0 1 (1.6) 1
Seborrhoeic keratosis 1 (2.4) 1 0 0 1 (1.6) 1
Squamous cell carcinoma of skin 0 0 1 (4.3) 1 1 (1.6) 1
*10 subjects in emricasan group and 2 subjects in placebo group had HCC prior to transplant

Figure Legends:

Figure 1. CONSORT diagram of study screening, enrollment, and completion. Figure 2: Fibrosis outcomes
Figure 2a. Primary endpoint of study included subjects that had either improvements in hepatic fibrosis or stability after 24 months of treatment.
Figure 2b. Ishak fibrosis scores of subjects that competed study at 24 months
Figure 2c. Fibrosis outcomes at 24 months for subjects with moderate-to-advanced hepatic fibrosis at baseline.
Figure 2d: Ishak Fibrosis Scores at Baseline, Month 12, and Month 24
Figure 3. Histologic Activity Index (HAI) comparing baseline to 24 month liver biopsy Figure 3a. Interface hepatitis
Figure 3b. Parenchymal Injury Figure 3c. Portal Inflammation
Figure 3d. Interface Hepatitis among subjects with baseline interface hepatitis activity score 2-4. Figure S1. Serial measurements of Caspase 3/7 (a) and ALT (b) over the course of the study

Disclosure:

EMW: consulting fees for Mallinckrodt Pharmaceuticals and Sequana Medical

MC: Research Support: Gilead Sciences Inc., Mallinckrodt, Afimmune. Consulting: Mallinckrodt

CF: Consulting with Conatus, Bayer, Exelixis, Eisai, Gilead, Genentech, Wako/Fujifilm Speakers Bureau: BMS, Eisai, Exelixis, Gilead, Abbvie, Genentech, Salix
Research support: Conatus, Bayer, Merck, Exelixis, Genfit

FR: Research Support: Intercept, Celgene. Speaking and Teaching: Gilead, Intercept. Advisor: Gilead

ES: Consultant for Dova Pharmaceutical. Grant/ research support from Eiger, Galmed, Zydus,

Celgene, Beckman, Biokit, Bristol Myers Squibb, Conatus, Celgene, Discovery Life Sciences, Genfit, Gilead, Intercept, Novartis, Novo Nordisk, Orasure Technologies, Ortho Diagnostics, Pfizer, Prometheus Lab, Roche Diagnostics, Shire, Siemens, Target Pharma Solutions, Tobira, Zydus, Glaxo Smith Kline. Royalties from Wiley.

ZG: Research grants from Conatus, Intercept, Gilead Sciences, Allergan (now Abbvie), Bristol- Myers Squibb, Novartis, NGM.

JMR, JC, JI: Previously employed by Conatus Pharmaceuticals

KRR: Advisory Board- Mallinckrodt, Gilead. Research support (to Institution)-Mallinckrodt, Grifols, Gilead, Merck, BMS, Intercept, Exact Sciences, NASH-TARGET, HCC-TARGET

Funding Source:

The study was funded by Conatus Pharmaceuticals, Inc. (San Diego, California, United States) and Novartis (Basel, Switzerland).

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