Download Therpay of hepatitis C: basic approaches and clinical applications

THERAPY OF HEPATITIS C:
BASIC APPROACHES AND CLINICAL
APPLICATIONS
Erik DE CLERCQ
Rega Institute for Medical Research, K.U.Leuven
B-3000 Leuven, Belgium
Flaviviridae
Flaviviruses
Yellow fever virus
Dengue virus
West Nile virus
Japanese encephalitis virus
Tick-borne encephalitis virus
St. Louis encephalitis virus
.
.
.
Pestiviruses
Bovine viral diarrhea virus
Classical swine fever
Border disease virus
Hepaciviruses
Hepatitis C virus (HCV)
Hepatitisviruses
HAV
HBV
HCV
Enterovirus
type 72
Hepadnavirus
Hepacivirus
Picornaviridae
Hepadnaviridae
Flaviviridae
HDV
-agens
[circular
(-)RNA]
HEV
Calicivirus
Picornaviridae
Transmission of hepatitisviruses
HAV
HBV
HCV
HDV
HEV
Faeco-oral
Parenteral
Parenteral
Parenteral
Faeco-oral
Sexual
Sexual
Sexual
Perinatal
(Perinatal)
(Perinatal)
Hepatitisvirus infections
HAV
HBV
HCV
HDV
HEV
Acute hepatitis





Chronic carrier (risk)
O



O
Chronic hepatitis (risk)
O



O
Cirrhosis (risk)
O



O
Hepatocellular carcinoma (risk)
O


?
O
Hepatitisvirus infections: vaccination
HAV
HBV
HCV
HDV
HEV
Yes
Yes
No
No
No
Features of hepatitis C virus infection
Incubation period
Average 6-7 weeks
Range 2-26 weeks
Acute illness (jaundice)
Mild ( 20%)
Case fatality rate
Low
Chronic infection
60%-85%
Chronic hepatitis
10%-70%
Cirrhosis
< 5%-20%
Mortality from CLD
1%-5%
Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
Evolution of chronic hepatitis C
Primary
hepatocellular
carcinoma
Cirrhosis
42%
Average 3 years
(0-15 years)
Global distribution of HCV infection
Transmission routes for HCV
Centers for Disease Control and Prevention
Hepatitis C: Risk groups
•
•
•
•
•
•
•
Blood transfusion before 1990
Injecting drug use
Household transmission of HCV
Health care workers
Tattooing, body piercing
Promiscuity
Unknown
General population
Surgeons
Centers for Disease Control and Prevention
Other transmission issues
• HCV not spread by kissing, hugging, sneezing,
coughing, food or water, sharing eating utensils
or drinking glasses, or casual contact
• Do not exclude from work, school, play,
childcare or other settings based on HCV
infection status
Centers for Disease Control and Prevention
GENERAL STRUCTURE OF A FLAVIVIRUS
HCV GENOME ORGANIZATION
HCV genome and sites for current drug development
At the 5’ untranslated region resides the internal ribosomal entry site (IRES), which is
highly conserved and represents a site for development of translation inhibitors such
as antisense oligonucleotides and ribozymes. NS3 encodes for a specific helicase and
the NS5B region encodes for an RNA-dependent RNA polymerase enzyme, both important
in viral replication. These also represent sites for the development of specific viral
enzyme inhibitors. Other potential enzyme targets include the HCV specific proteases
(NS2/3 and NS3/4). These enzymes are involved in processing the viral polyprotein at
specific sites as indicated.
McHutchison and Patel, Hepatology 36: S245-S252 (2002)
Schematic representation of the HCV genome and encoded viral proteins
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Schematic representation of the organization of the HCV genome and the
structure of a subgenomic replicon
Bartenschlager, Nature Reviews/Drug Discovery 1: 911-916 (2002)
Proposed replicative cycle of HCV and potential sites of therapeutic intervention
Tan et al., Nature Revievs/Drug Discovery 1: 867-881 (2002)
Crystal structure of HCV NS3 protease-inhibitor complex
Ribbon conformation of the three-dimensional crystal structure of two hepatitis C virus (HCV)
non-structural protein 3 (NS3) serine-protease domains complexed with an NS4A cofactor
peptide (residues 956-967; red) and the tripeptide inhibitor (inhibitor I; ball-and-stick model)
L-BOC,L-Glu,L-Leu-(difluoro)aminobutyric acid. BOC, tert-butyloxycarbonyl group.
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
N
O
O
O
N
N
OH
O
O
O
O
N
H
Macrocyclic inhibitor of HCV NS3 protease
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Tsantrizos et al., Int. Patent Appl. WO 00/59929 (2000)
Crystal structure of HCV NS3 helicase complexed with single-stranded DNA
Ribbon diagram of the hepatitis C virus (HCV) non-structural protein 3 (NS3) helicase RNA-helicase
domain complexed with a deoxyuridine octamer (dU8; yellow)
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Kim et al., Structure 6: 89-100 (1998)
Crystal structure of HCV NS5B polymerase
Ribbon representation of the first 570 residues from the amino terminus of hepatitis C virus
(HCV) non-structural protein 5B (NS5B), with -helices and -strands represented in red and
cyan, respectively.
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Cl
O
HO
N
O
N
O
HN S
O
CH3
Benzimidazole derivative
Analogue of JTK-003, an orally active inhibitor of
non-structural protein 5B (NS5B)
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Hashimoto et al., Int. Patent Appl. WO 01/47883 (2001)
Iminosugar derivatives based on the glucose analogue DNJ
H
N
HO
HO
N
N
HO
HO
OH
OH
Deoxynojirimycin
HO
OH
OH
N-butyl-DNJ
HO
OH
OH
N-nonyl-DNJ
Durantel et al., J. Virol. 75: 8987-8998 (2001)
Iminosugar derivatives based on the galactose analogue DGJ
H
N
HO
HO
N
N
HO
HO
OH
OH
Deoxygalactonojirimycin
HO
OH
OH
N-butyl-DGJ
HO
OH
OH
N-nonyl-DGJ
Durantel et al., J. Virol. 75: 8987-8998 (2001)
Mechanism of action of short- and long-alkylchain DNJ and DGJ derivatives against BVDV
(Bovine Viral Diarrhea Virus)
• Reduction in viral secretion and reduction in infectivity
of newly released viral particles.
• No correlation between antiviral effect and inhibition of
–glucosidases at the endoplasmic reticulum (ER).
Durantel et al., J. Virol. 75: 8987-8998 (2001)
PEG
Polyethylene glycol
CH3(OCH2CH2)nOH
CH3OCH2CH2OCH2CH2.......OCH2CH2OCH2CH2OH
Glycol
HOCH2CH2OH
Polyethylene
-(CH2CH2)n-
Ethylene
-CH2-CH2-
O
CH3O(CH2CH2O)n
O
C
NH
 (CH2)4
CH3O(CH2CH2O)n
O
C
O
 CH
N
C
H
O
O
O
NHS
N
O
Branched polyethylene glycol (PEG) that was created by coupling a monofunctional
PEG (mPEG)-benzatriazole carbonate of molecular mass 40 kDa to lysine. Conjugation
of this PEG moiety to interferon-2a (IFN-2a) results in an agent with a significantly
longer half-life, which requires less frequent administration and has an improved
toxicity profile. NHS, N-hydroxysuccinimide.
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
Pegylated interferon -2b plus ribavirin compared with interferon  2b plus
ribavirin for the initial treatment of chronic hepatitis C
Virological response at the end of treatment and follow-up
Endpoint
Sustained viral response (SVR) rate (number responding/total treated)
Higher-dose peginterferon
1.5 µg/kg/week
Lower-dose peginterferon
0.5 µg/kg/week
Interferon
3 MU x 3/week
+ Ribavirin
(800 mg/day)
+ Ribavirin
(1000-1200 mg/day)
+ Ribavirin
(1000-1200 mg/day)
Overall
End of treatment: all patients
SVR at end of follow-up: all patients
65% (333/511)
54% (274/511)
56% (289/514)
47% (244/514)
54% (271/505)
47% (235/505)
SVR by genotype
1
2/3
4/5/6
42% (145/348)
82% (121/147)
50% (8/16)
34% (118/349)
80% (122/153)
33% (4/12)
33% (114/343)
79% (115/146)
38% (6/16)
Manns et al., Lancet 358: 958-965 (2001)
Peginterferon -2b plus ribavirin for initial treatment of chronic hepatitis C
Logistic regression analyses
Sustained virological response (SVR) as a function of ribavirin dose (mg/kg)
and dose of peginterferon alfa-2B
Proportion with SVR (%)
100
Higher-dose
peginterferon alfa-2b
(1.5 µg/kg/week)
80
60
40
Lower-dose
peginterferon alfa-2b
(0.5 µg/kg/week)
20
0
5
7
9
11
13
15
17
19
21
23
25 27
Ribavirin (mg/kg)
Manns et al., Lancet 358: 958-965 (2001)
% HCV-negative patients
Pegylated interferon -2b compared to interferon -2b for the initial
treatment of chronic hepatitis C
Virologic response at end of treatment and end of follow-up
49
41
33
25
23
24
18
12
Percentage of subjects with virologic responses (loss of detectable serum HCV
RNA) at the end of treatment ( ) and at the end of follow-up ( )
Lindsay et al., Hepatology 34: 395-403 (2001)
Pegylated interferon -2a, as compared to interferon -2b, plus ribavirin
for the treatment of chronic hepatitis C virus infection
Fried et al., N. Engl. J. Med. 347: 975-982 (2002)
Pegylated interferon -2a, as compared to interferon -2b, plus ribavirin
for the treatment of chronic hepatitis C virus infection
Fried et al., N. Engl. J. Med. 347: 975-982 (2002)
Pegylated interferon -2a, as compared to interferon -2b, plus
ribavirin for the treatment of chronic hepatitis C virus infection
Proportion of patients with a sustained virologic response as a
function of HCV genotypea
Peginterferon alfa-2a
plus ribavirin
(N = 453)
Interferon alfa-2b
plus ribavrin
(N = 444)
Peginterferon alfa-2a
plus placebo
(N = 224)
No./total no. (%)
HCV genotypeb
All patients
255/453 (56)
197/444 (44)
66/224 (29)
Genotype 1
138/298 (46)
103/285 (36)
30/145 (21)
Genotype 2 or 3
106/140 (76)
88/145 (61)
31/69 (45)
10/13 (77)
4/11 (36)
Genotype 4
4/9
(44)
aA
sustained virologic response was defined as no detectable hepatitis C virus (HCV)
RNA 24 weeks after the cessation of therapy.
bSix patients had other genotypes
Fried et al., N. Engl. J. Med. 347: 975-982 (2002)
Pegylated interferon -2a plus ribavirin for the treatment of chronic hepatitis C virus infection
Predictability of sustained virologic response
Fried et al., N. Engl. J. Med. 347: 975-982 (2002)
Kinetics of HCV RNA and proportions of patients who became HCV RNA
negative at different times with the high and low doses of
peginterferon -2b plus ribavirin
···· High dose
3 µg, then 1.5 µg, then 1.0 µg/kg/week
____ Low dose
0.5 µg/kg/week
Buti et al., Hepatology 35: 930-936 (2002)
Adverse events in 453 patients with chronic hepatitis C virus infecton who
received peginterferon alfa-2a plus ribavirin
(percentage of patients in parentheses)
Adverse events
Peginterferon alfa-2a plus ribavirin
Fatigue*
242
(54)
Headache*
211
47)
Pyrexia*
195
(43)
Myalgia*
189
(42)
Insomnia
168
(37)
Nausea
130
(29)
Alopecia
128
(28)
Arthralgia
121
(27)
Irritability
109
(24)
Rigors*
106
(24)
Pruritus
101
(22)
Depression
100
(22)
Decreased appetite
96
(21)
Dermatitis
95
(21)
*This symptom is one of the influenza-like symptoms often seen with interferon treatment
Fried et al., N. Engl. J. Med. 347: 975-982 (2002)
O
N
H2N
N
N
HO
O
HO
OH
Ribavirin
NH
N
H2N
N
N
HO
O
HO
OH
Viramidine
O
N
H2N
N
N
OH
O
HO
OH
Levovirin
L-Ribavirin
O
H3CO
H
N
O
H
N
N
H
O
O
N
VX-497
O
O
OH
CH3
OH
C
O
O
OCH3
CH3
Mycophenolic acid
O
OH
CH3
O
C
N
O
O
O
OCH3
CH3
Mycophenylate mofetil (Cellcept®)
2-Morpholinoethyl ester of mycophenolic acid
H
NH2.HCl
H
H
Amantadine
H
NH2.HCl
H
CH3
H
Rimantadine
Current clinical hepatitis C drug development
Drug type
Compound
Alternative interferons
Natural interferon
II
Albuferon
I
Oral interferons
Oral interferon inducers
Nucleoside analogues
IMPDH inhibitors
Broad spectrum antivirals
Phase of
development
I
Preclinical/I
Levovirin
I/II
Viramidine
I/II
VX-497
II
Mycophenylate mofetil
II
Amantadine
Rimantadine
II
II
Comments
Leukocyte-derived interferon alfa, alternative
to recombinant interferons
Fusion of interferon with albumin to increase
half-life
Oral absorption of interferon
Drugs that induce interferon production
L-isomer of ribavirin, reported to cause less
hemolysis
Ribavirin “prodrug” with preferential liver
uptake
Specific inhibitor, no hemolysis, further trials
with interferons in progress
Evaluation of efficacy combined with
interferon alfa in nonresponders in progress
Numerous clinical trials evaluating efficacy
with interferon or interferon and ribavirin in
naive and nonresponder populations
McHutchison and Patel, Hepatology 36: S245-S252 (2002)
Current clinical hepatitis C drug development (continued)
Drug type
Compound
Phase of
development
Comments
BILN-2061
Preclinical/I
A multitude of agents from different classes is in
preclinical development. One agent has entered phase
I trials (BILN-2061)
Preclinical/I
Numerous agents in preclinical stages. Development
of one compound halted in early dose ranging studies
Preclinical/I
Several compounds in development. A single drug in
phase I trials (JTK-003)
Small molecule targets and
viral enzyme inhibitors
NS3 protease inhibitors
NS3 helicase inhibitors
NS5B polymerase inhibitors
Antisense oligonucleotides
JTK-003
ISIS-14803
II
McHutchison and Patel, Hepatology 36: S245-S252 (2002)
Selected IFN-based therapies for the treatment of HCV infection
Drug name
Company
Clinical phase
Intron A (IFN-2b, recombinant)
Schering-Plough
FDA approval, 1995
Roferon A (IFN-2a, recombinant)
Roche
FDA approval, 1996
Infergen A (IFN alfacon-1)
InterMune Pharmaceuticals
FDA approval, 1997
Welferon (lymphoblastoid IFN-n1)
GlaxoSmithKline
FDA approval, 1999
PEG-INTRON (PEGylated IFN-2b)
Schering-Plough
FDA approval, 2001
Pegasys (PEGylated IFN-2a)
Roche
FDA approval, 2001
Omniferon (natural IFN-)
Viragen (Scotland)
Phase II
Omega IFN (IFN-)
BioMedicines
Phase II
Albuferon-  (albumin-IFN-2b)
Human Genome Sciences
Phase I
Rebif (IFN-1a)
Serono
Preclinical
Rebetron (Intron A and ribavirin)
Schering-Plough
FDA approval, 1998
PEG-INTRON and ribavirin
Schering-Plough
FDA approval, 2001
Pegasys and ribavirin
Roche
FDA application, submitted
Monotherapy
Combination therapies
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)
A sample of the drug pipeline for hepatitis C and related treatments
Target/
indication
Drug name
Mechanism/
drug category
Company
IRES
ISIS 14803
Antisense
ISIS Pharmaceuticals/
Elan Corporation
Heptazyme
Ribozyme
Ribozyme Pharmaceuticals
BILN-2061
Serine-protease inhibitor Boehringer Ingelheim
VX-950/LY-570310
Serine-protease inhibitor Vertex Pharmaceuticals/Lilly
NS5B
JTK-003
RdRp inhibitor
Japan Tobacco
IMPDH
VX-497
IMPDH inhibitor
Vertex Pharmaceuticals
Levovirin
IMPDH inhibitor
Ribapharm
Viramidine
IMPDH inhibitor
Ribapharm
NS3
Tan et al., Nature Reviews/Drug Discovery 1: 867-881 (2002)