Study of the Impact of Nitazoxanide on Chronic Hepatitis Patients
Information source: National Liver Institute, Egypt
Information obtained from ClinicalTrials.gov on December 08, 2011
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Hepatitis C
Intervention: Placebo (Drug); Nitazoxanide (Drug)
Phase: Phase 2/Phase 3
Sponsored by: National Liver Institute, Egypt
Official(s) and/or principal investigator(s):
Mohamed A Kohla, MD, Principal Investigator, Affiliation: National Liver Institute, Menoufiya University, Egypt
Hossam A Taha, MD, Study Director, Affiliation: National Liver Institute, Menoufiya University, Egypt
Mohamed A Kohla, MD, Phone: +2/0111047684, Email: firstname.lastname@example.org
The main objective of antiviral therapy of patients with chronic hepatitis C (CHC) is the
sustained elimination of the hepatitis C virus (HCV). The standard of care (SOC) is
peginterferon alfa-2a/-2b with ribavirin for 48 weeks or 24 weeks according to HCV genotype.
However, this approach is not sufficient to substantially improve the sustained virologic
response (SVR) rates. Therefore, new therapies are needed to treat patients with hepatitis C
virus (HCV) infection. Nitazoxanide (NTZ), originally used to treat cryptosporidium parvum
infection, recently was shown to have an unexpected antiviral activity in the HCV replicon
system and in chronically infected patients.
The aim of this work is to study impact of nitazoxanide therapy in addition to
peginterferon/ribavirin combination on virologic responses in patients with chronic
hepatitis C genotype 4.
Patients will be enrolled in this study and will be randomly assigned in a 1: 1 ratio into 2
Group A: comprises 100 CHC patients who will receive the standard of care treatment,
peginterferon-alf 2a plus weight-based ribavirin for 48 weeks.
Group B: comprises 100 CHC patients who will receive nitazoxanide monotherapy at a dose of
500 mg twice daily for 12 weeks as a lead-in phase followed by triple therapy, nitazoxanide
500 mg twice daily plus peginterferon alfa-2a, and weight-based ribavirin for 48 weeks.
Data will be collected and statistical analysis will be done comparing the groups regarding
response to antiviral therapy. Final results will be discussed and compared to similar
studies published in peer reviewed journals and international conferences.
Official title: Impact of Nitazoxanide on Virologic Responses in Chronic HCV Infected Patients With Genotype 4: A Placebo-controlled Randomized Trial
Study design: Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator), Primary Purpose: Treatment
Primary outcome: Assessment of efficacy of Nitazoxanide as an add-on therapy in terms of achieving a sustained virologic response
assessment of rapid virologic response
Assessment of early virologic response
Assessment of end-of-treatment response
Safety of Nitazoxanide
Assessment of the efficacy of Nitazoxanide monotherapy following the lead-in phase
Chronic hepatitis C virus (CHC) infects approximately 170 million individuals worldwide.
Egypt has the highest hepatitis C virus prevalence in the world (overall prevalence is 12%
among the general population, and up to 40% in persons above 40 years of age and is more in
Approximately, 90% of hepatitis C patients in Egypt are infected with HCV genotype 4.
The main objective of antiviral therapy of patients with chronic hepatitis C is the
sustained elimination of the hepatitis C virus (HCV).
The standard of care for the treatment of chronic hepatitis C is a 24- to 48- week course of
peginterferon plus ribavirin, depending on genotype.
Overall, approximately, half of the patients can be cured by SOC. For patients with genotype
4, the sustained virologic response (SVR) rate with 48 weeks of therapy ranges from 50 to 60
%. Based on baseline viral load and the speed of virologic response during treatment,
individualization of treatment duration is possible. However, this approach is not
sufficient to substantially improve the sustained virologic response (SVR) rates. A
significant proportion of treated patients thus either fail to respond or relapse following
an initial response and a substantial number of patients are unable to tolerate treatment.
There is at present no alternative therapy for these patients and thus a need for new drugs
for the treatment of chronic hepatitis C.
Nitazoxanide, the first member of the thiazolidide anti-infective class of compounds, is an
oral anti-parasitic agent with no major side effects that was developed and licensed in the
US (Alinia; Romark Laboratories, L. C., Tampa FL, USA) for the treatment of cryptosporidium
parvum and Giardia lamblia, recently was shown to have an unexpected antiviral activity in
the HCV replicon system and in chronically infected patients. A serendipitous observation
during drug development revealed that some patients with cryptosporidiosis and acquired
immunodeficiency syndrome who are co-infected with hepatitis C or B viruses, had a reduction
in serum alanine aminotransferase (ALT) levels during therapy. This observation led to
studies of the anti-viral activity of nitazoxanide and its active metabolite tizoxanide in
HCV genotype 1a and 1b replicons and a genotype 2 infectious clone, which showed a potent
inhibition of HCV replication by both compounds at submicromolar concentrations.
In addition, pretreatment of HCV replicon-containing cells with nitazoxanide was shown to
enhance the antiviral effect of subsequent treatment with nitazoxanide plus interferon.
The mechanism of action of nitazoxanide in protozoa and anaerobic bacteria has been shown to
result from direct inhibition of pyruvate ferredoxin oxidoreductase enzyme-dependent
electron transfer reaction which is essential to anaerobic energy metabolism. However, the
antiviral mechanism of action of nitazoxanide appears to be different.
Recent studies of the mechanism of action of nitazoxanide against HCV have shown that it
induces double-stranded RNA-activated protein kinase (PKR) phosphorylation, which results in
an increased intracellular concentration of phosphorylated eukaryotic initiation factor 2α,
a naturally occurring antiviral intracellular protein and a key mediator of host cell
defenses against viral infection, this mechanism of action is triggered only when a cell is
infected with HCV, whereas nitazoxanide has no effect on in uninfected cells, which provides
a potential explanation for its very low rate of toxicity.
It worth mentioning that resistance to nitazoxanide is unlikely as it exerts its antiviral
activity by modulating cell signaling, an interferon-like mechanism, rather than by
targeting the virus directly and that nitazoxanide does not induce mutations that confer
viral resistance, suggesting that the genetic barrier to the development of resistance to
nitazoxanide is high.
These clinical and laboratory observations prompted study of the potential effect of
nitazoxanide in patients with chronic hepatitis C.
Rossingol JF et al,demonstrated that treatment with nitazoxanide monotherapy at a dose of
500 mg twice daily orally, was associated with an ETR in 7 of 23 (30. 4%) patients with
chronic hepatitis C genotype 4, the virologic responses occurred between 4 and 20 weeks of
therapy (three at week 4, three at week 8 and one at week 20) and continued through the end
of treatment with no virological breakthroughs. A low serum HCV RNA ≤ 400,000 IU/ml, was the
most significant predictor of virological response (p=0. 009). In addition, none of the
patients with cirrhosis, poorly controlled diabetes, or the one patient with HBV coinfection
responded to treatment. Four of the 7 patients with an ETR (17. 4% of 23 treated patients)
had an SVR, 24 weeks after the end of treatment.
This preliminary data prompted the study of the efficacy and safety of Nitazoxanide as a
triple therapy in combination with peginterferon and ribavirin in patients with chronic
hepatitis C genotype 4 aiming at improving the rate of sustained virological response (SVR).
A recent study by Rossignol JF et al, conducted on a total 97 treatment - naïve patients
conducted in 2 centers in Egypt demonstrated that, significantly more patients receiving
triple therapy with peginterferon alfa-2a, ribavirin and nitazoxanide experienced SVR
compared with the standard of care (79% vs 50%; p=0-023). The SVR rates for the
peginterferon plus nitazoxanide group was higher than the standard of care (61% vs 50%)
although this difference was not statistically significant.
The percentages of rapid virologic response (RVR), defined as undetectable HCV RNA at week 4
of combination therapy, and SVR were significantly higher in patients given the triple
(Nitazoxanide/ peginterferon/ ribavirin) therapy compared with the standard of care (64% vs
38%, P = .048; and 79% vs 50%, P = .023; respectively). Patients given nitazoxanide plus
peginterferon alfa-2a had intermediate rates of RVR (54%). There were no added side effects
associated with the use of nitazoxanide.
Mean reductions in serum HCV RNA from baseline to the RVR visit were - 2. 86, -3. 74, and -4. 5
log10 IU/ml for the peginterferon plus ribavirin, dual therapy with peginterferon plus
nitazoxanide, and triple therapy with peginterferon, ribavirin and nitazoxanide groups,
respectively (p=0. 008).
Changes in ALT levels from baseline to week 72 in patients who achieved an SVR were
evaluated, nearly all patients had normalization of ALT levels (15/16 patients in groups 1
and 3, and all patients in group 2), in parallel with loss of detectable serum HCV RNA.
Interestingly, the use of nitazoxanide in the dual- and triple-treatment arms was associated
with reduced relapse rates (3/20 patients and 1/23 patients, respectively) compared with the
standard of care arm (10/30 patients).
The rationale for a nitazoxanide lead-in phase before combined therapy with peginterferon,
with or without ribavirin, was based on an initial pilot experience that showed greater
antiviral efficacy if nitazoxanide was administered before peginterferon rather than
The required duration of nitazoxanide lead-in phase is unknown, and 12 weeks was selected as
an initial conservative estimate to optimize the potential benefit of nitazoxanide
pretreatment. A subsequent study has shown that a 4-week lead-in phase may be satisfactory,
and this study also provides further confirmation of the antiviral efficacy of nitazoxanide
combined with peginterferon.
In this open-labeled study, 44 treatment-naïve patients with chronic hepatitis C were
treated with 4 weeks on nitazoxanide 500 mg twice daily followed by combination dual therapy
of peginterferon alfa-2a 180 µg weekly plus nitazoxanide 500 mg twice daily for an
additional 36 weeks. Interestingly, the SVR rate with dual therapy (80%), was similar to the
SVR rate with triple therapy (79%) seen in the previous study using a 12-week lead-in phase.
This shorter lead-in period might be adequate.
In a preliminary experience with interferon nonresponders, a small number of patients with
chronic hepatitis C genotype 4 who had failed prior interferon-based therapy were re-treated
using triple therapy with nitazoxanide, peginterferon and ribavirin and achieved an SVR rate
of 25% (3/12 patients) compared with 8% (1/12 patients) retreated with the standard of care
using peginterferon alfa-2a plus ribavirin.
All these data show that nitazoxanide, a novel protein kinase inducer, has the potential to
increase the SVR rate in patients with chronic hepatitis C, however, further studies to
test these hypotheses on larger numbers of both naïve and nonresponder patients are still
Minimum age: 18 Years.
Maximum age: 60 Years.
- Age > 18 and <60.
- Liver biopsy showing chronic hepatitis with significant fibrosis using Ishak scoring
- Compensated liver disease; serum bilirubin < 1. 5 mg/dl, INR no more than 1. 5, serum
albumin > 3. 4, platelet count >75,000 mm, and no evidence of hepatic decompensation
(hepatic encephalopathy or ascites).
- Acceptable hematological and biochemical indices (hemoglobin 13g/dl for men and 12
g/dl for women; neutrophil count 1500/mm3 or more and serum creatinine <1. 5 mg/dl.
- Willing to be treated and to adhere to treatment requirements
- Major uncontrolled depressive illness.
- Solid organ transplantation.
- Autoimmune conditions, known to be exacerbated by peginterferon and ribavirin.
- Untreated thyroid disease.
- Pregnant or unwilling to comply with adequate contraception.
- Severe concurrent medical disease such as severe hypertension, heart failure,
significant coronary heart disease, poorly controlled diabetes, chronic obstructive
- Known hypersensitivity to drugs used to treat HCV.
Locations and Contacts
Mohamed A Kohla, MD, Phone: +2/0111047684, Email: email@example.com
National Liver Institute, Shebin El-Kom, Menoufiya, Egypt; Recruiting
Mohamed A Kohla, MD, Phone: +20111047684, Email: firstname.lastname@example.org
Hossam A Taha, MD, Phone: +20129772285, Email: email@example.com
Mohamed A Kohla, MD, Principal Investigator
Hossam A Taha, MD, Sub-Investigator
Starting date: September 2010
Last updated: September 16, 2011