Studies highlight important features of nitazoxanide and other thiazolidesas therapeutic agents for chronic hepatitis C
TAMPA, Fla., Nov. 1, 2010 /PRNewswire/ -- Romark Laboratories announced that data from studies of nitazoxanide in hepatitis C are being presented at the 61st Annual Meeting of the American Association for the Study of Liver Diseases (AASLD), also known as The Liver Meeting® in Boston, October 30 – November 2, 2010.
"The data presented at AASLD provide important support for our ongoing clinical development program for nitazoxanide in chronic hepatitis C (CHC)," said Jean-Francois Rossignol, M.D., Ph.D., Chairman and Chief Science Officer of Romark. "Extensive studies have shown that nitazoxanide does not induce mutations that confer viral resistance – one of the most challenging problems associated with antiviral therapy. Other studies highlight the important role of nitazoxanide in stimulating the interferon signaling pathway and a potential role for nitazoxanide in special populations such as relapsers and liver transplant patients."
Another major finding reported at AASLD is the activity of nitazoxanide-related compounds (called thiazolides) against HCV. Collectively, these studies provide further rationale for the use of nitazoxanide and other thiazolides as part of a new approach to chronic hepatitis C therapy – an approach that focuses on reducing the number of drugs and the toxicities associated with treatment.
Investigators from Georgetown University, the National Institutes of Health, and Mayo Clinic have presented or will present their data on October 31 and November 2. The three presentations are listed and described briefly below:
1. HCV Resistance to Nitazoxanide is not due to Changes in the Viral Sequence. Brent Korba, Microbiology & Immunology, Georgetown Univ. Med. Ctr., Washington, DC. Poster session: Tuesday, November 2, 7:00 am – 12:00 pm.
Dr. Korba reports an extensive series of studies designed to evaluate mechanisms of potential resistance of hepatitis C virus (HCV) to nitazoxanide. These studies show that nitazoxanide does not induce mutations in HCV that confer resistance. Importantly, these findings distinguish nitazoxanide from direct-acting antiviral drugs (e.g., protease and polymerase inhibitors) and other host-targeting anti-HCV agents, such as the cyclophilin inhibitors, where resistance appears to be primarily due to mutations in viral sequences.
2. Augmentation of Interferon Signaling Pathway by Nitazoxanide: A Novel Therapeutic Strategy for Relapsers to Peginterferon and Ribavirin Therapy. Crystal Wang(1), Ziaozhen Zhang(1), Anu Osinusi(1), Henry Masur(2), Dawn Fishbein(3), Shyam Kottilil(1); (1)LIR, NIAID, NIH, Bethesda, MD; (2)CCMD, CC, NIH, Bethesda, MD; (3)SAIC-Frederick, Inc., CMRP in support of CCMD, NIH, Frederick, MD. Poster session: Tuesday, November 2, 7:00 am – 12:00 pm.
This team of researchers from NIH reports that nitazoxanide has potent in vitro anti-HCV activity in the Huh7.5/JFH-1 HCV genotype 2a continuous cell culture system and that the activity is synergistic with interferon. In PBMCs collected from SVR and relapser patients co-infected with HCV and HIV, nitazoxanide significantly enhanced interferon-inducible gene expression. The addition of nitazoxanide to interferon also significantly enhanced interferon-inducible gene expression compared to interferon alone. Importantly, these investigators also report, for the first time, the activity of new nitazoxanide-related compounds (thiazolides) against HCV.
3. Nitazoxanide for the Prevention of Recurrent Hepatitis C Virus Infection after Liver Transplantation: A Pilot Study. Sumeet K. Asrani, Stacy Anderson, Jennie Wilnso, Laura J. Myhre, Julie Heimbach, Walter K. Kremers, Charles B. Rosen, Terry M. Therneau, W. Ray Kim; Mayo Clinic College of Medicine, Rochester, MN. Poster session: Sunday, October 31, 8:00 am – 5:30 pm.
Dr. Kim and his colleagues from the Mayo Clinic have reported results of a pilot study of nitazoxanide in 5 male liver transplant patients who received oral nitazoxanide 1000 mg b.i.d. immediately prior to transplant and for 72 hours thereafter. Each of the 5 patients experienced a decrease in HCV viral load during the first 72 hours. Within 4 days after completing therapy, HCV RNA levels were similar to pre-transplant levels. Nitazoxanide was well tolerated with the primary adverse events being abdominal pain and nausea which resolved. Post-transplant viral kinetics for these 5 patients were similar to a historical control group of 5 transplant recipients, except that there was a greater log drop in nitazoxanide-treated patients within the first 24 hours. The authors concluded that this suggests that peri-transplant induction with nitazoxanide, potentially at a higher dose, may serve as a novel adjunct to other antiviral regimens to prevent HCV recurrence.
About Hepatitis C
Hepatitis C is a blood-borne infectious disease that is caused by the hepatitis C virus (HCV). It is the most common cause of chronic hepatitis in the U.S. and may eventually lead to cirrhosis, liver cancer and liver failure. The disease is transmitted by contact with HCV-infected blood. A large majority of those infected do not show symptoms, but fatigue, abdominal pain and nausea can be common. The current standard treatment of care, peginterferon and ribavirin, is effective in about half of all patients treated. Treatment outcomes vary based on a number of factors including genotype, viral load, genetic factors, stage of liver disease, co-infections and ability to adhere to treatment. According to the Centers for Disease Control, approximately 3.2 million Americans are chronically infected with HCV.
About Nitazoxanide in CHC
Nitazoxanide, the first of a new class of broad-spectrum antiviral drugs called the thiazolides,(1,2,3) is an investigational new drug for CHC. It is a potent inhibitor of HCV in replicon studies,(2) and laboratory studies indicate that it does not induce viral mutations that confer drug resistance.(3,4) Nitazoxanide is synergistic with interferon and direct acting antivirals in replicon studies.(2,5) In a clinical trial of nitazoxanide monotherapy in patients with genotype 4 CHC, 17% (4 of 23) patients achieved sustained virologic response (undetectable serum HCV RNA 24 weeks after end of therapy), with all responders having low baseline serum HCV RNA levels (<400,000 IU/mL).(6) In other clinical trials, the addition of nitazoxanide to peginterferon or peginterferon plus ribavirin was associated with improvement in sustained virologic response rates without increasing the toxicities associated with peginterferon and ribavirin.(7,8) Romark is preparing to initiate phase III clinical trials of nitazoxanide plus peginterferon for treatment of CHC and has recently announced plans to initiate clinical trials of nitazoxanide in combination with IC41, a therapeutic vaccine under development by Intercell AG.
About Romark Laboratories
Romark Laboratories, L.C. (www.romark.com) is a biopharmaceutical company committed to the discovery and development of innovative new small molecules for treating infectious diseases and cancers. The Company is developing a new class of broad-spectrum antiviral drugs called the thiazolides. The first thiazolide, nitazoxanide, is an investigational new drug in late-stage clinical development for the treatment of chronic hepatitis C and influenza. Other new thiazolides are expected to enter clinical development in 2011. Romark markets Alinia® (nitazoxanide) tablets, 500 mg and Alinia® (nitazoxanide) for Oral Suspension, 100 mg/5 mL in the United States.
(1) Rossignol JF. Thiazolides: a new class of antiviral drugs. Expert Opin Drug Metab Toxicol. 2009;5:667-674.
(2) Korba BE, Montero AB, Farrar K, et al. Nitazoxanide, tizoxanide, and other thiazolides are potent inhibitors of hepatitis B virus and hepatitis C virus replication. Antivir Res. 2008;77:56-63.
(3) Korba BE, Elazar M, Lui P, et al. Studies of the potential for hepatitis C virus resistance to nitazoxanide or tizoxanide. Antimicrob Agents Chemother. 2008;52:4069-4071.
(4) Yon C, Viswanathan P, Rossignol JF, Korba BE. Resistance to nitazoxanide is associated with alterations in the host and not the virus in HCV replicon-containing cultures. Submitted for publication.
(5) Korba BE, Elazar M, Liu P, et al. Potential role for nitazoxanide in combination with STAT-C agents for the inhibition of HCV replication without the development of resistance. Hepatology. 2008;48(suppl):356A.
(6) Rossignol JF, Kabil SM, El-Gohary Y, Elfert A, Keeffe EB. Clinical trial: randomized, double-blind, placebo-controlled study of nitazoxanide monotherapy for the treatment of patients with chronic hepatitis C genotype 4. Aliment Pharmacol Ther. 2008;28:574-580.
(7) Rossignol JF, Elfert A, El-Gohary Y, et al. Improved virologic response in patients with chronic hepatitis C genotype 4 treated with nitazoxanide plus peginterferon alfa-2a with or without ribavirin. Gastroenterology. 2009;136:856-862.
(8) Rossignol JF, Elfert A, Keeffe EB. Treatment of chronic hepatitis C using a 4-week lead-in with nitazoxanide before peginterferon plus nitazoxanide. J Clin Gastroenterol. 2010;44:504-509.
SOURCE Romark Laboratories, L.C.
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