New Anti-Viral Drug Shows Promise for Dramatic Improvement in Hepatitis C Treatment

Research team, led by Paul Kwo, M.D., of Indiana University School of Medicine, reported that adding the drug boceprevir, nearly doubled the treatment's effectiveness when given for 48 weeks in one treatment arm of the study. We knew that, Boceprevir (see structure) is a protease inhibitor being studied as a treatment for hepatitis C. It was being developed by Schering-Plough and has since been absorbed into the Merck's new pipeline since its acquired Schering in 2009. As of 2008, it is in phase II clinical trials (SPRINT-1 trial). Researchers claim that, adding a direct acting anti-viral drug to the standard treatment regimen for hepatitis C significantly increases the cure rate in the most difficult to treat patients.

Researchers claim that, the drug boceprevir increased the cure rate to as high as 75 percent in those who received 48 weeks of the three-drug combination therapy, compared to 38 percent of those in the control group, who received the standard two-drug treatment (peginterferon alfa-2b plus ribavirin)   for 48 weeks, said Dr. Kwo, associate professor of medicine at the IU School of Medicine. The two-year phase 2 trial was conducted at 67 sites with 520 patients in the US, Canada and Europe.

In the boceprevir study, known as the SPRINT-1 trial, researchers tested several different options to evaluate the effectiveness of the combination therapy.

"Both 28- and 48-week boceprevir regimens significantly increased sustained virologic response rates  which is the best definition of a cure we have  compared to the 48 week control," said Dr. Kwo. "The 48-week treatment arm with 4 weeks of peg interferon lead-in and 44 weeks of peg interferon, ribavirin, and boceprevir led to the largest improvement over the control group ever reported. That's very impressive." 

Researchers conclude that, best results were reported for the 103 patients who were treated for four weeks with the standard two drug regiment, followed by 44 weeks of the three-drug regimen including boceprevir: 75 percent of these patients tested negative for evidence of the virus six months after the end of treatment.

As per the lead researcher, Dr. Kwo, based on this phase 2 study, it appears that if this drug receives final approval approximately two-thirds of patients will be able to be treated successfully with 28 weeks of treatment and one-third will need 48 weeks of treatment, though this will require confirmation from the phase 3 trials, from which preliminary results were recently released.

Ref  : http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2810%2960934-8/fulltext

Telaprevir-based regimens increase rates of SVR in patients with genotype 1 HCV infection

In continuation of my update on telaprevir-based regimens, I found this article interesting to share with.....

In a clinical trial known as PROVE 3 published in this week's New England Journal of Medicine, treatment with telaprevir-based regimens significantly increased rates of sustained viral response (SVR) in patients with genotype 1 hepatitis C virus (HCV) infection who did not achieve SVR with at least one prior course of pegylated-interferon and ribavirin therapy. In the trial, 51 percent and 53 percent of patients who received telaprevir in combination with pegylated-interferon and ribavirin as part of a 24-week or 48-week regimen, respectively, achieved SVR.   More...

SPC3649 ( LNA- locked nucleic acid) - a new hope for hepatitis C.....

When  I was working with Innovasynth Technologies, Khopoli, I had an opportunity to do literature survey about  Lock Nucleic Acids (LNAs) and Peptide Nucleic Acids (PNAs) (we were supposed to work on the preparation of  some of the LNAs & PNAs for US based companies). In my opinion though these class of compounds (including oligonucleotides) are  still emerging,  I think in the days to come there will be more and more drugs from oligonucleotides, Locked Nucleic Acids (LNAs) and Peptide Nucleic Acids, (PNAs) class of compounds.

LNAs : A locked nucleic acid (LNA) (see the right side general structure), is a modified RNA nucleotide. Ribose moiety of an LNA nucleotide is modified with an extra bridge

connecting the 2' oxygen and 4' carbon. The bridge "locks" the ribose  in the 3'-endo (North) conformation, which is often found in the A-form of DNA or RNA. LNA nucleotides can be mixed with DNA or RNA bases in the oligonucleotide whenever desired. This locking  significantly increases the thermal stability (mp) of oligonucleotide.

LNA nucleotides are used to increase the sensitivity and specificity of expression in DNA microarrays, FISH probes, real-time PCR probes and other molecular biology techniques based on oligonucleotides. For the in situ detection of miRNA the use of LNA is currently the only efficient method. A triplet of LNA nucleotides surrounding a single-base mismatch site maximizes LNA probe specificity unless the probe contains the  G-T mismatch. We have already seen some antisense drugs (oligonucleotides from Geron & Isis) and some are into clinical trials.

Now its interesting to see that Santaris Pharma   is currently advancing LNA based compounds within infectious diseases, metabolic disorders, oncology, inflammatory and rare genetic disorders.

Santaris Pharama, has developed a LNA,  SPC3649 - which captures a small RNA molecule in the liver, called microRNA122, that is required for HCV replication.

As per the claim by the company, SPC3649 works by altering the environment in the host liver cell to inhibit viral replication rather than inhibiting the virus itself. This subtle difference (in comparison  with other therapies) may have significant implications, as it may reduce the risk of the virus becoming resistant to therapy – a major concern with current therapies.

As per the claim by Dr. Robert Lanford,  (who has collaboration with Santaris Pharma), that in a preclinical study  SPC3649 successfully inhibited miR-122, a liver-expressed microRNA important for Hepatitis C viral replication. By inhibiting miR-122, SPC3649 dramatically reduced Hepatitis C virus in the liver and in the bloodstream in chimpanzees chronically infected with the Hepatitis C virus. Four HCV chronically infected chimpanzees were treated weekly with 5 or 1 mg/kg of SPC3649 for 12 weeks followed by a treatment free period of 17 weeks. The two animals that received the 5 mg/kg dose had a significant decline in viral levels in the blood and liver of approximately 2.5 orders of magnitude or approximately 350 fold. Hope the new therapy could potentially replace interferon (interferon and ribavirin is  approved by FDA for hepatitis C and this treatment is very toxic, requires 48 weeks with 50% success) in future cocktails, since it provides a high barrier to resistance. This antiviral could be used alone to treat disease progression and there are indications that it can convert interferon non-responders to responders, so that non-responders to the current therapy could be treated with the combination of this drug with interferon.   More....

Those interested  can see the video demo with the link

Quercetin blocks Hepatitis C infection....

The conventional treatments for hepatitis C are interferon and ribavirin, which can cause major side effects and aren't effective in all patients. But something interesting and unique has been achieved  by UCLA researchers.

As per the claim by the lead researcher Samuel French Assistant Professor, Pathology of UCLA, they have  identified major two cellular proteins (HSPs, heat shock proteins 40 and 70) that play an important role in hepatitis C infection, and they say the finding may point to new and less toxic treatments for the disease, which can lead to cirrhosis and liver cancer. The researchers also found that Quercetin,  blocks the synthesis of two heat shock proteins 40 and 70proteins  and significantly inhibited viral infection in tissue culture.

 

Quercetin (see the structure) :  

Is a plant-derived flavonoid, specifically a flavonol, used as a nutritional supplement. Laboratory studies show it may have anti-inflammatory and antioxidant properties,  and it is being investigated for a wide range of potential health benefits.Interestingly American cancer society, says that while quercetin has been promoted as being effective against a wide variety of diseases, including cancer, There is current early-stage clinical research on quercetin addressing safety and efficacy against sarcoidosis, asthma and glucose absorption in obesity and diabetes. Food riches in Quercetin includes, capers, lovage, apples, tea (Camellia sinensis), onion, especially red onion (higher concentrations of quercetin occur in the outermost rings), red grapes, citrus fruit, tomato, broccoli and other leafy green vegetables, cherries and berries.

Significant claims by the researchers are ;

a. quercetin targets cellular proteins rather than viral proteins, there is less likelihood of developing viral

    resistance (cellular proteins cannot change like viral proteins can);

b. quercetin may allow for the dissection of the viral life cycle and has potential therapeutic use to reduce
    virus  production with low associated toxicity.

Hope the researcher will have positive results from the phase 1 clinical trial.....

Ref :http://www.cancer.ucla.edu/Index.aspx?page=644&recordid=312

Triple-combo Drug for Antiviral-resistant H1N1 ?

In laboratory testing, the triple combination of oseltamivir (Tamiflu), amantadine (Symmetrel) and ribavirin showed a significant capacity to stop flu-virus growth, says Mark Prichard....

More...http://www.sciencedaily.com/releases/2009/10/091027132426.htm

Telaprevir for Hepatitis C, soooon...

We did know that Telaprevir (VX-950), is a member of a class of antiviral drugs known as 'Protease Inhibitors' was an experimental treatment for Hepatitis and two companies Vertex and Johnson & Johnson jointly developed and phase II clinical trials were being done. Now thanx, to Dr. Ira M. Jacobson chief of the Division of Gastroenterology and Hepatology at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, and the Vincent Astor Distinguished Professor of Clinical Medicine at Weill Cornell Medical College, who has come up with the results of Phase IIb clinical trial.

Th results are really encouraging and as per the author, "the findings point the way to a new era in the treatment of hepatitis C". The most significant part of the research lies in the fact that, by adding Telaprevir the treatment was more effective and quicker and there by reducing the therapy to half (from 48 weeks to 24 weeks).

Results showed that 67 percent of patients taking telaprevir in combination with standard therapy for 12 weeks followed by standard therapy alone for 36 weeks were cured; and 61 percent of those taking telaprevir in combination with standard therapy for 12 weeks followed by standard therapy alone for 12 weeks were cured. This is compared to 41 percent cure rate in the 48-week control group. And more over the study also showed that the percentage of patients who relapsed in the 24-week and 48-week telaprevir-based groups (2 percent and 6 percent, respectively) was much lower than the control group (23 percent). Also the authors found that it can be used alongwith Ribavirin, for those with HIV & Hepatitis C. Congratulations for this achievement. Phase III clinical trials are currently underway at the NewYork-Presbyterian/Weill Cornell and centers worldwide will attempt to confirm the results, potentially leading to FDA approval of telaprevir and hope there will be a relief to the sufferers very soooon......

Ref : http://news.med.cornell.edu/wcmc/wcmc_2009/06_04_09.shtml