Drug-resistant variants emerge in most patients who fail to achieve SVR with telaprevir-based regimen

Drug Resistance

Over 40 posters were presented at the EASL with data highlighting resistance in patients who fail to achieve SVR when treating with the new protease inhibitors, you can view them here .

Yesterday, we received a heads up with this EASL press release " New data suggests liver experts should exercise caution when prescribing novel antiviral HCV drugs".

Data presented at the International Liver CongressTM highlight the fact that new novel antiviral compounds for the treatment of hepatitis C virus (HCV) must be prescribed and monitored by experts and specialists to ensure resistance is minimised.

Several studies observed the rapid onset of HCV resistance in patients treated with NS3-protease, NS5b-polymerase and NS5a inhibitors. Although these direct anti-virals are effective in both treatment-naive HCV patients and those who've been previously unresponsive to current treatment options, the development of resistant viral variants may cause problems in the future. In fact, two studies found HCV strains resistant to novel antiviral compounds pre-existed in patients who had never previously been exposed to the new antiviral compounds. In these patients, the variants were selected out by treatment.

Professor Heiner Wedemeyer, EASL's Secretary General, said: "While the regulatory approval of these new treatments is a highly anticipated milestone in HCV therapy, these studies show that care must be taken in the prescription and use of the new compounds. What we want to avoid is a rapid spread of HCV resistance within the patient population, which could drastically lower the effectiveness of the new drugs."

Because we're on the topic of drug resistance, CCO who provides an expert analysis on data presented at the EASL, today, just published this;
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Telaprevir-Resistant HCV Variants Present at Time of Treatment Failure Replaced by Wild-Type Virus Over Time in Majority of Patients
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*Drug-resistant variants emerge in most patients who fail to achieve SVR with telaprevir-based regimen
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Excerpt;

Summary of Key Conclusions

Telaprevir-resistant HCV NS3 protease variants present at time of telaprevir-based treatment failure replaced by wild-type virus over time in most treatment-naive and treatment-experienced patients with genotype 1 HCV infection

  *Within 1 year after treatment discontinuation, 71% of patients had only wild-type  virus detected with population sequencing

Resistant variants become undetectable more rapidly in patients infected with genotype 1b vs genotype 1a HCV

  *Median time to wild-type virus: 0.8 vs 10.0 months, respectively

Different predominant mutations observed in patients with genotype 1a vs 1b


Further research in patients with resistance at treatment failure and subsequent loss of resistant variants over time to evaluate response to future therapy with same drug class

Click here for complete data

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Also Ready To View At CCO;

PSI-938 and PSI-7977 Purine and Pyrimidine Nucleotide Analogues Demonstrate Favorable Safety/Tolerability and Robust 14-Day Antiviral Activity Alone and in Combination Against Genotype 1 HCV

Addition of Alisporivir to PegIFN/RBV Yields Superior Efficacy vs PegIFN/RBV Alone in Treatment-Naive Patients With Genotype 1 HCV

Main Page;

CCO Independent Conference Coverage of the 2011 Annual Meeting of the European Association for the Study of the Liver*

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