IL28B allele in SOC arm of Anadys Pharmaceuticals ANA598 clinical study leading to a higher cEVR than previously seen in SOC arm?

Anadys Pharmaceuticals announced that it has completed 12-week results from an ongoing Phase II study, which demonstrated that 75% of HCV patients treated with 400 mg ANA598 twice daily in combination with pegylated interferon and ribavirin (current standard of care, or SOC) achieved undetectable levels of virus (1 log from any prior measurement) between weeks 10 and 12. No other patient who received either dose of ANA598 experienced viral breakthrough.


The company can offer additional perspective on the response of the patients who received placebo plus standard of care (control arm) in the study based on a preliminary assessment of IL28B genotyping from approximately 60% of the patients in the Phase II study. Recent scientific studies have shown that individuals with the IL28B CC genotype, present in approximately 37% of Caucasian HCV patients and a lower percentage of patients in other ethnic groups, are substantially more responsive to SOC than patients with other IL28B genotypes. In the SOC control arm of the ANA598 study, 56% of the patients who have been genotyped to date are of the CC genotype while in the ANA598-treated arms only 21% of the patients who have been genotyped to date are of the CC genotype. The company believes that the high proportion of CC patients in the SOC control arm of the ANA598 Phase II study relative to the overall population likely contributed to a higher cEVR rate than has been seen historically.

Source: http://www.anadyspharma.com/pr_pdfs/ana598%20complete%2012-week%20data%20%20final%205.21.10.pdf