COBAS TAQMAN HCV QUANTITATIVE TEST, V2.0 FOR HCV-RNA DETECTION AND QUANTIFICATION

COBAS TAQMAN HCV QUANTITATIVE TEST, V2.0 FOR HCV-RNA DETECTION AND QUANTIFICATION

POSTERS Conclusion: Achieving SVR in CHC patients with advanced liver fibrosis is associated with a substantially lower incidence of HCC. If not cured,...

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POSTERS Conclusion: Achieving SVR in CHC patients with advanced liver fibrosis is associated with a substantially lower incidence of HCC. If not cured, patients with liver cirrhosis have a profoundly higher risk of HCC, especially those diagnosed with diabetes mellitus or genotype 3 infection. 933 PERFORMANCE CHARACTERISTICS OF THE COBAS AMPLIPREP/COBAS TAQMAN HCV QUANTITATIVE TEST, V2.0 FOR HCV-RNA DETECTION AND QUANTIFICATION 1 J. Vermehren1 , S. Susser1 , M. Schutten2 , C. Fuller ¨ , D. Perner1 , S. Diepstraten-Pas2 , R. Molenkamp3 , P. Gohl4 , G. Colucci5 , H. Zitzer5 , C. Sarrazin1 . 1 Medizinische Klinik 1, Klinikum der J.W. Goethe Universit¨ at, Frankfurt/Main, Germany; 2 Department of Virology, Erasmus MC Rotterdam, Rotterdam, 3 Department of Medical Microbiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; 4 Bioscientia Institut f¨ ur Medizinische Diagnostik, Ingelheim, Germany; 5 Roche Molecular Diagnostics Ltd., Rotkreuz, Switzerland E-mail: [email protected]

Background: HCV-RNA detection and quantification is essential for the management of antiviral therapy in patients with chronic hepatitis C. The COBAS® AmpliPrep/COBAS® TaqMan® HCV Test (CAP/CTM v1.0; Roche Diagnostics) has been widely used in clinical practice. However, concerns have been raised regarding over- or under-quantification of certain HCV genotypes (GT) and the difference between the limit-of-detection (15 IU/mL) and lower limit-of-quantification (43 IU/mL). Our aim was to evaluate the intrinsic characteristics and clinical performance of the fullyautomated second-generation CAP/CTM v2.0 assay. Methods: Assay sensitivity, specificity and the invalid rate of the internal Quantitative Standard of CAP/CTM v2.0, a twoprobe real-time PCR-based assay, were evaluated. Furthermore, the clinical performance of CAP/CTM v2.0 was tested by measuring the genotype-specific linearity and agreement in quantification of 412 clinical samples containing HCV GTs 1–6 (GT1: 150, GT2: 50, GT3: 95, GT4: 104; GT5: 4; GT6: 9) with CAP/CTM v1.0, COBAS TaqMan HCV v2.0 For Use With The High Pure System (HPS/CTM v2.0; Roche) and VERSANT® HCV-RNA 3.0 (bDNA; Siemens Healthcare). Results: CAP/CTM v2.0 showed a hit-rate of 68–94% and 97– 100% at a level of 5 IU/mL and 15 IU/mL, respectively, for HCV GTs 1–6 in both plasma and serum samples. The specificity tested in 400 anti-HCV negative serum and plasma samples each was 100% (95% CI: 99%-100%). The Quantification Standard invalid rate was 0.1% (17/18,096 replicates). CAP/CTM v2.0 was linear over a range from 15 IU/mL to 1.0E+08 IU/mL across GTs 1–6, with an absolute deviation from linearity of ≤0.2 log10 IU/mL. Overall, CAP/CTM v2.0 showed excellent agreement with CAP/CTM v1.0 (mean difference, 0.05 log10 IU/mL; 95%-limits-of-agreement, −0.72; 0.81) and HPS/CTM v2.0 (mean difference, 0.13 log10 IU/mL; limits-of-agreement, −0.56; 0.83). Mean quantification differences for GT4 specimens (n = 49) between CAP/CTM v1.0, CAP/CTM v2.0 and bDNA were −0.36 (95%-limits-of-agreement, −1.09; 0.37; moderately/severely underquantifed [≥0.5/≥1.0log10 ] samples: 16 and 2) log10 IU/mL HCV-RNA and 0.15 (limits-of-agreement, −0.30; 0.60; no moderately/severely underquantifed samples) log10 IU/mL HCV-RNA, respectively. Conclusions: CAP/CTM v2.0 is highly sensitive and specific and has an improved linear range and genotype inclusivity for the quantification of clinical samples representing GTs 1–6, thus supporting its use in the management of patients with chronic HCV infection.

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934 DIFFERENCES IN HCV GENOTYPE 1 RVR RATES AMONG CLINICAL TRIALS IN EUROPE DEPEND ON HCV RNA ASSAY SENSITIVITY J. Vermehren1 , A. Aghemo2 , S. Susser1 , T.M. Scherzer3 , M.G. Rumi4 , M. Colombo2 , P. Ferenci3 , C. Sarrazin1 . 1 Medizinische Klinik 1, Klinikum der J. W. Goethe Universit¨ at, Frankfurt/Main, Germany; 2 1st Division of Gastroenterology, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Uiversit` a degli Studi di Milano, Milan, Italy; 3 Internal Medicine III, Medical University of Vienna, Vienna, Austria; 4 Division of Hepatology, Ospedale San Giuseppe, Universit` a degli Studi di Milano, Milan, Italy E-mail: [email protected] Background: Treatment with peg-interferon-a/ribavirin in patients with HCV genotype-1-infection has resulted in comparable SVR rates (48%-55%) in different clinical trials across Europe. However, significant differences in rapid virologic response rates (RVR) have been observed, ranging from 12%-37%. In this study, the impact of assay sensitivity on RVR-rates was assessed. Methods: Stored RVR-sera from three large published trials in genotype-1-patients (one single-centre and two multi-centre trials conducted in Austria, Germany and Italy, respectively) were reanalyzed with the VERSANT HCV-RNA Qualitative Assay (TMA; Siemens Healthcare). In the original studies, RVR-analysis was based on the quantitative COBAS AmpliPrep/COBAS TaqMan HCVRNA Assay (CAP/CTM; Roche Diagnostics) in Austria, the qualitative COBAS Amplicor HCV-RNA 2.0 Test (CA; Roche) in Italy, and TMA in Germany, respectively. Results: A total of 136 RVR-patient samples were available for TMA re-analysis. Baseline characteristics and RVR rates according to the assay used in each trial and TMA are shown in Table 1. The drop in RVR rates according to TMA was highest in samples originally tested with CA (10% vs. 31%) and lower in those originally tested with CAP/CTM (23% vs. 27%). Overall, positive predictive values of RVR for SVR were only slightly increased with the more sensitive TMA assay (87% vs. 86% with CA; 76% vs. 70% with CAP/CTM). Table 1

Baseline viral load, log10 IU/ml F3/F4 fibrosis IL28B rs12979860 TT genotype RVR (CA; LOD <50 IU/ml), n (%) SVR (% of CA-neg. patients) RVR (CAP/CTM; LOD ~10 IU/ml), n (%) SVR (% of CAP/CTM-neg. patients) RVR (TMA; LOD ~5 IU/ml), n (%) SVR (% of TMA-neg. patients)

Austria (n = 132)

Italy (n = 170)

Germany (n = 398)

6.3 25% 15% − − 35 (27%)

6.5 36% 17% 53 (31%) 70% −

6.0 15% 14% − − −

86% 30 (23%) 87%

− 17 (10%) 76%

− 48 (12%) 88%

Conclusions: Significant differences in RVR rates among clinical trials seem to be mainly attributable to HCV-RNA assay sensitivity. When using the highly-sensitive TMA assay, the positive predictive value of RVR was only slightly improved compared to the CA and CAP/CTM assays.

Journal of Hepatology 2012 vol. 56 | S225–S388