0 (CTM) assays. Results: Discordant test results for HCV RNA detectability were observed in 23% at week 4, 17% at week 8/12 and 9% at week 24 on treatment. The ART

detected HCV RNA in 41% of week 4 samples classified as negative by the CTM. However, the positive predictive value of an undetectable week 4 result for SVR was similar for both assays (80% and 82%). Discordance was also found for application of stopping rules. In 27% of samples who met stopping rules by CTM the ART measured Rapamycin levels below the respective cut-offs of 100 or 1000 IU/ml for boceprevir or telaprevir-based therapy, respectively, which would have allowed treatment continuation. In contrast, in nine patients with negative HCV RNA by CTM at week 24 treatment would have been discontinued

due to detectable residual HCV RNA by the ART assay. Still, only four of these patients failed to achieve SVR. Conclusion: Both assays are in principle suitable to predict treatment outcome and to determine treatment http://www.selleckchem.com/screening/fda-approved-drug-library.html decisions. However, significant discordance at early stages of treatment needs to be considered. Application of identical stopping rules determined in approval studies by one assay to other HCV RNA assays may lead to over and undertreatment in a significant number of patients. Detectable residual HCV RNA (<12 IU/ml) at week 24 in the ART i.e. might not be considered as necessary

stopping rule during PI based selleck compound triple therapy. Disclosures: Benjamin Maasoumy – Advisory Committees or Review Panels: Abbott Molecular, Janssen-Cilaq; Grant/Research Support: Abbott Molecular; Speaking and Teaching: MSD, Roche Diagnostics, Roche Pharma, Janssen-Cilaq, Fujirebio Bela Hunyady – Advisory Committees or Review Panels: MSD, AbbVie, Janssen; Speaking and Teaching: Roche, Fresenius-Kabi Michael Makara – Advisory Committees or Review Panels: MSD, BMS, Gilead; Consulting: MSD, Roche, Janssen; Grant/Research Support: Janssen, Idera, Novartis, Boehringer Ingelheim Gavin A. Cloherty – Employment: Abbott Molecular; Stock Shareholder: Abbott Laboratories Michael P.