Automated summaries of serious adverse events in the hepatitis C antiviral long-term treatment against cirrhosis trial.

BACKGROUND: Even though adverse event (AE) collection and official accounting are mandatory for clinical trials, there are limited detailed guidelines specifying how to summarize the event for reporting in a timely and expeditious manner. This article details the AE and serious adverse event (SAE) reporting summary developed for a large multi-center National Institutes of Health (NIH)-sponsored clinical trial. PURPOSE: To review and analyze the large volume of AE data reported by 10 sites (806 SAEs and 19,034 AEs from August 2000 to May 2007) the automated SAE summary was developed. It was designed to ensure timeliness and clarity in the complex process of AE review and reporting. METHODS: The AE and SAE case report forms (CRFs) as well as the automated SAE summary were developed within a database management system developed by the Data Coordinating Center (DCC) which allowed for web-based data entry at the DCC and 10 sites and offered immediate overall and site-specific reports accessible by the DCC, site, and NIH project staff. RESULTS: The automated SAE summary pulled data from multiple CRFs to create a succinct and informative summary and allowed for prompt and easy reporting to the regulatory agencies. The summary was adaptable to the needs of reviewers because of the availability of multiple search options.

Identification of a ribavirin-resistant NS5B mutation of hepatitis C virus during ribavirin monotherapy.

Ribavirin (RBV), a guanosine analogue, has been suggested to exert an antiviral action against hepatitis C virus (HCV) by causing lethal mutations and suppressing RNA polymerase in vitro, but the mechanism of its clinical therapeutic effects is currently unknown. To test the hypothesis that RBV could act both as an RNA mutagen and inhibit viral RNA synthesis in vivo, we studied the evolution of the nucleotide sequences of HCV RNA at the nonstructural (NS) 5B region in patients receiving RBV, placebo, or interferon alfa (IFN-alpha) monotherapy. The RBV group showed a slightly more accelerated evolution rate of HCV RNA quasispecies than either the IFN-alpha or placebo group. RBV caused preferentially A-to-G and U-to-A mutations. Interestingly, an NS5B amino acid 415 Phe-to-Tyr (F415Y) mutation emerged in all (5 of 5) patients infected with HCV genotype 1a during the RBV treatment. Subsequently, the parental 415F strain reemerged in some patients after the treatment was discontinued. The effect of the amino acid substitution at NS5B415 on HCV RNA replication was then investigated using an HCV subgenomic replicon in Huh7 cells. We showed that treatment of replicon cells with RBV reduced the HCV RNA level of NS5B415F replicon, but not NS5B415Y, in a dose-dependent manner. Thus, NS5B F415Y mutation represents an RBV-resistant variant. The 3-dimensional modeling and structure analysis of NS5B protein revealed that the 415th amino acid is located at the P helix region of the thumb subdomain, which may interact with the minor groove of the template-primer duplex in the putative RNA-binding cleft. In conclusion, RBV could work as a weak mutagen for HCV RNA in HCV-infected patients. Furthermore, the selection of an RBV-resistant variant with a single amino acid substitution in NS5B suggested that RBV may directly interact with HCV RNA polymerase, thus interfering with its enzymatic activity.