Three-year Follow-up of Participants After Administration of Boceprevir or Narlaprevir for the Treatment of Chronic Hepatitis C (P05063)

Durability of response was assessed by the number of participants who relapsed during the LTFU among those that had achieved sustained virologic response (SVR) by 24 weeks after treatment with boceprevir or narlaprevir in a previous Phase 1, 2, or 3 treatment study. In the current LTFU, participants were classified based on the last Hepatitis C Virus ribonucleic acid (HCV-RNA) result available at the time of the data cut-off date as follows: A participant was classified as a sustained virologic responder at a given time point if serum HCV-RNA was undetectable at that time point and there had not been a positive HCV-RNA since the participant was determined to have achieved SVR in the previous study. A participant was classified as a relapser if they were a sustained virologic responder in the previous treatment study and became serum HCV-RNA positive with no subsequent negative results during LTFU.

The distribution of time to relapse was summarized using Kaplan-Meier estimates for all participants who were sustained responders at 24 weeks post-treatment in the previous study. Exposure Adjusted Relapse Rate = 1000 × (number of relapses) / (Total exposure time in years). Total exposure time in years = [(total number of days from last day of treatment to the last follow-up day for all subjects who did not relapse) + (total number of days from last day of treatment to the day of relapse for those who relapsed)] / 365.25 days [for 1 year].

Plasma samples of all participants receiving at least one dose of study medication in a previous treatment protocol were evaluated by population sequencing and analyzed to detect amino acid variants in the NS3/4A protease known to be associated with reduced susceptibility to boceprevir and narlaprevir. RAVs in the NS3/4A protease gene were evaluated at 12 loci (V36, Q41, F43, T54, V55, V107, R155, A156, V158, D168, I/V170 and M175) on the basis of in vitro studies. A TE-RAV was defined as a RAV not present at baseline and that had not returned to wild type (WT) while the participant was still on treatment. The number of participants with TE-RAVS detected at the EOT in the previous treatment study are reported below, followed by those participants with TE-RAVS that returned to WT during the LTFU (among those with detected TE-RAVS).

Long-term safety was assessed based on the SAEs reported during the LTFU period. An SAE was any adverse drug or biologic or device experience occurring at any dose that resulted in any of the following outcomes: death, life-threatening AE, persistent or significant disability/incapacity, required in-patient hospitalization or prolongs hospitalization, congenital anomaly or birth defect. Important medical events that did not result in any of these outcomes could still be considered SAEs if they jeopardized the participant and/or required medical/surgical intervention, based on appropriate medical judgment. Grade 4 laboratory abnormalities and out of normal range liver function tests that were not accompanied by clinical manifestations were NOT considered SAEs.

An SAE was any adverse drug or biologic or device experience occurring at any dose that resulted in any of the following outcomes: death, life-threatening AE, persistent or significant disability/incapacity, required in-patient hospitalization or prolongs hospitalization, congenital anomaly or birth defect. Important medical events that did not result in any of these outcomes could still be considered SAEs if they jeopardized the participant and/or required medical/surgical intervention, based on appropriate medical judgment. Grade 4 laboratory abnormalities and out of normal range liver function tests that were not accompanied by clinical manifestations were NOT considered SAEs.