Related Experiment Video
Updated: May 5, 2026

Prediction of HIV-1 Coreceptor Usage Tropism by Sequence Analysis using a Genotypic Approach
Published on: December 1, 2011
In routine clinical practice, few physicians use early viral kinetics to guide HCV dual therapy treatment decisions
Alessandra Mangia1, Tivadar Bányai, Giuseppe De Bartolomeo
1Liver Unit, IRCCS Hospital 'Casa Sollievo della Sofferenza', San Giovanni Rotondo, Italy.
Background & Aims:
PROPHESYS is a large, multinational, non-interventional prospective cohort study of chronic hepatitis C patients treated with peginterferon alfa/ribavirin. This subanalysis assesses rates of premature treatment discontinuation stratified by on-treatment virological response (VR).
Methods:
This PROPHESYS subanalysis is restricted to treatment-naive, hepatitis C virus (HCV) genotype (G)1/2/3 mono-infected patients who received peginterferon alfa-2a (40KD)/ribavirin with intended treatment duration of 48 (G1) or 24 weeks (G2/3). Early virological responses were classified into four mutually exclusive categories [rapid VR (RVR), complete early VR (cEVR), partial EVR (pEVR), no RVR/EVR], using standard criteria.
Results:
The likelihood for shortening treatment owing to good efficacy was highest among patients with an RVR and HCV RNA≤400 000 IU/ml (G1 10.0%; G2/3 5.8%) whereas for poor efficacy, it was highest in G1 non-RVR/EVR patients with HCV RNA>400 000 IU/ml (56.6%). Factors significantly associated with early treatment discontinuation as a result of good efficacy in G1 patients included RVR vs. no RVR/EVR and, at baseline, lower HCV RNA, lower FIB-4 score, HCV infection via injection drug use. For G2/3 patients, factors included lower baseline HCV RNA and G2 vs. G3 infection. Most patients started with the recommended peginterferon alfa-2a dose, but a high proportion received a higher-than-recommended ribavirin dose.
Conclusions:
Despite international guidelines, few physicians used early viral kinetics to abbreviate treatment. Therefore, relatively few patients with an RVR and low baseline HCV RNA abbreviated treatment. In addition, there were deviations in ribavirin starting doses, suggesting that physicians tailor treatment according to local guidelines or previous experience.
Related Concept Videos
Retrovirus Life Cycles
Effect of Hepatic Disease on Pharmacokinetics: Drug Dosing and Hepatic Blood Flow
Effect of Hepatic Disease on Pharmacokinetics: Pathophysiologic Assessment and Liver Function Test
Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment
Dosage Regimens: Partial Pharmacokinetic Parameters
Pharmacokinetics in Pediatric Patients: Drug Excretion

