Safety of peginterferon alfa-2a plus ribavirin in a large multinational cohort of chronic hepatitis C patients.

BACKGROUND & AIMS: Peginterferon plus ribavirin has been the standard of care for chronic hepatitis C for a decade and an essential component of combination regimens for this disease. This large multinational open-label study aimed to better define the incidence of serious adverse events (SAEs) and non-serious adverse events of special interest in patients receiving peginterferon alfa-2a/ribavirin. METHODS: Patients were assigned at the investigator's discretion to 24- or 48-week treatment with peginterferon alfa-2a 180 µg/week and ribavirin 800 mg/day or 1000/1200 mg/day. All AEs, defined as SAEs and non-SAEs of special interest, were recorded during treatment and for 12 weeks thereafter. Non-SAEs of special interest included those leading to dose reduction/discontinuation, neutropenia, thrombocytopenia, anaemia, ALT elevations leading to dose modification and unknown/unexpected AEs. RESULTS: Of 1675 and 7178 patients assigned to 24 and 48 weeks of treatment, respectively, 87.6 and 68.3% completed therapy, whereas 6.4 and 10.3% prematurely stopped peginterferon alfa-2a treatment because of AEs. Among patients assigned to 24 and 48 weeks, 37.4 and 46.9%, respectively, reported any AE (SAE or non-SAE of special interest); 4.2 and 6.6% reported SAEs and 35.2 and 44.0% reported non-SAEs of special interest. Female gender, increasing age and cirrhosis were significantly associated with dose reductions of either drug. Increasing age (and female gender in the case of ribavirin) was significantly associated with treatment discontinuation. CONCLUSION: This study confirmed the safety and tolerability profile of peginterferon alfa-2a/ribavirin and identified patient subgroups at higher risk of dose reductions and discontinuations, thus allowing optimum management of AEs.

Hepatitis B e antigen levels and response to peginterferon: influence of precore and basal core promoter mutants.

Hepatitis B e antigen (HBeAg) levels may predict response to peginterferon (PEG-IFN) but are also influenced by presence of precore (PC) and core promoter (BCP) mutants. HBeAg was measured in 214 patients treated with PEG-IFN±lamivudine for 52weeks. Patients were classified at baseline as wildtype (WT) or non-WT (detectable PC/BCP mutants). Combined response (HBeAg loss with HBV DNA<2000IU/mL), HBeAg response (HBeAg loss with HBV DNA>2000IU/mL) or non-response was assessed at week78. Mean baseline HBeAg levels were 2.65logIU/mL in combined responders, 2.48 in non-responders and 2.24 in HBeAg responders (p=0.034). Baseline HBeAg levels were not associated with combined response after stratification by WT/non-WT. Within the PEG-IFN monotherapy group (n=104), patients with HBeAg<1logIU/mL at week24 had a higher probability of combined response (29% versus 12%, p=0.041). After stratification by WT/non-WT, WT patients with HBeAg<1logIU/mL at week24 had a probability of combined response of 78% (versus 19% in patients with >1logIU/mL, p<0.001), whereas no difference in response rates was observed in non-WT patients (p=0.848). The relationship between HBeAg levels and response to PEG-IFN depends upon the presence of PC/BCP mutants. HBeAg levels should therefore not be routinely used to select patients for PEG-IFN, nor for monitoring of therapy.