Faculty Bibliography

Boceprevir or telaprevir plus ribavirin (RBV) and pegylated interferon-alpha (pegIFN-alpha) is the new standard-of-care therapy for patients who are chronically infected with genotype 1 hepatitis C virus (HCV). The addition of these protease inhibitors to the RBV/pegIFN-alpha combination regimen has significantly improved rates of sustained virologic response (SVR); however, the incidence of anemia has also increased significantly. Anemia can interfere with patients' quality of life, work productivity, and treatment adherence. Severe anemia can cause morbidity and even mortality. For the management of anemia during triple combination therapy, RBV dose reduction is recommended as an initial course of action. Retrospective analyses of carefully selected patient cohorts suggest that RBV dose reduction does not reduce SVR rates. However, this observation needs to be confirmed in prospective trials with cohorts that more accurately reflect the challenging patients treated in real-world practice. Adequate doses of RBV should be maintained during triple combination therapy, as phase II trials have demonstrated that RBV is essential for attaining optimal SVR rates and preventing viral breakthrough, relapse, and emergence of resistant variants. This roundtable addresses key points related to the management of anemia in the era of triple combination therapy, including the increasing problem of anemia, strategies for anemia management, and the importance of maintaining adequate RBV exposure as part of the HCV treatment regimen.

BACKGROUND & AIMS: Little is known about factors associated with a sustained virologic response (SVR) among patients with hepatitis C virus (HCV) infection to treatment with protease inhibitors. METHODS: Previously untreated patients (from the Serine Protease Inhibitor Therapy 2 [SPRINT-2] trial) and those who did not respond to prior therapy (from the Retreatment with HCV Serine Protease Inhibitor Boceprevir and PegIntron/Rebetol 2 [RESPOND-2] trial) received either a combination of peginterferon and ribavirin for 48 weeks or boceprevir, peginterferon, and ribavirin (triple therapy) after 4 weeks of peginterferon and ribavirin (total treatment duration, 28-48 wk). A good response to interferon was defined as a >/= 1 log(10) decrease in HCV RNA at week 4; a poor response was defined as a <1 log(10) decrease. We used multivariate regression analyses to identify baseline factors of the host (including the polymorphism interleukin [IL]-28B rs12979860) associated with response. The polymorphism IL-28B rs8099917 also was assessed. RESULTS: In the SPRINT-2 trial, factors that predicted a SVR to triple therapy included low viral load (odds ratio [OR], 11.6), IL-28B genotype (rs 12979860 CC vs TT and CT; ORs, 2.6 and 2.1, respectively), absence of cirrhosis (OR, 4.3), HCV subtype 1b (OR, 2.0), and non-black race (OR, 2.0). In the RESPOND-2 trial, the only factor significantly associated with a SVR was previous relapse, compared with previous nonresponse (OR, 2.6). Most patients with rs12979860 CC who received triple therapy had undetectable levels of HCV RNA by week 8 (76%-89%), and were eligible for shortened therapy. In both studies, IL-28B rs12979860 CC was associated more strongly with a good response to interferon than other baseline factors; however, a >/= 1 log(10) decrease in HCV-RNA level at week 4 was associated more strongly with SVR than IL-28B rs12979860. Combining the rs8099917 and rs12979860 genotypes does not increase the association with SVR. CONCLUSIONS: The CC polymorphism at IL-28B rs12979860 is associated with response to triple therapy and can identify candidates for shorter treatment durations. A >/= 1 log(10) decrease in HCV RNA at week 4 of therapy is the strongest predictor of a SVR, regardless of polymorphisms in IL-28B.

Albinterferon alfa-2b (albIFN) is a fusion protein of recombinant human albumin/recombinant interferon (IFN)-alpha-2b, with approximately 200-h half-life. Safety/efficacy of albIFN q4wk was evaluated in 391 treatment-naive patients with chronic hepatitis C virus (HCV) genotype 2/3. Patients were randomized 3:4:4:4 to one of four open-label treatment groups: pegylated IFN (Peg-IFN)-alpha-2a 180 mug qwk or albIFN 900, 1200 or 1500 mug q4wk, plus oral ribavirin 800 mg/day, for 24 weeks. Primary efficacy endpoint was sustained virologic response (SVR; HCV RNA <20 IU/mL 24 weeks post-treatment). SVR rates were as follows: 85%, 76%, 76% and 78% with Peg-IFNalpha-2a and albIFN 900, 1200 and 1500 mug, respectively (P = NS); corresponding rapid virologic response rates (HCV RNA <43 IU/mL at week 4) were as follows: 78%, 49% (P < 0.001), 60% (P = 0.01) and 71%. SVR rates were not influenced by interleukin 28B genotype, although rapid virologic response rates were greater with interleukin 28B CC (P = NS). Serious adverse event rates were as follows: 4%, 11%, 3% and 3% with Peg-IFNalpha-2a and albIFN 900, 1200 and 1500 mug, respectively. No increase in serious/severe respiratory events was noted with albIFN. Fewer absolute neutrophil count reductions <750/mm(3) occurred with albIFN (P = 0.03), leading to fewer IFN dose reductions. Haemoglobin reductions <10 g/dL were less frequent with albIFN 900 and 1200 mug vs 1500 mug and Peg-IFNalpha-2a (P = 0.02), leading to fewer ribavirin dose reductions. albIFN administered q4wk produced fewer haematologic reductions than Peg-IFNalpha-2a, but had numerically lower SVR rates (P = NS) in patients with chronic HCV genotype 2/3.

BACKGROUND: Shortened courses of treatment with pegylated interferon alfa and ribavirin for patients with hepatitis C virus infection who experience rapid virologic response can be effective in appropriately selected patients. The cost-effectiveness of truncated therapy is not known. OBJECTIVE: To assess the cost-effectiveness of response-guided therapy versus standard-duration therapy on the basis of best available evidence. METHODS: We developed a decision model for chronic hepatitis C virus infection representing two treatment strategies: 1) standard-duration therapy with pegylated interferon alfa and ribavirin for 48 weeks in patients with genotype 1 or 4 and for 24 weeks in patients with genotype 2 or 3 and 2) truncated therapy (i.e., 50% decrease in treatment duration) in patients with rapid virologic response. Patients for whom truncated therapy failed began standard-duration therapy guided by genotype. We used a Markov model to estimate lifetime costs and quality-adjusted life-years. RESULTS: In the base-case analysis, mean lifetime costs were $46,623 +/- $2,483 with standard-duration therapy and $42,354 +/- $2,489 with truncated therapy. Mean lifetime quality-adjusted life-years were similar between the groups (17.1 +/- 0.7 with standard therapy; 17.2 +/- 0.7 with truncated therapy). Across model simulations, the probability of truncated therapy being economically dominant (i.e., both cost saving and more effective) was 78.6%. The results were consistent when we stratified the data by genotype. In one-way sensitivity analyses, the results were sensitive only to changes in treatment efficacy. CONCLUSION: Truncated therapy based on rapid virologic response is likely to be cost saving for treatment-naive patients with chronic hepatitis C virus infection. Cost-effectiveness varied with small changes in relative treatment efficacy.

UNLABELLED: In comparison with peginterferon/ribavirin alone, boceprevir with peginterferon/ribavirin significantly improves sustained virological response (SVR) rates in patients with chronic hepatitis C virus (HCV) genotype 1 infections, but treatment failure remains a significant problem. Using phase 3 trial databases, we sought to develop stopping rules for patients destined to fail boceprevir-based combination therapy in order to minimize drug toxicity, resistance, and costs in the face of ultimate futility. Exploratory post hoc analyses using data from the Serine Protease Inhibitor Therapy 2 (SPRINT-2) study (treatment-naive patients) and the Retreatment With HCV Serine Protease Inhibitor Boceprevir and Pegintron/Rebetol 2 (RESPOND-2) study (treatment-experienced patients) were undertaken to determine whether protocol-specified stopping rules (detectable HCV RNA at week 24 for SPRINT-2 and at week 12 for RESPOND-2) could be refined and harmonized. In SPRINT-2, a week 12 rule with an HCV RNA cutoff of >/= 100 IU/mL would have discontinued therapy in 65 of 195 failures (sensitivity = 33%) without sacrificing a single SVR among 475 successes (specificity = 100%). Viral variants emerged after week 12 in 36 of the 49 evaluable patients (73%) who would have discontinued at week 12 using a >/= 100 IU/mL stopping rule. In RESPOND-2, five of six patients with week 12 HCV RNA levels between the lower limit of detection (9.3 IU/mL) and the lower limit of quantification (25 IU/mL) who continued therapy despite the protocol-stipulated futility rule achieved SVR; one additional patient with a week 12 HCV RNA level of 148 IU/mL also continued therapy, had undetectable HCV RNA at week 16, and attained SVR. CONCLUSION: Although a stopping rule of detectable HCV RNA at week 12 would have forfeited some SVR cases, week 12 HCV RNA levels >/= 100 IU/mL almost universally predicted a failure to achieve SVR in both treatment-naive and treatment-experienced patients. In boceprevir recipients, the combination of 2 stopping rules-an HCV RNA level >/= 100 IU/mL at week 12 and detectable HCV RNA at week 24--maximized the early discontinuation of futile therapy and minimized premature treatment discontinuation.