Long-term open-label vebicorvir for chronic HBV infection: Safety and off-treatment responses

Background & Aims

The investigational first-generation core inhibitor vebicorvir (VBR) demonstrated safety and antiviral activity over 24 weeks in two phase IIa studies in patients with chronic HBV infection. In this long-term extension study, patients received open-label VBR with nucleos(t)ide reverse transcriptase inhibitors (NrtIs).

Methods

Patients in this study (NCT03780543) previously received VBR + NrtI or placebo + NrtI in parent studies 201 (NCT03576066) or 202 (NCT03577171). After receiving VBR + NrtI for ≥52 weeks, stopping criteria (based on the treatment history and hepatitis B e antigen status in the parent studies) were applied, and patients either discontinued both VBR + NrtI, discontinued VBR only, or continued both VBR + NrtI. The primary efficacy endpoint was the proportion of patients with HBV DNA <20 IU/ml at 24 weeks off treatment.

Results

Ninety-two patients entered the extension study and received VBR + NrtI. Long-term VBR + NrtI treatment led to continued suppression of HBV nucleic acids and, to a lesser extent, HBV antigens. Forty-three patients met criteria to discontinue VBR + NrtI, with no patients achieving the primary endpoint; the majority of virologic rebound occurred ≥4 weeks off treatment. Treatment was generally well tolerated, with few discontinuations due to adverse events (AEs). There were no deaths. Most AEs and laboratory abnormalities were related to elevations in alanine aminotransferase and occurred during the off-treatment or NrtI-restart phases. No drug-drug interactions between VBR + NrtI and no cases of treatment-emergent resistance among patients who adhered to treatment were observed.

Conclusions

Long-term VBR + NrtI was safe and resulted in continued reductions in HBV nucleic acids following completion of the 24-week parent studies. Following treatment discontinuation, virologic relapse was observed in all patients. This first-generation core inhibitor administered with NrtI for at least 52 weeks was not sufficient for HBV cure.

Clinical trial number

NCT03780543.

Impact and implications

Approved treatments for chronic hepatitis B virus infection (cHBV) suppress viral replication, but viral rebound is almost always observed after treatment discontinuation, highlighting an unmet need for improved therapies with finite treatment duration producing greater therapeutic responses that can be sustained off treatment. First-generation core inhibitors, such as vebicorvir, have mechanisms of action orthogonal to standard-of-care therapies that deeply suppress HBV viral replication during treatment; however, to date, durable virologic responses have not been observed after treatment discontinuation. The results reported here will help researchers with the design and interpretation of future studies investigating core inhibitors as possible components of finite treatment regimens for patients with cHBV. It is possible that next-generation core inhibitors with enhanced potency may produce deeper and more durable antiviral activity than first-generation agents, including vebicorvir.

Simeprevir with peginterferon/ribavirin for patients with hepatitis C virus genotype 1: high frequency of viral relapse in elderly patients

Purpose

The tolerability and efficacy of simeprevir in combination with peginterferon and ribavirin in patients infected with hepatitis C virus (HCV) genotype 1 under actual clinical conditions were investigated.

Methods

A total of 176 patients with chronic HCV genotype 1 infection were treated with simeprevir for 12 weeks plus Peg-IFN/RBV for 24 weeks. Overall, 107 (60.7 %) patients were aged 60 years or more, and 16 (9 %) patients were aged 70 years or more. Treatment discontinuation, sustained virological response 12 (SVR12), and viral relapse were evaluated and compared between younger patients and elderly patients.

Results

The rates of undetectable HCV RNA at the end of treatment were 95.8, 100 and 93.1 % in treatment-naïve, prior relapse, and prior non-responders, respectively. However, the rates of SVR12 were 82.4, 88.2 and 69.2 %, respectively. Especially in prior non-responders, viral relapse was relatively frequent. Treatment discontinuation and SVR12 were not different between patients aged <70 and ≥70 years, but viral relapse after completing treatment was significantly more frequent in patients aged ≥70 years (p = 0.012).

Conclusions

In simeprevir with peginterferon and ribavirin therapy, viral relapse was relatively frequent. Especially in elderly patients, the relapse rate was high after completing treatment, instead of low frequency of discontinuation by the adverse events.

Predictive factors for 24 weeks sustained virologic response (SVR24) and viral relapse in patients treated with simeprevir plus peginterferon and ribavirin

BACKGROUND

Simeprevir with peginterferon and ribavirin has been used for the treatment of chronic hepatitis caused by genotype 1 hepatitis C virus (HCV). We explored the predictive factors for sustained virological response (SVR) and viral relapse using datasets from four Japanese phase 3 studies (CONCERTO).

METHODS

We used a multiple logistic regression model. First, an integrated dataset comprising 357 patients was analyzed. Subsequently, prior treatment-naïve and relapser (223 patients) and nonresponder (134 patients) of interferon-based treatment subsets were analyzed to identify predictors of SVR. A subset of nonresponders (106 patients) who were treated ≥24 weeks was also analyzed to identify predictors for viral relapse.

RESULTS

In the integrated dataset, prior treatment response was significantly associated with SVR. In subset analyses, interleukin-28B (IL28B) TT genotype and undetectable plasma HCV RNA level at week 4 were associated in treatment-naïve patients and relapsers [odds ratio (OR); 4.106 and 3.701, respectively]. In the nonresponders, the IL28B TT genotype population was very small, and inosine triphosphatase (ITPA) and undetectable plasma HCV RNA at week 4 were associated (OR; 2.506 and 3.333, respectively). Furthermore, ribavirin dose intensity (RBV-DI) and detectable plasma HCV RNA at week 4 were significantly associated with viral relapse (OR; 0.327 and 2.922, respectively).

CONCLUSION

IL28B and plasma HCV RNA level at week 4 were clinically relevant predictive factors for SVR in treatment-naïve patients and relapsers. Moreover, RBV-DI and plasma HCV level at week 4 were identified as relevant predictive factors for viral relapse in nonresponders.