Evaluation of Resistance-Associated Substitutions in NS5A Using Direct Sequence and Cycleave Method and Treatment Outcome with Daclatasvir and Asunaprevir for Chronic Hepatitis C Genotype 1

Sustained virologic response to direct-acting antiviral therapy in patients with chronic hepatitis C and hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND & AIMS

The effect of hepatocellular carcinoma (HCC) on the response to interferon-free direct-acting antiviral (DAA) therapy in patients with chronic hepatitis C (CHC) infection remains unclear. Using a systematic review and meta-analysis approach, we aimed to investigate the effect of DAA therapy on sustained virologic response (SVR) among patients with CHC and either active, inactive or no HCC.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched from 1/1/2013 to 9/24/2018. The pooled SVR rates were computed using DerSimonian-Laird random-effects models.

RESULTS

We included 49 studies from 15 countries, comprised of 3,341 patients with HCC and 35,701 without HCC. Overall, the pooled SVR was lower in patients with HCC than in those without HCC (89.6%, 95% CI 86.8-92.1%, I2 = 79.1% vs. 93.3%, 95% CI 91.9-94.7%, I2 = 95.0%, p = 0.0012), translating to a 4.8% (95% CI 0.2-7.4%) SVR reduction by meta-regression analysis. The largest SVR reduction (18.8%) occurred in patients with active/residual HCC vs. inactive/ablated HCC (SVR 73.1% vs. 92.6%, p = 0.002). Meanwhile, patients with HCC who received a prior liver transplant had higher SVR rates than those who did not (p <0.001). Regarding specific DAA regimens, patients with HCC treated with ledipasvir/sofosbuvir had lower SVR rates than patients without HCC (92.6%, n = 884 vs. 97.8%, n = 13,141, p = 0.026), but heterogeneity was high (I2 = 84.7%, p <0.001). The SVR rate was similar in patients with/without HCC who were treated with ombitasvir/paritaprevir/ritonavir ± dasabuvir (n = 101) (97.2% vs. 94.8%, p = 0.79), or daclatasvir/asunaprevir (91.7% vs. 89.8%, p = 0.66).

CONCLUSION

Overall, SVR rates were lower in patients with HCC, especially with active HCC, compared to those without HCC, though heterogeneity was high. Continued efforts are needed to aggressively screen, diagnose, and treat HCC to ensure higher CHC cure rates.

LAY SUMMARY

There are now medications (direct-acting antivirals or "DAAs") that can "cure" hepatitis C virus, but patients with hepatitis C and liver cancer may be less likely to achieve cure than those without liver cancer. However, patients with liver cancer are also more likely to have advanced liver disease and risk factors that can decrease cure rates, so better controlled studies are needed to confirm these findings.

Real-world virological efficacy and safety of elbasvir and grazoprevir in patients with chronic hepatitis C virus genotype 1 infection in Japan

BACKGROUND

The real-world virological efficacy and safety of an interferon (IFN)-free direct-acting antiviral (DAA) therapy with elbasvir (EBR) and grazoprevir (GZR) were evaluated in Japanese patients chronically infected with hepatitis C virus (HCV) genotype 1.

METHODS

The rate of sustained virologic response (SVR) and safety were analyzed in patients who started the EBR/GZR regimen between November 2016 and July 2017. SVR rates were compared based on patient baseline characteristics.

RESULTS

Overall, 371 of 381 patients (97.4%) achieved SVR. Multivariate analysis identified a history of failure to IFN-free DAA therapy and the presence of double resistance-associated substitutions (RASs) in HCV non-structural protein 5A (NS5A) as factors significantly associated with failure to EBR/GZR treatment. The SVR rates of patients with a history of IFN-free DAA therapy and those with double RASs were 55.6 and 63.6%, respectively. In all other subpopulations, the SVR rates were more than 90%. There were no severe adverse events associated with the treatment.

CONCLUSIONS

The EBR/GZR regimen yielded high virological efficacy with acceptable safety. Patients with a history of failure to IFN-free DAA therapy or with double RASs in HCV-NS5A remained difficult to treat with this regimen.

Hepatitis C resistance to NS5A inhibitors: Is it going to be a problem?

Treatment of hepatitis C virus (HCV) infection has evolved greatly through the recent decade. The availability of direct-acting antiviral agents (DAAs) targeting the functional proteins of HCV has resulted in the introduction of DAA-based combination therapies, providing an optimal rate of treatment success. Among the DAAs, NS5A inhibitors are used in most of the introduced and approved HCV antiviral regimens. Resistance-associated substitutions (RASs) are amino acid substitutions in HCV protein sequences that result in decreased antiviral efficacy of the HCV DAAs. Among the HCV RASs, the NS5A RASs were found to effectively modify and decrease treatment response to NS5A inhibitor-containing regimens. As a baseline predictor of treatment response, NS5A RAS draws attention for pretreatment testing in targeted patient groups. Given NS5A RASs are either naturally-occurring or DAA-selected, the application of NS5A RAS testing can be considered in two settings of NS5A inhibitor-naïve patients and NS5A inhibitor-experienced patients. Less than 5% of NS5A inhibitor-naïve patients harbor naturally-occurring NS5A RAS with high resistance level (> 100X resistance fold-change). In NS5A inhibitor-naïve patients, NS5A RAS testing accompanied by treatment optimization cannot increase treatment response more than 2%-3%, while in NS5A inhibitor-experienced patients, > 75% are found to have NS5A RASs > 100X and NS5A RAS testing in this group of patients seems to be reasonable. This editorial will address the debate on the application of NS5A RAS testing and will discuss if the NS5A RAS testing has any role in clinical management of hepatitis C.

Daclatasvir and asunaprevir treatment in patients infected by genotype 1b of hepatitis C virus with no or subtle resistant associated substitutions (RAS) in NS5A-Y93

In this study, we investigated the real-world data of the first approved interferon-free regimen in Japan, daclatasvir and asunaprevir (DCV+ASV), in chronic hepatitis C patients infected HCV genotype 1b with no or subtle amount of baseline resistant associated substitutions (RAS). Among 924 patients registered in our multicenter study, 750 patients who were proven not to be infected with NS5A-Y93H RAS by direct sequencing and to have no or subtle amount (less than 20%) of NS5A-Y93H RAS by probe assays (Cycleave or PCR invader assay) were included in this study. We investigated the anti-viral effect and factors associated with SVR12. In statistical analysis, P < 0.05 was considered as significant. The SVR12 rate in this population was 92.1% (562/618). Factors associated with SVR12 were male (odds ratio: 2.128; 95%CI: 1.134-4.000, P = 0.019); lower serum γGTP (odds ratio: 1.007; 95%CI: 1.002-1.012, P = 0.006); lower HCV-RNA (odds ratio: 1.848; 95%CI: 1.087-3.145, P = 0.023), and RVR (odds ratio: 6.250; 95%CI: 2.445-15.873, P < 0.001). No patients with γGTP ≧ 80 IU/L without RVR showed SVR12 (0/4, 0%) and one patients with γGTP ≧ 20-< 80 IU/L and HCV-RNA ≧ 6.5 logIU/mL without RVR (5/10, 50%) and two female patients with RVR but γGTP ≧ 80 IU/L and HCV-RNA ≧ 6.5 logIU/mL (7/13, 53.8%) showed a low SVR12 rate. In the present study, we showed a good viral response with DCV-ASV treatment and identified four predictive factors associated with SVR12. These four markers could be a good predictive markers for the viral effect of this treatment regimen in patients with no or subtle amount of RAS in NS5A-Y93.

Systematic review with meta-analysis: effectiveness and tolerability of interferon-free direct-acting antiviral regimens for chronic hepatitis C genotype 1 in routine clinical practice in Asia

BACKGROUND

Direct-acting antiviral (DAA) regimens have shown high efficacy and tolerability for patients with HCV genotype 1/1b (GT1/1b) in clinical trials. However, robust real-world evidence of interferon (IFN)-free DAA treatment for HCV GT1-infected patients in Asia is still lacking.

AIM

To systematically review and meta-analyse the effectiveness and tolerability of IFN-free DAA therapy for HCV GT1 infection in Asia.

METHODS

We included studies that enrolled adult patients with HCV GT1 infection in routine clinical practice in Asia, using IFN-free DAA regimens, and reported sustained virological response (SVR) after 12/24 weeks end-of-treatment by 31 May 2017. The pooled SVR rates were computed with a random-effects model. Subgroup analysis and meta-regression as previously registered in PROSPERO were performed to determine how pre-planned variables might have affected the pooled estimates.

RESULTS

We included 41 studies from eight countries and regions, comprising of 8574 individuals. The pooled SVR rates for GT1 were 89.9% (95% CI 88.6-91.1, I2  = 55.1%) with daclatasvir/asunaprevir (DCV/ASV) and 98.1% (95% CI 97.0-99.0, I2  = 41.0%) with ledipasvir/sofosbuvir ± ribavirin (LDV/SOF ± RBV). Baseline cirrhosis but not prior treatment history and age, attenuated the effectiveness of both regimens. Baseline resistance associated substitutions (RASs) severely attenuated SVR of DCV/ASV (65.4% vs 94.3%, P < 0.001) and only minimally with LDV/SOF ± RBV (94.5% vs 99.2%, P = 0.003). Patients with renal dysfunction treated with DCV/ASV showed a higher SVR rate (93.9% vs 89.8%, P = 0.046). Patients with hepatocellular carcinoma (HCC) LDV/SOF ± RBV achieved a lower SVR than those without HCC (94.1% vs 98.7%, P = 0.001).

CONCLUSION

All oral DAA treatment of HCV GT1 resulted in high cure rates in Asian patients in routine clinical practice setting including elderly patients and those with end-stage renal disease.

Usefulness of semiquantitative PCR-Invader assay for selecting candidates for daclatasvir plus asunaprevir combination therapy among patients with hepatitis C virus genotype 1b

AIMS

PCR-Invader is a highly sensitive assay for detecting non-structural protein 5A (NS5A) resistance-associated variants (RAVs) of hepatitis C virus (HCV). Here, we validated the accuracy of the semiquantitative PCR-Invader (SQ-PI) assay compared to direct sequencing (DS) for identifying NS5A RAVs, and we evaluated the treatment efficacy of daclatasvir plus asunaprevir (DCV + ASV) for patients judged to be non-positive for NS5A RAVs by SQ-PI.

METHODS

Detection rates of NS5A RAVs by SQ-PI and DS were compared for 204 patients with HCV genotype 1b. Patients with non-positive results for NS5A RAVs by SQ-PI were treated by DCV + ASV, and the efficacy of this treatment was examined.

RESULTS

All samples judged as negative for NS5A RAVs by SQ-PI were similarly judged by DS. However, 29.7% of samples judged as negative for Y93H by DS were judged as weakly positive or positive by SQ-PI. Among 108 patients who were judged as negative by SQ-PI and treated by DCV + ASV, rates of sustained virologic response at 24 weeks (SVR24) were 96.3% in intention-to-treat analysis and 99.0% in patients who completed treatment. Among patients who were weakly positive for Y93H on SQ-PI, the SVR24 rate was 95.0% (19/20). This rate was 100% (78/78) in patients who were negative for Y93H on SQ-PI and completed treatment.

CONCLUSION

Treatment efficacy of DCV + ASV was extremely high among patients who were non-positive for NS5A RAVs on SQ-PI, especially for patients with negative results.