The practical management of chronic hepatitis C infection in Japan - dual therapy of daclatasvir + asunaprevir

Significance of serum IP-10/CXCL10 measurement in predicting post-direct acting antiviral treatment liver function in patients with HCV-decompensated liver cirrhosis

BACKGROUND

Recently, with the advent of sofosbuvir/velpatasvir therapy, sustained virological response (SVR) can now be achieved even in patients with decompensated cirrhosis (dLC). However, the prognosis after SVR does not always improve in dLC, and appropriate indicators enabling prediction of prognosis is desired.

PATIENTS AND METHODS

Serum IP-10/CXCL10 levels were measured in 47 patients (15 chronic hepatitis [CH], 17 compensated cirrhosis [cLC], and 15 dLC) receiving direct acting antiviral (DAA) therapy, and their changes during the therapy were examined.

RESULTS

All the patients achieved SVR. In patients with CH, the average IP-10 level was 367, 102, and 68 pg/ml respectively at baseline, at the end of therapy and at 12 weeks after SVR (SVR12), and was decreased upon DAA therapy (P < 0.001). In patients with cLC, IP-10 was respectively 215, 91, and 77 pg/ml, and was decreased upon DAA therapy (P < 0.001) while it was 283, 131, and 182 pg/ml in patients with dLC and there was no evident decrease (P = 0.55). When patients with dLC were further classified depending on the difference in Child-Pugh (CP) score improvement at SVR12, a significant decrease in IP-10 was observed after treatment in those with improvement (P = 0.023) while a significant increase was observed in those without improvement (P = 0.016).

CONCLUSION

While serum IP-10 level was decreased in patients with CH/cLC and dLC with post-SVR-CP improvement following SVR, it was increased in patients with dLC without post-SVR CP improvement. The result indicates that IP-10 dynamics may be useful for predicting liver function after DAA therapy.

Decline incidence in upper gastrointestinal bleeding in several recent years: data of the Japan claims database of 13 million accumulated patients

This study was to examine the recent trends in upper gastrointestinal bleeding in Japan using a large-scale real-world database. The incidence of upper gastrointestinal bleeding was evaluated in the Japan Medical Data Center claims database of 13,019,713 patients aged 20 to 74 years with traceability for 3 months from 2009 to 2014. The incidence was compared with peptic ulcers and gastroesophageal reflux disease. The prescription of medications was also evaluated. The incidence of bleeding was 0.137%, 0.121%, 0.113%, 0.106%, 0.099%, and 0.105% during 2009 to 2014 with a time-dependent decline (p<0.001). Peptic ulcers (>10 times higher than the incidence of bleeding) decreased with time (p<0.001), whereas gastroesophageal reflux disease increased (p = 0.006). Upper gastrointestinal bleeding was higher in male patients and older patients (60–74 years old) (p<0.001 respectively). The prescription rate of antithrombotic medications and proton pump inhibitors increased from 2009 to 2014 (p<0.001 respectively). The incidence of upper gastrointestinal bleeding decreased from 2009 to 2014 in this relatively large-scale real-world database in Japan, concomitant with the decrease in peptic ulcers. The decreased incidence might have been due to changes in the disease structure and therapeutic strategies over time.

The Discovery and Early Clinical Evaluation of the HCV NS3/4A Protease Inhibitor Asunaprevir (BMS-650032)

The discovery of asunaprevir (1) began with the concept of engaging the small and well-defined S₁’ pocket of the hepatitis C virus (HCV) NS3/4A protease that was explored in the context of tripeptide carboxylic acid-based inhibitors. A cyclopropyl-acyl sulfonamide moiety was found to be the optimal element at the P₁-P₁’ interface enhancing the potency of carboxylic acid-based prototypes by 10- to >100-fold, dependent upon the specific background. Optimization for oral bioavailability identified a 1-substituted isoquinoline-based P₂* element that conferred a significant exposure advantage in rats compared to the matched 4-substituted quinoline isomer. BMS-605339 (30) was the first cyclopropyl-acyl sulfonamide derivative advanced into clinical trials that demonstrated dose-related reductions in plasma viral RNA in HCV-infected patients. However, 30 was associated with cardiac events observed in a normal healthy volunteer (NHV) and an HCV-infected patient that led to the suspension of the development program. Using a Langendorff rabbit heart model, a limited structure-cardiac liability relationship was quickly established that led to the discovery of 1. This compound, which differs from 30 only by changes in the substitution pattern of the P₂* isoquinoline heterocycle and the addition of a single chlorine atom to the molecular formula, gave a dose-dependent reduction in plasma viral RNA following oral administration to HCV-infected patients without the burden of the cardiac events that had been observed with 30. A small clinical trial of the combination of 1 with the HCV NS5A inhibitor daclatasvir (2) established for the first time that a chronic genotype 1 (GT-1) HCV infection could be cured by therapy with two direct-acting antiviral agents in the absence of exogenous immune-stimulating agents. Development of the combination of 1 and 2 was initially focused on Japan where the patient population is predominantly infected with GT-1b virus, culminating in marketing approval which was granted on July 4, 2014. In order to broaden therapy to include GT-1a infections, a fixed dose triple combination of 1, 2, and the allosteric NS5B inhibitor beclabuvir (3) was developed, approved by the Japanese health authorities for the treatment of HCV GT-1 infection on December 20, 2016 and marketed as Ximency^®.

Association between alanine aminotransferase elevation and UGT1A1*6 polymorphisms in daclatasvir and asunaprevir combination therapy for chronic hepatitis C

BACKGROUND

Liver damage presented as alanine aminotransferase (ALT) elevation and high ALT-caused treatment discontinuation occurs with high frequency in Japanese patients receiving daclatasvir plus asunaprevir (DCV/ASV) therapy for hepatitis C virus (HCV) infection, and its mechanism is unknown.

METHODS

A total of 247 Japanese patients consisting of two independent cohorts with genotype-1b HCV infection receiving DCV/ASV therapy were included. The association of ALT levels during therapy and single nucleotide polymorphisms (SNP) of five drug-metabolizing enzyme loci selected for their possible influence on NS3/4A and NS5A inhibitors was investigated.

RESULTS

Among five SNPs, we found a significant correlation between the presence of the UGT1A1 rs4148323 A allele and ALT elevation (Grade 3 elevation in AA 57%, AG 18%, and GG 4%, P = 8.4E - 06) and drug discontinuation (AA 22%, AG 11%, and GG 2.5%, P = 8.7E - 04), while no association was observed with ALT values at baseline (Grade 3 elevation AA 0%, AG 4%, and GG 2%, P = 0.5). In contrast, patients with risk A allele for drug-induced ALT elevation had a tendency to respond more favorably to treatment (AA 100%, AG 93%, and GG 90%, P = 0.29).

CONCLUSIONS

Through the analysis we suggest that the A allele in UGT1A1 rs4148323 (UGT1A1*6), which is highly prevalent in the Japanese population, should be considered a risk for the development of DCV/ASV therapy-induced ALT elevation. Pretreatment SNP testing of UGT1A1*6 might be beneficial for the prediction of liver damage induced by DCV/ASV or even by DCV/ASV plus beclabuvir.

HCV kinetic and modeling analyses project shorter durations to cure under combined therapy with daclatasvir and asunaprevir in chronic HCV-infected patients

BACKGROUND & AIMS

High cure rates are achieved in HCV genotype-1b patients treated with daclatasvir and asunaprevir, DCV/ASV. Here we analyzed early HCV kinetics in genotype-1b infected Japanese subjects treated with DCV/ASV and retrospectively projected, using mathematical modeling, whether shorter treatment durations might be effective.

METHODS

HCV RNA levels were measured frequently during DCV/ASV therapy in 95 consecutively treated patients at a single center in Japan. Mathematical modeling was used to predict the time to cure, i.e, <1 virus copy in the extracellular body fluid. Patients with HCV<15 IU/ml at week 1 (n = 27) were excluded from modeling analysis due to insufficient HCV RNA data points.

RESULTS

Eighty nine of the 95 included patients (94%) achieved cure, 3 (3%) relapsed due to treatment-emergent resistance, and 3 (3%) completed therapy but were lost during follow up. Model fits from 68 patients with sufficient data points indicate that after a short pharmacological delay (15.4 min [relative standard error, rse = 26%]), DCV/ASV effectiveness in blocking HCV production was 0.999 [rse~0%], HCV half-life in blood was t1/2 = 1.7 hr [rse = 21%], and HCV-infected cell loss rate was 0.391/d [rse = 5%]. Modeling predicted that 100% and 98.5% of patients who had HCV<15 IU/ml at days 14 and 28 might have been cured with 6 and 8 weeks of therapy, respectively. There was a trend (p = 0.058) between younger age and shorter time to cure.

CONCLUSION

Modeling early HCV kinetics under DCV/ASV predicts that most patients would achieve cure with short treatment durations, suggesting that 24 weeks of DCV/ASV treatment can be significantly shortened.