Telaprevir enhances ribavirin-induced anaemia through renal function impairment

ITPA deficiency and ribavirin level are still predictive of anaemia in HCV-HIV-coinfected patients receiving ribavirin combined with a first-generation DAA (ANRS HC27 study)

BACKGROUND

We aimed to determine the impact of inosine triphosphatase (ITPA) deficiency on ribavirin (RBV)-induced anaemia in HIV-HCV-coinfected patients receiving a triple therapy including the haematotoxic direct-acting antiviral agent boceprevir (BOC).

METHODS

Patients of the ANRS HC27 BocepreVIH study were genotyped for two ITPA single nucleotide polymorphisms involved in ITPA deficiency. RBV trough concentration (Ctrough) was determined at week (W)4 and W8. Impact of ITPA deficiency on anaemia, RBV Ctrough, response and haematotoxicity (grade 3/4 anaemia, erythropoietin [EPO] use, RBV dose reduction or transfusion between day [D]0 and W8) was evaluated. Impact of RBV Ctrough on anaemia was also studied.

RESULTS

Among the 63 genotyped patients, 33% had a predicted ITPA deficiency. ITPA deficiency was associated with a lower haemoglobin (Hb) decline both at W4 (-1.0 g/dl versus -2.1 g/dl; P=0.02) and W8 (-2.7 g/dl versus -4.1 g/dl; P=0.05). None of the patients with ITPA deficiency received EPO between D0-W8 versus 26% of patients without ITPA deficiency (P=0.01). RBV Ctrough was associated with Hb decrease both at W4 and W8 and an RBV Ctrough cutoff value of 2 µg/ml was significantly associated with a W4 Hb decline >2 g/dl. Haematotoxicity was significantly associated with a lower W4 Hb level (P=0.017), absence of ITPA deficiency (P=0.018) and higher RBV Ctrough (P=0.012). ITPA deficiency, W4 RBV Ctrough and gender were independent predictors of anaemia at W4. ITPA deficiency was not associated with virological response.

CONCLUSIONS

ITPA deficiency and RBV Ctrough are still predictive of RBV-induced anaemia in HIV-HCV-coinfected patients treated with RBV combined with a first-generation direct antiviral agent.

Estimated glomerular filtration rate but not solute carrier polymorphisms influences anemia in HIV-hepatitis C virus coinfected patients treated with boceprevir or telaprevir-based therapy

OBJECTIVES

Ribavirin (RBV) induced anemia may be influenced by host genetic factors affecting RBV transport solute carrier (SLC) or metabolism inosine triphosphatase (ITPA), as already reported. We investigated the influence of single nucleotide polymorphisms (SNPs) on SLC genes on anemia, RBV trough concentration (Ctrough) and response in HIV-hepatitis C virus coinfected patients receiving triple therapy with boceprevir or telaprevir.

METHODS

Patients from the ANRS HC26/HC27 studies were genotyped for SLC28A3 SNPs (rs10868138 and rs56350726) and SL29A1 SNPs (rs760370). Hemoglobin (Hb) decline was collected at baseline day 0 (D0), week 4 (W4) and week 8 (W8), and RBV Ctrough was measured at W4 and W8 by HPLC. A multivariate analysis including SLC SNPs, estimated glomerular filtration rate (eGFR), ITPA deficiency and RBV Ctrough was performed to determine predictive factors of anemia and response.

RESULTS

SLC genotyping was performed in 130 patients. Neither SLC28A3 nor SLC29A1 SNPs were associated with Hb decline both at W4 and W8. No association was found between SLC polymorphisms and RBV Ctrough. Independent predictive factors of Hb decline at W4 were D0 Hb, ITPA deficiency and W4 RBV Ctrough in the multivariate analysis (P < 0.05). Only D0 Hb, W4 RBV Ctrough and eGFRD0-W8 were predictive of anemia at W8 (P < 0.05). Response was not influenced by SLC SNPs.

CONCLUSION

eGFR, but not SLC polymorphisms, influences anemia in HIV-hepatitis C virus coinfected patients receiving boceprevir-based or telaprevir-based therapy. RBV is still a cornerstone of hepatitis C treatment, thus renal function and RBV Ctrough should be monitored in patients receiving RBV regimen combined with first-generation direct-acting antiviral agent.

Hepatitis C virus markers in infection by hepatitis C virus: In the era of directly acting antivirals

About 130-170 million people are infected with the hepatitis C virus (HCV) worldwide and more than 350000 people die each year of HCV-related liver diseases. The combination of pegylated interferon (Peg-IFN) and ribavirin (RBV) was recommended as the treatment of choice for chronic hepatitis C for nearly a decade. In 2011 the directly acting antivirals (DAA) HCV NS3/4A protease inhibitors, telaprevir and boceprevir, were approved to treat HCV-genotype-1 infection, each in triple combination with Peg-IFN and RBV. These treatments allowed higher rates of SVR than the double Peg-IFN + RBV, but the low tolerability and high pill burden of these triple regimes were responsible for reduced adherence and early treatment discontinuation. The second and third wave DAAs introduced in 2013-2014 enhanced the efficacy and tolerability of anti-HCV treatment. Consequently, the traditional indicators for disease management and predictors of treatment response should be revised in light of these new therapeutic options. This review article will focus on the use of the markers of HCV infection and replication, of laboratory and instrumental data to define the stage of the disease and of predictors, if any, of response to therapy in the DAA era. The article is addressed particularly to physicians who have patients with hepatitis C in care in their everyday clinical practice.

Increased Ribavirin Bioavailability Associated With Telaprevir Use in Hepatitis C Patients Treated With PEGylated -Interferon/Ribavirin/Telaprevir Triple Therapy

BACKGROUND

Anemia is more frequent in patients receiving telaprevir with PEGylated interferon/ribavirin (PEG-IFN/RBV) than in those receiving PEG-IFN/RBV alone.

OBJECTIVES

The objective was to measure the impact of telaprevir on RBV bioavailability and to assess the concomitant renal function.

MATERIALS AND METHODS

Thirty-seven hepatitis C virus (HCV) patients non-responders to a previous course of PEG-IFN/RBV therapy and re-treated with triple therapy combining PEG-IFN/RBV and telaprevir were analyzed. RBV bioavailability was measured before the triple therapy initiation, during telaprevir treatment at week (W) 4 and W8, and after telaprevir cessation (post W16). The renal function was assessed by estimating the glomerular filtration rate (eGFR).

RESULTS

At W4, RBV bioavailability, expressed as mg/L/daily dose/kg body weight, was significantly increased (median increase = 0.06 mg/L/dose/kg; P < 0.001). In parallel, the renal function was impaired with a mean eGFR decrease of -6.8 mL/minutes/1.73 m² (P = 0.109). Between W4 and W8, RBV bioavailability continued to increase (P < 0.001) but subsequently decreased slightly after telaprevir discontinuation with a concomitant restoration of the renal function (eGFR increase of 6.34 mL/minutes/1.73 m²).

CONCLUSIONS

Our results indicated a reversible increase in RBV bioavailability after telaprevir exposure, which might be linked to the impairment of the GFR. This also suggests a RBV-telaprevir pharmacological interaction, a possible source of severe anemia observed under triple therapy. These results suggest that RBV pharmacological monitoring may be clinically relevant, especially in the context of first-generation HCV protease inhibitor-based therapy.