Patients with chronic hepatitis C and insulin resistance are less likely to respond to anti-hepatitis C virus (HCV) therapy and are at risk for more rapid fibrosis progression. Coadministration of pioglitazone with peginterferon/ribavirin improves insulin sensitivity and increases virologic response rates in insulin-resistant HCV genotype 4 patients, but it is unclear whether this finding applies to genotype 1 patients. For this reason we randomized treatment-naive HCV genotype 1 patients with insulin resistance to receive either standard care (peginterferon alpha-2a plus ribavirin for 48 weeks, n = 73) or pioglitazone 30-45 mg/day plus standard care (n = 77) in an open-label multicenter trial. Patients randomized to pioglitazone received the drug during a 16-week run-in phase, the 48-week standard-care phase, and the 24-week untreated follow-up phase. Pioglitazone treatment improved hemoglobin A1c (HbA1c), plasma glucose, insulin levels, and homeostasis model assessment of insulin resistance score and increased serum adiponectin levels during the 16-week run-in phase and maintained these improvements during the standard-care phase. However, we observed no statistically significant difference between the two groups in the primary efficacy endpoint, the decrease from baseline to Week 12 of peginterferon alpha-2a/ribavirin treatment in mean log10 HCV RNA titer (−3.5 ± 1.71 and −3.7 ± 1.62 IU/mL in the pioglitazone and standard-care groups, respectively, Δ = 0.21 IU/mL, P = 0.4394). Conclusion : Treatment with pioglitazone before and during treatment with peginterferon alpha-2a plus ribavirin improved several indices of glycemic control in patients with chronic hepatitis C and insulin resistance, but did not improve virologic response rates compared with peginterferon alpha-2a plus ribavirin alone. (HEPATOLOGY 2012)
A no-carrier-added synthesis of 9-[(3-[18F]-fluoro-1-hydroxy-2-propoxy)methyl]-guanine ([18F]-FHPG) is reported. The 9-[(1,3-dihydroxy-2-propoxy)methyl)guanine (DHPG) was converted to 9-[N2,O-bis(methoxytrityl)-3-(tosyl)-2-propoxy-methyl]guanine by treatment with methoxytrityl chloride followed by tosylation. The tosylate was reacted with [18F]-KF in the presence of kryptofix 2.2.2. to produce the 3-fluoro-N2-O-bis-(methoxytrityl) derivative. Removal of the methoxytrityl protecting groups by acid hydrolysis produced [18F]-FHPG. The labeled product was purified by HPLC on a reverse-phase C18 column, and eluted in 9 min with a mobile phase of 5% acetonitrile in water. The radiochemical yield was 7-17%, with an average of 10% in 10 runs (corrected for decay to EOB). The radiochemical purity was > 99%, and specific activities with an average of 526 mCi/mumol were obtained. The synthesis time was 70-80 min, including HPLC purification and determination of radiochemical purity and specific activity.
Background Combined administration of the human immunodeficiency virus protease inhibitor indinavir (800 mg every 8 hours) with the antimycobacterial rifabutin (300 mg daily) results in a significant decrease in indinavir concentrations with subsequent risk of treatment failure, as well as a significant increase in rifabutin concentrations with increased toxicity. Therefore this study was designed to evaluate alternative dosing regimens. Methods Eighteen healthy volunteers received 300 mg rifabutin daily alone for 14 days and then 1000 mg indinavir every 8 hours plus rifabutin at a reduced dose of 150 mg daily, given at 8 AM or noon in a randomized crossover sequence for 14 days. Ten human immunodeficiency virus‐infected subjects received 800 mg indinavir every 8 hours for 14 days and then 1000 mg indinavir every 8 hours plus 150 mg rifabutin daily at 8 AM for 14 days. Twenty‐four‐hour pharmacokinetic sampling was performed at the end of each 14‐day study period. Results Indinavir, 1000 mg every 8 hours, coadministered with 150 mg rifabutin daily produced an area under the concentration‐time curve similar to that of 800 mg indinavir every 8 hours. The mean area under the concentration‐time curve values of rifabutin and 25‐desacetyl rifabutin, when 150 mg rifabutin every morning was coadministered simultaneously with 1000 mg indinavir every 8 hours, were 70% and 120% higher than with 300 mg rifabutin daily alone. Drug concentrations were not different when rifabutin and indinavir were administered simultaneously at 8 AM or staggered by 4 hours. Conclusions Increasing indinavir's dose to 1000 mg every 8 hours when coadministered with rifabutin at a reduced dose of 150 mg daily compensates for rifabutin induction of indinavir metabolism. Rifabutin concentrations were still higher than with rifabutin alone despite a 50% reduction of rifabutin dose, which is the current recommendation when these 2 drugs are combined. The clinical significance of the increase in rifabutin and 25‐desacetyl rifabutin concentrations is not known. Clinical Pharmacology & Therapeutics (2003) 73 , 159–169; doi: 10.1067/mcp.2003.3
Rapid virologic response (RVR) and complete early virologic response (cEVR) are associated with sustained virologic response to hepatitis C virus (HCV) therapy. We retrospectively examined baseline and on-treatment factors associated with RVR (HCV RNA undetectable at week 4) and cEVR (HCV RNA undetectable at week 12, regardless of week 4 response). The analysis comprised 1550 HCV genotype-1 patients from five clinical trials, including three enriched with difficult-to-treat populations, randomized to peginterferon alfa-2a 180 microg/week plus ribavirin 1000-1200 mg/day. Overall, 15.6% achieved RVR and 54.0% achieved cEVR. Baseline factors predictive of RVR were serum HCV RNA 3 x ULN (OR: 2.01; P < 0.0001), non-cirrhotic status (OR: 1.92; P = 0.0087), age 13 mg/kg/day was predictive of RVR (OR: 1.69; P = 0.005) and cEVR (OR: 1.24; P = 0.09), whereas peginterferon alfa-2a dose reduction was not. Greater decreases in haematologic parameters were observed in patients who achieved cEVR compared with patients who did not. In conclusion, several baseline and on-treatment factors were associated with RVR and cEVR to peginterferon alfa-2a plus ribavirin in difficult-to-treat HCV genotype-1 patients, providing important prognostic information on the antiviral response in a patient cohort that is reflective of the general chronic hepatitis C population.
Evaluation of the elevation of host cell biosynthesis of deoxynucleoside triphosphates (dNTP's) induced by human cytomegalovirus (HCMV) infection as a target for antiviral therapeutics was carried out. The concentrations of all four intracellular dNTP's rose rapidly following HCMV infection, and were markedly above baseline by 8 h post infection (p.i.). All four deoxynucleoside triphosphates remained elevated above baseline for at least 72 h p.i. The effects of inhibitors of the de-novo pathway of pyrimidine biosynthesis on HCMV viral replication-were quantified by DNA dot blot. All pyrimidine biosynthesis inhibitors examined inhibited the HCMV DNA replication at concentrations that were non-toxic to the cell. These drugs were also more effective against HCMV, which is highly dependent on host denovo synthesis, than against HSV-1 which encodes enzymes capable of increasing the supply of dNTP's. The antiviral effect of brequinar, an inhibitor of one of the enzymes of the de-novo pathway (dihydroorotate dehydrogenase), was examined to determine if it coincided with a decrease in dNTP's. HCMV-infected fibroblasts and uninfected control cells were treated with a concentration of brequinar able to inhibit HCMV DNA levels 90%. It was found that brequinar markedly lowered the levels of dTTP found in treated cells compared to untreated cells in both HCMV-infected and uninfected cells.
Hepatitis C virus (HCV) infection increases total healthcare costs but the effect of the severity of liver disease associated with chronic hepatitis C (CHC) on healthcare costs has not been well studied. We analyzed the demographics, healthcare utilization, and healthcare costs of CHC patients in a large U.S. private insurance database (January, 2002 to August, 2010), with at least 1 year of baseline enrollment and 30 days of continuous follow-up. Patients were stratified by liver disease severity: noncirrhotic liver disease (NCD), compensated cirrhosis (CC), and endstage liver disease (ESLD), as defined by the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9) codes. Mean all-cause and HCV-related healthcare costs per-patient-per-month (PPPM) during follow-up (mean 634 days) are reported in 2010 U.S.$ from the payer's perspective. A total of 53,796 patients with CHC were included (NCD: 41,858 [78%]; CC: 3,718 [7%]; and ESLD: 8,220 [15%]). Mean all-cause PPPM healthcare costs were 32% and 247% higher for patients with CC and ESLD compared to those with NCD ($1,870 and $4,931 versus $1,420; P < 0.001) and were independent of age or comorbid conditions. Pharmacy, ambulatory, and inpatient care collectively accounted for 90% of NCD costs and 93% of CC and ESLD costs. The largest cost components were inpatient costs for those with ESLD (56%) and ambulatory costs for those with CC and NCD (37% and 36%, respectively). Overall, 56% of costs were HCV-related and this proportion increased with severity (46%, 57%, and 71% for patients with NCD, CC, and ESLD, respectively).The direct healthcare costs associated with CHC are high, increase in association with the progression of liver disease, and are highest in those with ESLD.
Hydroxyurea (HU) significantly enhances the antiretroviral effects of the adenosine analog reverse transcriptase inhibitor dideoxyinosine (ddI). This is believed to be due to a reduction in intracellular de-oxyadenosine triphosphate (dATP) concentrations resulting from HU-mediated inhibition of ribonucleotide reductase (RnR). The effect of combined HU–ddI treatment on intracellular dATP pools in vivo has not been examined. We measured intracellular dATP concentrations in peripheral blood mononuclear cells (PBMCs) from 69 HIV-infected patients receiving 1000 or 1500 mg HU daily for 14 days, 200 mg ddI twice daily for 14 days, or a combination of the two drugs. Median intracellular dATP concentrations decreased from base-line to day 14 by 46% in the ddI + 1000 mg HU arm and by 62% in the ddI + 1500 mg HU arm. When compared to the HU monotherapy arms, these changes proved statistically significant (p = 0.018; stratified Wilcoxon rank-sum test). These findings support reduced intracellular dATP as the mechanism of ddI–HU synergistic activity, and indicate that changes in intracellular nucleotides contribute to HU activity and toxicity in patients. Since a significant reduction in dATP was measurable only when ddI was combined with HU, the antiretroviral activity of ddI may be more complex than previously assumed.
Infection with human cytomegalovirus in the presence of the antiviral nucleotide analog ganciclovir results in continuing low-level viral DNA synthesis and the accumulation of relatively small fragments of double-stranded progency DNA. These fragments consistently proved to represent amplification of sequences from only one small section of the viral genome (EcoRI-V) lying near the center of the unique L segment. Further mapping revealed that the viral sequences represented in these fragments occurred in gradients of abundance that decreased in both directions from a point near 0.35 to 0.4 map unit. The proportion of amplified sequences increased with both time after infection and dosage of ganciclovir used. We conclude that the primary lytic cycle replication origin of human cytomegalovirus lies within a 3- to 4-kb region immediately upstream and to the right of the promoter for the single-stranded DNA-binding protein (DB140). The amplified origin-containing DNA molecules appeared to arise by continuing rounds of bidirectional initiation on truncated fragments of the genome that were generated as a result of chain termination effects induced by the incorporation of ganciclovir into the viral DNA. Inspection of the DNA sequence in the vicinity of ori-Lyt revealed a large complex upstream region that may be a noncoding intergenic domain and that bears no homology to any previously described herpesvirus origin. This 2.5-kb region includes many duplicated and inverted sequences, together with consensus CRE/ATF and other transcription factor-binding sites, and an interesting set of 23 copies of an interspersed decamer consensus element AAAACACCGT that is also conserved at the equivalent locus in simian cytomegalovirus. This work represents the first identification of an origin domain in a cytomegalovirus genome and is the first demonstration of a bidirectional mechanism for any herpesvirus lytic cycle origin.
