Pharmacokinetic food-effect study of abiraterone acetate (AA) in patients with metastatic castration resistant prostate cancer (mCRPC): The ABIFOOD trial (EudraCt number: 2012-003226-25)

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Background: A.A has been approved for the treatment of mCRPC before and after docetaxel. The standard regime consists on daily A.A. 1.000 mg in a fasting state along with prednisone 10mg q.d. However, data from pharmacokinetic (PK) studies in patients (pts) and healthy volunteers has revealed a significant food-effect with up to 7-10 folder increase in area under plasma concentration-time curve (AUC) when A.A is given with food, specially with fat content, [Chi KN, J Clin Pharmacol 2015]. Methods: ABIFOOD is a phase I, randomized trial to evaluate the short and long-term effect of diet on the PKs of A.A. in pts with mCRPC who have progressed to docetaxel. Eligible pts include men ≥ 18 years old with mCRPC, ECOG performance status (PS) < 2 and an adequate organ function. Pts are randomly assigned to receive 4-weekly cycles of 250 mg A.A with standard meal (Arm A), 250 mg A.A with high-fat meal (Arm B) or 1000 mg A.A in fasting conditions (Arm C). PK analyses are conducted at week 1 (W1) and cycle 5. Results: Fifteen pts (5, 3 and 7 in arms A, B and C respectively) have been included and 6 are still on treatment. Median age is 72, 97% have ECOG-PS 1. Gleason Score is > 8 in 6 (40%) pts.Geometric mean abiraterone [AUC (ng.h/ml) (IQR)] at W1 did not significantly differ between treatment arms [arm A: 404.68 (368.4 - 488.2), arm B: 372 (334.6 - 440.5) arm C: 656.51 (387.8 – 1144.5) p 0.15]. PK data did not influence activity or toxicity. Progression free survival was 8.50, 6.33 and 4.86 months in Arms A, B and C respectively (p 0.53). One patient in arm A is still on treatment after 17 cycles. Conclusions: The administration of lower doses of A.A with food [regardless the fat content], might achieve comparable plasma levels to standard dosing with no detriment in efficacy or toxicity parameters. The study is actively recruiting and data on additional pts and long term PK parameters will be presented. Clinical trial information: EudraCt number: 2012-003226-25.

Dimension of chronic hepatitis C virus in HIV-infected patients in the interferon-free era: an overview from south Spain

The implementation of hepatitis C (HCV) direct-acting antiviral drugs is prioritized in several populations in which its application provides the most immediate and impactful benefit. In this scenario, a precise knowledge of the situation of human immunodeficiency virus (HIV)/HCV chronic co-infection is required to adequately address this disease. This cross-sectional study was performed in 21 hospitals in Andalusia (Spain). The study population consisted of HIV-infected patients with an active HCV chronic infection who were not receiving HCV treatment at the time of inclusion. A total of 13,506 HIV-infected patients were included in the study. Of them, 2561 (18.9 %) presented chronic HCV infection. The majority of the patients included were on highly active antiretroviral therapy (HAART; 96.2 %), showed plasma levels with an undetectable HIV viral load (92.5 %), and had a good immunological status (median CD4+ cell count of 486 cells/mL). The HCV genotype distribution was as follows: 58.1 % were genotype 1, 1.1 % were genotype 2, 16.1 % were genotype 3, and 22.1 % were genotype 4 (2.6 % were missing data). In total, 24.8 % of the patients showed liver fibrosis stage F0-F1, 27.9 % showed stage F2, 16.7 % showed stage F3, and 21 % showed stage F4 (9.6 % were missing data). With regards to previous HCV treatment experiences, 68.05 % of the patients were naïve and 31.95 % had failed to respond to a previous treatment. The burden of HCV/HIV co-infected patients in our population was reported as one in five HIV-infected patients requiring HCV treatment. The implementation of extra resources to face this important health challenge is mandatory.

Low concordance and resistance mutation emergence in the HIV protease gene among circulating and cell-associated viruses at viral replication episodes during darunavir/ritonavir monotherapy

OBJECTIVE

To assess the changes on the HIV protease gene in plasma and peripheral blood mononuclear cell (PBMC) compartments during viral replication episodes in patients on boosted-darunavir monotherapy (mtDRV/rtv).

METHODS

A prospective study was carried out in which adult HIV-1-infected patients who started mtDRV/rtv after viral suppression for ≥ 6 months with no major darunavir-related resistance mutations were enrolled. Patients with two consecutive plasma HIV RNA measurements >200 HIV-1 RNA copies/mL were considered as having virological failure (VF), while patients with two consecutive plasma HIV RNA measurements >50 copies/mL without meeting the VF criteria were considered to have virological rebound (VR). HIV protease genotypic profiles from plasma and PBMCs were performed at baseline and at VF and VR episodes.

RESULTS

One hundred and fifty patients were included in the study, with overall VF and VR rates of 14% (n=21) and 14.7% (n=22), respectively. No major darunavir resistance mutations were observed in the plasma or PBMC samples. Circulating and cell-associated viruses showed a wild-type protease gene sequence in 54% and 23% of patients, respectively while the remainder patients only harboured minor protease inhibitor-associated mutations. Full concordance between plasma RNA and PBMC DNA protease genotypes was found in 23% of the sequences.

CONCLUSIONS

No darunavir-related mutations were found in patients with VF or VR, either in plasma or in PBMCs; thus, simplification to mtDRV/rtv does not comprise future antiretroviral treatment options.

Impact of the peginterferon-α 2a and ribavirin plasma levels on viral kinetics and sustained virological response in genotype 1 HCV/HIV-co-infected patients with the unfavourable non-CC IL28B genotypes

Studies on the association between the peginterferon-α and ribavirin levels and sustained virological response (SVR) have shown yielded conflicting results, but most of them were performed before the influence of IL28B polymorphisms was known. Our aim was to assess the effects of peginterferon-α 2a and ribavirin plasma levels on viral kinetics and SVR in hepatitis C virus genotype 1 HCV-1/HIV-co-infected patients according to IL28B genotype. This was a cohort study of HCV-1/HIV-co-infected patients who were HCV-treatment naïve and for whom the efficacy of peginterferon-α 2a plus ribavirin was evaluated by per-protocol analysis. The peginterferon-α 2a and ribavirin levels were measured by ELISA and HPLC-UV, respectively. The relationships among host and viral factors, the trough drugs levels and virological responses were analysed by multivariate regression analyses. A total of 131 Caucasian patients were included (cirrhosis:38.9%). Overall, SVR rate was 39.6%. In patients with CC IL28B genotype, SVR was related neither to peginterferon-α 2a nor to ribavirin plasma levels, while higher levels of both drugs were the only variables independently associated with SVR in individuals with CT/TT IL28B genotypes (OR, 5.02; CI95 , 1.45-17.1; P = 0.001 and 4.0; CI95 , 1.08-14.7; P = 0.038, respectively). Moreover, faster viral declines were observed in CT/TT patients when pegIFN-α 2a and ribavirin plasma levels were greater than 3400 pg/mL and 1.6 μg/mL, respectively. In contrast to the results for CC patients, the results in patients carrying the unfavourable CT/TT IL28B genotypes showed that plasma levels of both drugs have significant effects on viral kinetics and SVR.