bItraconazole is an orally active antifungal agent that has complex and highly variable absorption kinetics that is highly affected by food. This study aimed to develop a population pharmacokinetic model for itraconazole and the active metabolite hydroxyitraconazole, in particular, quantifying the effects of food and formulation on oral absorption. Plasma pharmacokinetic data were collected from seven phase I crossover trials comparing the SUBA-itraconazole and Sporanox formulations of itraconazole. First, a model of single-dose itraconazole data was developed, which was then extended to the multidose data. Covariate effects on itraconazole were then examined before extending the model to describe hydroxyitraconazole. The final itraconazole model was a 2-compartment model with oral absorption described by 4-transit compartments. Multidose kinetics was described by total effective daily dose-and time-dependent changes in clearance and bioavailability. Hydroxyitraconazole was best described by a 1-compartment model with mixed first-order and Michaelis-Menten elimination for the single-dose data and a time-dependent clearance for the multidose data. The relative bioavailability of SUBA-itraconazole compared to that of Sporanox was 173% and was 21% less variable between subjects. Food resulted in a 27% reduction in bioavailability and 58% reduction in the transit absorption rate constant compared to that with the fasted state, irrespective of the formulation. This analysis presents the most extensive population pharmacokinetic model of itraconazole and hydroxyitraconazole in the literature performed in healthy subjects. The presented model can be used for simulating food effects on itraconazole exposure and for performing prestudy power analysis and sample size estimation, which are important aspects of clinical trial design of bioequivalence studies. Itraconazole is a broad-spectrum orally active triazole antifungal used for both prophylaxis and treatment of systemic fungal infections (1, 2). Itraconazole exerts antifungal activity through the inhibition of fungal cytochrome P450 (CYP) 3A isoenzymes, which mediate the synthesis of ergosterol, a vital component of the fungal cell membrane (3). Itraconazole undergoes extensive hepatic metabolism by human CYP3A4 isoenzymes. Both itraconazole and its major active metabolite, hydroxyitraconazole, inhibit mammalian CYP3A4, although to a lesser extent than that with the fungal CYP3A isoenzymes (4).Itraconazole is currently available as oral capsules in two marketed formulations: Sporanox, the brand product (Janssen Pharmaceuticals, Inc.[5]), and SUBA-itraconazole, the alternative product. SUBA-itraconazole is a novel formulation containing a solid dispersion of itraconazole in a pH-dependent polymeric matrix to enhance its dissolution and intestinal absorption; therefore, it exhibits greater bioavailability than the innovator product. As of 30 June 2015, SUBA-itraconazole has marketing approval in Australia, Spain, Germany, Sweden, and United Kingdom; currently, it is ava...

An IVIVC model was established and internally evaluated for the two itraconazole formulations. The IVIVC model provides more insight into the observed variability of itraconazole pharmacokinetics and indicated that GI pH and transit times influence in vivo dissolution and exposure.

#3113 Background: The 21-gene Recurrence Score (RS) assay has been validated to quantify the risk of distant recurrence in tamoxifen treated patients (pts) in node negative, estrogen receptor positive breast cancer (BC) and predict magnitude of chemotherapy benefit. We previously showed that the RS impacted medical oncologists (MOs) and pts adjuvant treatment decision making, decreased situational anxiety and decisional conflict, and improved pt satisfaction regarding adjuvant treatment decisions. Herein, we present the 12 month post-RS data for MOs and pts.
 Material and Methods: MOs stated their treatment recommendation and confidence in it pre- and post-RS assay, and completed a 12 month questionnaire. Pts completed 4 questionnaires pre- and immediately post-RS, and 12 months later: 1) Patient Treatment Decision Making Questionnaire; 2) Decisional Conflict Scale (DCS); 3) State-Trait Anxiety Inventory; and 4) Functional Assessment of Cancer Therapy-Breast. Frequency distributions, means and standard deviations summarized data. Paired samples t-tests and repeated measures ANOVA assessed quality of life, decisional conflict and anxiety.
 Results: Accrual goal was met with 89 evaluable pts. 16/17 (94%) MOs and 67 pts (75%) completed the 12 month assessment. There were no breast cancer recurrences recorded at 12 months. The majority of MOs reported increase confidence in their treatment recommendation (n=15, 93.8%), felt the RS provided additional information (n=15, 93.8%), and influenced treatment recommendation (n=14, 87.6%). Results from the DCS immediately post-RS indicate reduced conflict over treatment (p <.0001), greater pt satisfaction, and increased confidence with choice of adjuvant therapy (p <.0001). Pts reported they were glad they took the test 12 months later (n=62, 92.5%), found results easy to understand (n=60, 89.6%), and the test influenced treatment decision (n=54, 80.6%). Sixty four (95.5%) were satisfied with their adjuvant decision. State anxiety decreased over the year (mean 38.9 to 34.0, p. = 007), the most significant decline occurred pre- to immediately post-RS. Quality of life remained constant.
 Conclusions: The RS assay has an immediate and enduring impact on MOs and pts adjuvant decision making. MOs and pts report continued confidence and satisfaction with the assay. Pts had a decrease in decisional conflict right after the test, situational anxiety declined over the next 12 months and quality of life remained stable.
 Investigator initiated trial supported by an unrestricted clinical trials grant from Genomic Health Inc. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 3113.

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