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    ABSTRACT: PURPOSE: Many tyrosine kinase inhibitors (TKIs) undergo extensive hepatic metabolism, but mechanisms of their hepatocellular uptake remain poorly understood. We hypothesized that liver uptake of TKIs is mediated by the solute carriers OATP1B1 and OATP1B3. EXPERIMENTAL DESIGN: Transport of crizotinib, dasatinib, gefitinib, imatinib, nilotinib, pazopanib, sorafenib, sunitinib, vandetanib, and vemurafenib was studied in vitro using artificial membranes (PAMPA) and HEK293 cell lines stably transfected with OATP1B1, OATP1B3, or the ortholog mouse transporter, Oatp1b2. Pharmacokinetic studies were performed with Oatp1b2-knockout mice and humanized OATP1B1- or OATP1B3-transgenic mice. RESULTS: All 10 TKIs were identified as substrates of OATP1B1, OATP1B3, or both. Transport of sorafenib was investigated further, since its diffusion was particularly low in the PAMPA assay (<2%) compared to other TKIs that were transported by both OATP1B1 and OATP1B3. While Oatp1b2 deficiency in vivo had minimal influence on parent and active metabolite N-oxide drug exposure, plasma levels of the glucuronic-acid metabolite of sorafenib (sorafenib-glucuronide) were increased >8-fold in Oatp1b2-knockout mice. This finding was unrelated to possible changes in intrinsic metabolic capacity for sorafenib-glucuronide formation in hepatic or intestinal microsomes ex vivo. Ensuing experiments revealed that sorafenib-glucuronide was itself a transported substrate of Oatp1b2 (17.5-fold vs control), OATP1B1 (10.6-fold), and OATP1B3 (6.4-fold), and introduction of the human transporters in Oatp1b2-knockout mice provided partial restoration of function. CONCLUSIONS: These findings signify a unique role for OATP1B1 and OATP1B3 in the elimination of sorafenib-glucuronide, and suggest a role for these transporters in the in vivo handling of glucuronic acid conjugates of drugs.
    Clinical Cancer Research 01/2013; · 7.84 Impact Factor
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    ABSTRACT: The efficacy of sorafenib against hepatocellular carcinoma (HCC) has been extensively reported. However, there is little information available about the use of sorafenib for HCC patients with end-stage renal failure. We herein report the safe introduction of sorafenib therapy for a HCC patient on hemodialysis. A 63-year-old male had received multidisciplinary treatments, including transarterial chemoembolization (TACE) and radio frequency ablation, for HCC since 1996, and had been undergoing hemodialysis since 2005. He also underwent TACE for multiple liver recurrence of HCC in 2011. Sorafenib therapy (200 mg/day) started eight days after the TACE. The pharmacokinetic parameters of sorafenib and its active metabolite, M-2, were within the reference levels observed in patients with normal renal function eight and nine days after the initiation of sorafenib. The dose of sorafenib was reduced to 200 mg every other day on day 154 due to hypertension and general fatigue. Because of the progression of disease after five months, sorafenib was withdrawn on day 180. He was admitted to the emergency department because of a high fever during hemodialysis on day 201, and died of septic shock induced by Staphylococcus lugdunensis on day 203. Sorafenib was well tolerated at an initial dose of 200 mg/day for an HCC patient undergoing hemodialysis, thus indicating that renal failure is not necessarily a contraindication for sorafenib therapy.
    Hepatology Research 05/2013; · 2.07 Impact Factor
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    ABSTRACT: We performed a literature search that shed light on the signaling pathways involved in the sorafenib activity as first- or subsequent-line treatment, taking into account its toxicity profile. Sorafenib appears to have better tolerability when compared with other agents in the same indication. Cross-resistance between tyrosine kinase inhibitors (TKIs) may be limited, even after failure with a previous VEGFR inhibitor, but the optimal sequence with TKIs remains to be determined. Randomized trials of second-line treatment options have showed either modest or no differences in terms of progression-free and overall survival (OS). Direct comparison between sorafenib and axitinib demonstrated differences in terms of PFS in favor of axitinib, but not in terms of OS as second-line treatment. In contrast, a phase III study showed a benefit in OS, favoring sorafenib when compared with temsirolimus. In conclusion, after using other VEGF inhibitor such as sunitinib, sorafenib is active and safe for the treatment of patients with advanced or metastatic RCC.
    Clinical and Translational Oncology 02/2013; · 1.28 Impact Factor

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May 27, 2014