[The effect of ferric citrate hydrate as an iron replacement therapy in Japanese patients with iron deficiency anemia].

Patients with iron deficiency anemia (IDA) need to take oral iron preparations, which serve as the first-line treatment in IDA, for several months in order to replenish body iron stores after the improvement of anemia. However, existing oral iron preparations have concerns regarding its long-term use due to side effects, such as gastrointestinal symptoms. Previous clinical studies have shown that ferric citrate hydrate (FC) exhibits sufficient therapeutic efficacy in patients with IDA and lowers the risks of nausea and vomiting in comparison with existing oral iron preparations. In this study, we evaluated the efficacy and safety of FC administration at doses of 500 and 1,000 mg/day for up to 24 weeks as iron replacement therapy in patients with IDA. The results of this study showed that both the doses of FC improved anemia and iron-deficiency conditions and led to sufficient iron replacement response in most patients with IDA. No safety concerns were identified. Therefore, FC is expected to be a novel oral iron preparation for patients with IDA.

Efficacy and safety of ferric citrate hydrate compared with sodium ferrous citrate in Japanese patients with iron deficiency anemia: a randomized, double-blind, phase 3 non-inferiority study.

Oral iron preparations are used as first-line treatment for iron deficiency anemia (IDA), but their gastrointestinal side effects prevent patients from appropriate adherence. We recently conducted a randomized, double-blind, phase 3 non-inferiority study to evaluate the efficacy and safety of two dosages of ferric citrate hydrate (FC) compared with sodium ferrous citrate (SF) in patients with IDA. FC at both 500 and 1000 mg/day was non-inferior to SF at 100 mg/day in terms of the change in the hemoglobin concentration at Week 7 from baseline. Logistic regression analysis suggested that the cumulative proportion of patients who achieved the target hemoglobin concentration (≥ 13.0 g/dL in male patients and ≥ 12.0 g/dL in female patients) at Week 7 was highest among those treated with FC at 1000 mg/day, followed by SF at 100 mg/day and FC at 500 mg/day. Both dosages of FC were well tolerated in patients with IDA. The incidences of nausea and vomiting were significantly lower in the FC treatment groups than in the SF group. In conclusion, FC has potential to be an oral iron preparation with sufficient efficacy for the treatment of IDA and a lower risk of nausea and vomiting.

Pharmacokinetics of Tenofovir Alafenamide, Tenofovir, and Emtricitabine Following Administration of Coformulated Emtricitabine/Tenofovir Alafenamide in Healthy Japanese Subjects.

A fixed-dose combination of tenofovir alafenamide (TAF) and emtricitabine (FTC) is available in 2 tablet strengths in Japan (FTC/TAF 200/10 mg and FTC/TAF 200/25 mg). These are used once daily in combination with other antiretroviral agents for the treatment of human immunodeficiency virus type 1 infection. The primary objective of this study was to investigate if there is any clinically relevant pharmacokinetic difference for TAF, tenofovir (TFV), and FTC between Japanese and non-Japanese with historical data. Three treatment groups were set in the study; FTC/TAF 200/10 mg in combination with darunavir (DRV) 800 mg + ritonavir (RTV) 100 mg (treatment A) or DRV/cobicistat (COBI) 800/150 mg (treatment B) and FTC/TAF 200/25 mg alone (treatment C). Especially for treatment C, it was designated for another purpose to evaluate the pharmacokinetic boosting effects of RTV and COBI on TAF bioavailability. As a result, the mean exposure of TAF among treatment groups was 125 to 154 ng/mL for Cmax and 119 to 179 ng·h/mL for AUCinf , which were comparable with the historical data in non-Japanese. The exposures of TFV and FTC were also consistent with the historical data. Therefore, no clinically relevant pharmacokinetic differences for TAF, TFV, and FTC were observed between Japanese and non-Japanese. Boosting effects of RTV and COBI on TAF bioavailability were slightly lower than we expected, less than a 2.5-fold increase, but it was within the range of exposures associated with efficacy and safety in phase 3 studies. Therefore, it was not considered clinically relevant.

Effects of a Nutritional Protein-Rich Drink on the Pharmacokinetics of Elvitegravir, Cobicistat, Emtricitabine, Tenofovir Alafenamide, and Tenofovir Compared With a Standard Meal in Healthy Japanese Male Subjects.

This study investigated the effects of ingested meal types on the pharmacokinetics of elvitegravir (EVG), cobicistat (COBI), emtricitabine (FTC), tenofovir alafenamide (TAF), and tenofovir (TFV) following a single administration of the single-tablet regimen (STR) of EVG/COBI/FTC/TAF (150/150/200/10 mg) in Japanese HIV-negative healthy subjects (n = 12). In this open-label, randomized, 3-way crossover study, the bioequivalence of the EVG/COBI/FTC/TAF STR following ingestion of a nutritional protein-rich drink with a reference treatment of taking a standard breakfast was evaluated. Administration under fasted conditions, no food intake, resulted in decreases in the mean AUCinf and Cmax of EVG by 50% and 57%, respectively, relative to the administration with a standard breakfast, whereas the systemic exposure of EVG with a nutritional protein-rich drink was comparable to that with a standard breakfast. The mean AUCinf and Cmax of COBI, FTC, TAF, and TFV were comparable regardless of meal intake or meal types. Although the package insert of the EVG/COBI/FTC/TAF STR states that the medication is recommended to be taken with food, this study provides an additional insight into HIV-1-infected patients that a light meal like a nutritional protein-rich drink can be an alternative to a standard meal.

Involvement of the system L amino acid transporter on uptake of S-nitroso-L-cysteine, an endogenous S-nitrosothiol, in PC12 cells.

Previously, we proposed that S-nitroso-L-cysteine, an endogenous S-nitrosothiol, was incorporated via the system L-like amino acid transporter(s) in rat brain slices. In this study, we investigated the effect of S-nitroso-L-cysteine on L-[3H]leucine uptake in PC12 cells (a neuronal cell line). L-[3H]Leucine uptake in PC12 cells was Na(+) independent and significantly inhibited by an inhibitor of system L and by L-phenylalanine, L-cysteine, L-methionine and L-leucine at 1 mM. The effects of L-alanine, L-serine and L-threonine were limited. S-Nitroso-L-cysteine, but not other nitric oxide compounds, inhibited L-[3H]leucine uptake, and this inhibitory effect was eliminated by washing with buffer. System L is composed of the 4F2 light chains (LAT1 or LAT2) and the heavy chain, and the transcripts of these components were detected in RNA from PC12 cells. These findings suggest that S-nitroso-L-cysteine is incorporated via the system L amino acid transporter and thus regulates cell responses in PC12 cells.