Prevention of post COVID-19 condition by early treatment with ensitrelvir in the phase 3 SCORPIO-SR trial.

This exploratory analysis of the double-blind, phase 3, SCORPIO-SR trial assessed the effect of ensitrelvir in preventing post coronavirus disease 2019 (COVID-19) condition (PCC). Patients with mild-to-moderate COVID-19 were randomized (1:1:1) within 120 h of symptom onset; received 5-day oral ensitrelvir 125 mg (375 mg on day 1), 250 mg (750 mg on day 1), or a matching placebo once daily; and were assessed for the severity of typical PCC symptoms using a self-administered questionnaire. In total, 341, 317, and 333 patients were assessed in the ensitrelvir 125-mg, ensitrelvir 250-mg, and placebo groups, respectively (mean age, 35.6-36.5 years; men, 53.3%-58.3%). On days 85, 169, and 337, ensitrelvir 125-mg treatment showed 32.7% (95% confidence interval [CI]: -30.6, 66.1), 21.5% (95% CI: -37.3, 55.6), and 24.6% (95% CI: -43.7, 60.9) reductions versus placebo, respectively, in the risk of any of the 14 acute-phase COVID-19 symptoms (at least one mild, moderate, or severe symptom with general health not returning to the usual level). Ensitrelvir 250-mg treatment showed 10.9% (95% CI: -67.0, 52.8), 9.5% (95% CI: -56.6, 48.0), and 30.6% (95% CI: -36.2, 65.5) risk reductions versus placebo on days 85, 169, and 337, respectively. Risk reductions were observed in any of the 4 neurological symptoms and were more pronounced among patients with high acute-phase symptom scores at baseline and among those with a baseline body mass index ≥25 kg/m2. Ensitrelvir treatment in the acute phase of COVID-19 may reduce the risk of various symptoms associated with PCC. TRIAL REGISTRATION NUMBER: jRCT2031210350.

Efficacy and Safety of Ensitrelvir for Asymptomatic or Mild COVID-19: An Exploratory Analysis of a Multicenter, Randomized, Phase 2b/3 Clinical Trial.

BACKGROUND: This phase 2b/3, randomized, placebo-controlled trial explored the efficacy and evaluated the safety of ensitrelvir. This trial involved individuals with asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patients with mild symptoms of coronavirus disease 2019 (COVID-19). METHODS: The trial was conducted at 57 medical institutions in Japan, South Korea, and Vietnam (study period: January 6-August 14, 2022). Eligible participants were randomized (1:1:1) to the ensitrelvir 125-mg, ensitrelvir 250-mg, or placebo group, received the allocated intervention orally, and were followed up until Day 28. Participants self-rated the severity of 14 typical COVID-19 symptoms and recorded the data in an electronic diary. RESULTS: In total, 572 participants (194, 189, and 189 in the ensitrelvir 125-mg, ensitrelvir 250-mg, and placebo groups, respectively) were included in the intention-to-treat population. Ensitrelvir 125-mg group observed a 77% reduction in the risk of developing any of the 14 COVID-19 symptoms or fever and a 29% reduction in the risk of worsening of such symptoms or fever versus placebo (statistically nonsignificant). The viral RNA, viral titer, and time to infectious viral clearance observed a statistically significant decrease versus placebo. Most treatment-related adverse events (TEAEs) were mild to moderate in severity, and the most common TEAE observed across groups was a decrease in high-density lipoprotein. CONCLUSIONS: Our exploratory results suggest a potential reduction in the risk of development or worsening of COVID-19 symptoms with ensitrelvir. Ensitrelvir showed antiviral efficacy and was well tolerated. TRIAL REGISTRATION: Japan Registry of Clinical Trials identifier: jRCT2031210350.

Functional characterization of apical transporters expressed in rat proximal tubular cells (PTCs) in primary culture.

Since in vitro cell culture models often show altered apical transporter expression, they are not necessarily suitable for the analysis of renal transport processes. Therefore, we aimed here to investigate the usefulness of primary-cultured rat proximal tubular cells (PTCs) for this purpose. After isolation of renal cortical cells from rat kidneys, PTCs were enriched and the gene expression and function of apical transporters were analyzed by means of microarray, RT-PCR and uptake experiments. RT-PCR confirmed that the major apical transporters were expressed in rat PTCs. Na(+)-dependent uptake of α-methyl-d-glucopyranoside (αMG), ergothioneine and carnitine by the PTCs suggests functional expression of Sglts, Octn1 and Octn2, respectively. Inhibition of pH-dependent glycylsarcosine uptake by low concentration of cephalexin, which is a ß-lactam antibiotics recognized by Pepts, indicates a predominant role of high affinity type Pept2, but not low affinity type Pept1, in the PTCs. Moreover, the permeability ratio of [(14)C]αMG (apical to basolateral/basolateral to apical) across PTCs was 4.3, suggesting that Sglt-mediated reabsorptive transport is characterized. In conclusion, our results indicate that rat PTCs in primary culture are found to be a promising in vitro model to evaluate reabsorption processes mediated at least by Sglts, Pept2, Octn1 and Octn2.

Long-term study of lisdexamfetamine dimesylate in Japanese children and adolescents with attention-deficit/hyperactivity disorder.

AIMS: As an extension of a phase 2/3 study evaluating the efficacy and safety of lisdexamfetamine dimesylate (LDX) 30, 50, or 70 mg/d for 4 weeks in Japanese patients aged 6-17 years with attention-deficit/hyperactivity disorder (ADHD), this study evaluated its long-term safety and efficacy. METHODS: This was a multicenter, open-label study of LDX for 53 weeks. Safety was assessed by regular medical examination for treatment-emergent adverse events (TEAEs); regular recording of body weight, vital signs, and laboratory test values; and completion of dependence questionnaires. Efficacy was assessed using Japanese versions of the ADHD-Rating Scale-IV (ADHD-RS-IV) and Conners' 3rd edition Parent Rating Scale (Conners 3); plus Clinical Global Impression-Improvement (CGI-I), Clinical Global Impression-Severity, and Parent Global Assessment (PGA) scales. RESULTS: Of 132 enrolled patients, 104 completed the trial. Most frequent treatment-related TEAEs were decreased appetite (73.5%), initial insomnia (39.4%), and weight decrease (22.0%). Most TEAEs were mild (82.6% of patients). There were no serious or severe TEAEs or deaths. No treatment-related TEAEs were associated with blood pressure or pulse rate, and no patient had a QTcF interval >500 ms. Statistically significant improvement from baseline to week 53 was observed in the mean ADHD-Rating Scale-IV total score and mean Conners 3 subscale scores. Most patients showed improvement on the CGI-I (78%) and PGA (76.5%) scales. CONCLUSIONS: No significant safety issues were observed with LDX 30, 50, or 70 mg/d administered for 1 year in Japanese children and adolescents with ADHD. LDX was associated with long-term reductions in ADHD symptoms and severity.

Phase II/III Study of Lisdexamfetamine Dimesylate in Japanese Pediatric Patients with Attention-Deficit/Hyperactivity Disorder.

Objective: To further define the efficacy and safety profiles of lisdexamfetamine dimesylate (LDX) in Japanese pediatric patients with attention-deficit/hyperactivity disorder (ADHD). Methods: This was a multicenter, randomized, double-blind, placebo-controlled study of LDX 30, 50, or 70 mg/day for 4 weeks in 76 patients 6-17 years of age with ADHD in Japan. The primary efficacy endpoint was the change in the ADHD Rating Scale-IV (ADHD-RS-IV) total score from baseline to 4 weeks. Secondary efficacy endpoints were: Conners' Third Edition (Japanese version) Parent Rating Scale (Conners 3), Clinical Global Impression-Improvement (CGI-I) scale, and Parent Global Assessment (PGA) scale. Results: Change in the ADHD-RS-IV total score from baseline to 4 weeks was significantly greater (p < 0.0001) in all LDX dosage groups versus placebo (30 mg, -16.38; 50 mg, -18.10; 70 mg, -16.47; placebo, -2.78). At all time points, improvements (decreases) in the ADHD-RS-IV total score were significantly greater in all LDX groups versus placebo. At weeks 3 and 4, improvements from baseline in Conners 3 inattention plus hyperactivity/impulsivity subscale scores were significantly greater (p ≤ 0.0082) for all LDX dosages versus placebo. At week 4, the proportion of LDX-treated patients "much improved" or "very much improved" was 61%-71% on the CGI-I scale (p ≤ 0.0019) and 56%-65% on the PGA scale (p ≤ 0.0170). LDX was generally well tolerated. The most frequent treatment-emergent adverse events (AEs) were decreased appetite, headache, and initial insomnia. No severe/serious AEs occurred, and no AEs specific to Japanese patients were evident. Conclusions: The superiority of LDX 30, 50, and 70 mg/day over placebo was confirmed in Japanese pediatric patients with ADHD, and no major safety or tolerability concerns were identified.

Transport characteristics of L-citrulline in renal apical membrane of proximal tubular cells.

L-Citrulline has diagnostic potential for renal function, because its plasma concentration increases with the progression of renal failure. Although L-citrulline extracted by glomerular filtration in kidney is mostly reabsorbed, the mechanism involved is not clearly understood. The present study was designed to characterize L-citrulline transport across the apical membranes of renal epithelial tubular cells, using primary-cultured rat renal proximal tubular cells, as well as the human kidney proximal tubular cell line HK-2. L-Citrulline was transported in a Na(+)-dependent manner from the apical side of both cell types cultured on permeable supports with a microporous membrane. Kinetic analysis indicated that the transport involves two distinct Na(+)-dependent saturable systems and one Na(+)-independent saturable system in HK-2 cells. The uptake was competitively inhibited by neutral and cationic, but not anionic amino acids. Relatively large cationic and anionic compounds inhibited the uptake, but smaller ones did not. In HK-2 cells, mRNA expression of SLC6A19 and SLC7A9, which encode B(0)AT1 and b(0,+)AT, respectively, was detected by RT-PCR. In addition, L-citrulline transport was significantly decreased in HK-2 cells in which either SLC6A19 or SLC7A9 was silenced. Hence, these results suggest that amino acid transporters B(0)AT1 and b(0,+)AT are involved in the reabsorption of L-citrulline in the kidney, at least in part, by mediating the apical membrane transport of L-citrulline in renal tubule cells.

Regulation of Octn2 transporter (SLC22A5) by peroxisome proliferator activated receptor alpha.

The tissue distribution and disposition of carnitine, which plays an important role in the transport of long-chain fatty acids across the mitochondrial inner membrane for beta-oxidation, are well controlled by carnitine transporter organic cation/carnitine transporter 2 (OCTN2). Since little information is available on regulation of the expression of the OCTN2 gene, we examined the factors that affect the expression level of rat Octn2 (rOctn2), focusing on nuclear receptor peroxisome proliferator activated receptor alpha (PPARalpha), which regulates expression of genes associated with beta-oxidation of fatty acids. mRNA of rOctn2 was induced by the PPARalpha ligand fenofibrate in primary-cultured rat hepatocytes. Further, the PPARalpha ligand Wy14643 increased the expression of Octn2 in wild-type mice, but not in PPARalpha knockout mice. Analysis of the rOctn2 promoter region suggested the presence of putative cis elements of PPARalpha. Wistar rats treated with intraperitoneal fenofibrate administration showed increased expression of rOctn2 mRNA in liver, and uptake of [3H]carnitine by freshly isolated hepatocytes derived from those rats was also increased. In conclusion, our results indicate that the nuclear receptor PPARalpha directly up-regulates the expression of rOctn2 and increases the hepatic uptake of carnitine via rOctn2.

Effects of angiotensin II receptor blockers on renal handling of uric acid in rats.

Elevated serum uric acid level has been associated with increased cardiovascular risk in hypertensive patients. Several angiotensin II receptor blockers exhibit differential effects on regulation of serum uric acid level in humans. We have demonstrated that some angiotensin II receptor blockers trans-stimulate the uptake of uric acid by human URAT1 and others inhibit the transport of uric acid mediated by human URAT1, OAT1, OAT3 and MRP4 in vitro. This study investigated the effects of candesartan, pratosartan and telmisartan on renal handling of uric acid in rats in vivo and in vitro. Candesartan (0.1 mg/kg) significantly decreased the urinary excretion of uric acid and increased the plasma uric acid concentration. The kidney candesartan level after low-dose treatment is close to that required to trans-stimulate uric acid uptake in vitro. Pratosartan exhibited dose-dependent hypouricemic and uricosuric effects, while telmisartan showed no effects on plasma uric acid level. Furthermore, we confirmed the effects of the tested drugs on uric acid transport by rat renal brush border membrane transporter(s) and basolateral Oat1 and Oat3. Effects of angiotensin II receptor blockers in rats may be mainly determined by their intrinsic effects (cis-inhibition and trans-stimulation) on uric acid reabsorption transporter(s) and their pharmacokinetic properties in rats.