Tamibarotene targets heparin-binding protein for attenuating lung injury in sepsis

Background: Excessively active pulmonary inflammation is a hallmark of sepsis-induced lung damage. A synthetic retinoid drug called tamibarotene reduces inflammation in a variety of conditions, including acute promyelocytic leukemia (APL), renal fibrosis, and neuroinflammation. Its effect on sepsis-related lung injury, however, has not been explained. Purpose: The purpose of the study was to investigate how tamibarotene affected lung damage induced by cecal ligation and puncture (CLP) procedure. Methods: A CLP sepsis mouse model was developed, and tamibarotene was pretreated to determine whether it improved lung injury and survival. The degree of lung injury was evaluated using the Hematoxylin and eosin staining and lung injury score. In order to determine pulmonary vascular permeability, measurements were taken for total protein and cell content of bronchoalveolar lavage fluid (BALF), wet/dry ratio of the lung, and Evans blue stain. The BALF inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-17A were discovered by enzyme-linked immunosorbent serologic assay (ELISA). Then, the levels of heparin-binding protein (HBP), and phospho-nuclear factor kappa-B (p-NF-κB) P65, and NF-κB P65 were determined using ELISA and Western blot analysis, respectively. Results: Tamibarotene considerably increases survival and lessens lung damage stimulated by sepsis. Specifically, tamibarotene significantly relieves pulmonary vascular permeability and inhibits inflammation response in sepsis. Moreover, we further confirmed that these ameliorating effects of tamibarotene on sepsis may be exerted by targeting HBP and regulating the activation of NF-κB signaling pathway. Conclusion: These findings demonstrated that tamibarotene lessens sepsis-induced lung injury, and the effect could be exerted by targeting HBP and thereby deregulating the NF-κB signaling pathway (AU)

Eltrombopag for Post-Transplant Poor Graft Function in East Asian Patients.

Poor graft function (PGF) is a serious, potentially life-threatening complication of allogeneic hematopoietic stem cell transplantation. Eltrombopag has shown multilineage responses in patients with refractory severe aplastic anemia, supporting the idea that it may improve cytopenia in patients with PGF. This retrospective, single center analysis included 8 Korean patients receiving eltrombopag for PGF. Median interval between transplant and eltrombopag treatment was 73 days, and the median duration treatment was 3.5 weeks. With median maximum daily dose of 50 mg, the time to best response was 93 days. Median hemoglobin increased from 8.2 g/dL to 10.9 g/dL, platelet from 18.5 × 109/L to 54 × 109/L, and absolute neutrophil count from 1.25 × 109/L to 3.32 × 109/L. In conclusion, eltrombopag is a good option for PGF in Korean patients, even at a lower dose compared to western patients.

Safety and efficacy of MIKE-1 in patients with advanced pancreatic cancer: a study protocol for an open-label phase I/II investigator-initiated clinical trial based on a drug repositioning approach that reprograms the tumour stroma.

BACKGROUND: Cancer-associated fibroblasts (CAFs) are an important component of the tumour microenvironment. Recent studies revealed CAFs are heterogeneous and CAF subset(s) that suppress cancer progression (cancer-restraining CAFs [rCAFs]) must exist in addition to well-characterised cancer-promoting CAFs (pCAFs). However, the identity and specific markers of rCAFs are not yet reported. We recently identified Meflin as a specific marker of rCAFs in pancreatic and colon cancers. Our studies revealed that rCAFs may represent proliferating resident fibroblasts. Interestingly, a lineage tracing experiment showed Meflin-positive rCAFs differentiate into α-smooth muscle actin-positive and Meflin-negative CAFs, which are generally hypothesised as pCAFs, during cancer progression. Using a pharmacological approach, we identified AM80, a synthetic unnatural retinoid, as a reagent that effectively converts Meflin-negative pCAFs to Meflin-positive rCAFs. We aimed to investigate the efficacy of a combination of AM80 and gemcitabine (GEM) and nab-paclitaxel (nab-PTX) in patients with advanced pancreatic cancer. METHODS: The phase I part is a 3 + 3 design, open-label, and dose-finding study. The dose-limiting toxicity (DLT) of these combination therapies would be evaluated for 4 weeks. After the DLT evaluation period, if no disease progression is noted based on the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 or if the patient has no intolerable toxicity, administration of AM80 with GEM and nab-PTX would be continued for up to 24 weeks. The phase II part is an open-label, single-arm study. The maximum tolerated dose (MTD) of AM80 with GEM and nab-PTX, determined in phase I, would be administered until intolerable toxicity or disease progression occurs, up to a maximum of 24 weeks, to confirm efficacy and safety. The primary endpoints are frequency of DLT and MTD of AM80 with GEM and nab-PTX in the phase I part and response rate based on the RECIST in the phase II part. Given the historical control data, we hope that the response rate will be over 23% in phase II. DISCUSSION: Strategies to convert pCAFs into rCAFs have been developed in recent years. We hypothesised that AM80 would be a promising enhancer of chemosensitivity and drug distribution through CAF conversion in the stroma. TRIAL REGISTRATION: Clinicaltrial.gov: NCT05064618 , registered on 1 October 2021. jRCT: jRCT2041210056 , registered on 27 August 2021.

Eltrombopag in the treatment of patients with persistent thrombocytopenia after haploidentical peripheral blood stem cell transplantation: a single-center experience.

Persistent thrombocytopenia (PT) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is associated with an increased risk of bleeding and poor survival. The exact pathogenesis underlying PT remains unclear, and its management is difficult. Here we conducted a retrospective study to evaluate the efficacy and safety of eltrombopag (EPAG) in 34 patients with PT after allo-HSCT. Seven patients suffered from prolonged isolated thrombocytopenia (PIT), and 27 had secondary failure of platelet recovery (SFPR). For most patients, the initial dose was 25 mg or 50 mg daily, then adjusted to the maximum dose of 50-100 mg per day according to the response of platelet recovery and toleration of patients. The cumulative incidence (CI) of platelet recovery to at least 20 × 109/L and 50 × 109/L without transfusion support for at least 7 days was 72.1% and 60.7%, respectively. Nineteen (86.4%) of 22 responders were able to taper off the medication; furthermore, the platelet counts remained stable 1 month after withdrawal of EPAG. Although two patients discontinued EPAG during treatment due to headache and nausea, no patients developed grade 3 or 4 toxicities. Hypoplasia of bone marrow and decreased megakaryocytes (MKs) were found to be risk factors for overall response (OR) and complete response (CR) in multivariate analysis, respectively. Overall, our results indicated that EPAG can be used in the treatment of PT and that continuous exposure to EPAG may not be necessary.

Eltrombopag Add-on Treatment in a Child With Fanconi Aplastic Anemia Awaiting Hematopoietic Stem Cell Transplantation.

Fanconi aplastic anemia (FAA) is a rare inherited bone marrow failure disorder characterized by congenital defects and pancytopenia. Hematopoietic stem cell transplantation (HSCT) is a curative treatment for patients with FAA due to the risk of cancer and pancytopenia. Blood transfusions are the best supportive therapy. Oxymetholone (5 mg/kg daily) is most commonly used; however, it is not curative. Extensive transfusions should be avoided because of alloimmunization and graft-versus-host disease because they have poor outcomes in patients with HSCT. This is a case report of a 5-year-old Syrian male patient with FAA, who was successfully treated with eltrombopag (50 mg daily) in conjunction with oxymetholone (5 mg/kg daily). The patient required platelet transfusions despite oxymetholone therapy and there was no suitable donor for HSCT. After the addition of eltrombopag therapy, platelet transfusions were no longer required. Eltrombopag can be effectively used as a bridge to HSCT in patients with FAA.

The gelling properties of Dillenia indica mucilage in benzyl benzoate emulgel formulations

Abstract The objective of the study was to evaluate the gelling properties of Dillenia indica mucilage in benzyl benzoate emulgel formulation. Mucilage was extracted from the fruits of Dillenia indica using established methods and characterized by rheology and swelling. Emulsion (F1) was prepared using the continental emulsification method. Gelling agents (2 %w /v) were prepared by dispersing in distilled water with constant stirring at a moderate speed using a magnetic stirrer. F1 was added to the gel (0-75 %w /w) to obtain emulgel formulations and evaluated using viscosity, globule size, pH, release profiles and kinetic modeling. Data were expressed as mean ± SD, and similarity factor (f2) was used to compare all formulations. Formulation viscosity was significantly higher with carbopol than with Dillenia; globule sizes increased with concentration of gelling agents, and pH reduced as the concentration of Dillenia increased. All formulations showed controlled release properties with t80 ranging between 114 and 660 min. The release was governed by Korsmeyer-Peppas model. Formulation F5 prepared with 50 % Dillenia showed highest similarity to F4 prepared with 75 %w /w carbopol. Dillenia indica demonstrated acceptable gelling properties comparable with that of carbopol and could be improved for use in emulgel formulations.

Treatment of difficult-to-treat-dermatophytosis: results of a randomized, double-blind, placebo-controlled study.

INTRODUCTION: Difficult-to-treat dermatophytosis is an emerging public health problem in Sri Lanka. Safe, effective and affordable treatment is needed to solve this problem. Therefore this study has assessed the effectiveness and safety of modified Whitfield ointment applied twice daily with oral griseofulvin 500 mg daily given over 8 weeks in patients with difficult-to-treat dermatophytosis. METHODOLOGY: A randomized, double-blind, within-patient-placebo-controlled trial was conducted in patients with clinico- mycologically (history, physical examination, direct light microscopy examination of scales in potassium hydroxide mount) confirmed difficult-to-treat dermatophytosis. Lesions were randomized to receive modified Whitfield ointment (5% benzoic acid and 5% salicylic acid) or emulsifying ointment. All patients were given oral griseofulvin 500mg once daily. The outcome measures were clinical assessment of disease severity, the total surface area of the lesions and the patient's perception of the disease severity at baseline and every two weeks up to a maximum of 8 weeks. RESULTS: Thirty patients completed the study. At two weeks, there was a statistically significant improvement in modified Whitfield ointment arm in the clinical assessment of disease severity and the patients' perception. There was a 7.59% reduction in the surface area of lesions in modified Whitfield ointment arm and a 5.83% increase in the surface area of lesions in the emulsifying ointment arm at two weeks. The difference between the two arms in surface area changes was not statistically significant (p = 0.107, df = 29). CONCLUSIONS: A combination of modified Whitfield ointment with griseofulvin is significantly effective, safe and affordable option for treating difficult-to-treat dermatophytosis in the tropics.

Effects of low-dose insulin or a soluble guanylate cyclase activator on lower urinary tract dysfunction in streptozotocin-induced diabetic rats.

AIMS: To examine the effects of low-dose insulin or a soluble guanylate cyclase activator (sGC) on lower urinary tract dysfunction (LUTD) in rats with diabetes mellitus (DM). MAIN METHODS: Female Sprague-Dawley rats were divided into non-DM control (N), DM induced by streptozotocin (65 mg/kg), with low-dose insulin (DI), DM with vehicle (D), and DM with sGC (GC) groups. In GC group, BAY 60-2770 (1 mg/kg/day) was orally administered in 6-8 weeks after DM. Voiding assay at 2, 4, and 8 weeks after DM, cystometry, and urethral pressure recordings at 8 weeks of DM were performed. mRNA levels of NO-related markers and cGMP protein levels in the urethra, and ischemia and inflammation markers in the bladder were evaluated by RT-PCR. KEY FINDINGS: Moderate levels of high blood glucose were maintained in Group DI versus Group D. The 24-h voided volume was significantly higher in Group D versus Groups N and DI. Non-voiding contractions were significantly greater, and voiding efficiency and urethral pressure reduction were significantly lower in Group D versus Groups N, DI, and GC. Urethral cGMP levels were significantly lower in Group D versus Groups N and GC. mRNA levels of PDE5 in the urethra and ischemia and inflammation markers in the bladder increased in Group D versus Group N or DI was reduced after sGC treatment. SIGNIFICANCE: DI rats with a lesser degree of bladder and urethral dysfunction might be useful as a slow-progressive DM model. sGC activation could be an effective treatment of LUTD in DM.

Accelerative action of topical piperonylic acid on mice full thickness wound by modulating inflammation and collagen deposition.

Epidermal growth factor (EGF) promotes cell growth, proliferation, and survival in numerous tissues. Piperonylic acid, a metabolite present in peppers (Piper nigrum L. and Piper longum L.), can bind to the epidermal growth factor receptor (EGFR) and induce an intracellular signaling cascade leading to the transcription of genes responsible for these actions, especially in keratinocytes. These cells are fundamental in maintaining cutaneous homeostasis and are the first to be damaged in the case of a wound. Thus, we hypothesized that piperonylic acid improves wound healing. C57BL6/J male mice were submitted to dorsal skin wounds caused by a 6 mm punch and treated topically with piperonylic acid or vehicle. The wounds were evaluated macro- and microscopically, and tissue samples were collected for immunofluorescence and real-time PCR analyses on days 6, 9 and 19 post-injury. Topical piperonylic acid improved wound healing from day 6 post-injury until closure. This phenomenon apparently occurred through EGFR activation. In addition, piperonylic acid modulated the gene expression of interleukin (Il)-6, il-1ß, tumor necrosis factor (Tnf)-α, il-10, monocyte chemoattractant protein (Mcp)-1 and insulin-like growth factor (Igf)-1, which are important for the healing process. By day 19 post-injury, the new tissue showed greater deposition of type I collagen and a morphology closer to intact skin, with more dermal papillae and hair follicles. We conclude that piperonylic acid may be a viable option for the treatment of skin wounds.

A Close Look at the Clinical Efficacy of Rho-Associated Protein Kinase Inhibitor Eye Drops for Fuchs Endothelial Corneal Dystrophy.

ABSTRACT: The current understanding on the clinical efficacy of Rho-associated protein kinase (ROCK) inhibitor for treating Fuchs endothelial corneal dystrophy is summarized to clarify whether the "off-label" ROCK-inhibitor eye-drop application are appropriate. ROCK-inhibitor eye drops may eventually be deemed a cutting-edge therapy for Fuchs endothelial corneal dystrophy patients with acute corneal endothelial defect.

Treatment patterns in adults with immune thrombocytopenia before, during and after use of thrombopoietin receptor agonists: a longitudinal prescription database study from Germany.

OBJECTIVE: To assess real-world treatment patterns in patients with immune thrombocytopenia (ITP) who received thrombopoietin receptor agonists (TPO-RAs) in Germany. METHODS: This was a longitudinal, retrospective study using anonymized patient-level data (IQVIA healthcare prescription database, covering 82% of German statutory prescriptions). Eligible patients (aged ≥18 years) had received ≥1 TPO-RA prescription (romiplostim/eltrombopag) from July 2016 to June 2019 (treatment duration ≥30 days). ITP medication use was assessed for 18 months prior to, during and for ≥6 months after TPO-RA treatment. RESULTS: A total of 3553 patients (median age 64 years) were included. Median persistence on TPO-RAs was 12 months (range 1-34). In the periods before, during and after TPO-RA treatment, oral corticosteroids were the most commonly used therapy (64.4%, 43.4% and 36.1% of patients, respectively); median cumulative doses across each period were 2521.9, 2000.0 and 2277.8 mg. The median total duration of corticosteroid use before, during and after TPO-RA therapy was 15, 18 and 32 weeks, respectively. The total median cumulative corticosteroid dose was 6799.7 mg. CONCLUSION: We identified a potential overuse of corticosteroids in patients with ITP in Germany. Earlier use of TPO-RA therapy after a short course of corticosteroids could avoid side effects associated with long-term use.

Differential Effects of 17,18-EEQ and 19,20-EDP Combined with Soluble Epoxide Hydrolase Inhibitor t-TUCB on Diet-Induced Obesity in Mice.

17,18-Epoxyeicosatetraenoic acid (17,18-EEQ) and 19,20-epoxydocosapentaenoic acid (19,20-EDP) are bioactive epoxides produced from n-3 polyunsaturated fatty acid eicosapentaenoic acid and docosahexaenoic acid, respectively. However, these epoxides are quickly metabolized into less active diols by soluble epoxide hydrolase (sEH). We have previously demonstrated that an sEH inhibitor, t-TUCB, decreased serum triglycerides (TG) and increased lipid metabolic protein expression in the brown adipose tissue (BAT) of diet-induced obese mice. This study investigates the preventive effects of t-TUCB (T) alone or combined with 19,20-EDP (T + EDP) or 17,18-EEQ (T + EEQ) on BAT activation in the development of diet-induced obesity and metabolic disorders via osmotic minipump delivery in mice. Both T + EDP and T + EEQ groups showed significant improvement in fasting glucose, serum triglycerides, and higher core body temperature, whereas heat production was only significantly increased in the T + EEQ group. Moreover, both the T + EDP and T + EEQ groups showed less lipid accumulation in the BAT. Although UCP1 expression was not changed, PGC1α expression was increased in all three treated groups. In contrast, the expression of CPT1A and CPT1B, which are responsible for the rate-limiting step for fatty acid oxidation, was only increased in the T + EDP and T + EEQ groups. Interestingly, as a fatty acid transporter, CD36 expression was only increased in the T + EEQ group. Furthermore, both the T + EDP and T + EEQ groups showed decreased inflammatory NFκB signaling in the BAT. Our results suggest that 17,18-EEQ or 19,20-EDP combined with t-TUCB may prevent high-fat diet-induced metabolic disorders, in part through increased thermogenesis, upregulating lipid metabolic protein expression, and decreasing inflammation in the BAT.

Activation of the Hippocampal LXRß Improves Sleep-Deprived Cognitive Impairment by Inhibiting Neuroinflammation.

Sleep deprivation (SD) leads to cognitive impairment due to neuroinflammation associated with impaired hippocampal neuronal plasticity and memory processes. Liver X receptors (LXRs), including LXRα and LXRß isoforms, are crucial for synaptic plasticity and neuroinflammation. However, the potential roles of LXRs in the pathogenesis of cognitive impairment induced by SD remain unclear. We revealed that SD resulted in LXRß reduction in the hippocampus, which was associated with upregulated expression of high mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4)/NF-κB p65, and knockdown of hippocampal LXRß by shRNA (shLXRß) led to cognitive impairment. GW3965, a dual agonist for both LXRα and LXRß, ameliorated SD-induced cognitive impairment by inhibiting microglia activation, suppressing HMGB1/TLR4/NF-κB p65 pathway, and ultimately affecting the hippocampal expression of inflammatory cytokines in SD mice. LXRß knockdown by shLXRß abrogated the GW3965-mediated inhibition of the HMGB1/TLR4/NF-κB p65 pathway, therefore, abolishing the cognitive improvement. Moreover, inhibition of HMGB1 by glycyrrhizin (GLY) synergistic promoted GW3965-mediated anti-inflammation in activated microglia after lipopolysaccharide (LPS)/ATP stimulation and facilitated the cognitive improvement after GW administration by activating LXRß. All the data suggested that GW3965 ameliorated impaired cognition in SD mice by suppressing the HMGB1/TLR4/NF-κB p65 pathway followed LXRß activation. This study correlates a deficit of LXRß in cognitive dysfunction in SD associated with HMGB1 inflammatory pathway in hippocampus, and LXRs may serve as a potential therapeutic target for cognitive impairment with anti-inflammation.

Targeted Delivery of Soluble Guanylate Cyclase (sGC) Activator Cinaciguat to Renal Mesangial Cells via Virus-Mimetic Nanoparticles Potentiates Anti-Fibrotic Effects by cGMP-Mediated Suppression of the TGF-ß Pathway.

Diabetic nephropathy (DN) ranks among the most detrimental long-term effects of diabetes, affecting more than 30% of all patients. Within the diseased kidney, intraglomerular mesangial cells play a key role in facilitating the pro-fibrotic turnover of extracellular matrix components and a progredient glomerular hyperproliferation. These pathological effects are in part caused by an impaired functionality of soluble guanylate cyclase (sGC) and a consequentially reduced synthesis of anti-fibrotic messenger 3',5'-cyclic guanosine monophosphate (cGMP). Bay 58-2667 (cinaciguat) is able to re-activate defective sGC; however, the drug suffers from poor bioavailability and its systemic administration is linked to adverse events such as severe hypotension, which can hamper the therapeutic effect. In this study, cinaciguat was therefore efficiently encapsulated into virus-mimetic nanoparticles (NPs) that are able to specifically target renal mesangial cells and therefore increase the intracellular drug accumulation. NP-assisted drug delivery thereby increased in vitro potency of cinaciguat-induced sGC stabilization and activation, as well as the related downstream signaling 4- to 5-fold. Additionally, administration of drug-loaded NPs provided a considerable suppression of the non-canonical transforming growth factor ß (TGF-ß) signaling pathway and the resulting pro-fibrotic remodeling by 50-100%, making the system a promising tool for a more refined therapy of DN and other related kidney pathologies.

Real-world use of thrombopoietin receptor agonists in older patients with primary immune thrombocytopenia.

The efficacy and safety of thrombopoietin receptor agonists (TRAs) in older patients with primary immune thrombocytopenia (ITP) are unknown. We investigated TRA response and switch, thrombotic/hemorrhagic risk, and sustained responses off-treatment (SROTs) in 384 patients with ITP aged ≥60 years. After 3 months, 82.5% and 74.3% of eltrombopag- and romiplostim-treated patients, respectively, achieved a response; 66.7% maintained the response (median follow-up, 2.7 years). Eighty-five (22.2%) patients switched to the alternative TRA; although no cross-toxicity was observed, 83.3% of resistant patients had a response after the switch. Thirty-four major thromboses (3 fatal) and 14 major hemorrhages (none fatal) occurred in 18 and 10 patients, respectively, while on TRAs and were associated with thrombosis history (subdistribution hazard ratio, 2.04, P = .05) and platelet count <20 × 109/L (subdistribution hazard ratio, 1.69; P = .04), respectively, at TRA start. A recurrent event occurred in 15.6% of patients surviving thrombosis, in all cases but 1 during persisting TRA treatment (incidence rate, 7.7 per 100 patient-years). All recurrences occurred in the absence of adequate antithrombotic secondary prophylaxis. Sixty-two (16.5%) responding patients discontinued TRAs; 53 (13.8%) patients maintained SROTs, which were associated with TRA discontinuation in complete response (P < .001). Very old age (≥75 years; 41.1%) was associated with the more frequent start of TRAs in the persistent/acute phase but not with response or thrombotic/hemorrhagic risk. TRAs are effective in older patients with ITP, with no fatal hemorrhages and with SROTs in a significant portion of patients. Caution is warranted in patients with a history of thrombosis, and a careful risk/benefit balance should be considered.

Management of primary immune thrombocytopenia in a real-world setting in Japan: eltrombopag versus corticosteroids.

This real-world study in Japan assessed the long-term safety of persistent use of eltrombopag compared to corticosteroids. Overall, 1887 patients with primary immune thrombocytopenia were included in the study cohort, based on hospital claims data. Eltrombopag was frequently used as a second- or third-line therapy (monotherapy: 13.1% and 25.7%; combination: 24.39% and 16.52%, respectively). The risk of bleeding was approximately 30% lower in the eltrombopag group (as monotherapy and in combination with other drugs including corticosteroids) than the corticosteroid group (hazard ratio, 0.66; 95% confidence interval, 0.45-0.96). Results from univariate and multivariate Cox models indicated that patients aged ≥ 60 years, male patients and patients who received the drugs for peptic ulcer or gastroesophageal reflux disease have a higher risk of cerebral haemorrhage or gastrointestinal bleeding. Surgeries were more common among patients on corticosteroids compared to patients on eltrombopag (39.1% vs 34.6%, P = 0.004), while splenectomies were very rare. There was no significant difference in the costs of scheduled, emergency, or any type of hospitalisations between the exposure groups. The risk of infections, cataracts, and thrombosis did not differ between the exposure groups.

Phase I study of tamibarotene monotherapy in pediatric and young adult patients with recurrent/refractory solid tumors.

PURPOSE: Tamibarotene is a synthetic retinoid that inhibits proliferation and induces differentiation of malignant cells by binding to the retinoic acid receptor α/ß. Previous in vitro studies have shown that some pediatric solid tumors with retinoic acid receptors differentiate in response to retinoic acid. We conducted a phase I dose-escalation study to determine the recommended dose of tamibarotene for further study in pediatric and young adult patients with recurrent/refractory solid tumors. METHODS: Pediatric and young adult patients with recurrent/refractory solid tumors were administered tamibarotene at 4, 6, 8, 10, and 12 mg/m2/day for 14 or 21 days of a 28 day cycle. Safety, efficacy, and pharmacokinetics of tamibarotene were evaluated. RESULTS: Twenty-two patients (median age 8 years) were enrolled in this study. No dose-limiting toxicity (DLT) was encountered, and tamibarotene was generally well tolerated. Two patients experienced severe adverse events (AEs), leading to discontinuation of the treatment. One grade 4 venous thrombosis and one grade 2 erythema multiforme were observed, which promptly resolved after tamibarotene discontinuance. The grade 4 venous thrombosis was a severe AE but not DLT because it occurred after the evaluation period. Pharmacokinetic analyses showed a dose-dependent increase in the maximum drug concentration (Cmax) and area under the concentration-time curve (AUC). None of the patients achieved a complete response or partial response. Seven patients had stable disease lasting longer than 18 weeks. CONCLUSIONS: The recommended dose for phase II study of tamibarotene in pediatric and young adult patients with refractory solid tumors is 12 mg/m2/day for 21 days in a 28 day cycle.

Pharmacokinetics of Eltrombopag in Healthy Chinese Subjects and Effect of Sex and Genetic Polymorphism on its Pharmacokinetic and Pharmacodynamic Variability.

BACKGROUND AND OBJECTIVE: Eltrombopag is the first oral, small-molecule, non-peptide thrombopoietin receptor agonist for the treatment of idiopathic thrombocytopenic purpura. This study investigated the pharmacokinetics of eltrombopag in healthy Chinese subjects and evaluated the effect of sex and genetic polymorphisms on its variability. METHODS: Forty-eight healthy subjects were administered a single dose of eltrombopag (25 mg). Plasma concentrations of eltrombopag were determined using a validated liquid chromatography-tandem mass spectrometry method, and platelet counts were determined by blood tests. CYP1A2 rs762551, CYP2C8*3 rs10509681, CYP2C8*3 rs11572080, UGT1A1 rs887829, UGT1A3 rs3806596, and BCRP rs2231142 polymorphisms were genotyped by Sanger sequencing. A back-propagation artificial neural network (BP-ANN) model was constructed to predict pharmacokinetics based on physiological factors and genetic polymorphism data. RESULTS: Compared with male subjects, female subjects who received a single 25-mg dose of eltrombopag exhibited a significantly increased mean maximum plasma concentration (Cmax) and significantly decreased apparent clearance. Additionally, CYP1A2 rs762551 C>A single nucleotide polymorphism influenced distribution and elimination. C-allele carriers exhibited 30% higher systemic exposure and 20% lower apparent clearance compared with homozygous A-allele carriers. Mean percentage increases in platelet counts from baseline to Day 5 were 9.38% and 17.06% in male and female subjects, respectively. The BP-ANN model had a high goodness-of-fit index and good coherence between predicted and measured concentrations (R = 0.98979). CONCLUSION: Sex and CYP1A2 rs762551 C>A were associated with the pharmacokinetic variability of eltrombopag in healthy Chinese subjects. Females exhibited a better platelet-elevating effect compared with males administered the same dosage. The developed BP-ANN model based on physiological factors and genetic polymorphism data could be promising for applications in pharmacokinetic studies. TRIAL REGISTRATIONS: https://www.Chinadrugtrials.org.cn CTR20190898.