IMPROVEMENT IN MULTIFOCAL ELECTRORETINOGRAPHY AFTER HALF-DOSE VERTEPORFIN PHOTODYNAMIC THERAPY FOR CENTRAL SEROUS CHORIORETINOPATHY: A Randomized Placebo-Controlled Trial

Predictive performance of population pharmacokinetic models of imatinib in chronic myeloid leukemia patients

BACKGROUND AND AIM

Chronic myeloid leukemia is a myeloproliferative neoplasm associated with the specific chromosomal translocation known as the Philadelphia chromosome. Imatinib is a potent BCR-ABL tyrosine kinase inhibitor, which is approved as the first line therapy for CML patients. There are various population pharmacokinetic studies available in the literature for this population. However, their use in other populations outside of their cohort for the model development has not been evaluated. This study was aimed to perform the predictive performance of the published population pharmacokinetic models for imatinib in CML population and propose a dosing nomogram.

METHODS

A systematic review was conducted through PubMed, and WoS databases to identify PopPK models. Clinical data collected in adult CML patients treated with imatinib was used for evaluation of these models. Various prediction-based metrics were used for assessing the bias and precision of PopPK models using individual predictions.

RESULTS

Eight imatinib PopPK model were selected for evaluating the model performance. A total of 145 plasma imatinib samples were collected from 43 adult patients diagnosed with CML and treated with imatinib. The PopPK model reported by Menon et al. had better performance than all other PopPK models.

CONCLUSION

Menon et al. model was able to predict well for our clinical data where it had the relative mean prediction error percentage ≤ 20%, relative median absolute prediction error ≤ 30% and relative root mean square error close to zero. Based on this final model, we proposed a dosing nomogram for various weight groups, which could potentially help to maintain the trough concentrations in the therapeutic range.

Central Serous Chorioretinopathy: An Update on the Current State of Management

Central serous chorioretinopathy (CSCR) is a relatively common retinal disorder that leads to central vision impairment, often with a high recurrence rate. The exact etiology and pathogenetic mechanisms have not been fully elucidated but are likely to be associated with hyperpermeability of the choroidal capillaries and failure of the retinal pigment epithelium (RPE), leading to serous detachment of the neurosensory retina. Multimodal imaging plays a critical role in the diagnostic approach and monitoring of CSCR. Fortunately, the natural course of the disease is usually self-limiting, with spontaneous resolution and total fluid reabsorption. However, some patients may exhibit recurrences or persistent subretinal fluid (chronic CSCR), leading to progressive and irreversible RPE atrophy or photoreceptor damage. Thus, to prevent permanent visual loss, individualized treatment should be considered. Recent developments in the diagnostic and therapeutic approach have contributed to better outcomes in patients with CSCR. More studies are required to improve our understanding of epidemiology, pathogenesis, diagnosis, and treatment, with a significant impact on the management of this challenging clinical entity. The purpose of this review is to summarize the current knowledge about the clinical features, diagnostic workup, and therapeutic approach of CSCR.

The Uses of Photodynamic Therapy Versus Anti-vascular Endothelial Growth Factor in the Management of Acute Central Serous Chorioretinopathy: A Systematic Review and Meta-Analysis

Central serous chorioretinopathy (CSCR) is an idiopathic chorioretinal disease characterized by localized serous detachment of the neurosensory retina at the macula. To date, there is no high-quality evidence of recent updates on treating acute CSCR, focusing on photodynamic therapy (PDT) and anti-vascular endothelial growth factor (anti-VEGF). Hence, this review aims to conduct a comprehensive systematic review of the most recent therapeutic approaches for acute CSCR using the following electronic databases for a comprehensive and systematic literature review: MEDLINE, EMBASE, and Cochrane. In addition, we analyzed studies comparing PDT with placebo, anti-VEGF with placebo, or PDT with anti-VEGF in treating acute CSC eyes with no previous intervention. Seven studies were included, with a total of 292 eyes. The overall positive results were significantly higher among patients who received PDT compared to control groups (odds ratio [OR] = 7.96, 95% confidence interval [CI], 3.02 to 20.95, p < 0.001). The proportions of positive results were 81.0% and 97.1% among patients who received anti-VEGF and PDT, respectively, with no statistically significant differences between the groups. In addition, there were no significant differences between anti-VEGF and control groups. In contrast, PDT was significantly associated with lower recurrence odds than the control groups (OR = 0.12, 95% CI, 0.04 to 0.39, p = 0.042). According to our findings, PDT showed higher positive results than anti-VEGF in acute CSCR. In addition, PDT was significantly associated with a lower recurrence rate than the control group. However, the analysis needs to be confirmed and updated by large-scale, well-designed randomized clinical trials.

Comparing treatment outcomes in randomized controlled trials of central serous chorioretinopathy

PURPOSE

To perform a qualitative analysis of outcomes published from randomized controlled trials (RCTs) on central serous chorioretinopathy (CSCR) from 1979 to 2022.

DESIGN

Systematic review.

METHODS

All RCTs (including both therapeutic and non-therapeutic interventions) on CSCR available online till July 2022 were included after an electronic search in multiple databases such as PubMed, CENTRAL, MEDLINE, EMBASE, BIOSIS, Scopus, and Cochrane database. We analyzed and compared the inclusion criteria, imaging modalities, study endpoints, duration, and the results of the study.

RESULTS

The literature search yielded 498 potential publications. After excluding duplicate studies and studies that met clear exclusion criteria, 64 were screened for further evaluation, of which 7 were removed due to a lack of necessary inclusion criteria. A total of 57 eligible studies are described in this review.

CONCLUSION

This review provides a comparative overview of key outcomes reported between RCTs investigating CSCR. We describe the current landscape of treatment modalities for CSCR and note the discrepancies between results in these published studies. Challenges arise when attempting to compare similar study designs without comparable outcome measures (i.e., clinical vs. structural) which may limit the overall evidence presented. To mitigate this issue, we present the collected data from each study in tables detailing the measures that are and are not assessed in each publication.

Multifocal Electroretinography Changes over 12 Months after Resolution of Central Serous Chorioretinopathy: Prospective Observational Study

INTRODUCTION

This prospective observational study aimed to evaluate the changes in retinal function after the anatomical resolution of central serous chorioretinopathy by multifocal electroretinography.

METHODS

Thirty-two eyes of 32 patients with unilaterally resolved central serous chorioretinopathy were prospectively studied. Serial multifocal electroretinography examinations were performed at the initial visit for active central serous chorioretinopathy, the time of anatomical resolution (resolved central serous chorioretinopathy), and 3, 6, and 12 months after resolution. The peak amplitudes of the first kernel responses were analysed and compared with those in 27 age-matched normal controls.

RESULTS

Compared with controls, the N1 amplitudes of rings 1-4 and P1 amplitudes of rings 1-3 showed statistically significant reductions at 12 months after the resolution of central serous chorioretinopathy (p < 0.05). The multifocal electroretinography amplitude substantially increased at the time of resolution and gradually improved until 3 months after the resolution of central serous chorioretinopathy.

CONCLUSION

Serial examinations with multifocal electroretinography showed that retinal responses increased mostly after the resolution of central serous chorioretinopathy, and this improvement slowly progressed until 3 months; however, the multifocal electroretinography amplitudes remained statistically reduced 12 months after the anatomical resolution of central serous chorioretinopathy, indicating the residual functional deficits detected by multifocal electroretinography.

Personalized Dose of Adjuvant Imatinib in Patients with Gastrointestinal Stromal Tumors: Results from a Population Pharmacokinetic Analysis

Purpose

Imatinib is the first-line treatment for patients with gastrointestinal stromal tumors (GIST) after surgery. However, its pharmacokinetic profile varies remarkably between individuals and has not been well characterized in postoperative Chinese patients with GIST. Therefore, this study aimed to develop a population pharmacokinetic (PPK) model and recommend appropriate doses for different patients to achieve the target trough concentration in such a population.

Patients and Methods

A total of 110 surgically treated GIST patients were enrolled, of which 85 were applied to conduct a PPK analysis with a nonlinear mixed-effect model and 25 for external validation of the model. Demographic and biomedical covariates, as well as six single nucleotide polymorphisms were tested to explore the sources of variation in pharmacokinetic parameters of imatinib. Monte Carlo simulations were performed to establish the initial dosing regimens.

Results

A one-compartment model was established in postoperative GIST patients. The red blood cell count (RBC) and ABCG2 rs2231142 were observed to have a significant effect on the clearance of imatinib. The typical values estimated by the final model were 9.72 L/h for clearance (CL/F) and 229 L for volume of distribution (V/F). Different from the fixed dose regimen of 400 mg each day, patients carrying rs2231142 heterozygous type and with a lower level of RBC (2.9 × 10¹²/L), 300 mg imatinib daily is enough to achieve the target trough concentration. When RBC rises to 4.9 × 10¹²/L, 500 mg daily is recommended. For patients with rs2231142 GG genotype, 500 mg a day is required at RBCs of 3.9 × 10¹²/L and 4.9 × 10¹²/L.

Conclusion

RBC and rs2231142 contribute to the pharmacokinetic variation of imatinib and personalized dose recommendations based on patient characteristics may be necessary.

Role of Drug Transporters in Elucidating Inter-Individual Variability in Pediatric Chemotherapy-Related Toxicities and Response

Pediatric cancer treatment has evolved significantly in recent decades. The implementation of risk stratification strategies and the selection of evidence-based chemotherapy combinations have improved survival outcomes. However, there is large interindividual variability in terms of chemotherapy-related toxicities and, sometimes, the response among this population. This variability is partly attributed to the functional variability of drug-metabolizing enzymes (DME) and drug transporters (DTS) involved in the process of absorption, distribution, metabolism and excretion (ADME). The DTS, being ubiquitous, affects drug disposition across membranes and has relevance in determining chemotherapy response in pediatric cancer patients. Among the factors affecting DTS function, ontogeny or maturation is important in the pediatric population. In this narrative review, we describe the role of drug uptake/efflux transporters in defining pediatric chemotherapy-treatment-related toxicities and responses. Developmental differences in DTS and the consequent implications are also briefly discussed for the most commonly used chemotherapeutic drugs in the pediatric population.

Population pharmacokinetic modelling of imatinib in healthy subjects receiving a single dose of 400 mg

Purpose

Imatinib is indicated for treatment of CML, GIST, etc. The population pharmacokinetics (popPK) of imatinib in patients under long-term treatment are reported in literature. Data obtained from bioequivalence trials for healthy subjects were used to evaluate the influence of demographic and pharmacogenetic factors on imatinib pharmacokinetics (PK) in a collective without concurrent drugs, organ dysfunction, inflammation etc. In addition, the differences in PK between the healthy subjects and a patient cohort was examined to identify possible disease effects.

Methods

26 volunteers were administered orally with single dose of 400 mg imatinib. 16–19 plasma samples per volunteer were collected from 0.5 up to 72 h post-dose. The popPK was built and post hoc estimates were compared with previously published PK parameters evaluated by non-compartmental analysis in the same cohort. The predictivity of the model for data collected from 40 patients with gastrointestinal stromal tumors at steady state was evaluated.

Results

The popPK was best described by a two-compartment transit model with first-order elimination. No significant covariates were identified, probably due to the small cohort and the narrow range of demographic covariates; CYP3A5 phenotypes appeared to have some influence on the clearance of imatinib. Good agreement between non-compartment and popPK analyses was observed with the differences of the geometric means/ median of PK estimates below 10%. The model indicated lower clearance for patients compared to healthy volunteers (p value < 0.01).

Conclusion

The two-compartment transit model adequately describes the absorption and distribution of imatinib in healthy volunteers. For patients, a lower clearance of imatinib compared to healthy volunteer was estimated by the model. The model can be applied for dose individualization based on trough concentrations assuming no significant differences in absorption between patients and healthy volunteers.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04454-y.

Systematic Review of Pharmacogenetics of ABC and SLC Transporter Genes in Acute Myeloid Leukemia

Antineoplastic uptake by blast cells in acute myeloid leukemia (AML) could be influenced by influx and efflux transporters, especially solute carriers (SLCs) and ATP-binding cassette family (ABC) pumps. Genetic variability in SLC and ABC could produce interindividual differences in clinical outcomes. A systematic review was performed to evaluate the influence of SLC and ABC polymorphisms and their combinations on efficacy and safety in AML cohorts. Anthracycline intake was especially influenced by SLCO1B1 polymorphisms, associated with lower hepatic uptake, showing higher survival rates and toxicity in AML studies. The variant alleles of ABCB1 were related to anthracycline intracellular accumulation, increasing complete remission, survival and toxicity. Similar findings have been suggested with ABCC1 and ABCG2 polymorphisms. Polymorphisms of SLC29A1, responsible for cytarabine uptake, demonstrated significant associations with survival and response in Asian populations. Promising results were observed with SLC and ABC combinations regarding anthracycline toxicities. Knowledge of the role of transporter pharmacogenetics could explain the differences observed in drug disposition in the blast. Further studies including novel targeted therapies should be performed to determine the influence of genetic variability to individualize chemotherapy schemes.

TRANSIENT PARADOXICAL WORSENING OF VISION DUE TO GRAVITATIONAL SHIFT OF SUBRETINAL FLUID AFTER PHOTODYNAMIC THERAPY FOR CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To report an atypical treatment-related complication from photodynamic therapy in central serous chorioretinopathy patient and explain its mechanism.

METHODS

History, physical examination, and imaging data were retrospectively reviewed and obtained from the electronic medical records of the patient.

RESULTS

A central serous chorioretinopathy patient with several focal leakage spots near the superotemporal arcade was treated with half-fluence verteporfin photodynamic therapy. The patient complained of worse vision after the treatment. Examination showed relocation of subretinal fluid from the superior macula to the central and submacular area, explained by a gravitational shift of subretinal fluid and the predisposing factor of a previously weakened junction between the retinal pigment epithelium and neurosensory retina. Without further treatment, the fluid reabsorbed, and the patient's vision returned to normal.

CONCLUSION

This is the first report to describe this transient atypical adverse visual outcome early after photodynamic therapy in a central serous chorioretinopathy patient, caused by a gravitational shift of viscous subretinal fluid.

Intronic LINE-1 insertion in SLCO1B3 as a highly prevalent cause of rotor syndrome in East Asian population

Rotor syndrome is caused by digenic loss-of-function variants in SLCO1B1 and SLCO1B3 but only a few studies have reported co-occurring inactivating variants from both genes. A rotor syndrome-causing long interspersed element-1 (LINE-1) insertion in SLCO1B3 had been reported to be highly prevalent in the Japanese population but there has been no additional report. In spite of its known association with various human diseases, LINE-1 is hard to detect with current sequencing technologies. In this study, we aimed to devise a method to screen the LINE-1 insertion variant and investigate the frequency of this variant in various populations. A chimeric sequence, that was generated by concatenating the reference sequence at the junction and a part of inserted LINE-1 sequence, was searched from 725 raw sequencing data files. In cases containing the chimeric sequence, confirmatory long-range PCR and gap-PCR were performed. In total, 95 (13.1%) of 725 patients were positive for the chimeric sequence, and all were confirmed to have the SLCO1B3 LINE-1 insertion by PCR-based tests. The same chimeric sequence was searched from the 1000 Genomes Project data repository and the carrier frequency was remarkably high in the East Asian populations (10.1%), especially in Southern Han Chinese (18.5%), but almost absent in other populations. This SLCO1B3 LINE-1 insertion should be screened in a population-specific manner under suspicion of Rotor syndrome and the methods proposed in this study would enable this in a simple way.

Venous overload choroidopathy: A hypothetical framework for central serous chorioretinopathy and allied disorders

In central serous chorioretinopathy (CSC), the macula is detached because of fluid leakage at the level of the retinal pigment epithelium. The fluid appears to originate from choroidal vascular hyperpermeability, but the etiology for the fluid is controversial. The choroidal vascular findings as elucidated by recent optical coherence tomography (OCT) and wide-field indocyanine green (ICG) angiographic evaluation show eyes with CSC have many of the same venous patterns that are found in eyes following occlusion of the vortex veins or carotid cavernous sinus fistulas (CCSF). The eyes show delayed choroidal filling, dilated veins, intervortex venous anastomoses, and choroidal vascular hyperpermeability. While patients with occlusion of the vortex veins or CCSF have extraocular abnormalities accounting for the venous outflow problems, eyes with CSC appear to have venous outflow abnormalities as an intrinsic phenomenon. Control of venous outflow from the eye involves a Starling resistor effect, which appears to be abnormal in CSC. Similar choroidal vascular abnormalities have been found in peripapillary pachychoroid syndrome. However, peripapillary pachychoroid syndrome has intervortex venous anastomoses located in the peripapillary region while in CSC these are seen to be located in the macular region. Spaceflight associated neuro-ocular syndrome appears to share many of the pathophysiologic problems of abnormal venous outflow from the choroid along with a host of associated abnormalities. These diseases vary according to their underlying etiologies but are linked by the venous decompensation in the choroid that leads to significant vision loss. Choroidal venous overload provides a unifying concept and theory for an improved understanding of the pathophysiology and classification of a group of diseases to a greater extent than previous proposals.

[Central serous chorioretinopathy]

Central serous chorioretinopathy (CSC) is the fourth most common disease of the macula after age-related macular degeneration, diabetic retinopathy and retinal vein occlusion and a cause of irreversible visual loss. This article gives an overview of the epidemiology, risk factors, pathophysiology, clinical presentation, multimodal imaging and discusses current therapeutic options for CSC.

ABCB1, ABCG2, ABCC1, ABCC2, and ABCC3 drug transporter polymorphisms and their impact on drug bioavailability: what is our current understanding?

INTRODUCTION

Interindividual differences in drug response are a frequent clinical challenge partly due to variation in pharmacokinetics. ATP-binding cassette (ABC) transporters are crucial determinants of drug disposition. They are subject of gene regulation and drug-interaction; however, it is still under debate to which extend genetic variants in these transporters contribute to interindividual variability of a wide range of drugs.

AREAS COVERED

This review discusses the current literature on the impact of genetic variants in ABCB1, ABCG2 as well as ABCC1, ABCC2, and ABCC3 on pharmacokinetics and drug response. The aim was to evaluate if results from recent studies would increase the evidence for potential clinically relevant pharmacogenetic effects.

EXPERT OPINION

Although enormous efforts have been made to investigate effects of ABC transporter genotypes on drug pharmacokinetics and response, the majority of studies showed only weak if any associations. Despite few unique results, studies mostly failed to confirm earlier findings or still remained inconsistent. The impact of genetic variants on drug bioavailability is only minor and other factors regulating the transporter expression and function seem to be more critical. In our opinion, the findings on the so far investigated genetic variants in ABC efflux transporters are not suitable as predictive biomarkers.

Central Serous Chorioretinopathy Classification

Central serous chorioretinopathy is characterized by an idiopathic neurosensory detachment of the retina. This narrative review aims to discuss the classification system used for central serous chorioretinopathy. Based on our current knowledge, there is no universally adopted classification system. This is the result of the unknown aspects related to pathogenesis and clinical spectrum and evolution. The best option could be to aggregate multimodal pieces of information alongside temporal and phenotypic characteristics.

Factors Influencing the Steady-State Plasma Concentration of Imatinib Mesylate in Patients With Gastrointestinal Stromal Tumors and Chronic Myeloid Leukemia

Imatinib mesylate (IM) is the standard treatment for advanced, metastatic gastrointestinal stromal tumors (GISTs) and chronic myeloid leukemia (CML) with a fixed daily standard dosage via the oral route. Interindividual and intraindividual variability in plasma concentrations have been closely linked to the efficacy of IM therapy. Therefore, this review identifies and describes the key factors influencing the plasma concentration of IM in patients with GISTs and CML. We used the following keywords to search the PubMed, EMBASE, Ovid, Wangfang, and CNKI databases to identify published reports: IM, plasma concentration, GISTs, CML, drug combination/interaction, pathology, and genotype/genetic polymorphism, either alone or in combination. This literature review revealed that only 10 countries have reported the mean concentrations of IM in GISTs or CML patients and the clinical outcomes in different ethnic groups and populations. There were totally 24 different gene polymorphisms, which were examined for any potential influence on the steady-state plasma concentration of IM. As a result, some genotype locus made discrepant conclusion. Herein, the more sample capacity, multicenter, long-term study was worthy to carry out. Eleven reports were enumerated on clinical drug interactions with IM, while there is not sufficient information on the pharmacokinetic parameters altered by drug combinations with IM that could help in investigating the actual drug interactions. The drug interaction with IM should be paid more attention in the future research.

Recent developments in the management of congenital cataract

Congenital cataract is a rare eye disease, one of the leading treatable causes of low vision in children worldwide. Hereditary cataracts can be divided in syndromic and non-syndromic cataracts. Early diagnosis in congenital cataracts is key to reach good visual function. Current surgical techniques, that combine microincision cataract extraction and primary intraocular lens (IOL) implantation, have improved childhood cataract outcome. Complications include posterior capsule opacification (PCO), aphakic or pseudophakic glaucoma, uveitis, pupil displacement and IOL decentration. A recent study using a modified Delphi approach identified areas of consensus and disagreement in the management of pediatric cataract. A consensus or near consensus was achieved for 79% of the questions, however 21% of the questions remained controversial, as for IOL implantation strategy. Congenital cataracts show a highly variable phenotype and genotype, and can be related to different mutations, genetic variance, and other risk factors. Congenital cataracts can be associated with other ocular developmental abnormalities, including microphthalmia, microcornea, or aniridia and with systemic findings. Next-generation sequencing (NGS) and forthcoming new ultra-high-throughput sequencing represent excellent tools to investigate the genetic causes of congenital cataracts. A better recognition of different clinical presentations and underlying etiologies of congenital cataracts may lead to the development of new approaches to improve visual outcome after cataract surgery and promote early detection of systemic associated syndromes.

Short Term Presence of Subretinal Fluid in Central Serous Chorioretinopathy Affects Retinal Thickness and Function

Background: Acute central serous chorioretinopathy (CSCR), with subretinal fluid (SRF) resolving spontaneously within a few months from disease onset, has been considered as a benign and self-limiting disease for many years. This study sought to discover if a short presence of SRF can result in morphological and functional damage to the retina. Materials and methods: The study included patients treated by subthreshold diode micropulse laser (SDM) application for acute CSCR at the Dobry Wzrok Ophthalmological Clinic between January 2018 and November 2019. Inclusion criteria were: first episode of CSCR; duration of symptoms of two months or less; complete resolution of subretinal fluid (SRF) after a single session of SDM; and a lack of any retinal pathology, previous CSCR episode, significant anisometropia or amblyopia in the collateral eye. Fifteen patients fulfilled the inclusion criteria, including 13 males and two females aged 42.3 ± 9.5 years. The mean duration of symptoms before treatment was 4.7 ± 1.3 weeks on average. Baseline and follow-up examinations were performed in both the affected and collateral eyes and included best-corrected visual acuity (BCVA); spectral-domain optical coherent tomography measurements such as central retinal thickness (CRT) and minimal foveal thickness (MFT) (at the follow-up visit only); fluorescein angiography (at presentation only) and fundus autofluorescence. The first follow-up visit, when the total resolution of SRF was noted, was conducted between 8 and 12 weeks after SDM. Results: Resolved CSCR eyes had significantly poorer BCVA, CRT, and MFT findings in comparison with healthy collateral eyes (respectively, 0.11 +/− 0.1 vs. 0.01 +/− 0.04 logMAR; 238.80 +/− 23.39 vs. 264.87 +/− 21.22 µm and 178.93 +/− 16.88 vs. 199.47 +/− 17.87 µm) despite the short period of CSCR duration (maximum of 14 ± 2.15 weeks on average). Conclusion: Short presence of SRF typical for acute CSCR can affect retinal function and morphology resulting in poorer visual outcome.

Effect of Cytochrome P450 and ABCB1 Polymorphisms on Imatinib Pharmacokinetics After Single-Dose Administration to Healthy Subjects

BACKGROUND

Validated genomic biomarkers for oncological drugs are expanding to improve targeted therapies. Pharmacogenetics research focusing on the mechanisms underlying imatinib suboptimal response might help to explain the different treatment outcomes and drug safety profiles.

OBJECTIVE

To investigate whether polymorphisms in genes encoding cytochrome P450 (CYP) enzymes and ABCB1 transporter affect imatinib pharmacokinetic parameters.

METHODS

A prospective, multicenter, pharmacogenetic pilot study was performed in the context of two separate oral imatinib bioequivalence clinical trials, which included 26 healthy volunteers. DNA was extracted in order to analyze polymorphisms in genes CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5 and ABCB1. Imatinib plasma concentrations were measured by HPLC-MS/MS. Pharmacokinetic parameters were calculated by non-compartmental methods using WinNonlin software.

RESULTS

Volunteers (n = 26; aged 24 ± 3 years; 69% male) presented regular pharmacokinetic imatinib data (concentration at 24 h, 436 ± 140 ng/mL and at 72 h, 40 ± 26 ng/mL; AUC_0-72 32,868 ± 10,713 ng/mL⋅h; and C_max 2074 ± 604 ng/mL). CYP2B6 516GT carriers showed a significant reduction of imatinib concentration at 24 h (23%, 391 ng/dL vs 511 ng/dL in 516GG carriers, p = 0.005) and elimination half-life (11%, 12.6 h vs 14.1 h in 516GG carriers, p = 0.041). Carriers for CYP3A4 (*22/*22, *1/*20 and *1/*22 variants) showed a reduced frequency of adverse events compared to *1/*1 carriers (0 vs 64%, p = 0.033). The other polymorphisms analyzed did not influence pharmacokinetics or drug toxicity.

CONCLUSION

CYP2B6 G516T and CYP3A4 *20,*22 polymorphisms could influence imatinib plasma concentrations and safety profile, after single-dose administration to healthy subjects. This finding needs to be confirmed before it is implemented in clinical practice in oncological patients under treatment with imatinib.

Association of the Trough, Peak/Trough Ratio of Imatinib, Pyridine-N-Oxide Imatinib and ABCG2 SNPs 34 G>A and SLCO1B3 334 T>G With Imatinib Response in Egyptian Chronic Myeloid Leukemia Patients

Imatinib mesylate (IM) is highly efficacious in the treatment of chronic myeloid leukemia (CML). Therapeutic drug monitoring and pharmacogenetic screening are affirmed for better management of IM therapy. The goal of this study was to gain a greater mechanistic understanding of the factors controlling variability in IM level and its relation to the response. One hundred and two patients with CML at chronic phase were recruited in this study. Blood samples were withdrawn at least 30 days after drug administration, and trough and peak concentrations of imatinib, N-des-methyl imatinib, and pyridine-N-oxide imatinib were determined by HPLC/MS/MS. Genetic polymorphism of the genes ABCG2 SNPs 34 G>A and 421C >A; ABCB1 SNPs 2677 G>A/T, 1236 C>T, 3435 C>T; SLCO1B3 SNPs 334 T>G and CYP3A5 were studied using PCR-RFLP technique. Our study presented significant higher trough IM (1,281 ± 578 ng/ml), lower Peak/Trough ratio, clearance (Cl), and elimination rate constant, k_e, among patients who achieved favorable responses (N = 64) than those for patients who suffered unfavorable response (N = 37). The P/T ratio was the only significant independent factor affecting response, as the P/T ratio increased by one, the risk of unfavorable response increased by more than double as compared to favorable response with 95% CI (1.28-3.92, P = 00.005). Moreover, like the results of IM, the trough concentration of Pyridine-N-oxide imatinib was significantly higher (P = 0.01) and its P/T ratio was significantly lower (P = 0.008) in patients achieved favorable response than those without. The wild GG genotype of the ABCG2.34 G>A gene was associated with favorable response (P = 0.01), lower Cl, K_e and high plasma IM trough level than both (AA+GA) genotypes. ABCG2.421C >A (CC) genotype had a significantly higher plasma peak of IM, N-des-methyl imatinib and higher C_ss. The GG and TG alleles of the SLCO1B3.334 T>G gene were significantly correlated to favorable response, while the wild allele TT was linked to unfavorable response (P = 0.03). In conclusion, the trough and P/ T ratio for both IM and Pyridine-N-oxide imatinib, in addition to Polymorphism of ABCG2 SNPs 34 G>A and SLCO1B3.334 T>G gene, is a good predictor for response of IM in CML Egyptian patients.

Potential for pharmacokinetic interactions between Schisandra sphenanthera and bosutinib, but not imatinib: in vitro metabolism study combined with a physiologically-based pharmacokinetic modelling approach

AIMS

This study aimed to investigate the potential interaction between Schisandra sphenanthera, imatinib and bosutinib combining in vitro and in silico methods.

METHODS

In vitro metabolism of imatinib and bosutinib using recombinant enzymes and human liver microsomes were investigated in the presence and absence of Schisandra lignans. Physiologically-based pharmacokinetic (PBPK) models for the lignans accounting for reversible and mechanism-based inhibitions and induction of CYP3A enzymes were built in the Simcyp Simulator (version 17) and evaluated for their capability to predict interactions with midazolam and tacrolimus. Their potential effect on systemic exposures of imatinib and bosutinib were predicted using PBPK in silico simulations.

RESULTS

Schisantherin A and schisandrol B, but not schisandrin A, potently inhibited CYP3A4-mediated metabolism of imatinib and bosutinib. All three compounds showed a strong reversible inhibition on CYP2C8 enzyme with k_i of less than 0.5 μmol L^-1 . The verified PBPK models were able to describe the increase in systemic exposure of midazolam and tacrolimus due to co-administration of S. sphenanthera, consistent with the reported changes in the corresponding clinical interaction study (AUC ratio of 2.0 vs 2.1 and 2.4 vs 2.1, respectively). The PBPK simulation predicted that at recommended dosing regimens of S. sphenanthera, co-administration would result in an increase in bosutinib exposure (AUC ratio 3.0) but not in imatinib exposure.

CONCLUSION

PBPK models for Schisandra lignans were successfully developed. Interaction between imatinib and Schisandra lignans was unlikely to be of clinical importance. Conversely, S. sphenanthera at a clinically-relevant dose results in a predicted three-fold increase in bosutinib systemic exposure.

Influences of ABC transporter and CYP3A4/5 genetic polymorphisms on the pharmacokinetics of lenvatinib in Chinese healthy subjects

PURPOSE

To investigate whether the CYP3A4/5 and ABC transporter genetic polymorphisms could affect the pharmacokinetics of lenvatinib in Chinese healthy subjects.

METHODS

Thirty-two healthy Chinese volunteers were enrolled and took oral administration of 8 mg lenvatinib. Plasma concentration of lenvatinib was determined by UPLC-MS/MS, the CYP3A4*1G, CYP3A5*3, ABCB1 (3435 C>T, 1236 C>T, 2677 G>T/A), ABCG2 (421 C>A, 34 G>A), and ABCC2-24 C>T genotypes were determined by SnapShot Technique.

RESULTS

In ABCB1 3435T carriers (n = 19), AUC_0-120h (815.7 (701.9-923.9) ng·h/mL) and AUC_0-∞ (843.3 (722.2-977.7) ng·h/mL) were significantly higher than ABCB1 3435CC homozygous subjects (n = 13, 575.3 (513.7-756.9) ng·h/mL and 590.0 (540.5-782.0) ng·h/mL, respectively); on the contrary, the clearance (CL/F) of ABCB1 3435T carriers was significantly lower (9.5 (8.2-11.1) L/h vs. 13.6 (10.4-14.8) L/h). And the C_max in CYP3A4*1G/*1G allele carrier subjects was higher than *1 carrier (73.4 ng/mL vs. 53.5 (46.1-60.6) ng/mL), but did not reach the level of significantly statistical difference. Genetic polymorphisms of ABCC2, ABCG2, and CYP3A5 could not influence pharmacokinetic parameters of lenvatinib.

CONCLUSIONS

This work presented an evidence that the ABCB1 3435 C>T polymorphism could significantly affect the exposure and clearance of lenvatinib. These findings may explain the reasons for the huge inter-individual differences in lenvatinib, and should contribute to clinical individualized treatment.

Imatinib, sunitinib and pazopanib: From flat-fixed dosing towards a pharmacokinetically guided personalized dose

Tyrosine kinase inhibitors (TKIs) are anti‐cancer drugs that target tyrosine kinases, enzymes that are involved in multiple cellular processes. Currently, multiple oral TKIs have been introduced in the treatment of solid tumours, all administered in a fixed dose, although large interpatient pharmacokinetic (PK) variability is described. For imatinib, sunitinib and pazopanib exposure‐treatment outcome (efficacy and toxicity) relationships have been established and therapeutic windows have been defined, therefore dose optimization based on the measured blood concentration, called therapeutic drug monitoring (TDM), can be valuable in increasing efficacy and reducing the toxicity of these drugs.

In this review, an overview of the current knowledge on TDM guided individualized dosing of imatinib, sunitinib and pazopanib for the treatment of solid tumours is presented. We summarize preclinical and clinical data that have defined thresholds for efficacy and toxicity. Furthermore, PK models and factors that influence the PK of these drugs which partly explain the interpatient PK variability are summarized. Finally, pharmacological interventions that have been performed to optimize plasma concentrations are described. Based on current literature, we advise which methods should be used to optimize exposure to imatinib, sunitinib and pazopanib.

Optical Coherence Tomography Angiography for Diagnosis of Choroidal Neovascularization in Chronic Central Serous Chorioretinopathy after Photodynamic Therapy

The authors evaluated the proportion of choroidal neovascularization (CNV) detected by spectral-domain optical coherence tomography angiography (OCTA) in eyes with chronic central serous chorioretinopathy (CSC) (more than 3 months) with previous treatment via half-dose photodynamic therapy (PDT). All patients were followed up with at least twelve months. Macular angiograms were obtained using spectral-domain OCT (SD-OCT, RTVue XR; Optovue). CNV was defined as flow in the outer retinal slab between the outer plexiform layer and Bruch's membrane. Clinical characteristics were compared between CNV and non-CNV groups. Seventy eyes of 61 patients (51 male and 10 female) were included. The average age was 46.2 years old. The average duration of symptom was 32.9 months. All patients were treated with half-dose PDT initially. Eleven eyes (15.7%) received more than one session of PDT. CNV was diagnosed in 32 of 70 eyes (45.7%) based on OCTA. Only 6 of the 32 eyes (18.8%) needed intravitreal anti- vascular endothelial growth factor (VEGF) therapy for the exudative activity of CNV. Older age (p = 0.059), larger PDT spot size (p = 0.024), and thinner subfoveal choroidal thickness (p = 0.008) were noted in CNV group. The authors conclude that OCTA reveals high rates of CNV associated with chronic CSC after PDT. Patients in the CNV group had older age, larger PDT spot size, and thinner subfoveal choroidal thickness. OCTA may be considered as a first step in identifying CNV in chronic CSC following PDT.

Genetics of clozapine-associated neutropenia: recent advances, challenges and future perspective

Clozapine is the only effective antipsychotic for treatment-resistant schizophrenia but remains widely under prescribed, at least in part due to its potential to cause agranulocytosis and neutropenia. In this article, we provide an overview of the current understanding of the genetics of clozapine-associated agranulocytosis and neutropenia. We now know that the genetic etiology of clozapine-associated neutropenia is complex and is likely to involve variants from several genes including HLA-DQB1, HLA-B and SLCO1B3/SLCO1B7. We describe recent findings relating to the Duffy-null genotype and its association with benign neutropenia in individuals with African ancestry. Further advances will come from sequencing studies, large, cross-population studies and in understanding the molecular mechanisms underlying these associations.

Pharmacogenetics and Pharmacogenomics of Targeted Therapeutics in Chronic Myeloid Leukemia

The advent of targeted therapeutics has greatly improved outcomes of chronic myeloid leukemia (CML) patients. Despite increased efficacy and better clinical responses over cytotoxic chemotherapies, many patients receiving targeted drugs exhibit a poor initial response, develop drug resistance, or undergo relapse after initial success. This inter-individual variation in response has heightened the interest in studying pharmacogenetics and pharmacogenomics (PGx) of cancer drugs. In this review, we discuss the influence of various germline and somatic factors on targeted drug response in CML. Specifically, we examine the role of genetic variants in drug metabolism genes, i.e. CYP3A family genes, and drug transporters, i.e. ABC and SLC family genes. Additionally, we focus on acquired somatic variations in BCR-ABL1, and the potential role played by additional downstream signaling pathways, in conferring resistance to targeted drugs in CML. This review highlights the importance of PGx of targeted therapeutics and its potential application to improving treatment decisions and patient outcomes.

Spironolactone versus observation in the treatment of acute central serous chorioretinopathy

Purpose

To evaluate the efficacy of oral spironolactone in patients with acute central serous chorioretinopathy (CSC).

Methods

This is a prospective, randomised controlled clinical study. Thirty patients with acute CSC were the participants, including 18 patients who were treated with spironolactone (40 mg orally, twice daily) for 2 months in the experimental group and 12 patients who received observation in the control group. Main outcome measures included the proportion of eyes achieving complete resolution of subretinal fluid (SRF), changes in central macular thickness (CMT), the height of SRF (SRFH), best corrected visual acuity (BCVA) and subfoveal choroidal thickness (SFCT). The follow-up period was 2 months.

Results

Complete resolution of SRF was achieved in 55.6% (10/18) and 8.3% (1/12) of the eyes in the treatment group and the control group, respectively, at 2 months (p=0.018). The mean CMT and SRFH decreased significantly at each visit in both groups (p<0.05), and there was significant difference between the two groups at 2 months (p<0.05 and p<0.05, respectively). BCVA (in logarithm of the minimum angle of resolution; mean) improved in both groups at 2 months (p<0.05). In the treatment group, the mean baseline SFCT significantly decreased from 502.50±87.38 µm to 427.44±74.37 µm at 2 months (p<0.01), while the change from baseline (from 480.33±102.38 µm to 463.75±100.63 µm) was not significant in the control group (p=0.195). But the differences between the two groups in BCVA and SFCT were not significant.

Conclusions

Oral spironolactone is more effective with a faster absorption of SRF than observations. It is a promising treatment for acute CSC.

Trial registration number

ChiCTR-IPR-16008428, Results.

Genome-wide common and rare variant analysis provides novel insights into clozapine-associated neutropenia

The antipsychotic clozapine is uniquely effective in the management of schizophrenia; however, its use is limited by its potential to induce agranulocytosis. The causes of this, and of its precursor neutropenia, are largely unknown, although genetic factors have an important role. We sought risk alleles for clozapine-associated neutropenia in a sample of 66 cases and 5583 clozapine-treated controls, through a genome-wide association study (GWAS), imputed human leukocyte antigen (HLA) alleles, exome array and copy-number variation (CNV) analyses. We then combined associated variants in a meta-analysis with data from the Clozapine-Induced Agranulocytosis Consortium (up to 163 cases and 7970 controls). In the largest combined sample to date, we identified a novel association with rs149104283 (odds ratio (OR)=4.32, P=1.79 × 10^-8), intronic to transcripts of SLCO1B3 and SLCO1B7, members of a family of hepatic transporter genes previously implicated in adverse drug reactions including simvastatin-induced myopathy and docetaxel-induced neutropenia. Exome array analysis identified gene-wide associations of uncommon non-synonymous variants within UBAP2 and STARD9. We additionally provide independent replication of a previously identified variant in HLA-DQB1 (OR=15.6, P=0.015, positive predictive value=35.1%). These results implicate biological pathways through which clozapine may act to cause this serious adverse effect.

A validated UPLC-MS/MS method for simultaneous determination of imatinib, dasatinib and nilotinib in human plasma

A sensitive, rapid, simple and economical ultra-performance liquid chromatography–tandem mass spectrometric method (UPLC–MS/MS) was developed and validated for simultaneous determination of imatinib, dasatinib and nilotinib in human plasma using gliquidone as internal standard (IS). Liquid-liquid extraction method with ethyl acetate was used for sample pre-treatment. The separation was performed on an Xtimate Phenyl column using isocratic mobile phase consisting of A (aqueous phase: 0.15% formic acid and 0.05% ammonium acetate) and B (organic phase: acetonitrile) (A:B=40:60, v/v). The flow rate was 0.25 mL/min and the total run time was 6 min. The multiple reaction monitoring (MRM) transitions, m/z 494.5→394.5 for imatinib, 488.7→401.5 for dasatinib, 530.7→289.5 for nilotinib and 528.5→403.4 for IS, were chosen to achieve high selectivity in the simultaneous analyses. The method exhibited great improvement in sensitivity and good linearity over the concentration range of 2.6–5250.0 ng/mL for imatinib, 2.0–490.0 ng/mL for dasatinib, and 2.4–4700.0 ng/mL for nilotinib. The method showed acceptable results on sensitivity, specificity, recovery, precision, accuracy and stability tests. This UPLC–MS/MS assay was successfully used for human plasma samples analysis and no significant differences were found in imatinib steady-state trough concentrations among the SLC22A5 −1889T>C or SLCO1B3 699G>A genotypes (P>0.05). This validated method can provide support for clinical therapeutic drug monitoring and pharmacokinetic investigations of these three tyrosine kinase inhibitors (TKIs).

COMPARISON OF PHOTODYNAMIC THERAPY USING HALF-DOSE OF VERTEPORFIN OR HALF-FLUENCE OF LASER LIGHT FOR THE TREATMENT OF CHRONIC CENTRAL SEROUS CHORIORETINOPATHY

PURPOSE

To compare the efficacy and the detrimental effects of half-drug dose and half-laser light fluence of photodynamic therapy (PDT) for the treatment of chronic central serous chorioretinopathy.

DESIGN

We conducted a prospective randomized, observer-masked comparison study.

METHODS

Forty eyes (40 patients) with chronic central serous chorioretinopathy were enrolled in this study and were equally divided into 2 groups. The first (half-dose) group received only half the standard dose of verteporfin infusion (3 mg/m) and were irradiated by the standard 83 seconds of laser light (50 J/cm) for the PDT treatment; the second (half-fluence) group received the standard dose of verteporfin infusion (6 mg/m) and were irradiated by only 42 seconds of laser light (25 J/cm). Patients were examined at baseline and 1 week, 1 month, 3 months, and 6 months after PDT treatments with best-corrected visual acuity and optical coherence tomography. Fluorescein angiography and indocyanine green angiography (ICGA) were performed at baseline and at 1 month, 3 months, and 6 months after PDT treatment. Primary outcome measures were the changes in the best-corrected visual acuity and in central retinal thickness and subretinal fluid in optical coherence tomography. Secondary outcomes were the changes in the choroidal perfusion in the ICGA, which was measured as the fluorescein ratio of the PDT-treated area to a nontreated reference area in ICGA.

RESULTS

Best-corrected visual acuity was significantly improved at post-PDT 1 month, 3 months, and 6 months (all P < 0.01) in both the half-dose and the half-fluence group. Central retinal thickness was significantly improved at all post-PDT time points in both groups (P < 0.05). All patients in the half-dose group and 19 patients (95%) in the half-fluence group had complete absorption of subretinal fluid at post-PDT 3 months and 6 months. The choroidal perfusion (as reflected by the decrease of the ratio of fluorescence) in ICGA was significantly decreased at all post-PDT follow-up time points in both groups (P < 0.01). However, there were no significant differences in all the measurements between the two groups, including best-corrected visual acuity, central retinal thickness, and hypofluorescence in ICGA at baseline and at each post-PDT follow-up time point.

CONCLUSION

Both half-dose and half-fluence modifications of PDT were similarly effective in improving the visual acuity and subretinal fluid for chronic CSC. Both types of modification of PDT were also similar in causing postlaser choroidal hypoperfusion.

SUBFOVEAL CHOROIDAL THICKNESS CHANGES IN TREATED IDIOPATHIC CENTRAL SEROUS CHORIORETINOPATHY AND THEIR ASSOCIATION WITH RECURRENCE

PURPOSE

To analyze the changes in subfoveal choroidal thickness (SFChT) before and after resolution of central serous chorioretinopathy (CSC) and their association with recurrence during follow-up.

METHODS

Seventy-six eyes with CSC that were completely resolved after treatment with either intravitreal bevacizumab (IVB, 42 eyes) or with half-fluence photodynamic therapy (34 eyes) were included. Best-corrected visual acuity and spectral domain optical coherence tomography were performed at baseline, after complete resolution, and at regular intervals thereafter.

RESULTS

Subfoveal choroidal thickness was similar in the IVB-treated and half-fluence photodynamic therapy-treated eyes at baseline, as well as after complete resolution of the CSC. However, recurrence was more frequent in the IVB-treated eyes (19.0% vs. 2.9%, P = 0.037). The reduction of SFChT after CSC resolution was greater in the nonrecurrent eyes than in the recurrent eyes (91.35 ± 46.40 vs. 19.25 ± 16.47 μm, P < 0.001), and the extent of SFChT reduction was associated with the rate of recurrence of CSC (odds ratio = 0.877, P = 0.019). When CSC recurred, SFChT increased toward the baseline value.

CONCLUSION

Treatment of idiopathic CSC by both IVB and half-fluence photodynamic therapy can reduce SFChT when subretinal fluid is completely resolved. Recurrence is more frequent after IVB and specifically in eyes with a smaller reduction in SFChT after resolution of the CSC.

Finasteride is effective for the treatment of central serous chorioretinopathy

PurposeTo evaluate the safety and efficacy of finasteride treatment in patients with central serous chorioretinopathy (CSC).MethodsRetrospective review of 29 eyes of 23 patients who were treated with finasteride for CSC. Previous medical and ocular history, steroid use, length of finasteride treatment, additional treatments for CSC, visual acuity (VA), central macular thickness (CMT), and presence of subretinal fluid (SRF) throughout the follow-up period, and the occurrence of any complications were recorded.ResultsInitial VA was 0.29±0.31 logMAR, and a trend towards improved VA was noted after 3 months (0.25±0.36 logMAR; P=0.07). VA was significantly improved at the final follow-up (0.23±0.27 logMAR; P=0.024). Initial CMT was 354±160 μm, and was significantly reduced after 1 month of treatment (284±77 μm; P=0.002) and this was maintained to the end of follow-up (247±85 μm; P=0.001). A significant reduction in SRF presence was found at all time points, with an overall 75.9% rate of complete resolution. Following discontinuation, SRF recurrence was noted in 37.5% of cases. No adverse events were recorded.ConclusionsFinasteride is a safe and effective treatment for CSC. It may be a possible new option for the initial management of patient with CSC, and a suggested treatment approach is presented.

Interventions for central serous chorioretinopathy: a network meta-analysis

BACKGROUND

Central serous chorioretinopathy (CSC) is characterized by serous detachment of the neural retina with dysfunction of the choroid and retinal pigment epithelium (RPE). The effects on the retina are usually self limited, although some people are left with irreversible vision loss due to progressive and permanent photoreceptor damage or RPE atrophy. There have been a variety of interventions used in CSC, including, but not limited to, laser treatment, photodynamic therapy (PDT), and intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents. However, it is not known whether these or other treatments offer significant advantages over observation or other interventions. At present there is no evidence-based consensus on the management of CSC. Due in large part to the propensity for CSC to resolve spontaneously or to follow a waxing and waning course, the most common initial approach to treatment is observation. It remains unclear whether this is the best approach with regard to safety and efficacy.

OBJECTIVES

To compare the relative effectiveness of interventions for central serous chorioretinopathy.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2014), EMBASE (January 1980 to October 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 October 2015.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that compared any intervention for CSC with any other intervention for CSC or control.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We pooled data from all studies using a fixed-effect model. For interventions applied to the eye (i.e. not systemic interventions), we synthesized direct and indirect evidence in a network meta-analysis model.

MAIN RESULTS

We included 25 studies with 1098 participants (1098 eyes) and follow-up from 16 weeks to 12 years. Studies were conducted in Europe, North and South America, Middle East, and Asia. The trials were small (most trials enrolled fewer than 50 participants) and poorly reported; often it was unclear whether key aspects of the trial, such as allocation concealment, had been done. A substantial proportion of the trials were not masked.The studies considered a variety of treatments: anti-VEGF (ranibizumab, bevacizumab), PDT (full-dose, half-dose, 30%, low-fluence), laser treatment (argon, krypton and micropulse laser), beta-blockers, carbonic anhydrase inhibitors, Helicobactor pylori treatment, and nutritional supplements (Icaps, lutein); there were only one or two trials contributing data for each comparison. We downgraded for risk of bias and imprecision for most analyses, reflecting study limitations and imprecise estimates. Network meta-analysis (as planned in our protocol) did not help to resolve this uncertainty due to a lack of trials, and problems with intransitivity, particularly with respect to acute or chronic CSC.Low quality evidence from two trials suggested little difference in the effect of anti-VEGF (ranibizumab or bevacizumab) or observation on change in visual acuity at six months in acute CSC (mean difference (MD) 0.01 LogMAR (logarithm of the minimal angle of resolution), 95% confidence interval (CI) -0.02 to 0.03; 64 participants). CSC had resolved in all participants by six months. There were no significant adverse effects noted.Low quality evidence from one study (58 participants) suggested that half-dose PDT treatment of acute CSC probably results in a small improvement in vision (MD -0.10 logMAR, 95% CI -0.18 to -0.02), less recurrence (risk ratio (RR) 0.10, 95% CI 0.01 to 0.81) and less persistent CSC (RR 0.12, 95% CI 0.01 to 1.02) at 12 months compared to sham treatment. There were no significant adverse events noted.Low quality evidence from two trials (56 participants) comparing anti-VEGF to low-fluence PDT in chronic CSC found little evidence for any difference in visual acuity at 12 months (MD 0.03 logMAR, 95% CI -0.08 to 0.15). There was some evidence that more people in the anti-VEGF group had recurrent CSC compared to people treated with PDT but, due to inconsistency between trials, it was difficult to estimate an effect. More people in the anti-VEGF group had persistent CSC at 12 months (RR 6.19, 95% CI 1.61 to 23.81; 34 participants).Two small trials of micropulse laser, one in people with acute CSC and one in people with chronic CSC, provided low quality evidence that laser treatment may lead to better visual acuity (MD -0.20 logMAR, 95% CI -0.30 to -0.11; 45 participants). There were no significant adverse effects noted.Other comparisons were largely inconclusive.We identified 12 ongoing trials covering the following interventions: aflibercept and eplerenone in acute CSC; spironolactone, eplerenone, lutein, PDT, and micropulse laser in chronic CSC; and micropulse laser and oral mifepristone in two trials where type of CSC not clearly specified.

AUTHORS' CONCLUSIONS

CSC remains an enigmatic condition in large part due to a natural history of spontaneous improvement in a high proportion of people and also because no single treatment has provided overwhelming evidence of efficacy in published RCTs. While a number of interventions have been proposed as potentially efficacious, the quality of study design, execution of the study and the relatively small number of participants enrolled and followed to revealing endpoints limits the utility of existing data. It is not clear whether there is a clinically important benefit to treating acute CSC which often resolves spontaneously as part of its natural history. RCTs comparing individual treatments to the natural history would be valuable in identifying potential treatment groups for head-to-head comparison. Of the interventions studied to date, PDT or micropulse laser treatment appear the most promising for study in future trials.

Role of SLC22A1 polymorphic variants in drug disposition, therapeutic responses, and drug-drug interactions

The SCL22A1 gene encodes the broad selectivity transporter hOCT1. hOCT1 is expressed in most epithelial barriers thereby contributing to drug pharmacokinetics. It is also expressed in different drug target cells, including immune system cells and others. Thus, this membrane protein might also contribute to drug pharmacodynamics. Up to 1000 hOCT1 polymorphisms have been identified so far, although only a small fraction of those have been mechanistically studied. A paradigm in the field of drug transporter pharmacogenetics is the impact of hOCT1 gene variability on metformin clinical parameters, affecting area under the concentration-time curve, Cmax and responsiveness. However, hOCT1 also mediates the translocation of a variety of drugs used as anticancer, antiviral, anti-inflammatory, antiemetic agents as well as drugs used in the treatment of neurological diseases among. This review focuses exclusively on those drugs for which some pharmacogenetic data are available, and aims at highlighting the need for further clinical research in this area.

Photodynamic therapy and anti-vascular endothelial growth factor for acute central serous chorioretinopathy: a systematic review and meta-analysis

This systematic review aims to update current evidence on the efficacy and safety of photodynamic therapy (PDT) and anti-vascular endothelial growth factor (anti-VEGF) injections for acute central serous chorioretinopathy (CSC). A comprehensive literature search was conducted in PubMed, EMBASE, and Cochrane Library. Studies comparing (1) PDT versus placebo, (2) anti-VEGF versus placebo, and (3) PDT versus anti-VEGF were included and meta-analyzes were performed when appropriate. Ocular and systemic adverse effects were also summarized. Literature search yielded six comparative studies, among which five were included for this review. Meta-analysis with three studies indicated that eyes treated with PDT achieved better best-corrected visual acuity (BCVA) and central macular thickness (CMT) than the placebo group throughout a follow-up of 12 months. Meta-analysis with another two studies comparing anti-VEGF injections and placebo showed that BCVA at first month was better in anti-VEGF group than in placebo group, though the differences of BCVA and CMT no longer existed at 3 and 6 months after injection. There was no report directly comparing PDT and anti-VEGF for acute CSC. No severe complications was reported in included studies. In this review, current evidence suggested that early treatment of acute CSC by PDT is valuable in improving visual acuity, reducing subretinal fluid, and maintaining long term effectiveness. Anti-VEGF injection could shorten the duration of symptoms and accelerate visual improvement at early stage of disease. Direct comparison between these two treatment will be needed in the future.

Comparing half-dose photodynamic therapy with high-density subthreshold micropulse laser treatment in patients with chronic central serous chorioretinopathy (the PLACE trial): study protocol for a randomized controlled trial

Background

Chronic central serous chorioretinopathy (cCSC) is an eye disease characterized by an accumulation of serous fluid under the retina. It is postulated that this fluid accumulation results from hyperpermeability and swelling of the choroid, the underlying vascular tissue of the eye, causing a dysfunction of the retinal pigment epithelium. This fluid accumulation causes neuroretinal detachment. A prolonged neuroretinal detachment in the macula can lead to permanent vision loss. Therefore, treatment is aimed primarily at achieving resolution of subretinal fluid, preferably within the first 4 months after diagnosis of the disease. A broad spectrum of treatment modalities has been investigated in cCSC, but no consensus exists on the optimal treatment of cCSC. Currently, photodynamic therapy (PDT) and high-density subthreshold micropulse laser treatment (HSML) are among the most frequently cited treatments in obtaining successful neuroretinal reattachment.

Methods/Design

This is a randomized, controlled, open-label, multicenter trial comparing the efficacy of half-dose PDT to HSML in treating patients with cCSC. A total of 156 patients will be recruited, 78 patients in each treatment arm, with a maximum follow-up duration of 8 months after the first treatment. A complete ophthalmological examination with vision-related quality of life (NEI VFQ-25) and stress questionnaires, will be performed at baseline, 6 to 8 weeks after the first treatment, 6 to 8 weeks after a second treatment (if necessary), and at the final follow-up visit at 7 to 8 months after the first treatment. Treatment visits will be scheduled within 3 weeks after the baseline visit, and within 3 weeks after the first control visit, if a second treatment is required.

Discussion

Both half-dose PDT and HSML may be effective treatments in cCSC, but because of the lack of prospective randomized controlled trials, which treatment should be the first choice remains unclear. The aim of this study is to compare the efficacy of half-dose PDT to HSML. The primary endpoint to evaluate efficacy will be a complete absence of subretinal fluid on optical coherence tomography after treatment. Secondary functional endpoints include change in Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity, retinal sensitivity on microperimetry, and NEI VFQ-25 questionnaire of visual functioning.

Registration number Institutional Review Board (CMO Arnhem-Nijmegen, the Netherlands): 2013/203 NL nr.: 41266.091.13

Trial registration

ClinicalTrials.gov identifier: NCT01797861. Date of registration: 21 February 2013.

1-year results of combined half-dose photodynamic therapy and ranibizumab for polypoidal choroidal vasculopathy

Background

To evaluate the efficacy and safety of half-dose photodynamic therapy (PDT combined with ranibizumab for polypoidal choroidal vasculopathy (PCV). PCV is commonly treated with a combination of anti-vascular endothelial growth factor and standard-dose photodynamic therapy (PDT). Choroidal ischemia and visual loss can be resulted from the standard-dose PDT. Half-dose PDT has proved to produce similar results and safety profile in treating central serous chorioretinopathy. Half-dose PDT may offer an alternative for PCV cases where the damage to choroidal vasculature maybe less. Here, we report the efficacy of treating PCV cases with combination of ranibizumab and half-dose PDT.

Methods

In this prospective, non-comparative, interventional case series, 19 treatment-naive eyes were treated with combined half-dose PDT and ranibizumab. All subjects were followed up for 12 months with measurement of best-corrected visual acuity (BCVA), central foveal thickness (CFT) by optical coherence tomography. Indocyanine green angiogram (ICG) was performed every 3-monthly, and subjects assessed in terms of polyp regression rates, changes in vision and central foveal thickness, need to repeat half-dose PDT. Subgroup analysis was performed based on ICG features.

Results

The mean logMAR BCVA improved from 0.64 at baseline to 0.41 at 12 months. The mean CFT improved from 459.6mum at baseline to 384.2mum at 12 months. The difference between baseline BCVA and CFT and that at 12 months were statistically significant (both P = 0.03). Polyp regression rate after one half-dose PDT was 42.1 %. This was 61.5 % in the polyp-only group, while that in the branching-vascular-network (BVN) group was 0 % (P = <0.01).

Conclusion

Half-dose PDT combined with intravitreal ranibizumab was able to induce high polyp regression rate in PCV cases that had one single polyp.

The effect of ABCG2 genotype on the population pharmacokinetics of sunitinib in patients with renal cell carcinoma

BACKGROUND

Sunitinib, a multitargeted tyrosine kinase inhibitor, offers favorable therapeutic outcomes to patients with advanced renal cell carcinoma. However, to maximize the clinical benefits, an effective therapeutic management strategy with dose optimization is essential. The objectives of this analysis were to describe the pharmacokinetics (PK) of sunitinib by a population PK approach and to quantitatively evaluate the effect of potential predictive factors including ABCG2 genotype on the PK of sunitinib.

METHODS

Plasma concentration-time profiles at 3 consecutive days including a total of 245 sunitinib plasma concentrations were available from 19 Japanese patients with renal cell carcinoma. Blood samples were collected on days 2, 8, and 15 after the start of the therapy. Population PK analysis was performed using NONMEM 7.2. Body weight, gender, and genotype of ABCG2 421C>A were evaluated as potential covariates. Interoccasion variability (IOV) among the 3 sampling days was also assessed as a random effect parameter.

RESULTS

The sunitinib PK profiles were best described by a 1-compartment model with first-order absorption. The ABCG2 421C>A genotype was identified as a significant covariate for the prediction of oral clearance (CL/F). No significant improvement in model fit was observed by including body weight and/or gender. A systematic difference in estimated population CL/F was observed between days 2 and 8, which was quantified as approximately 30% decrease over time. This difference was described as a covariate for CL/F in the model. IOV included as a random effect parameter significantly improved the model fit.

CONCLUSIONS

This analysis provides a population PK model of sunitinib with the ABCG2 421C>A genotype as a predictive covariate for CL/F. It also suggests that IOV and change of CL/F over time need to be considered to predict the sunitinib PK more accurately. These findings will be implemented to optimize the pharmacotherapy of sunitinib.

System review and meta-analysis on photodynamic therapy in central serous chorioretinopathy

PURPOSE

To evaluate the effect of photodynamic therapy (PDT) on central serous chorioretinopathy (CSC) compared with laser therapy and intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) drugs, and to find the maximum treatment effect with minimal dose and fluence of PDT.

METHODS

A systematic electronic search was conducted in Feb 2013 in PubMed, Embase, ISI Web of Knowledge and the Cochrane library. The main outcome factors were compared in best-corrected visual acuity (BCVA), central macular thickness (CMT) and resolution of subretinal fluid (SRF). Meta-analysis was performed when it is appropriate. The comparisons were designed into four groups: group 1, PDT versus laser photocoagulation; group 2, PDT versus intravitreal injection of anti-VEGF drugs; group 3, half-dose verteporfin PDT versus placebo; group 4, half-fluence PDT versus full-fluence PDT.

RESULTS

We retrieved nine reports of studies including a total of 319 patients. In group 1, the summary result indicated that PDT was superior in resolution of SRF (p = 0.005) than laser photocoagulation. In group 2, PDT could resolute SRF (p = 0.007) and decrease CMT (p = 0.002) more rapidly than intravitreal injection of anti-VEGF drugs. In group 3, half-dose PDT was effective in improving BCVA (p < 0.00001), decreasing CMT (p = 0.001) and resolving SRF (p < 0.001). In group 4, half-fluence PDT was effective and could significantly decrease the hypoxic damage which was caused by PDT (p < 0.001).

CONCLUSION

PDT is a promising therapy for CSC patients and the parameters of PDT can be adjusted to obtain the maximum treatment effect with minimal adverse effects.

Correlations of ezrin expression with pathological characteristics and prognosis of osteosarcoma: a meta-analysis

We conducted a meta-analysis to comprehensively evaluate the correlations of ezrin expression with pathological characteristics and the prognosis of osteosarcoma. The MEDLINE (1966–2013), the Cochrane Library Database, EMBASE, CINAHL, Web of Science (1945–2013), and the Chinese Biomedical Database were searched without language restrictions. Meta-analyses conducted using STATA software were calculated. Ten studies met the inclusion criteria, including 459 patients with osteosarcoma. Meta-analysis results illustrated that ezrin expression may be closely associated with the recurrence of osteosarcoma or metastasis in osteosarcoma. Our findings also demonstrated that patients with grade III-IV osteosarcoma showed a higher frequency of ezrin expression than those with histological grade I-II osteosarcoma. Furthermore, we found that patients with positive expression of ezrin exhibited a shorter overall survival than those with negative ezrin expression. The results also indicated that positive ezrin expression was strongly correlated with poorer metastasis-free survival. Nevertheless, no significant relationships were observed between ezrin expression and clinical variables (age and gender). In the current meta-analysis, our results illustrated significant relationships of ezrin expression with pathological characteristics and prognosis of osteosarcoma. Thus, ezrin expression could be a promising marker in predicting the clinical outcome of patients with osteosarcoma.