The clinical pharmacology of methotrexate: new applications of an old drug

Evaluation of a scoring system to predict treatment success with single-dose methotrexate in ectopic pregnancy

PURPOSE

This study sought to assess the efficacy of a newly developed scoring system in predicting treatment outcomes for ectopic pregnancy among patients undergoing single-dose methotrexate therapy. The primary research question centered on the reliability and predictive accuracy of objective parameters in determining methotrexate therapy success.

METHODS

Conducted as a retrospective single-center cohort study, data from 172 ectopic pregnancy patients treated with methotrexate between January 2021 and January 2023 were analyzed. Parameters including adnexal mass size, peritoneal fluid presence, yolk sac identification, endometrial thickness, ectopic pregnancy location, and initial B-hCG levels were meticulously evaluated for their association with treatment outcomes.

RESULTS

Following the exclusion of 21 emergency surgery cases, the final analysis comprised 151 patients. Notable associations were observed between specific parameters (fetal cardiac activity, adnexal mass size  > 3.5 cm, peritoneal fluid presence, yolk sac identification, endometrial thickness  > 10 mm, and initial B-hCG levels) and treatment outcomes (p < 0.001). Additionally, the novel scoring system demonstrated promising predictive performance. At a cutoff of 2.50, it achieved a sensitivity of 91.7% and a specificity of 59.7%. Increasing the cutoff to 3.50 resulted in a sensitivity of 94.0%, with a specificity of 46.3%.

CONCLUSION

Objective parameters, particularly those integrated into the developed scoring system, exhibited substantial associations with methotrexate therapy outcomes in ectopic pregnancy. These findings underscore the potential of an objective scoring model to significantly influence clinical decision-making in therapy, offering avenues for enhanced prognostication and patient care in treatment outcomes.

DSPE-PEG2000-methotrexate nanoparticles encapsulating phenobarbital sodium kill cancer cells by inducing pyroptosis

Cancer is a life-threatening disease worldwide. Nanomedicine and nanodelivery systems are recently developed scientific field that employs specific materials in the nanoscale range to deliver drugs. Lipid-based nanoparticles are an ideal delivery system since they exhibit many advantages, including high bioavailability, self-assembly, formulation simplicity, and the ability to exhibit a plethora of physicochemical properties. Herein, we report that phenobarbital sodium can kill cancer cells by using the DSPE-PEG2000-methotrexate nanoparticle delivery system, which can target folate receptors that are usually overexpressed on a variety of cancer cells. The released phenobarbital then executes cancer cells by inducing pyroptosis. Results from our animal model further indicate that the nanomedicine of nanoparticle-encapsulated phenobarbital sodium is a promising anticancer therapy.

A Delphi study to determine the epidemiology and clinical management of patients treated with HDMTX who develop methotrexate (MTX) delayed elimination in France, Germany, Italy, and the UK

Introduction

High-dose methotrexate (HDMTX) is administered for the treatment of some malignancies. Serious complications after the administration of HDMTX are rare, but occasionally MTX may precipitate in the renal tubes causing a delayed elimination leading to renal, multiorgan toxicities and to life-threatening complications. This study aims to estimate the incidence and clinical management of delayed MTX elimination in France, Germany, Italy, and the UK.

Methods

Twelve haemato-oncology and pediatric oncology clinical experts from leading European hospitals participated in the study. A two-round Delphi methodology was used to gather data on different variables relevant to evaluate the HDMTX induced-toxicity impact. For quantitative data, median and interquartile ranges were calculated. Data on prevalence was calculated considering the number of patients in each hospital and the population they cover, and then, extrapolated to the country population.

Results

The total number of patients treated annually with HDMTX in France, Germany, Italy, and the UK is estimated in 7155. Of these, 16% are estimated to develop delayed MTX elimination and around 9% may develop HDMTX-induced acute kidney injury (AKI). Leucovorin, hyperhydration and urine alkalinization are applied to prevent MTX toxicity and precipitation whilst glucarpidase, hemofiltration and hemodialysis are being used for persisting toxic MTX serum levels. Grade 3 systemic toxicities are common in these patients, hematologic and gastrointestinal being the most common ones.

Conclusions

This report provides expert clinical practice experience and opinion of the incidence and management of HDMTX-delayed elimination in France, Germany, Italy and the UK, thereby contributing to the evidence available on this relevant medical condition which can be life-threatening.

Advances in the implications of the gut microbiota on the treatment efficacy of disease-modifying anti-rheumatic drugs in rheumatoid arthritis

Alterations in the composition or function of the gut microbiota are associated with the etiology of human diseases. Drug-microbiota interactions can affect drug bioavailability, effectiveness, and toxicity through various routes. For instance, the direct effect of microbial enzymes on drugs can either boost or diminish their efficacy. Thus, considering its wide range of metabolic capabilities, the gut microbiota is a promising target for pharmacological modulation. Furthermore, drugs can alter the microbiota and the mechanisms by which they interact with their host. Individual variances in microbial profiles can also contribute to the different host responses to various drugs. However, the influence of interactions between the gut microbiota and drugs on treatment efficacy remains poorly elucidated. In this review, we will discuss the impact of microbiota dysbiosis in the pathogenesis of rheumatoid arthritis (RA), and we will attempt to elucidate the crosstalk between the gut microbiota and disease-modifying anti-rheumatic drugs (DMARDs), with an emphasis on how drug-microbiota interactions affect the treatment efficacy in RA. We speculate that improved knowledge of these critical interactions will facilitate the development of novel therapeutic options that use microbial markers for predicting or optimizing treatment outcomes.

Population Pharmacokinetic Model of Methotrexate in Brazilian Pediatric Patients with Acute Lymphoblastic Leukemia

OBJECTIVES

Methotrexate (MTX) is subject to therapeutic drug monitoring because of its high pharmacokinetic variability and safety risk outside the therapeutic window. This study aimed to develop a population pharmacokinetic model (popPK) of MTX for Brazilian pediatric acute lymphoblastic leukemia (ALL) patients who attended the Hospital de Clínicas de Porto Alegre, Brazil.

METHODS

The model was developed using NONMEM 7.4 (Icon®), ADVAN3 TRANS4, and FOCE-I. To explain inter-individual variability, we evaluated covariates from demographic, biochemical, and genetic data (single nucleotide polymorphisms [SNPs] related to the transport and metabolism of drugs).

RESULTS

A two-compartment model was built using 483 data points from 45 patients (0.33-17.83 years of age) treated with MTX (0.25-5 g/m2) in different cycles. Serum creatinine (SCR), height (HT), blood urea nitrogen (BUN) and a low BMI stratification (according to the z-score defined by the World Health Organization [LowBMI]) were added as clearance covariates. The final model described MTX clearance as [Formula: see text]. In the two-compartment structural model, the central and peripheral compartment volumes were 26.8 L and 8.47 L, respectively, and the inter-compartmental clearance was 0.218 L/h. External validation of the model was performed through a visual predictive test and metrics using data from 15 other pediatric ALL patients.

CONCLUSION

The first popPK model of MTX was developed for Brazilian pediatric ALL patients, which showed that inter-individual variability was explained by renal function and factors related to body size.

High-dose chemotherapy for relapsed testicular germ cell tumours

Relapsed testicular germ cell tumours (GCTs) might be cured with salvage chemotherapy. Accepted salvage treatment is conventional-dose chemotherapy (CDCT) or high-dose chemotherapy (HDCT). HDCT with peripheral blood stem cell transplant might produce a higher number of durable responses than CDCT. We discuss studies reporting on outcomes of salvage HDCT in relapsed GCTs. The most reproducible results were achieved with HDCT with two cycles of etoposide and carboplatin or three cycles of the paclitaxel, ifosfamide, carboplatin and etoposide regime. Using these two regimens, sustained cure rates of 50-66% were reported in phase I, phase II and retrospective studies published in the past two decades. Cure rates in patients with cisplatin-resistant disease are between 30% and 45%. Two phase III randomized studies were conducted with certain limitations and were unsuccessful in showing a survival benefit of HDCT. Thus, salvage treatment remains a controversial topic. Salvage HDCT with peripheral blood stem cell transplant and CDCT are two recommended treatment options for relapsed GCTs. Consistently reported cure rates from phase I, phase II and large retrospective studies support the use of HDCT in the hands of an experienced team of oncologists.

Fatal low-dose methotrexate toxicity: A case report and literature review

Methotrexate (MTX) is a chemotherapeutic agent that acts primarily by inhibiting the folic acid cycle. In addition to its application for treating malignancies, MTX is also used to treat chronic inflammatory diseases including psoriasis. Adverse effects have been reported even at low doses (up to 25 mg/week), and there is risk of toxicity in the form of myelosuppression, hepatotoxicity, or pulmonary fibrosis. Here, we report a case of a 67-year-old male with a past medical history of end stage renal disease on peritoneal dialysis and moderate-to-severe psoriasis with psoriatic arthritis presented with abdominal pain, diarrhea, rash, mucositis, and mucocutaneous ulcers and erosions. The patient was taking methotrexate 10 mg weekly without folic acid supplementation and was found to be pancytopenic. Despite treatment, the patient developed multiorgan failure and passed away after 16 days of hospitalization. Myelosuppression is considered the most serious side effect with the highest risk of mortality. Risk factors for toxicity include renal insufficiency, advanced age, lack of folate supplementation, drug interactions, and medication errors. Importantly, serum levels of MTX do not correlate with toxicity; therefore, folinic acid rescue therapy should be started as soon as MTX toxicity is suspected. MTX toxicity is rare with low dose, proper dose scheduling, and adherence to the recommended guidelines. It is imperative that physicians considering therapy with low dose MTX for dermatologic indications take into consideration a patient's risk factors for toxicity and monitor appropriately.

Alternative Methotrexate Oral Formulation: Enhanced Aqueous Solubility, Bioavailability, Photostability, and Permeability

The poor aqueous solubility and/or permeability and thereby limited bioavailability largely restricts the pharmaco-therapeutic implications of potent anticancer drugs such as methotrexate (MTX). Furthermore, MTX’s inherently unstable nature makes it difficult to develop a viable oral formulation. In this study we developed the spray-dried amorphous inclusion complexes of MTX with native β-cyclodextrin (β-CD) and its derivatives, namely HP-β-CD, M-β-CD, and DM-β-CD to enhance the aqueous solubility, photostability, permeability, and oral bioavailability of MTX in rats. Our findings show that the 1:1 stoichiometry ratio of MTX and CDs improves the aqueous solubility, stability, and pharmacokinetic profiles of the drug, the better results being obtained particularly with DM-β-CD as a host, which has a higher complexation ability with the drug compared to other β-CDs. Specifically, the pharmacokinetic analysis demonstrated 2.20- and 3.29-fold increments in AUC and Cmax, respectively, in comparison to free MTX. Even though the absorptive permeability of MTX and MTX/DM-β-CD inclusion complexes was similar, the efflux of the absorbed MTX from ICs was significantly lower compared to the free MTX (4.6- vs. 8.0-fold). Furthermore, the physicochemical characterization employing SEM, DSC, and PXRD confirmed the transformation of crystalline MTX to its amorphous state. In solution, ¹H NMR studies revealed that MTX embedded into the DM-β-CD cavity resulting in both H-3 and H-5 chemical shifts implied the presence of intermolecular interaction between the drug and CD moiety. It was, therefore, evident that an MTX IC could be a successful oral formulation technique, preventing MTX degradation and enhancing its pharmacologically relevant properties.

Leucovorin (folinic acid) rescue for high-dose methotrexate: A review

High-dose methotrexate (HDMTX) is active against various malignancies; it possesses serious toxicities and is associated with patient characteristics, dosage regimens, comedications, and physiological status. There are many strategies to overcome HDMTX-induced toxicities, such as hydration, alkalization, leucovorin rescue, and haemodialysis. Leucovorin rescue is a cornerstone for toxicity prevention in HDMTX treatment. However, the leucovorin dose adjustment and the existence of leucovorin overrescue are still controversial. At present, various methods for calculating leucovorin doses in different tumour types have been proposed, including empirical calculations based on MTX plasma concentration, the Bleyer nomogram, and other methods. Nonetheless, leucovorin rescue protocols differ greatly across tumour types and medical institutions. Further studies are needed to investigate the optimal dosage regimen for leucovorin rescue in various tumours using HDMTX.

An Oral 3D Printed PLGA-Tocopherol PEG Succinate Nanocomposite Hydrogel for High-Dose Methotrexate Delivery in Maintenance Chemotherapy

High-dose methotrexate (HDMTX) is one of the chemotherapeutic agents used to treat a variety of cancers in both adults and children. However, the toxicity associated with HDMTX has resulted in the spread of infections and treatment interruption. Further, poor bioavailability due to efflux pump activities mediated by P-glycoprotein has also been linked to poor therapeutic effects of methotrexate following oral administrations. D-α-Tocopheryl poly-ethylene glycol 1000 succinate (TPGS) is known to improve the bioavailability of poorly soluble drugs by inhibiting P-gp efflux activities, thus enhancing cellular uptake. Therefore, to achieve improved bioavailability for MTX, this study aimed to design and develop a novel drug delivery system employing TPGS and a biodegradable polymer, i.e., PLGA, to construct methotrexate-loaded nanoparticles fixated in alginate-gelatine 3D printable hydrogel ink to form a solid 3D printed tablet for oral delivery. The results indicated that high accuracy (>95%) of the 3D printed tablets was achieved using a 25 G needle. In vitro, drug release profiles were investigated at pH 1.2 and pH 7.4 to simulate the gastrointestinal environment. The in vitro release profile displayed a controlled and prolonged release of methotrexate over 24 h. The in silico modeling study displayed P-gp ATPase inhibition, suggesting enhanced MTX absorption from the gastrointestinal site. The 3D-printed hydrogel-based tablet has the potential to overcome the chemotherapeutic challenges that are experienced with conventional therapies.

Pancytopenia Due to Possible Drug-Drug Interactions Between Low-Dose Methotrexate and Proton Pump Inhibitors

Methotrexate (MTX) has been widely used with a wide range of doses in the treatment of certain neoplastic diseases, severe psoriasis, and rheumatoid arthritis. At higher dose, monitoring of serum MTX elimination is performed because delayed elimination can result in serious and potentially life-threatening toxicities. A number of medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), salicylates, phenylbutazone, phenytoin, sulfonamides, and some oral antibiotics, are known to interact with MTX therapy through various mechanisms. Accumulating evidence suggests that concomitant use of MTX (primarily at high doses) and proton pump inhibitors (PPIs) such as omeprazole, esomeprazole, and pantoprazole may decrease MTX clearance. The majority of the reported cases occurred with the administration of high-dose MTX in patients receiving doses of 300 mg/m² to 12 g/m². However, there were also cases of patients taking PPI and experiencing toxicity at doses as low as 10 mg of MTX per week. Although the dosage of MTX is small, the presence of side effect may be delayed and still dangerous. After literature review, it was found that common toxicities associated with low-dose MTX used for inflammatory arthritis include gastrointestinal adverse effects (>10%; ie nausea, stomatitis) and central nervous system toxicity (~20%; ie fatigue, malaise, dizziness, impaired cognition) with weekly administration. Bone marrow suppression (<3%; ie leukopenia, neutropenia, thrombocytopenia) and hepatotoxicity (~15%; ie reversible elevations in transaminases) are less common, and rarely MTX can also cause pulmonary (<1%) and other toxicities. Here, we report two cases who presented with severe pancytopenia 8 and 13 days after taking low-dose MTX and PPI. We highlight that in absence of risk/benefit ratio correctly set, an assessment of appropriateness of PPI prescription before MTX therapy can limit an iatrogenic risk.

Methotrexate Cutaneous Ulceration: A Systematic Review of Cases

BACKGROUND

Methotrexate cutaneous ulceration is a rare methotrexate complication, and has only been described in case reports and case series.

OBJECTIVE

To document patient characteristics, morphologic features, and mortality risk factors for methotrexate cutaneous ulceration.

METHODS

A systematic literature review of PubMed and Embase (last date 1 November 2021) was performed with data collected from case reports and case series. This study was limited to cases of cutaneous ulceration; presence of oral ulceration was collected from within these cases.

RESULTS

114 cases (men = 57.9%, mean age = 61 years) of methotrexate cutaneous ulceration met inclusion criteria. Psoriasis (69.3%), rheumatoid arthritis (18.4%), and mycosis fungoides (6.1%) were the most common indications for methotrexate use. Morphologies included erosions localized to psoriatic plaques (33.3%), epidermal necrosis/necrolysis (35.1%), localized ulceration (16.7%), and skin-fold erosions (5.3%). Methotrexate dose preceding toxicity varied greatly; median 20 mg/week, interquartile range 15-40 mg/week, range 5-150 mg/week. Most patients had risk factors for serum toxicity (baseline renal dysfunction = 37.8%, concurrent NSAID use = 28.1%, inadequate folic acid use = 89.1%). Thirty percent of cases involved mistakenly high methotrexate doses. Fourteen patients (12%) died. Absence of folic acid use (69% vs. 100%, p value < 0.001), pancytopenia (33% vs. 86%, p value < 0.001), and renal dysfunction at presentation (47% vs. 92%, p value < 0.001) were associated with increased mortality.

LIMITATIONS

Selection bias present due to abstraction from case reports and case series.

CONCLUSION

Methotrexate cutaneous ulceration is commonly preceded by dosage mistakes, absence of folic acid supplementation, and concurrent use of nephrotoxic medications. Renal impairment, pancytopenia, and absence of folic acid supplementation are key risk factors for mortality from this adverse medication reaction. Providers should regularly monitor methotrexate dosing adherence, drug-drug interactions, and perform routine laboratory evaluation. Index of suspicion for this toxicity should remain high given the varied clinical presentation and high mortality.

Incidence and management of patients with methotrexate delayed elimination in the clinical practice: A Delphi study

INTRODUCTION

High-dose methotrexate (HDMTX) is administered for the treatment of some cancers. HDMTX is usually safe but may crystallize in renal tubules causing acute kidney injury (AKI). Consequently, MTX elimination is delayed, resulting in a severe and life-threatening condition. No studies have been published about the impact of MTX toxicity in Spain. This study aims to estimate the incidence and management of MTX delayed elimination and toxicity.

METHODS

A two-round Delphi study was performed to reach consensus between 10 medical experts on haemato-oncology and paediatric oncology with experience in the management of HDMTX treated patients from leading Spanish hospitals. An online questionnaire was developed based on national and international guidelines and previous evidence regarding HDMTX-related toxicity. Consensus was established at 80% agreement. Median and interquartile ranges were calculated, and incidence data were extrapolated to the Spanish general population.

RESULTS

Out of 1.475 patients estimated to receive HDMTX treatment annually in Spain, 27.5% present MTX delayed elimination and 11.6% develop HDMTX-induced AKI (35.4% with severe systemic toxicities (>grade 3) and 18.8% develop chronic renal disease). Mortality is estimated in 4.2%. Immuno-enzymatic assay is used in most of the hospitals (90%) for MTX serum level monitoring. All experts use increased supportive care and high leucovorin as first-line treatment. Available treatments in experts' hospitals in case toxicity persists are haemodialysis (90% of hospitals), glucarpidase (60%) and hemofiltration (50%). Most prevalent non-renal systemic toxicities are haematologic and mucositis (21-40% of patients). Patients with HDMTX-induced AKI require from intensive care (5% of patients), more than 3 sessions and 4 days of dialysis, and about 8.5 days of hospitalization (non-ICU patients) and 12 days in case of patients requiring ICU.

CONCLUSIONS

These results are the first evidence regarding HDMTX-induced AKI in Spain. Incidence and mortality results are in line with previous studies. Clinical management is based on preventive measures and the treatment depend on the availability in the hospital. The need for effective, safe and rapid treatment for the reduction of MTX toxic levels and the improvement of monitoring methods were noted by experts as urgent needs. Further observational studies to validate these results would be needed.

Polydopamine-coated nanocomposite theranostic implants for localized chemotherapy and MRI imaging

Sustained and localized delivery of chemotherapeutics in postoperative cancer treatment leads to a radical improvement in prognosis and a much decreased risk of tumor recurrence. In this work, polydopamine (PDA)-coated superparamagnetic iron oxide nanoparticle (SPION)-loaded polycaprolactone and poly (lactic-co-glycolic acid) fibers were developed as a potential implant to ensure safe and sustained release of the chemotherapeutic drug methotrexate (MTX), as well as provide local contrast for magnetic resonance imaging (MRI). Fibres were prepared by co-axial electrospinning and loaded with MTX-layered double hydroxide (LDH) nanocomposites in the core, yielding organic-inorganic hybrids ranging from 1.23 to 1.48 µm in diameter. After surface coating with PDA, SPIONs were subsequently loaded on the fibre surface and found to be evenly distributed, providing high MRI contrast. In vitro drug release studies showed the PDA coated fibres gave sustained release of MTX over 18 days, and the release profile is responsive to conditions representative of the tumor microenvironment such as slightly acidic pH values or elevated concentrations of the reducing agent glutathione (GSH). In vitro studies with Caco-2 and A549 cells showed highly effective killing with the PDA coated formulations, which was further enhanced at higher levels of GSH. The fibres hence have the potential to act as an implantable drug-eluting platform for the sustained release of cytotoxic agents within a tumor site, providing a novel treatment option for post-operative cancer patients.

Gut Microbiota-Medication Interaction in Rheumatic Diseases

Besides its contribution to the development of rheumatic diseases, the gut microbiota interact with anti-rheumatic drugs. The intestinal microbiota can directly metabolize many drugs and indirectly change drug metabolism through a complex multi-dimensional interaction with the host, thus affecting individual response to drug therapy and adverse effects. The focus of the current review is to address recent advances and important progress in our understanding of how the gut microbiota interact with anti-rheumatic drugs and provide perspectives on promoting precision treatment, drug discovery, and better therapy for rheumatic diseases.

Piperine analogs arrest c-myc gene leading to downregulation of transcription for targeting cancer

G-quadruplex (G4) structures are considered a promising therapeutic target in cancer. Since Ayurveda, Piperine has been known for its medicinal properties. Piperine shows anticancer properties by stabilizing the G4 motif present upstream of the c-myc gene. This gene belongs to a group of proto-oncogenes, and its aberrant transcription drives tumorigenesis. The transcriptional regulation of the c-myc gene is an interesting approach for anticancer drug design. The present study employed a chemical similarity approach to identify Piperine similar compounds and analyzed their interaction with cancer-associated G-quadruplex motifs. Among all Piperine analogs, PIP-2 exhibited strong selectivity, specificity, and affinity towards c-myc G4 DNA as elaborated through biophysical studies such as fluorescence emission, isothermal calorimetry, and circular dichroism. Moreover, our biophysical observations are supported by molecular dynamics analysis and cellular-based studies. Our study showed that PIP-2 showed higher toxicity against the A549 lung cancer cell line but lower toxicity towards normal HEK 293 cells, indicating increased efficacy of the drug at the cellular level. Biological evaluation assays such as TFP reporter assay, quantitative real-time PCR (qRT- PCR), and western blotting suggest that the Piperine analog-2 (PIP-2) stabilizes the G-quadruplex motif located at the promoter site of c-myc oncogene and downregulates its expression. In conclusion, Piperine analog PIP-2 may be used as anticancer therapeutics as it affects the c-myc oncogene expression via G-quadruplex mediated mechanism.

The influence of MTHFR genetic polymorphisms on methotrexate therapy in pediatric acute lymphoblastic leukemia

MTHFR is a crucial enzyme in folate metabolism. This study aimed to determine the relationship between MTHFR genetic polymorphism and elimination and toxicities of methotrexate (MTX). To do that, the study enrolled 145 patients diagnosed with acute lymphoblastic leukemia, who received chemotherapy following the Chinese Children’s Cancer Group Acute Lymphoblastic Leukemia (CCCG-ALL)-2015 protocol (clinical trial number: ChiCTR-IPR-14005706). We analyzed the effects of MTHFR C677T and A1298C polymorphisms on MTX elimination and toxicities. Patients with the MTHFR C677T TT genotype could tolerate a significantly higher MTX dose than those with the CC/CT genotype. However, patients with C677T TT genotypes had an increased risk of hypokalemia (1.369 to CC and 1.409 to CT types). The MTX infusion rate in patients with the MTHFR A1298C AC genotype was slightly lower than that in those with CC or AA genotypes. Patients with the A1298C AA genotype had a 1.405-fold higher risk of hepatotoxicity than those with the AC genotype (P > 0.05). There was no significant difference between the prevalence of other toxicities among MTHFR C677T or A1298C genotypes (P > 0.05). Neither MTHFR C677T nor A1298C polymorphisms were significantly associated with delayed MTX clearance. To conclude, MTHFR polymorphisms were not good predictors of MTX-related toxicities.

Mechanisms, Management and Prevention of Pemetrexed-Related Toxicity

Pemetrexed is a cytostatic antifolate drug and a cornerstone in the treatment of lung cancer. Although generally well tolerated, a substantial part of the patient population experiences dose-limiting or even treatment-limiting toxicities. These include mucositis, skin problems, fatigue, renal toxicity, and neutropenia. Several studies confirmed that pemetrexed pharmacokinetics can serve as a prognostic factor for the development of toxicity, especially for neutropenia. Preventing and managing toxicity of pemetrexed can help to ensure durable treatment. Several evidence-based strategies are already implemented in clinical care. With the introduction of standard vitamin supplementation and dexamethasone, the incidence of hematological toxicity and skin reactions substantially decreased. In the case of high risk for toxicity, granulocyte colony-stimulating factor can be used to prevent severe hematological toxicity. Moreover, high-dose folinic acid can resolve severe pemetrexed-induced toxicity. There are several experimental options to prevent or manage pemetrexed-related toxicity, such as the use of standard folinic acid, hemodialysis, antidotes such as thymidine, hypoxanthine, and glucarpidase, and the use of therapeutic drug monitoring. These strategies still need clinical evaluation before implementation, but could enable treatment with pemetrexed for patients who are at risk for toxicity, such as in renal impairment.

Ultrasensitive fluorescence detection of antitumor drug methotrexate based on a terbium-doped silica dendritic probe

A novel strategy was developed for the detection of methotrexate (MTX) via the quenching effect of MTX on the fluorescence intensity of terbium-doped dendritic silica particles (Tb@KCC-1). The fluorescence intensity of Tb@KCC-1 can be effectively quenched by MTX at 546 nm under an excitation wavelength of 233 nm. The quenched fluorescence is proportional to the amount of MTX in both plasma and exhaled breath condensate (EBC) samples. Under the optimal conditions, the linear dynamic ranges of the developed method were 44 nM to 2.2 μM for EBC, 44 nM to 0.22 μM and 0.22-2.2 μM for plasma samples. The limit of detection (LOD) and limit of quantification (LOQ) in both plasma and EBC media are 35 and 116 nM, respectively. The developed method has the benefits of fast analysis time, simple approach, high specificity, and sensitivity for the detection of MTX in both media. This nanoprobe has been successfully utilized for the quantification of MTX in patients' plasma and spiked EBC samples, proving the applicability of the nanoprobe for MTX detection in real samples.

Recent Advances in Metal-Based Magnetic Composites as High-Efficiency Candidates for Ultrasound-Assisted Effects in Cancer Therapy

Metal-based magnetic materials have been used in different fields due to their particular physical or chemical properties. The original magnetic properties can be influenced by the composition of constituent metals. As utilized in different application fields, such as imaging monitoring, thermal treatment, and combined integration in cancer therapies, fabricated metal-based magnetic materials can be doped with target metal elements in research. Furthermore, there is one possible new trend in human activities and basic cancer treatment. As has appeared in characterizations such as magnetic resonance, catalytic performance, thermal efficiency, etc., structural information about the real morphology, size distribution, and composition play important roles in its further applications. In cancer studies, metal-based magnetic materials are considered one appropriate material because of their ability to penetrate biological tissues, interact with cellular components, and induce noxious effects. The disruptions of cytoskeletons, membranes, and the generation of reactive oxygen species (ROS) further influence the efficiency of metal-based magnetic materials in related applications. While combining with cancer cells, these magnetic materials are not only applied in imaging monitoring focus areas but also could give the exact area information in the cure process while integrating ultrasound treatment. Here, we provide an overview of metal-based magnetic materials of various types and then their real applications in the magnetic resonance imaging (MRI) field and cancer cell treatments. We will demonstrate advancements in using ultrasound fields co-worked with MRI or ROS approaches. Besides iron oxides, there is a super-family of heterogeneous magnetic materials used as magnetic agents, imaging materials, catalytic candidates in cell signaling and tissue imaging, and the expression of cancer cells and their high sensitivity to chemical, thermal, and mechanical stimuli. On the other hand, the interactions between magnetic candidates and cancer tissues may be used in drug delivery systems. The materials’ surface structure characteristics are introduced as drug loading substrates as much as possible. We emphasize that further research is required to fully characterize the mechanisms of underlying ultrasounds induced together, and their appropriate relevance for materials toxicology and biomedical applications.

A Dose-Confirmation Phase 1 Study to Evaluate the Safety and Pharmacology of Glucarpidase in Healthy Volunteers

Glucarpidase rapidly decomposes methotrexate. A phase 1 study of glucarpidase in an open‐label, randomized parallel group was conducted to evaluate the safety, pharmacokinetics, and other pharmacologic effects in Japanese healthy volunteers without methotrexate treatment. A dose of 50 U/kg (n = 8) or 20 U/kg (n = 8) of glucarpidase was administered as an intravenous injection, with 1 repeated dose at 48 hours after the first dose. No dose‐limiting toxicities, no significant clinical examination findings, and no clinically relevant differences between dose levels were observed. The pharmacokinetic parameters at a first dose of 20 or 50 U/kg were similar to those at a second dose and were as follows: half‐life, 7.45 and 7.25 hours; area under the plasma concentration–time curve from time 0 to infinity, 8.25 and 19.05 μg·h/mL; total clearance, 4.85 and 5.47 mL/min; and volume of distribution during the elimination phase, 3.12 and 3.41 L, respectively. The area under the plasma concentration–time curve increased in a generally linear dose‐proportional manner. An ethnicity specificity in the pharmacokinetic profile was not observed in Japanese volunteers. The serum folate concentration decreased after glucarpidase administration in all the volunteers. The production of anti‐glucarpidase antibody was observed in many cases in both cohorts. Although the long‐term effect of anti‐glucarpidase antibody will need to be investigated in the future, the effects produced by the anti‐glucarpidase antibody were not influenced by the pharmacokinetics of glucarpidase within 96 hours after the first dose. The observed safety and tolerability, pharmacokinetics, and pharmacodynamics support the continued evaluation of glucarpidase in the patients with lethal methotrexate toxicities.

Diabetes is a risk factor for high-dose methotrexate-associated AKI in lymphoma patients

Purpose

The aim of the study was to investigate the incidence of acute kidney injury (AKI) occurring after high-dose methotrexate (HDMTX) administration and the role of type 2 diabetes (T2D) playing in the occurrence of AKI.

Methods

We assessed associations between T2D along with other confounding factors mainly including baseline estimated glomerular filtration rate (eGFR), methotrexate (MTX) elimination and urine pH, and AKI occurrence. Patients who were diagnosed as primary central nervous system lymphoma with treatment of HDMTX and with eGFR ≥60 mL/min/1.73 m² were enrolled in this study.

Results

Of the 507 courses enrolled in this study, 132 courses have T2D. Lower baseline eGFR, delayed MTX elimination, lower urine pH, and higher incidence of AKI were observed in T2D group. Using univariate logistic regression, several confounding factors including baseline eGFR, hypertension, MTX elimination, and urine alkalinization statistically and clinically important were screened out. After adjusting for these factors, T2D remained an independent association with AKI occurrence. AKI outcome had no significant relationship with severe hematological toxicity or hepatotoxicity. AKI was associated with faster eGFR decline after a series of HDMTX treatment courses.

Conclusions

Patients with T2D have a higher sensitivity to AKI when administrated with HDMTX. This conclusion addresses safety concerns for making chemotherapy regimen for this population.

Development of antibacterial compounds that constrain evolutionary pathways to resistance

Antibiotic resistance is a worldwide challenge. A potential approach to block resistance is to simultaneously inhibit WT and known escape variants of the target bacterial protein. Here, we applied an integrated computational and experimental approach to discover compounds that inhibit both WT and trimethoprim (TMP) resistant mutants of E. coli dihydrofolate reductase (DHFR). We identified a novel compound (CD15-3) that inhibits WT DHFR and its TMP resistant variants L28R, P21L and A26T with IC₅₀ 50–75 µM against WT and TMP-resistant strains. Resistance to CD15-3 was dramatically delayed compared to TMP in in vitro evolution. Whole genome sequencing of CD15-3-resistant strains showed no mutations in the target folA locus. Rather, gene duplication of several efflux pumps gave rise to weak (about twofold increase in IC₅₀) resistance against CD15-3. Altogether, our results demonstrate the promise of strategy to develop evolution drugs - compounds which constrain evolutionary escape routes in pathogens.

Population Pharmacokinetics of High-Dose Methotrexate in Chinese Pediatric Patients With Acute Lymphoblastic Leukemia

High-dose methotrexate (HD-MTX) is widely used in pediatric acute lymphoblastic leukemia (ALL) treatment regimens. In this study, we aimed to develop a population pharmacokinetic (PK) model of HD-MTX in Chinese pediatric patients with ALL for designing personalized dosage regimens. In total, 4,517 MTX serum concentration data for 311 pediatric patients with ALL, aged 0.75–15.2 years and under HD-MTX treatment, were retrospectively collected at a tertiary Children’s Hospital in China. The non-linear mixed-effect model was used to establish the population PK model, using NONMEM software. The potential covariate effects of age, body weight, and biochemical measurements (renal and liver function) on MTX PK disposition were investigated. The model was then evaluated using goodness-of-fit, visual predictive check. MTX PK disposition was described using a three-compartment model reasonable well. Body weight, implemented as a fixed allometric function on all clearance and volume of distribution parameters, showed a substantial improvement in model fit. The final population model demonstrated that the MTX clearance estimate in a typical child with body weight of 19 kg was 6.9 L/h and the central distribution of volume estimate was 20.7 L. The serum creatinine significantly affected the MTX clearance, with a 0.97% decrease in clearance per 1 μmol/L of serum creatinine. Other covariates (e.g., age, sex, bilirubin, albumin, aspartate transaminase, concomitant medication) did not significantly affect PK properties of MTX. The proposed population PK model could describe the MTX concentration data in Chinese pediatric patients with ALL. This population PK model combined with a maximum a posteriori Bayesian approach could be used to estimate individual PK parameters, and optimize personalized MTX therapy in target patients, thus aiming to reduce toxicity and improve treatment outcomes.

Methotrexate impacts conserved pathways in diverse human gut bacteria leading to decreased host immune activation

Immunomodulatory drugs can inhibit bacterial growth, yet their mechanism of action, spectrum, and clinical relevance remain unknown. Methotrexate (MTX), a first-line rheumatoid arthritis (RA) treatment, inhibits mammalian dihydrofolate reductase (DHFR), but whether it directly impacts gut bacteria is unclear. We show that MTX broadly alters the human gut microbiota. Drug sensitivity varied across strains, but the mechanism of action against DHFR appears conserved between mammalian and bacterial cells. RA patient microbiotas were sensitive to MTX, and changes in gut bacterial taxa and gene family abundance were distinct between responders and non-responders. Transplantation of post-treatment samples into germ-free mice given an inflammatory trigger led to reduced immune activation relative to pre-treatment controls, enabling identification of MTX-modulated bacterial taxa associated with intestinal and splenic immune cells. Thus, conservation in cellular pathways across domains of life can result in broad off-target drug effects on the human gut microbiota with consequences for immune function.

Low Serum Albumin Level Is a Risk Factor for Delayed Methotrexate Elimination in High-Dose Methotrexate Treatment

BACKGROUND

In high-dose methotrexate (HD-MTX) therapy, delayed elimination of MTX from plasma leads to severe adverse effects. However, the risk factors for the delayed elimination of plasma MTX are still unclear.

OBJECTIVE

The purpose of this study was to investigate the factors related to the delayed MTX elimination in HD-MTX monotherapy.

METHODS

This retrospective study was performed on patients who received HD-MTX monotherapy between April 2009 and March 2019 at the Hiroshima University Hospital. Patients were divided into a "Normal" and a "Delayed" group according to their MTX plasma concentration at 48 or 72 hours after administration. Patient characteristics, dose of HD-MTX, MTX plasma concentration, and adverse effects were analyzed and compared between the 2 groups.

RESULTS

A total of 74 patients were included in this study. Logistic analysis of patient baseline characteristics was performed to identify risk factors for delayed MTX elimination. Serum albumin (ALB) was detected as a risk factor. Univariate and multivariate analysis revealed that low ALB level (<3.7 g/dL) and type of cancer were associated with delayed MTX elimination (univariate analysis: odds ratio [OR] = 6.00, P = 0.004, and OR = 4.33, P = 0.039, respectively; multivariate analysis: adjusted OR [AOR] = 6.45, P = 0.006, and AOR = 8.11, P = 0.018, respectively). Adverse effects were not significantly different between the 2 groups, excluding renal impairment.

CONCLUSIONS AND RELEVANCE

Our study showed that low ALB is a risk factor for delayed MTX elimination in HD-MTX monotherapy. Pharmacokinetic analysis is needed to establish the dose of HD-MTX in patients with a low ALB level.

Improved Bioavailability and High Photostability of Methotrexate by Spray-Dried Surface-Attached Solid Dispersion with an Aqueous Medium

Low aqueous solubility and poor bioavailability are major concerns in the development of oral solid-dosage drug forms. In this study, we fabricated surface-attached solid dispersion (SASD) to enhance the solubility, bioavailability, and photostability of methotrexate (MTX), a highly lipophilic and photo-unstable drug. Several MTX-loaded SASD formulations were developed for spray-drying using water as the solvent, and were investigated for their aqueous solubility and dissolution kinetics. An optimized ternary SASD formulation composed of MTX/ sodium carboxymethyl cellulose (Na-CMC)/sodium lauryl sulfate (SLS) at 3/0.5/0.5 (w/w) had 31.78-fold and 1.88-fold higher solubility and dissolution, respectively, than MTX powder. For SASD, the in vivo pharmacokinetic parameters AUC and C_max were 2.90- and 3.41-fold higher, respectively, than for the MTX powder. Solid-state characterizations by differential scanning calorimetry and X-ray diffraction revealed that MTX exists in its crystalline state within the spray-dried SASD. The MTX-loaded SASD formulation showed few physical changes with photostability testing. Overall, the results indicate that the spray-dried MTX-loaded SASD formulation without organic solvents enhances the solubility and oral bioavailability of MTX without a significant deterioration of its photochemical stability.

Rethinking the Application of Pemetrexed for Patients with Renal Impairment: A Pharmacokinetic Analysis

Background

Pemetrexed is used for the treatment for non-small cell lung cancer and mesothelioma. Patients with renal impairment are withheld treatment with this drug as it is unknown what dose is well tolerated in this population.

Objective

The purpose of our study was to investigate the pharmacokinetics (PK) of pemetrexed in patients with renal impairment.

Methods

A population PK analysis of pemetrexed was performed using non-linear mixed-effects modelling with phase I data obtained from the manufacturer. Additionally, the impact of renal function on pemetrexed PK was assessed with a simulation study using the developed PK model and a previously developed PK model lacking the phase I data.

Results

The dataset included 548 paired observations of 47 patients, with a wide range of estimated glomerular filtration rates (eGFR; 14.4–145.6 mL/min). Pemetrexed PK were best described by a three-compartment model with eGFR (calculated using the Chronic Kidney Disease–Epidemiology Collaboration [CKD-EPI] formula) as a linear covariate on renal pemetrexed clearance. Using the developed model, we found that renal clearance accounts for up to 84% (95% confidence interval 69–98%) of total pemetrexed clearance, whereas the manufacturer previously reported a 50% contribution of renal clearance.

Conclusion

Renal function is more important for the clearance of pemetrexed than previously thought and this should be taken into account in patients with renal impairment. Furthermore, a third compartment may contribute to prolonged exposure to pemetrexed during drug washout.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-020-00972-1.

Excellent Outcomes With Reduced Frequency of Vincristine and Dexamethasone Pulses in Standard-Risk B-Lymphoblastic Leukemia: Results From Children's Oncology Group AALL0932

PURPOSE

AALL0932 evaluated two randomized maintenance interventions to optimize disease-free survival (DFS) while reducing the burden of therapy in children with newly diagnosed NCI standard-risk (SR) B-acute lymphoblastic leukemia (B-ALL).

METHODS

AALL0932 enrolled 9,229 patients with B-ALL; 2,364 average-risk (AR) patients were randomly assigned (2 × 2 factorial design) at the start of maintenance therapy to vincristine/dexamethasone pulses every 4 (VCR/DEX4) or every 12 (VCR/DEX12) weeks, and a starting dose of weekly oral methotrexate of 20 mg/m² (MTX20) or 40 mg/m² (MTX40).

RESULTS

Five-year event-free survival and overall survival (OS) from enrollment (with 95% CIs), for all eligible and evaluable SR B-ALL patients (n = 9,226), were 92.0% (91.1% and 92.8%) and 96.8% (96.2% and 97.3%), respectively. The 5-year DFS and OS from the start of maintenance for randomly assigned AR patients were 94.6% (93.3% and 95.9%) and 98.5% (97.7% and 99.2%), respectively. The 5-year DFS and OS for patients randomly assigned to receive VCR/DEX4 (n = 1,186) versus VCR/DEX12 (n = 1,178) were 94.1% (92.2% and 96.0%) and 98.3% (97.2% and 99.4%) v 95.1% (93.3% and 96.9%) and 98.6% (97.7% and 99.6%), respectively (P = .86 and .69). The 5-year DFS and OS for AR patients randomly assigned to receive MTX20 versus MTX40 were 95.1% (93.3% and 96.8%) and 98.8% (97.9% and 99.7%) v 94.2% (92.2% and 96.1%) and 98.1% (97.0% and 99.2%), respectively (P = .92 and .89).

CONCLUSIONS

The 0NCI-SR AR B-ALL who received VCR/DEX12 had outstanding outcomes despite receiving one third of the vincristine/dexamethasone pulses previously used as standard of care on Children's Oncology Group (COG) trials. The higher starting dose of MTX of 40 mg/m²/week did not improve outcomes when compared with 20 mg/m²/week. The decreased frequency of vincristine/dexamethasone pulses has been incorporated into frontline COG B-ALL trials to decrease the burden of therapy for patients and their families.

Methotrexate Gold Nanocarriers: Loading and Release Study: Its Activity in Colon and Lung Cancer Cells

In the present study, the synthesis of gold nanoparticles (AuNPs) loaded with methotrexate (MTX) has been carried out in order to obtain controlled size and monodispersed nanocarriers of around 20 nm. The characterization study shows metallic AuNPs with MTX polydispersed on the surface. MTX is linked by the replacement of citrate by the MTX carboxyl group. The drug release profiles show faster MTX release when it is conjugated, which leads to the best control of plasma concentration. Moreover, the enhanced release observed at pH 5 could take advantage of the pH gradients that exist in tumor microenvironments to achieve high local drug concentrations. AuNP–MTX conjugates were tested by flow cytometry against lung (A-549) and colon (HTC-116) cancer cell lines. Results for A-549 showed a weaker dose–response effect than for colon cancer ones. This could be related to the presence of folate receptors in line HTC-116 in comparison to line A-549, supporting the specific uptake of folate-conjugated AuNP–MTX by folate receptor positive tumor cells. Conjugates exhibited considerably higher cytotoxic effects compared with the effects of equal doses of free MTX. Annexin V-PI tests sustained the cell death mechanism of apoptosis, which is normally disabled in cancer cells.

Poisoning related to therapeutic error in prolonged low-dose methotrexate treatment

AIMS

To study the predictive factors for the development of clinical manifestations in poisoning due to the erroneous taking of low-dose methotrexate (MTX).

METHODS

A retrospective observational study was performed. Only cases of erroneous administration in non-oncologic outpatients were included (July 2008-March 2020).

RESULTS

Forty-one cases were included. All patients were taking MTX for the first time. In 36 cases, patients took MTX daily instead of weekly. In the other five patients, MTX was sold instead of methylergometrine. Clinical manifestations were absent in 12/41 patients (29.3%). All 29 (70.7%) symptomatic patients recognized the medication error when they developed clinical manifestations: dermatological, haematological and gastrointestinal symptoms. Statistical results showed that symptomatic patients were older, received a higher amount of total dose and were treated for longer. Moreover, the probability of being symptomatic increases as a function of age and of total dose. Asymptomatic patients were treated with folinic acid (30 mg/m² /day) for 5 days. Symptomatic patients were treated with folinic acid together with treatments for the specific clinical manifestations. No patients were treated with glucarpidase. All patients fully recovered.

CONCLUSIONS

When MTX is prescribed for the first time, it is important to clearly communicate with patients to avoid therapeutic errors. In our experience, age, total dose taken and number of days of assumption are predictive for the presence/absence of clinical manifestations. These parameters must be evaluated together to identify patients needing maximum starting treatment with folinic acid and closer monitoring.

Inflammatory bowel disease amid the COVID-19 pandemic: impact, management strategies, and lessons learned

The current outbreak of COVID-19 pandemic caused by SARS-CoV-2 has affected nearly 188 countries. Patients with severe COVID-19 are more commonly elderly and suffer from comorbidities such as hypertension, diabetes mellitus, coronary artery disease, chronic pulmonary disease, obesity, and cancer. Inflammatory bowel disease (IBD) affects as many as 6.8 million people globally, and a significant proportion of them are treated with immunosuppressants. Hence, there is an ongoing concern over the impact of COVID-19 on IBD patients and their susceptibility to it. So far, there are about 1439 IBD patients in the Surveillance Epidemiology of Coronavirus under Research Exclusion (SECURE-IBD) registry reported to be infected with SARS-CoV-2. There are many unique challenges and dilemmas that need to be taken into account when managing an IBD patient with COVID-19. The management of each patient should be individualized. The IBD societies and experts have strongly recommended that patients should not discontinue their IBD medications. If the patients have symptoms of COVID-19 or IBD flare-up, they are recommended to call their IBD physician first to discuss their medication. In addition, IBD patients are urged to practice social distancing strictly to minimize the chances of infection. As COVID-19 is rapidly evolving, our experience and understanding of its impact on the IBD population may potentially change in the near future.

Intralesional methotrexate in dermatology: Diverse indications and practical considerations

Intralesional methotrexate (IL-MTX) is a long-established treatment, which is arguably underutilized by dermatologists. We describe the underlying evidence base and practical considerations for its broad range of cutaneous indications, including in cutaneous oncology (keratoacanthomas, squamous cell carcinomas, lymphomas), inflammatory dermatology (nail psoriasis, plaque psoriasis, pyoderma gangrenosum, cutaneous Crohn's disease, amyloidosis), cutaneous infections (viral warts) and for treatment of filler complications. In certain circumstances, IL-MTX can be more efficacious and less invasive than other treatments, with fewer adverse effects. Dermatologists should consider using IL-MTX for a range of recalcitrant cutaneous conditions, particularly for those patients not amenable to surgery or systemic therapy.

Influence of MTHFR C677T Polymorphism on High-Dose Methotrexate-Related Toxicity in Patients With Primary Central Nervous System Diffuse Large B-Cell Lymphoma

BACKGROUND

Primary central nervous system diffuse large B-cell lymphoma (PCNS-DLBCL) is a relatively rare and aggressive neoplasm. High-dose methotrexate (HD-MTX) is an effective regimen for the treatment of PCNS-DLBCL, but MTX-related toxicity remains a problem. The aim of this analysis study was to investigate the influence of the methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism on HD-MTX-related toxicity in patients with PCNS-DLBCL.

MATERIAL/METHODS

A prospective, observational study was conducted to analyze 148 MTX courses in 32 patients with PCNS-DLBCL.

RESULTS

The delayed MTX clearance was observed in 53 cycles (35.8%). The patients carrying the homozygous variant genotype had a higher risk of developing nephrotoxicity than those carrying the wild-type genotype (odds ratio [OR] 13.08; 95% confidence interval [CI], 1.65-103.86; P = .002) or heterozygous variant genotype (OR 8.43; 95% CI, 2.31-30.70; P < .001). Significant differences were observed in hepatotoxicity (OR 9.33; 95% CI, 2.54-34.27; P < .001) and hematologic toxicity (OR 3.09; 95% CI, 1.18-8.07; P = .024) in addition to nephrotoxicity between the homozygous variant genotype and the wild-type genotype.

CONCLUSION

The homozygous mutation of C to T at nucleotide 677 increases the risk on HD-MTX-related toxicity. The MTHFR C677T polymorphism can be used to predict HD-MTX-related toxicity for patients with PCNS-DLBCL.

Polymeric Nanoscale Drug Carriers Mediate the Delivery of Methotrexate for Developing Therapeutic Interventions Against Cancer and Rheumatoid Arthritis

Methotrexate (MTX) is widely used as an anticancer and anti-inflammtory drug for treating various types of cancer and autoimmune diseases. The optimal dose of MTX is known to inhibit the dihydrofolatereductase that hinders the replication of purines. The nanobiomedicine has been extensively explored in the past decade to develop myriad functional nanostructures to facilitate the delivery of therapeutic agents for various medical applications. This review is focused on understanding the design and development of MTX-loaded nanoparticles alongside the inclusion of recent findings for the treatment of cancers. In this paper, we have made a coordinated effort to show the potential of novel drug delivery systems by achieving effective and target-specific delivery of methotrexate.

Cerebral Microdialysis as a Tool for Assessing the Delivery of Chemotherapy in Brain Tumor Patients

The development of curative treatment for glioblastoma has been extremely challenging. Chemotherapeutic agents that have seemed promising have failed in clinical trials. Drugs that can successfully target cancer cells within the brain must first traverse the brain interstitial fluid. Cerebral microdialysis (CMD) is an invasive technique in which interstitial fluid can be directly sampled. CMD has primarily been used clinically in the setting of head trauma and subarachnoid hemorrhage. Our goal was to review the techniques, principles, and new data pertaining to CMD to highlight its use in neuro-oncology. We conducted a literature search using the PubMed database and selected studies in which the investigators had used CMD in either animal brain tumor models or clinical trials. The references were reviewed for additional information. Studies of CMD have shown its importance as a neurosurgical technique. CMD allows for the collection of pharmacokinetic data on drug penetrance across the blood-brain barrier and metabolic data to characterize the response to chemotherapy. Although no complications have been reported, the current CMD technique (as with any procedure) has risks and limitations, which we have described in the present report. Animal CMD experiments have been used to exclude central nervous system drug candidates from progressing to clinical trials. At present, patients undergoing CMD have been monitored in the intensive care unit, owing to the requisite tethering to the apparatus. This can be expected to change soon because of advances in microminiaturization. CMD is an extremely valuable, yet underused, technique. Future CMD applications will have central importance in assessing drug delivery to tumor cells in vivo, allowing a pathway to successful therapy for malignant brain tumors.

Methotrexate-Induced Pancytopenia and Mucositis Caused by Medication Error

The use of methotrexate in routine clinical practice is becoming more common among specialties such as rheumatology, dermatology, oncology and obstetrics. General clinicians are increasingly encountering patients on this drug. Though it has a high safety profile, there is a recognised risk of acute toxicity or long-term complications associated with its use, which can be worsened by several factors such as advanced age, moderate to severe renal impairment, low folate level and/or inadequate folate supplementation, hypoalbuminaemia, polypharmacy causing drug-drug interactions and wrongful administration. We present a case of a 45-year old woman with rheumatoid arthritis who presented with acute pancytopaenia and mucositis due to methotrexate toxicity. We highlight its peculiar dosing regimen to minimise prescribing errors.

A mathematical model of white blood cell dynamics during maintenance therapy of childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia is the most common malignancy in childhood and requires prolonged oral maintenance chemotherapy to prevent disease relapse after remission induction with intensive intravenous chemotherapy. In maintenance therapy, drug doses of 6-mercaptopurine (6-MP) and methotrexate (MTX) are adjusted to achieve sustained antileukemic activity without excessive myelosuppression. However, uncertainty exists regarding timing and extent of drug dose responses and optimal dose adaptation strategies. We propose a novel comprehensive mathematical model for 6-MP and MTX pharmacokinetics, pharmacodynamics and myelosuppression in acute lymphoblastic maintenance therapy. We personalize and cross-validate the mathematical model using clinical data and propose a real-time algorithm to predict chemotherapy responses with a clinical decision support system as a potential future application.

Slit-like hypertensive hydrocephalus: Report of a late, complex, and multifactorial complication in an oncologic patient

Background:

Several sophisticated techniques and many chemotherapy drugs have improved life expectancy of oncologic patients allowing us to observe late complications which present many years after the initial treatment.

Case Description:

We present a unique case of a patient affected by acute lymphoblastic leukemia at the age of 6 years, treated with whole brain radiotherapy and intrathecal chemotherapy, developing meningiomatosis and leptomeningeal alterations as late complications and the interaction of these two entities caused a peculiar form of hydrocephalus without ventricular dilation. The diagnosis of pseudotumor cerebri was excluded due the postradio/chemotherapy development of meningiomatosis, not present in a previously head magnetic resonance imaging, that exerted compression to the Sylvian aqueduct causing intracranial hypertension with papillary stasis without ventricles enlargement due to brain stiffness. Moreover, a peculiar intraoperative rubbery consistency of brain parenchyma was detected strengthening this complex diagnosis.

Conclusion:

At the best of our knowledge, this is the first report of obstructive hydrocephalus without ventricles dilation caused by brain stiffness related to late alterations of oncologic treatments. This report could be a guide for further complex patients diagnoses and for improving treatments efficacy.

Drug Resistance in Cancer Therapy and the Role of Epigenetics

Effective leukemia treatment is seriously hampered by drug resistance, and the potential role of epigenetic mechanisms in cancer drug resistance has recently been investigated. With conventional anticancer drugs, including alkylating drugs, anti-metabolite drugs, topoisomerase inhibitors, and microtubule inhibitors-which have been available for half a century-drug resistance often develops because of decreased expression of target enzymes, in conjunction with increased expression of drug export pumps. Alterations of target gene expression and increased export pump function might be caused by epigenetic changes, such as alterations in methylation status, as well as by changes in histone acetylation status. In addition, newly developed anticancer drugs, including small-molecule drugs, such as kinase inhibitors, antibody drugs, and immune modulatory drugs, also resulted in development of drug resistance within 1 year, although these drugs showed significant effectiveness for patients resistant to conventional anticancer drugs. The resistant cells exhibited increased expression of bypass pathways, activation of downstream cascades, decreased expression of antigens of tumor cells, increased DNA repair activity, and increased expression of drug export pumps, which also suggests the presence of epigenetic changes. This article reviews drug resistance in cancer therapy and the possible roles of epigenetic mechanisms.

The Role of Ca2+-NFATc1 Signaling and Its Modulation on Osteoclastogenesis

The increasing of intracellular calcium concentration is a fundamental process for mediating osteoclastogenesis, which is involved in osteoclastic bone resorption. Cytosolic calcium binds to calmodulin and subsequently activates calcineurin, leading to NFATc1 activation, a master transcription factor required for osteoclast differentiation. Targeting the various activation processes in osteoclastogenesis provides various therapeutic strategies for bone loss. Diverse compounds that modulate calcium signaling have been applied to regulate osteoclast differentiation and, subsequently, attenuate bone loss. Thus, in this review, we summarized the modulation of the NFATc1 pathway through various compounds that regulate calcium signaling and the calcium influx machinery. Furthermore, we addressed the involvement of transient receptor potential channels in osteoclastogenesis.

Role of plasminogen activator inhibitor-1 in methotrexate-induced epithelial-mesenchymal transition in alveolar epithelial A549 cells

There is increasing evidence that epithelial-mesenchymal transition (EMT) contributes to the development of organ fibrosis. We demonstrated that methotrexate (MTX) clearly induced EMT through the transforming growth factor (TGF)-β-related signaling pathway in human alveolar epithelial cell line, A549. However, critical factors associated with MTX-induced EMT have not yet been identified. In our study, we attempted to identify factors playing a crucial role in MTX-induced EMT in A549 cells. We focused on plasminogen activator inhibitor-1 (PAI-1) as the possible target for the prevention of MTX-induced EMT-related lung injury. Comprehensive gene expression analysis by microarray revealed that mRNA expression level of PAI-1 was clearly increased by MTX treatment. In addition, using several cloned A549 cells, we found a good correlation between MTX-induced increase in mRNA expression levels of α-smooth muscle actin (SMA), a representative EMT marker, and PAI-1. Furthermore, MTX upregulated mRNA and protein expression levels of PAI-1 in A549 cells; this upregulation was canceled by co-treatment with SB431542, a TGF-β-related signaling pathway inhibitor. Notably, tiplaxtinin, a PAI-1 inhibitor, and knockdown of urokinase-type plasminogen activator receptor (uPAR) prevented MTX-induced EMT in A549 cells. These findings indicate that MTX may induce EMT via upregulation of PAI-1 expression and interaction of PAI-1 with uPAR in A549 cells.

Application of either nano fibrillated cellulose methotrexate or nano silicon dioxide methotrexate composites against renal fibrosis in leukemia rat model

Cellulose derivatives have got growing interest due to their relative abundance and ability to sustain the release of medicaments. In this study, micro- and nano-fibrillated cellulose were prepared from rice straw and used as drug carriers. Both carriers in addition to another one which is nano silicon dioxide were characterized with various techniques. Methotrexate was chosen to be loaded on nano-fibrillated cellulose and nano silicon dioxide. Both methotrexate carriers were evaluated for their possible protective role against renal fibrosis induced by methotrexate in leukemia rat model. Results of this study exhibited that loading methotrexate on either nano-fibrillated cellulose or nano silicon dioxide seems to have an ameliorative role on renal function tests, inflammatory and fibrotic markers of renal tissues. Moreover, the sustained release of methotrexate for long time period maintained by nano-fibrillated cellulose carrier gives it more priority than nano silicon dioxide to be used as an effective novel drug carrier in further medical applications with minimal side effects on kidney tissue in leukemia model.

Pharmacokinetics and pharmacogenetics of high-dose methotrexate in Chinese adult patients with non-Hodgkin lymphoma: a population analysis

PURPOSE

High-dose methotrexate (HD-MTX) is widely used in the treatment of non-Hodgkin lymphoma (NHL), but the pharmacokinetic properties of HD-MTX in Chinese adult patients with NHL have not yet been established through an approach that integrates genetic covariates. The purposes of this study were to identify both physiological and pharmacogenomic covariates that can explain the inter- and intraindividual pharmacokinetic variability of MTX in Chinese adult patients with NHL and to explore a new sampling strategy for predicting delayed MTX elimination.

METHODS

A total of 852 MTX concentrations from 91 adult patients with NHL were analyzed using the nonlinear mixed-effects modeling method. FPGS, GGH, SLCO1B1, ABCB1 and MTHFR were genotyped using the Sequenom MassARRAY technology platform and were screened as covariates. The ability of different sampling strategies to predict the MTX concentration at 72 h was assessed through maximum a posteriori Bayesian forecasting using a validation dataset (18 patients).

RESULTS

A two-compartment model adequately described the data, and the estimated mean MTX clearance (CL) was 6.03 L/h (9%). Creatinine clearance (CrCL) was identified as a covariate for CL, whereas the intercompartmental clearance (Q) was significantly affected by the body surface area (BSA). However, none of the genotypes exerted a significant effect on the pharmacokinetic properties of MTX. The percentage of patients with concentrations below 0.2 µmol/L at 72 h decreased from 65.6 to 42.6% when the CrCL decreased from 90 to 60 ml/min/1.73 m² with a scheduled dosing of 3 g/m², and the same trend was observed with dose regimens of 1 g/m² and 2 g/m². Bayesian forecasting using the MTX concentrations at 24 and 42 h provided the best predictive performance for estimating the MTX concentration at 72 h after dosing.

CONCLUSIONS

The MTX population pharmacokinetic model developed in this study might provide useful information for establishing personalized therapy involving MTX for the treatment of adult patients with NHL.

Usefulness of daily folic acid supplementation during methotrexate treatment of Japanese patients with rheumatoid arthritis

OBJECTIVES

We investigated the effect of daily folic acid supplementation on methotrexate (MTX) toxicity and efficacy in Japanese patients with rheumatoid arthritis (RA).

METHODS

We followed 19 patients treated with MTX who switched from taking weekly 5 mg folic acid supplementation (weekly regimen) to 1.25 mg daily (daily regimen). White blood cell (WBC) and platelet (PLT) counts, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels were collected for 24 weeks following the change.

RESULTS

We observed no significant changes in WBC or PLT counts. AST and ALT levels, which had exceeded the upper limits of their normal ranges at the beginning of the study, were improved significantly at weeks 4 and 8, no subsequent deterioration in liver function was found. Further, no significant changes in ESR and CRP levels were observed.

CONCLUSION

Our data indicate that supplementing 1.25 mg of folic acid daily rather than 5 mg weekly reduces toxicity caused by MTX without affecting its efficacy.

Disease modifying drugs for rheumatological diseases: a brief history of everything

The rheumatological diseases are a group of chronic, painful, degenerative and debilitating conditions with an increasing prevalence across the globe. The pathogenesis of these disorders is complex, overlapping and not fully understood. As such, it is difficult and time consuming to achieve correct diagnosis and complete remission for an individual patient. In this review we describe the most common forms of inflammatory arthritis and discuss how the management and treatment options for these rheumatic diseases have developed over time. We outline the successes and the limitations of current treatment regimens and discuss the economic burden of the current options. With advancements in understanding of disease mechanisms, we discuss the importance of the biologics revolution in the context of rheumatological disease and how the development of biosimilars and small molecule inhibitors will impact current treatment options in order to alleviate some of the cost burden of biological therapies. The ideal treatment strategy for the future would involve personalized and predictive medicine where by treatments can be tailored to an individual patient's needs in order to achieve fast and successful remission with no adverse events.