Population Pharmacokinetics of Trametinib and Impact of Nonadherence on Drug Exposure in Oncology Patients as Part of the Optimizing Oral Targeted Anticancer Therapies Study.

Trametinib is a targeted therapy used for the treatment of solid tumours, with significant variability reported in real-life studies. This variability increases the risk of suboptimal exposure, which can lead to treatment failure or increased toxicity. Using model-based simulation, this study aims to characterize and investigate the pharmacokinetics and the adequacy of the currently recommended doses of trametinib. Additionally, the simulation of various suboptimal adherence scenarios allowed for an assessment of the impact of patients' drug adherence on the treatment outcome. The population data collected in 33 adult patients, providing 113 plasmatic trametinib concentrations, were best described by a two-compartment model with linear absorption and elimination. The study also identified a significant positive effect of fat-free mass and a negative effect of age on clearance, explaining 66% and 21% of the initial associated variability, respectively. Simulations showed that a maximum dose of 2 mg daily achieved the therapeutic target in 36% of male patients compared to 72% of female patients. A dose of 1.5 mg per day in patients over 65 years of age achieved similar rates, with 44% and 79% for male and female patients, respectively, reaching the therapeutic target. Poor adherence leads to a significant drop in concentrations and a high risk of subtherapeutic drug levels. These results underline the importance of interprofessional collaboration and patient partnership along the patient's journey to address patients' needs regarding trametinib and support medication adherence.

Novel Patient-Friendly Orodispersible Formulation of Ivermectin is Associated With Enhanced Palatability, Controlled Absorption, and Less Variability: High Potential for Pediatric Use.

Ivermectin has been used since the 1980s as an anthelmintic and antiectoparasite agent worldwide. Currently, the only available oral formulation is tablets designed for adult patients. A patient-friendly orodispersible tablet formulation designed for pediatric use (CHILD-IVITAB) has been developed and is entering early phase clinical trials. To inform the pediatric program of CHILD-IVITAB, 16 healthy adults were enrolled in a phase I, single-center, open-label, randomized, 2-period, crossover, single-dose trial which aimed to compare palatability, tolerability, and bioavailability and pharmacokinetics of CHILD-IVITAB and their variability against the marketed ivermectin tablets (STROMECTOL) at a single dose of 12 mg in a fasting state. Palatability with CHILD-IVITAB was considerably enhanced as compared to STROMECTOL. Both ivermectin formulations were well tolerated and safe. Relative bioavailability of CHILD-IVITAB compared to STROMECTOL was estimated as the ratios of geometric means for Cmax, AUC 0-∞, and AUC0-last, which were 1.52 [90% CI: 1.13-2.04], 1.27 [0.99-1.62], and 1.29 [1.00-1.66], respectively. Maximum drug concentrations occurred earlier with the CHILD-IVITAB formulation, with a median Tmax at 3.0 h [range 2.0-4.0 h] versus 4.0 h [range 2.0-5.0 h] with STROMECTOL (P = .004). With CHILD-IVITAB, variability in exposure was cut in half (coefficient of variation: 37% vs 70%) compared to STROMECTOL. Consistent with a more controlled absorption process, CHILD-IVITAB was associated with reduced variability in drug exposure as compared to STROMECTOL. Together with a favorable palatability and tolerability profile, these findings motivate for further clinical studies to evaluate benefits of such a patient-friendly ODT formulation in pediatric patients with a parasitic disease, including infants and young children <15 kg.

[Pharmacovigilance. Withdrawal and rebound effects: not just with psychotropic drugs]. / Pharmacovigilance. Sevrage et effet rebond: pas seulement avec les psychotropes.

The list of drugs whose abrupt discontinuation is likely to induce withdrawal symptoms or a rebound in the pathology being treated is not limited to psychotropic drugs. It includes a number of somatic drugs (e.g. proton pump inhibitors, opioids, triptans, fingolimod, corticosteroids, antiepileptics, nootropics, antiparkinsonians, denosumab, beta-blockers, laxatives, nasal vasoconstrictors, etc.). This type of unintended effect, often underestimated, generally results from a drug-induced homeostatic imbalance that persists after the drug has been discontinued. Taking this risk into account right from the initial prescription should make it possible to prevent such complications, by encouraging intermittent use of the drug, or by applying a very gradual reduction in dosage when a regular treatment is stopped.

La liste des médicaments dont l'arrêt brusque est susceptible d'entraîner des symptômes de sevrage ou un rebond de la pathologie traitée ne se limite pas aux psychotropes, mais inclut un certain nombre de médicaments somatiques (inhibiteurs de la pompe à protons, opioïdes, triptans, fingolimod, corticostéroïdes, antiépileptiques, nootropes, antiparkinsoniens, dénosumab, bêtabloquants, laxatifs, vasoconstricteurs nasaux, etc.). Ce type d'effet indésirable, souvent méconnu, résulte en général d'un déséquilibre homéostatique causé par le médicament, persistant après son interruption. La prise en compte de ce risque dès la prescription initiale devrait permettre de prévenir ces complications, en privilégiant un recours intermittent au médicament ou en prévoyant une diminution très progressive des posologies au moment de mettre un terme à un traitement continu.

5-Fluorouracil-associated severe hypertriglyceridaemia with positive rechallenge.

Chemotherapy-induced hypertriglyceridaemia (HTG) is a potential serious adverse event. Severe HTG with triglycerides (TG) >11.3 mmol/L (1000 mg/dL) can cause acute pancreatitis in addition to cardiovascular diseases such as coronary artery disease. While the association of capecitabine (5-fluorouracil (5-FU) prodrug) with clinically relevant HTG is a well-known adverse reaction, 5-FU is not typically associated with HTG. We here report the case of a patient who developed 5-FU-associated grade 4 HTG with TG level raising up to 37.1 mmol/L (3286 mg/dL) occurring after the ninth cycle of adjuvant FOLFOX (Fluorouracil and Oxaliplatin) chemotherapy. Fenofibrate treatment and diet were started. Chemotherapy was postponed and then resumed for two additional cycles. However, severe HTG recurred shortly after. Chemotherapy was therefore permanently stopped. Approximately 8 weeks after chemotherapy discontinuation, TG fell back to range at 2.1 mmol/L (189 mg/dL) allowing interruption of fenofibrate without HTG recurrence at 3 months.

An innovative ethosuximide granule formulation designed for pediatric use: Comparative pharmacokinetics, safety, tolerability, and palatability profile versus reference syrup.

Ethosuximide, the first-line therapy for childhood absence epilepsy, is currently formulated as a syrup (Zarontin®, Pfizer) with a bitter taste and high sugar content, poorly adapted to children, and a ketogenic diet. The collaborative European FP7 project KIEKIDS aimed at developing an innovative sugar-free, tasteless formulation convenient for pediatric use. This dual Phase-I study evaluated two granule formulations based on lipid multiparticulate (LMP) technology. Two panels of 6 healthy adult volunteers underwent a randomized, placebo-controlled, partly blinded, 3-way cross-over trial, comparing ethosuximide granules A or B with placebo granules and syrup at single 10 mg/kg doses. Corresponding plasma pharmacokinetic profiles of ethosuximide were compared, along with palatability, safety, and tolerability. The LMP granule A proved suboptimal due to bitterness and adherence to beaker walls, while the optimized granule B revealed excellent palatability, similar to placebo granules, and low adherence to glass. The relative bioavailability of granules A versus syrup, based on dose-normalized Cmax and AUC0-∞ was 93.7% [90% CI: 76.3-115.1] and 96.1% [91.0-101.5], respectively. For granules B it was 87.6% [81.6-94.0] and 92.5% [88.5-96.6], respectively, with slightly delayed tmax of 0.75 h [0.5-4.05] compared to syrup 0.5 h [0.3-0.8]. Tolerability visual analog scales revealed a trend for statistically non-significant improvement versus syrup at peak (30 min) for transient dizziness (both granules), fatigue (granules A), and anxiety (granules B). The innovative ethosuximide granule formulation B achieves a suitable profile for pediatric use, being sugar-free, tasteless, bioequivalent, and well-tolerated while enabling precise adjustment to body weight.

Optimized LC-MS/MS quantification of tuberculosis drug candidate macozinone (PBTZ169), its dearomatized Meisenheimer Complex and other metabolites, in human plasma and urine.

Tuberculosis, and especially multidrug-resistant tuberculosis (MDR-TB), is a major global health threat which emphasizes the need to develop new agents to improve and shorten treatment of this difficult-to-manage infectious disease. Among the new agents, macozinone (PBTZ169) is one of the most promising candidates, showing extraordinary potency in vitro and in murine models against drug-susceptible and drug-resistant Mycobacterium tuberculosis. A previous analytical method using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed by our group to support phase I clinical trials of PBTZ169. These plasma sample analyses revealed the presence of several additional metabolites among which the most prominent was H2PBTZ, a reduced species obtained by dearomatization of macozinone, one of the first examples of Meisenheimer Complex (MC) metabolites identified in mammals. Identification of these new metabolites required the optimization of our original method for enhancing the selectivity between isobaric metabolites as well as for ensuring optimal stability for H2PBTZ analyses. Sample preparation methods were also developed for plasma and urine, followed by extensive quantitative validation in accordance with international bioanalytical method recommendations, which include selectivity, linearity, qualitative and quantitative matrix effect, trueness, precision and the establishment of accuracy profiles using ß-expectation tolerance intervals for known and newer analytes. The newly optimized methods have been applied in a subsequent Phase Ib clinical trial conducted in our University Hospital with healthy subjects. H2PBTZ was found to be the most abundant species circulating in plasma, underscoring the importance of measuring accurately and precisely this unprecedented metabolite. Low concentrations were found in urine for all monitored analytes, suggesting extensive metabolism before renal excretion.

Systematic comparison with autoimmune liver disease identifies specific histological features of immune checkpoint inhibitor-related adverse events.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have become a mainstay of cancer treatment. Their immune-boosting quality has one major drawback, their proclivity to induce a broad array of immune-related adverse events (irAEs) affecting, among others, the liver and sharing some similarities with classic autoimmune liver diseases (AILD).We aimed to compare clinical, laboratory and histological features of patients with liver-related irAEs and AILD. METHODS: We systematically compared liver irAEs with AILD, namely autoimmune hepatitis (AIH) and primary biliary cholangitis, regarding their clinical, laboratory, and histological features. RESULTS: Twenty-seven patients with liver irAEs (ICI group) and 14 patients with AILD were identified. We observed three distinct ICI-induced histological liver injury patterns: hepatitic (52%), cholangitic (19%), and mixed (29%). When comparing the ICI and AILD groups, centrilobular injury as well as granuloma formation were more prevalent in the former (p=0.067 and 0.002, respectively). CD4+/CD8+ T cell ratios were heterogeneous between the two groups, without statistically significant difference but with a trend toward increased CD8+ T cells among hepatitic irAEs as compared with AIH. Pattern of liver function test alteration was predictive for the type of irAEs but did not correlate with histological severity. CONCLUSIONS: Liver irAEs have broad clinical, laboratory and histological presentations. Histological features of irAEs and AILD are distinct, likely underpinning their different immunological mechanisms.

[Metabolism and therapeutic monitoring of azathioprine in gastroenterology and hepatology]. / Métabolisme et suivi thérapeutique de l'azathioprine en gastroentérologie et hépatologie.

Azathioprine keeps an important place in the treatment of inflammatory bowel disease and autoimmune hepatitis. This molecule has a narrow therapeutic margin, associated with a risk of toxicity, particularly hematological and hepatic. Its complex metabolism is subject to genetic polymorphisms that are reflected in the inter-individual variability observed in the response to treatment and its tolerance profile. Hence, its use requires a good knowledge of this molecule. Treatment is initiated after a preliminary workup, followed by a progressive titration of the dosage while closely monitoring possible toxicities. Monitoring of blood levels of metabolites (including active ones) helps guide personalized dose adjustment.

L'azathioprine garde actuellement une place importante dans le traitement des maladies inflammatoires chroniques de l'intestin et de l'hépatite autoimmune. Il s'agit d'une molécule à marge thérapeutique étroite, associée à un risque de toxicité, notamment hématologique et hépatique. Son métabolisme complexe est influencé par des polymorphismes génétiques qui sont reflétés dans la variabilité interindividuelle observée dans la réponse au traitement et le profil de tolérance. Son utilisation nécessite donc une bonne connaissance de cette molécule. L'instauration du traitement se fait après un bilan préalable, puis une titration progressive des posologies, tout en surveillant étroitement les éventuelles toxicités. Le monitoring des concentrations sanguines des métabolites (notamment actifs) permet de guider l'adaptation personnalisée des posologies.

Quantification of serotonin and eight of its metabolites in plasma of healthy volunteers by mass spectrometry.

Serotonin is transformed into melatonin under the control of the light/dark cycle, representing a cornerstone of circadian rhythmicity. Serotonin also undergoes extensive metabolism to produce 5-hydroxyindoleacetic acid (5-HIAA), a biomarker for the diagnosis and monitoring of serotonin secreting neuroendocrine tumors (NETs). While serotonin, melatonin and their metabolites are part of an integrated comprehensive system, human observations about their respective plasma concentrations are still limited. We report here for the first time a multiplex UHPLC-MS/MS assay for the quantification of serotonin, 5-HIAA, 5-hydroxytryptophol (5-HTPL), N-acetyl-serotonin (NAS), Mel, 6-OH-Mel, 5-methoxytryptamine (5-MT), 5-methoxytryptophol (5-MTPL), and 5-methoxyindoleacetic acid (5-MIAA) in human plasma. Analytes were extracted by protein precipitation and solid phase extraction. Plasma concentrations for these analytes were determined in 102 healthy volunteers. The LLOQ of the assay ranges from 2.2 nM for serotonin to 1.0 pM for 6-OH-Mel. This sensitivity enables the quantification of circulating serotonin, 5-HIAA, NAS, Mel, and 5-MIAA, even at their lowest diurnal concentrations. This assay will enable specific, precise and accurate measurement of serotonin, Mel and their metabolites to draw a detailed picture of this complex pineal metabolism, allowing a dynamic understanding of these pathways and providing promising biomarkers and a metabolic signature for serotonin-secreting NETs.

Population Pharmacokinetics of Palbociclib and Its Correlation with Clinical Efficacy and Safety in Patients with Advanced Breast Cancer.

Neutropenia is the most frequent dose-limiting toxicity reported in patients with metastatic breast cancer receiving palbociclib. The objective of this study was to investigate the pharmacokinetic-pharmacodynamic (PK/PD) relationships for toxicity (i.e., absolute neutrophil count, ANC) and efficacy (i.e., progression-free survival, PFS). A semi-mechanistic PK/PD model was used to predict neutrophils' time course using a population approach (NONMEM). Influence of demographic and clinical characteristics was evaluated. Cox proportional hazards models were developed to evaluate the influence of palbociclib PK on PFS. A two-compartment model with first-order absorption and a lag time adequately described the 255 palbociclib concentrations provided by 44 patients. The effect of the co-administration of proton-pump inhibitors in fasting conditions increased palbociclib clearance by 56%. None of the tested covariates affected the PD parameters. Model-based simulations confirmed the concentration-dependent and non-cumulative properties of palbociclib-induced neutropenia, reversible after treatment withdrawal. The ANC nadir occurred approximately at day 24 of each cycle. Cox analyses revealed a trend for better PFS with increasing palbociclib exposure in older patients. By characterizing palbociclib-induced neutropenia, this model offers support to clinicians to rationally optimize treatment management through patient-individualized strategies.

[Pharmacovigilance - mRNA COVID-19 vaccines : current state of knowledge on their adverse effects]. / Pharmacovigilance - Vaccins à ARNm contre le Covid-19 : le point sur les effets indésirables.

The COVID-19 pandemic has stimulated the rapid development and large-scale use of technologically innovative vaccines, such as the mRNA vaccines Spikevax (Moderna) and Comirnaty (Pfizer-BioNTech). This unprecedented deployment has challenged pharmacovigilance, requiring combined skills in safety monitoring, prompt data analysis and continuous dissemination of knowledge. Main recognised adverse events of these vaccines are moderate and transient, linked to their significant reactogenicity. Active post-marketing surveillance has identified rare adverse events such as myopericarditis and a variety of skin reactions. A number of potential rare adverse events are being evaluated and could be retained at the individual level, but do not question the overall safety of these vaccines.

La pandémie de Covid-19 a conduit au développement rapide de vaccins à la technologie innovante, utilisés à large échelle, dont les vaccins à ARNm Spikevax (Moderna) et Comirnaty (Pfizer-BioNTech). Ce déploiement sans précédent défie la pharmacovigilance, nécessitant d'allier un suivi attentif de la sécurité, une analyse rapide des données et une diffusion continue des connaissances. Les principaux effets indésirables reconnus pour ces vaccins sont modérés et transitoires, liés à leur importante réactogénicité. Une pharmacovigilance active a permis d'identifier des effets indésirables rares, tels que des myopéricardites et diverses réactions cutanées. Un certain nombre d'effets indésirables rares potentiels sont en cours d'évaluation et pourraient être retenus à l'échelle individuelle, mais ne remettent pas en cause la sécurité vaccinale globale.

Case Report: Colchicine Toxicokinetic Analysis in a Poisoned Child Requiring Extracorporeal Life Support.

Colchicine poisoning is associated with a poor prognosis, especially when leading to shock and multi-organ failure, and management is limited to supportive care, including multiple-dose activated charcoal. At therapeutic concentrations, colchicine elimination occurs mainly through hepatic metabolism and involves an enterohepatic circulation, with a small contribution of renal elimination (10-30%). Colchicine toxicokinetics is however rarely described, especially in children. We present the case of a 4-year-old patient who survived a severe iatrogenic colchicine intoxication with a dose of 0.5 mg/kg. She developed multi-organ failure and shock, but recovered after receiving aggressive resuscitation, including extracorporeal life support. Close monitoring of colchicine blood levels showed a plateau for 6 days, indicating impeded elimination resulting from liver failure. We observed no significant clearance from renal replacement therapy, nor activated charcoal, during this period. Extracorporeal life support may play a supportive role in the management of severe colchicine poisoning. However, extracorporeal techniques do not seem to improve colchicine elimination.

Spontaneous Partial Remission in a Child With B-Lineage Acute Lymphoblastic Leukemia and Chickenpox: A Role For Acyclovir?

A 2.5-year-old boy presented to his pediatrician with progressive pallor, asthenia, fever, splenomegaly, and hematomas. Leukemia was suspected, and a bone marrow aspirate confirmed acute lymphoblastic leukemia. Before chemotherapy induction, the child developed a vesicular rash and was diagnosed clinically with chickenpox. Acyclovir treatment was initiated immediately, whereas induction chemotherapy was postponed by 10 days. At the time of chickenpox resolution, a spontaneous partial recovery of his blood counts and a 50% decrease of blastic bone marrow infiltration were noted. After a brief nonsystematic review, we discuss the potential beneficial effect of acyclovir and chickenpox infection in children with leukemia.

Ensuring Sufficient Trough Plasma Concentrations for Broad-Spectrum Beta-Lactam Antibiotics in Children With Malignancies: Beware of Augmented Renal Clearance!

Introduction: Broad-spectrum beta-lactams are commonly prescribed for empirical or selective treatment of bacterial infections in children with malignancies. In the immunocompromised, appropriate concentration exposure is crucial to ensure antimicrobial efficacy. Augmented renal clearance (ARC) is increasingly recognized in this population, and raises concern for unmet concentration targets. We conducted a retrospective evaluation of meropenem and piperacillin exposure in our hospital's pediatric hematology-oncology patients. Materials and Methods: We compared trough levels of meropenem and piperacillin in a cohort of unselected pediatric hematology-oncology patients stratified based on their estimated renal function as decreased, normal or with ARC, and on their neutrophil count. Results: Thirty-two children provided a total of 51 meropenem and 76 piperacillin samples. On standard intermittent intravenous regimen, 67% of all trough plasma concentrations were below targeted concentrations. In neutropenic children with bacterial infection, all meropenem and 60% of piperacillin levels were below target. Nearly two-thirds of total samples came from children with ARC. In these patients, antimicrobial exposure was insufficient in 85% of cases (compared to 36% in the decreased or normal renal function groups), despite a dosage sometimes exceeding the maximum recommended daily dose. Under continuous infusion of piperacillin, only 8% of plasma levels were insufficient. Discussion: Intermittent administration of meropenem and piperacillin often fails to ensure sufficient concentration exposure in children treated for malignancies, even at maximal recommended daily dosage. This can in part be attributed to ARC. We recommend thorough assessment of renal function, resolute dosage adjustment, continuous infusion whenever possible and systematic therapeutic drug monitoring.

Combined immune checkpoint inhibitor therapy with nivolumab and ipilimumab causing acute-onset type 1 diabetes mellitus following a single administration: two case reports.

BACKGROUND: The use of immune checkpoint inhibitor (ICI) therapy is becoming a standard of care for several cancers. Monoclonal antibodies targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death protein 1 (PD-1) or its ligand (PD-L1) cause a broad spectrum of autoimmune adverse events. ICI-induced type 1 diabetes mellitus (T1DM) is extremely rare (< 1%) but potentially life-threatening. It appears to be more common with PD-1 blockade (or combination immunotherapy) than with anti-CTLA-4 therapy, often during the first three to six months of therapy. CASES PRESENTATION: We report an acute onset T1DM with severe inaugural diabetic ketoacidosis (DKA) and remarkably elevated Glutamic Acid Decarboxylase antibody (GADA) titres following a single administration of combined ICI therapy with nivolumab (anti-PD-1) and ipilimumab (anti-CTLA-4) in two adult patients with advanced metastatic melanoma. In these cases, the time to diabetes onset was remarkably short (two and five weeks), and one presented with fulminous T1DM in a previous long-standing type 2 diabetes mellitus. CONCLUSIONS: Oncological patients treated with combination therapy of anti-PD-1 and anti-CTLA-4 can develop a particular pattern of T1DM, with very rapid onset within a few weeks after starting ICI therapy, even in the presence of an existing type 2 diabetes. ICI-induced T1DM is a medical emergency in presence of severe inaugural DKA and requires a collaboration between specialists and primary care physicians, as well as patient education, for early diagnosis and supportive care.

[Challenges in managing diabetes in chronic hemodialysis]. / Défis dans la prise en charge du diabète en hémodialyse chronique.

Hemodialysis (HD) centers are facing an increasing number of patients with diabetes. These cases require an intensive multidisciplinary approach of the consequences of renal failure, glycemic control and nutrition and the management of frequent co-morbidities, in particular the diabetic foot. A major challenge is to decrease glycemic variability and the risk of hypoglycemia. Because of increased risk of hypoglycemia-associated mortality, the HbA1C target is loosened in the majority of HD patients. Continuous glucose monitoring technology has identified important glycemic fluctuations during and after dialysis. However, their reliability in HD needs to be improved. New therapeutic pathways that decrease glucose excursions and hypoglycemia, such as GLP1 receptor agonists and sensor-coupled insulin pumps, have yet to be validated in HD.

Les centres d'hémodialyse (HD) sont confrontés à un nombre croissant de patients diabétiques. Leur prise en charge multidisciplinaire tient compte de l'insuffisance rénale, du contrôle glycémique, de la nutrition et des comorbidités fréquentes, en particulier le pied diabétique. La réduction de la variabilité glycémique et des hypoglycémies qui sont associées à une mortalité accrue reste un défi. La cible de l'HbA1C est assouplie chez la majorité des patients. L'usage du contrôle en continu de la glycémie permet d'identifier les fluctuations glycémiques per et interdialytiques importantes. Sa fiabilité doit cependant être améliorée en HD. Les nouvelles voies thérapeutiques qui diminuent les excursions glycémiques et le risque d'hypoglycémie comme les GLP1 agonistes et les pompes à insuline couplées aux sensors restent à valider en HD.