Induction failure in granulomatosis with polyangiitis: a nationwide case-control study of risk factors and outcomes.

OBJECTIVE: To identify characteristics of granulomatosis with polyangiitis (GPA) associated with induction failure, describe salvage therapies and their efficacy. METHODS: We conducted a nationwide retrospective case-control study of GPA with induction failure between 2006 and 2021. Each patient with induction failure was randomly paired to three controls matched for age, sex and induction treatment. RESULTS: We included 51 patients with GPA and induction failure (29 men and 22 women). At induction therapy, median age was 49 years. Twenty-seven patients received intravenous cyclophosphamide (ivCYC) and 24 rituximab (RTX) as induction therapy. Patients with ivCYC induction failure more frequently had PR3-ANCA (93% vs 70%, P = 0.02), relapsing disease (41% vs 7%, P < 0.001) and orbital mass (15% vs 0%, P < 0.01) compared with controls. Patients with disease progression despite RTX induction therapy more frequently had renal involvement (67% vs 25%, P = 0.02) with renal failure (serum creatinine >100 µmol/l in 42% vs 8%, P = 0.02) compared with controls. After salvage therapy, remission was achieved at 6 months in 35 (69%) patients. The most frequent salvage therapy was switching from ivCYC to RTX (or vice versa), showing an efficacy in 21/29 (72%). Remission was achieved in nine (50%) patients with inappropriate response to ivCYC, while in patients with progression after RTX induction, remission was achieved in four (100%) who received ivCYC (with or without immunomodulatory therapy), but only in three (50%) after adding immunomodulatory therapy alone. CONCLUSION: In patients with induction failure, characteristics of GPA, salvage therapies and their efficacy vary according to induction therapy and failure modality.

Eltrombopag for the Treatment of Severe Inherited Thrombocytopenia.

Inherited thrombocytopenias correspond to a group of hereditary disorders characterized by a reduced platelet count, platelet dysfunction, and a family history of thrombocytopenia. It is commonly associated with mucocutaneous bleeding. Thrombocytopenia results from mutations in genes involved in megakaryocyte differentiation, platelet formation, and clearance. Here we report on a patient presenting with severe syndromic inherited thrombocytopenia manifesting as spontaneous mucocutaneous bleeds, requiring frequent platelet transfusions. Thrombocytopenia was explained by the presence of 4 mutations in 3 hematopoietic transcription factor genes: FLI1, RUNX1, and ETV6. The patient was successfully treated with high-dose eltrombopag at 150 mg/day, an orally available non-peptide thrombopoietin receptor agonist. Since the start of treatment 23 months ago, the manifestations of bleeding have resolved, and no platelet transfusions or corticosteroids have been required. The patient has no clinical or laboratory evidence of myeloid malignancy so far.

Selection of dosing regimen with WST11 by Monte Carlo simulations, using PK data collected after single IV administration in healthy subjects and population PK modeling.

WST11, a novel generation of photo sensitizers to be used for vascular-targeted phototherapy (VTP), is effective at short interval between injection and illumination and it is expected to enable selective destruction of neovasculature with minimal side effects or skin photo toxicity. This study was conducted to evaluate the clinical and laboratory safety, tolerability and pharmacokinetic profile of WST11 given as a single intravenous administration (1.25, 2.5, 5, 7.5, 10, or 15 mg/kg) during an escalating dose study in healthy male subjects. This article describes WST11 population pharmacokinetic modeling and simulations performed to optimize the IV infusion-dosing regimen in combination with illumination, the target PK profile being plateau concentrations during approximately 30 min. The study included 42 healthy male subjects, administered 1.25, 2.5, 5, 7.5, 10, or 15 mg/kg as a 10-min IV infusion. A population pharmacokinetic model was developed using nonlinear mixed effects modeling (NONMEM). Monte Carlo simulations of the population PK dataset (NONMEM) were performed to select series of dosing regimen which would result in a plateau of concentration lasting at least 30 min and allow laser illumination. A two-compartment model with nonlinear elimination best described the data. No demographic factor was shown to affect the WST11 pharmacokinetics. The clearance was shown to decreases with the dose administered, ranging from 6 L/h (dose of 79 mg) to 2 L/h (dose of 1110 mg). The duration of the infusion was estimated at 12 min. The volume of distribution of the central compartment was 3 L and the volume of the peripheral compartment was 1.15 L. The apparent inter-compartmental clearance was 0.137 L/h. The between subjects variability on clearance and on volume was low. Residual variability was moderate with a CV of 21%. Due to the dose effect on clearance and the rapid elimination, simulations showed that different dosing inputs are necessary: for 5 and 10 mg/kg BW, a sufficiently good dosing scenario is to administer 80% of the dose over 5 min, 15% over 10 min and the remaining 5% over 10 min. For lower doses, the sequence 70% in 5 min/20% in 10 min/10% in 10 min is preferable. The pharmacokinetic profile of WST11 by IV administration would allow a treatment by laser illumination in good clinical conditions using controlled infusions. The study results do not indicate that the dose should be adjusted for body size. The only factor that determines the drug input profile is the dose level, since the elimination half-life decreases when the dose administered increases. The use of the population PK model for simulations has shown that, at dose level of 5 mg/kg or more, a loading dose of 80% dose given over 5 min followed by 15% of dose during 10 min and remained dose to give over 10 min would result in a favorable PK profile.

Olaparib does not cause clinically relevant QT/QTc interval prolongation in patients with advanced solid tumours: results from two phase I studies.

BACKGROUND: Some therapeutic agents in oncology can be causally associated with specific cardiovascular events including QT/QTc interval prolongation. We investigated the effect of multiple dosing of the oral poly (ADP-ribose)-polymerase (PARP) inhibitor, olaparib (tablet formulation) on QT/QTc interval. METHODS: Two phase I, open-label, three-part studies (NCT01921140 [study 4] and NCT01900028 [study 7]) were conducted in adults with refractory/resistant advanced solid tumours. In both studies, parts A and B assessed the QT/QTc interval effects of single-dose oral olaparib 100 (study 4) or 300 (study 7) mg and multiple-dose olaparib 300 mg bid for 5 days, respectively, while part C evaluated continued access to olaparib for additional safety analyses. An ANCOVA model tested the primary objective of multiple-dose effects of olaparib on QT interval corrected using Fridericia's formula (QTcF). RESULTS: Data from 119 and 109 patients were pooled from parts A and B, respectively, for QT/QTc analysis. At pre-dose and up to 12 h post-dose, the upper limits of the 90 % confidence intervals (CIs) for the difference in QTcF least squares means after olaparib multiple dosing versus control (day -1) were <10 ms, suggesting a lack of clinically relevant effect on cardiac repolarization. A slight shortening of QTcF was observed at most time points versus control. QTcF results for the individual studies and single-dose olaparib paralleled the primary multiple-dose pooled analysis, with upper limits of the 90 % CIs < 10 ms. CONCLUSION: Olaparib tablets administered as multiple or single doses had no clinically significant effect on QT/QTc interval.

Population pharmacokinetics of oral risperidone in children, adolescents and adults with psychiatric disorders.

BACKGROUND AND OBJECTIVES: Oral risperidone is licensed globally for the treatment of several psychiatric disorders in children, adolescents and adults. The pharmacokinetic profile of risperidone is well documented in adults. In this study, the pharmacokinetics of oral risperidone in children and adolescents were investigated along with population pharmacokinetics in paediatric and adult subjects. METHODS: The pharmacokinetics of oral risperidone in children and adolescents were investigated through non-compartmental analysis (paediatric phase I study; n = 24) and population pharmacokinetic analysis using nonlinear mixed-effects modelling software (NONMEM) on a pooled database including both paediatric (n = 304) and adult (n = 476) data. Monte Carlo simulations were performed to evaluate the relevance of the effects of covariates on the plasma exposure of the active antipsychotic fraction. RESULTS: Non-compartmental pharmacokinetic analysis showed that, after correcting doses for bodyweight, plasma exposure was comparable between children and adolescents and in line with historical adult data. Pooled population pharmacokinetic analysis, using a priori allometric scaling of the clearance and volume of distribution, showed that apparent renal clearance of the active antipsychotic fraction was 0.96 L/h and apparent metabolic clearance was 4.26 L/h for a typical patient weighing 62 kg, aged 18.1 years, with a median creatinine clearance of 117.6 mL/min. For a typical child (11 years, 39 kg), adolescent (15 years, 60 kg) and adult (33 years, 70 kg), the apparent total oral clearance values were 4.35, 5.30 and 5.04 L/h, respectively. None of the tested demographic or biochemical characteristics were found to have a relevant effect on any of the pharmacokinetic parameters of risperidone and the active antipsychotic fraction. CONCLUSION: Population pharmacokinetics and Monte Carlo simulations demonstrated similar pharmacokinetics of risperidone in children, adolescents and adults.