NSABP FB-10: a phase Ib/II trial evaluating ado-trastuzumab emtansine (T-DM1) with neratinib in women with metastatic HER2-positive breast cancer.

BACKGROUND: We previously reported our phase Ib trial, testing the safety, tolerability, and efficacy of T-DM1 + neratinib in HER2-positive metastatic breast cancer patients. Patients with ERBB2 amplification in ctDNA had deeper and more durable responses. This study extends these observations with in-depth analysis of molecular markers and mechanisms of resistance in additional patients. METHODS: Forty-nine HER2-positive patients (determined locally) who progressed on-treatment with trastuzumab + pertuzumab were enrolled in this phase Ib/II study. Mutations and HER2 amplifications were assessed in ctDNA before (C1D1) and on-treatment (C2D1) with the Guardant360 assay. Archived tissue (TP0) and study entry biopsies (TP1) were assayed for whole transcriptome, HER2 copy number, and mutations, with Ampli-Seq, and centrally for HER2 with CLIA assays. Patient responses were assessed with RECIST v1.1, and Molecular Response with the Guardant360 Response algorithm. RESULTS: The ORR in phase II was 7/22 (32%), which included all patients who had at least one dose of study therapy. In phase I, the ORR was 12/19 (63%), which included only patients who were considered evaluable, having received their first scan at 6 weeks. Central confirmation of HER2-positivity was found in 83% (30/36) of the TP0 samples. HER2-amplified ctDNA was found at C1D1 in 48% (20/42) of samples. Patients with ctHER2-amp versus non-amplified HER2 ctDNA determined in C1D1 ctDNA had a longer median progression-free survival (PFS): 480 days versus 60 days (P = 0.015). Molecular Response scores were significantly associated with both PFS (HR 0.28, 0.09-0.90, P = 0.033) and best response (P = 0.037). All five of the patients with ctHER2-amp at C1D1 who had undetectable ctDNA after study therapy had an objective response. Patients whose ctHER2-amp decreased on-treatment had better outcomes than patients whose ctHER2-amp remained unchanged. HER2 RNA levels show a correlation to HER2 CLIA IHC status and were significantly higher in patients with clinically documented responses compared to patients with progressive disease (P = 0.03). CONCLUSIONS: The following biomarkers were associated with better outcomes for patients treated with T-DM1 + neratinib: (1) ctHER2-amp (C1D1) or in TP1; (2) Molecular Response scores; (3) loss of detectable ctDNA; (4) RNA levels of HER2; and (5) on-treatment loss of detectable ctHER2-amp. HER2 transcriptional and IHC/FISH status identify HER2-low cases (IHC 1+ or IHC 2+ and FISH negative) in these heavily anti-HER2 treated patients. Due to the small number of patients and samples in this study, the associations we have shown are for hypothesis generation only and remain to be validated in future studies. Clinical Trials registration NCT02236000.

CyTOF analysis revealed platelet heterogeneity in breast cancer patients received T-DM1 treatment.

T-DM1 (Trastuzumab Emtansine) belongs to class of Antibody-Drug Conjugates (ADC), where cytotoxic drugs are conjugated with the antibody Trastuzumab to specifically target HER2-positive cancer cells. Platelets, as vital components of the blood system, intricately influence the immune response to tumors through complex mechanisms. In our study, we examined platelet surface proteins in the plasma of patients before and after T-DM1 treatment, categorizing them based on treatment response. We identified a subgroup of platelets with elevated expression of CD63 and CD9 exclusively in patients with favorable treatment responses, while this subgroup was absent in patients with poor responses. Another noteworthy discovery was the elevated expression of CD36 in the platelet subgroups of patients exhibiting inadequate responses to treatment. These findings suggest that the expression of these platelet surface proteins may be correlated with the prognosis of T-DM1 treatment. These indicators offer valuable insights for predicting the therapeutic response to T-DM1 and may become important references in future clinical practice, contributing to a better understanding of the impact of ADC therapies and optimizing personalized cancer treatment strategies.

Therapeutic drug monitoring of linezolid in Chinese premature neonates: a population pharmacokinetic analysis and dosage optimization.

This study aimed to develop a pharmacokinetic model of linezolid in premature neonates and evaluate and optimize the administration regimen. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to detect the blood concentration data of 54 premature neonates after intravenous administration of linezolid, and the relevant clinical data were collected. The population pharmacokinetic (PPK) model was established by nonlinear mixed effects modeling. Based on the final model parameters, the optimal administration regimen of linezolid in premature neonates with different body surface areas (BSA) was simulated and evaluated. The pharmacokinetic properties of linezolid in premature neonates are best described by a single-compartment model with primary elimination. The population typical values for apparent volume of distribution and clearance were 0.783 L and 0.154 L/h, respectively. BSA was a statistically significant covariate with clearance (CL) and volume of distribution (Vd). Monte Carlo simulations showed that the optimal administration regimen for linezolid in premature neonates was 6 mg/kg q8h for BSA 0.11 m2, 7 mg/kg q8h for BSA 0.13 m2, and 9 mg/kg q8h for BSA 0.15 m2 with minimum inhibitory concentration (MIC) ≤1 mg/L, 7 mg/kg q8h for BSA 0.11 m2, 8 mg/kg q8h for BSA 0.13 m2, and 10 mg/kg q8h for BSA 0.15 m2 with MIC = 2 mg/L. A pharmacokinetic model was developed to predict the blood concentration on linezolid in premature neonates. Based on this model, the optimal administration regimen of linezolid in premature neonates needs to be individualized according to different BSA levels.

A machine learning approach to predict daptomycin exposure from two concentrations based on Monte Carlo simulations.

Daptomycin is a concentration-dependent lipopeptide antibiotic for which exposure/effect relationships have been shown. Machine learning (ML) algorithms, developed to predict the individual exposure to drugs, have shown very good performances in comparison to maximum a posteriori Bayesian estimation (MAP-BE). The aim of this work was to predict the area under the blood concentration curve (AUC) of daptomycin from two samples and a few covariates using XGBoost ML algorithm trained on Monte Carlo simulations. Five thousand one hundred fifty patients were simulated from two literature population pharmacokinetics models. Data from the first model were split into a training set (75%) and a testing set (25%). Four ML algorithms were built to learn AUC based on daptomycin blood concentration samples at pre-dose and 1 h post-dose. The XGBoost model (best ML algorithm) with the lowest root mean square error (RMSE) in a 10-fold cross-validation experiment was evaluated in both the test set and the simulations from the second population pharmacokinetic model (validation). The ML model based on the two concentrations, the differences between these concentrations, and five other covariates (sex, weight, daptomycin dose, creatinine clearance, and body temperature) yielded very good AUC estimation in the test (relative bias/RMSE = 0.43/7.69%) and validation sets (relative bias/RMSE = 4.61/6.63%). The XGBoost ML model developed allowed accurate estimation of daptomycin AUC using C0, C1h, and a few covariates and could be used for exposure estimation and dose adjustment. This ML approach can facilitate the conduct of future therapeutic drug monitoring (TDM) studies.

Neratinib and ado-trastuzumab emtansine for pretreated and untreated human epidermal growth factor receptor 2 (HER2)-positive breast cancer brain metastases: Translational Breast Cancer Research Consortium trial 022.

BACKGROUND: Treatment options for human epidermal growth factor receptor 2 (HER2)-positive breast cancer brain metastases (BCBMs) remain limited. We previously reported central nervous system (CNS) activity for neratinib and neratinib-capecitabine. Preclinical data suggest that neratinib may overcome resistance to ado-trastuzumab emtansine (T-DM1) when given in combination. In Translational Breast Cancer Research Consortium (TBCRC) 022's cohort 4, we examined the efficacy of neratinib plus T-DM1 in patients with HER2-positive BCBM. PATIENTS AND METHODS: In this multicenter, phase II study, patients with measurable HER2-positive BCBM received neratinib 160 mg daily plus T-DM1 3.6 mg/kg intravenously every 21 days in three parallel-enrolling cohorts [cohort 4A-previously untreated BCBM, cohorts 4B and 4C-BCBM progressing after local CNS-directed therapy without (4B) and with (4C) prior exposure to T-DM1]. Cycle 1 diarrheal prophylaxis was required. The primary endpoint was the Response Assessment in Neuro-Oncology-Brain Metastases (RANO-BM) by cohort. The overall survival (OS) and toxicity were also assessed. RESULTS: Between 2018 and 2021, 6, 17, and 21 patients enrolled in cohorts 4A, 4B, and 4C. Enrollment was stopped prematurely for slow accrual. The CNS objective response rate in cohorts 4A, 4B, and 4C was 33.3% [95% confidence interval (CI) 4.3% to 77.7%], 35.3% (95% CI 14.2% to 61.7%), and 28.6% (95% CI 11.3% to 52.2%), respectively; 38.1%-50% experienced stable disease for ≥6 months or response. Diarrhea was the most common grade 3 toxicity (22.7%). The median OS was 30.2 [cohort 4A; 95% CI 21.9-not reached (NR)], 23.3 (cohort 4B; 95% CI 17.6-NR), and 20.9 (cohort 4C; 95% CI 14.9-NR) months. CONCLUSIONS: We observed intracranial activity for neratinib plus T-DM1, including those with prior T-DM1 exposure, suggesting synergistic effects with neratinib. Our data provide additional evidence for neratinib-based combinations in patients with HER2-positive BCBM, even those who are heavily pretreated.

Enhancing the Safety and Efficacy of Trastuzumab Emtansine (T-DM1) Through Nano-Delivery System in Breast Cancer Therapy.

Trastuzumab emtansine (T-DM1), an antibody-drug conjugate, revolutionizes breast cancer therapy by specifically delivering DM1 to human epidermal growth factor receptor 2 (HER2) overexpressing tumor cells, effectively inhibiting cell division and proliferation. While T-DM1 demonstrates superior efficacy and tolerability, T-DM1-induced thrombocytopenia remains a significant adverse event leading to treatment discontinuation. To address this issue, the study investigates the feasibility of using poly(lactic-co-glycolic acid) (PLGA) nanoparticles as a delivery vehicle to conjugate T-DM1, aiming to alleviate T-DM1-induced thrombocytopenia. The T-DM1-conjugated PLGA nanoparticles (NPs-T-DM1) reduce binding to megakaryocytes without compromising the targeting ability for HER2. Administration of NPs-T-DM1 not only significantly inhibits tumor growth but also reduces damage to megakaryocytes, inhibits T-DM1-induced thrombocytopenia, and remarkably improves the safety of antibody-conjugated drugs. This work presents a promising strategy to enhance the safety and efficacy of T-DM1 in antitumor therapy, offering significant potential for advancing clinical application in HER2-positive breast cancer patients.

Highly sensitive therapeutic drug monitoring of infliximab in serum by targeted mass spectrometry in comparison to ELISA data.

BACKGROUND: Presently, antibody concentration measurements for patients undergoing treatment are predominantly determined by ELISA, which still comes with known disadvantages. Therefore, our aim was to establish a targeted mass-spectrometric assay enabling the reproducible absolute quantification of peptides from the hypervariable and interaction regions of infliximab. METHODS: Peptides of infliximab were measured post-trypsin digestion and subsequent separation on a Vanquish Horizon UHPLC coupled to a TSQ Altis Triple-Quad mass spectrometer. Normalization and absolute quantification were conducted using stable isotope-synthesized peptides. Calibration curves covering a range of 0.25-50 µg/ml were employed for quantitation. RESULTS: We demonstrated the substantial influence of peptide selection, choice of hydrolase for digestion, and digestion time on absolute peptide yield (28-44% for peptide 1 and 64-97% for peptide 2). Furthermore, we showed that the generated calibration curves for absolute quantification were highly reproducible and robust (LLOQ1 0.72 µg/ml and LLOQ2 1.00 µg/ml) over several months. In comparison to ELISA values, the absolute values obtained by mass spectrometry often yielded lower results for both targeted peptides. CONCLUSIONS: In this study, a semi-automated workflow was employed and tested with 8 patients and corresponding replicates (n = 3-4). We demonstrated the robust implementation of calibration curves for the absolute quantification of infliximab in patient samples, with coefficients of variation ranging from 0.5 to 9%. Taken together, we have developed a platform enabling the rapid (2 days of sample preparation and 30 min of measurement time per sample) and robust quantification of Infliximab antibody concentration in patients. The use of mass spectrometry also facilitates the straightforward expansion of the method to include additional antibody peptides.

Therapeutic drug monitoring in Parkinson's disease.

A patient-tailored therapy of the heterogeneous, neuropsychiatric disorder of Parkinson's disease (PD) aims to improve dopamine sensitive motor symptoms and associated non-motor features. A repeated, individual adaptation of dopamine substituting compounds is required throughout the disease course due to the progress of neurodegeneration. Therapeutic drug monitoring of dopamine substituting drugs may be an essential tool to optimize drug applications. We suggest plasma determination of levodopa as an initial step. The complex pharmacology of levodopa is influenced by its short elimination half-life and the gastric emptying velocity. Both considerably contribute to the observed variability of plasma concentrations of levodopa and its metabolite 3-O-methyldopa. These amino acids compete with other aromatic amino acids as well as branched chain amino acids on the limited transport capacity in the gastrointestinal tract and the blood brain barrier. However, not much is known about plasma concentrations of levodopa and other drugs/drug combinations in PD. Some examples may illustrate this lack of knowledge: Levodopa measurements may allow further insights in the phenomenon of inappropriate levodopa response. They may result from missing compliance, interactions e.g. with treatments for other mainly age-related disorders, like hypertension, diabetes, hyperlipidaemia, rheumatism or by patients themselves independently taken herbal medicines. Indeed, uncontrolled combination of compounds for accompanying disorders as given above with PD drugs might increase the risk of side effects. Determination of other drugs used to treat PD in plasma such as dopamine receptor agonists, amantadine and inhibitors of catechol-O-methyltransferase or monoamine oxidase B may refine and improve the value of calculations of levodopa equivalents. How COMT-Is change levodopa plasma concentrations? How other dopaminergic and non-dopaminergic drugs influence levodopa levels? Also, delivery of drugs as well as single and repeated dosing and continuous levodopa administrations with a possible accumulation of levodopa, pharmacokinetic behaviour of generic and branded compounds appear to have a marked influence on efficacy of drug treatment and side effect profile. Their increase over time may reflect progression of PD to a certain degree. Therapeutic drug monitoring in PD is considered to improve the therapeutic efficacy in the course of this devastating neurologic disorder and therefore is able to contribute to the patients' precision medicine. State-of-the-art clinical studies are urgently needed to demonstrate the usefulness of TDM for optimizing the treatment of PD.

Early therapeutic drug monitoring helps to identify inflammatory bowel disease patients with a high risk to fail thiopurine treatment.

AIMS: Conventional thiopurines (azathioprine and mercaptopurine) remain standard therapy to maintain steroid sparing remission in inflammatory bowel disease (IBD), but are regularly discontinued due to adverse drug reactions (ADRs). Measurement of the metabolites 6-thioguanine nucleotides (6-TGN), 6-methylmercaptopurine ribonucleotides (6-MMPR) and the 6-MMPR/6-TGN ratio, may predict the development of these ADRs. Our aim was to evaluate whether early thiopurine metabolite measurements were associated with clinical outcomes. METHODS: A post-hoc analysis was conducted of a multicentre, prospective, observational study on thiopurine-induced hepatotoxicity. IBD patients who initiated thiopurine therapy were included and thiopurine metabolite concentrations were assessed after 7 days (±1) (T1). Patients were monitored for 12 weeks to document the occurrence of ADRs, early treatment discontinuation and effectiveness. RESULTS: In total, 181 patients were evaluated. At T1, 6-MMPR concentrations and 6-TGN/6-MMPR ratios were independently related to treatment discontinuation within 12 weeks after correction for sex, age and body mass index (BMI) (P = .034 and .002, respectively). The largest effects were observed for 6-MMPR ≥3000 pmol/8 × 108 RBC and 6-TGN/6-MMPR ratio ≥17. Furthermore, 6-MMPR concentrations and 6-TGN/6-MMPR ratios at T1 were independently related to skewed metabolism at steady state (Week 8, 6-MMPR/-6TGN ratio ≥11 and ≥20) (both P < .001). The occurrence of ADRs and effectiveness were not independently related to T1 thiopurine metabolite concentrations. CONCLUSIONS: Thiopurine metabolite concentrations at T1 were related to early treatment discontinuation and skewed metabolism at steady state, but not to effectiveness, helping to identify patients with a high risk of thiopurine treatment failure.

Infliximab in paediatric inflammatory bowel disease: External evaluation of population pharmacokinetic models.

AIMS: Use of infliximab (IFX) has improved outcomes in children with inflammatory bowel disease (IBD). However, a proportion of patients does not respond to IFX or loses response over time. Population pharmacokinetic (PopPK) modelling is a promising approach for IFX dose optimization, but with the increasing number of PopPK models in literature, model evaluation is essential. The aims of this study are: (i) to validate the predictive performance of existing IFX PopPK models using a cohort of children with IBD; and (ii) to perform a Bayesian estimation of the most suitable model to predict the next IFX concentrations. METHODS: PubMed was searched for IFX PopPK models in children. Selected models were rebuilt and analysed using R. Model performance was assessed through goodness-of-fit-plots, residuals against time, prediction error and prediction-corrected visual predictive checks. The validation cohort consisted of 73 children with IBD who were treated with IFX in our centre between 2017 and 2023 (340 IFX measurements). RESULTS: We identified 9 PopPK models. Model bias for individual predicted values ranged from -9.29% to 8.01% compared to bias for population predicted values. The model by Vande Casteele et al. demonstrated superior performance (individual predicted bias 2.13, population predicted bias -6.11); upon Bayesian estimation, it predicted induction trough levels with median error of 12.95% but had a median error of -69% predicting maintenance concentrations. CONCLUSION: The model by Vande Casteele et al. displayed superior performance in initial evaluations but had a high error in estimating next IFX levels and can only be used in practice to predict induction levels.

Adverse events during intravenous fosfomycin therapy in a real-life scenario. Risk factors and the potential role of therapeutic drug monitoring.

BACKGROUND: Intravenous fosfomycin (IVFOF) is gaining interest in severe infections. Its use may be limited by adverse events (AEs). Little experience exists on IVFOF therapeutic drug monitoring (TDM) in real-life setting. PATIENTS AND METHODS: Retrospective study of patients receiving IVFOF for > 48 h at Policlinico Hospital (Milan, Italy) from 01/01/2019 to 01/01/2023. AEs associated to IVFOF graded CTCAE ≥ II were considered. Demographic and clinical risk factors for IVFOF-related AEs were analysed with simple and multivariable regression models. The determination of IVFOF TDM was made by a rapid ultraperformance liquid chromatography mass spectrometry method (LC-MS/MS) on plasma samples. The performance of TDM (trough levels (Cmin) in intermittent infusion, steady state levels (Css) in continuous infusion) in predicting AEs ≤ 5 days after its assessment was evaluated. RESULTS: Two hundred and twenty-four patients were included. At IVFOF initiation, 81/224 (36.2%) patients were in ICU and 35/224 (15.7%) had septic shock. The most frequent infection site was the low respiratory tract (124/224, 55.4%). Ninety-five patients (42.4%) experienced ≥ 1AEs, with median time of 4.0 (2.0-7.0) days from IVFOF initiation. Hypernatremia was the most frequent AE (53/224, 23.7%). Therapy discontinuation due to AEs occurred in 38/224 (17.0%). ICU setting, low respiratory tract infections and septic shock resulted associated with AEs (RRadjusted 1.59 (95%CI:1.09-2.31), 1.46 (95%CI:1.03-2.07) and 1.73 (95%CI:1.27-2.37), respectively), while IVFOF daily dose did not. Of the 68 patients undergone IVFOF TDM, TDM values predicted overall AEs and hypernatremia with AUROC of 0.65 (95%CI:0.44-0.86) and 0.91 (95%CI:0.79-1.0) respectively for Cmin, 0.67 (95%CI:0.39-0.95) and 0.76 (95%CI:0.52-1.0) respectively for Css. CONCLUSIONS: We provided real world data on the use of IVFOF-based regimens and associated AEs. IVFOF TDM deserves further research as it may represent a valid tool to predict AEs. KEY POINTS: Real world data on intravenous fosfomycin for severe bacterial infections. AEs occurred in over 40% (therapy discontinuation in 17%) and were related to baseline clinical severity but not to fosfomycin dose. TDM showed promising results in predicting AEs.

Addressing Residual Disease in HER2-Positive and Triple-Negative Breast Cancer: What Is Next?

PURPOSE OF REVIEW: To summarize the treatment strategies for patients with human epidermal growth factor receptor 2 (HER2)-positive disease and triple-negative breast cancer (TNBC) who have residual disease after preoperative systemic therapy. RECENT FINDINGS: There has been a shift towards neoadjuvant systemic therapy for selected patients with HER2-positive and TNBC. Assessing the tumor's response to therapy provides prognostic information and allows individualization of the postoperative treatment for these patients based on the tumor response to neoadjuvant therapy. Patients with TNBC with residual disease after neoadjuvant therapy can be treated with pembrolizumab, capecitabine, or olaparib. Those with HER2-positive disease are treated with adjuvant trastuzumab emtansine. The treatment of early breast cancer has evolved significantly, and patient outcomes continue to improve. As better treatments are developed, we will need biomarkers to determine which patients may benefit from certain therapies to continue to improve outcomes by right-sizing treatments and limiting toxicities.

Different infliximab induction dosing regimens do not affect remission rates up to 1 year in children with Crohn's disease.

OBJECTIVES: Multiple studies in patients with Crohn's disease (CD) treated with anti-tumor necrosis factor alpha agents have shown that proactive therapeutic drug monitoring (TDM) during the maintenance phase leads to improved outcomes. We aimed to assess whether accelerated (IFX) administration during induction resulted in improved outcomes. METHODS: This retrospective study included CD patients aged 5-17.9 years that were treated with IFX. We compared outcomes of patients treated during induction with 5-8 mg/kg dosing at Weeks 0, 2, 6, and 14 (Group 1), versus accelerated dosing (≥8 mg/kg and/or >4 infusions until Week 14, Group 2) of IFX. Primary outcome was steroid-free clinical remission by Week 52. RESULTS: Sixty-eight patients were included, of whom seven discontinued IFX before Week 14, due to infusion reactions, immunogenic failure, or primary nonresponse. Comparison of Group 1 (n = 25) and Group 2 (n = 36) showed similar clinical characteristics, as well as inflammatory markers, at IFX initiation. Despite receiving significantly more IFX, and reaching a higher trough level by Week 14 (10.3 ± 1.2 vs. 3.3 ± 0.7, p < 0.001), the median Pediatric Crohn's disease Activity Index (PCDAI) was slightly higher in Group 2 versus Group 1 (14 [5-20] vs. 5 [0-15], p = 0.02). However, at Weeks 26 and 52 the PCDAI and inflammatory markers were comparable between the groups. Moreover, about 70% in both groups achieved the desirable trough IFX levels by Week 52. CONCLUSION: Accelerated IFX dosing during induction did not result in improved outcomes up to 12 months follow-up. Prospective studies are required to determine the exact timing in which proactive TDM should be applied.

Cardiac toxicity of HER-2 targeting antibody-drug conjugates: overview and clinical implications.

Antibody-drug conjugates (ADCs) have recently emerged as a promising therapeutic option that combine the specificity of monoclonal antibodies and the cytotoxic effect of chemotherapy. With numerous ADCs approved and on the market, a particular concern of ADCs that target HER-2 has been their cardiac side effects, in view of the crucial role of HER-2 in cardiac development and physiology. While rarely toxic and generally safe, numerous publications have outlined the consistent association of trastuzumab emtansine (T-DM1) and trastuzumab deruxtecan (T-DXd) with the development of cardiac toxicity. Despite not being clinically relevant in most cases, cardiac baseline evaluation, monitoring and early detection of cardiac adverse events remain pivotal with HER-2 targeting ADCs. This review aims to summarize and better characterize the complete cardiac toxicity profile of HER-2 ADCs, with the goal of improving clinical understanding of this adverse event, leading to better recognition, monitoring and management.

[Box: see text].

Impact of trastuzumab emtansine (T-DM1) on spleen volume in patients with HER2-positive metastatic breast cancer.

BACKGROUND: Trastuzumab emtansine (T-DM1) is a novel therapy for human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer, combining the targeted action of trastuzumab with the cytotoxic effects of emtansine. Although T-DM1 has demonstrated greater efficacy and safety compared to traditional therapies, concerns about hepatotoxicity and spleen-related complications have arisen. METHODS: We conducted a retrospective study of 64 HER2-positive metastatic breast cancer patients treated with T-DM1 at our institution. Patients underwent computed tomography or magnetic resonance imaging at baseline and during treatment cycles. Spleen volume, portal vein diameter, and laboratory values were compared between baseline and 12 months after T-DM1 treatment. RESULTS: Median spleen volume significantly increased from 201 cm3 (IQR, 157-275) at baseline to 291 cm3 (IQR, 215-420) after 12 months of T-DM1 treatment (P < 0.001). Spleen enlargement was observed in 87.5% of patients, while no significant alteration was detected in portal vein diameter. The change in spleen volume was positively correlated with changes in serum globulin levels, liver enzymes, and bilirubin levels, but did not impact survival outcomes. CONCLUSIONS: T-DM1 therapy in HER2-positive metastatic breast cancer leads to significant spleen enlargement and systemic biochemical changes. Future studies should focus on elucidating the long-term implications of these findings and optimizing monitoring strategies for spleen-related complications.

Vaccination and clozapine use: a systematic review and an analysis of the VAERS database.

In the context of COVID-19 concerns related to the potential interactions between clozapine and vaccination arose. With the ultimate goal of deriving recommendations for clinical practice, we systematically reviewed the current evidence regarding altered vaccine effectiveness in clozapine-treated patients and safety aspects of vaccination, such as haematological changes and the impact of vaccines on clozapine blood levels, in clozapine-treated patients. A systematic PRISMA-conform literature search of four databases (PubMed, PsycINFO, EMBASE and Cochrane Library) complemented by a case-by-case analysis of the Vaccine Adverse Event Reporting System (VAERS) database was performed. We then systematically appraised the joint evidence and tried to derive recommendations for clinical practice. 14 records were included in this analysis. These records consisted of 5 original articles and 9 case reports. Among the original articles, two studies provided data on the association between clozapine use and antibody responses to vaccination, both indicating that clozapine use in schizophrenia may be associated with reduced levels of immunoglobulins. Additionally, three studies examined vaccine safety in clozapine-treated patients, with no clinically significant adverse effects directly attributable to the interplay between vaccinations and clozapine. VAERS Analysis encompassed 137 reports and showed no consistent evidence of an increased risk for clozapine blood level increases or adverse events. We found no evidence indicating that clozapine impairs the effectiveness of vaccines. Moreover, no serious safety concerns seem to apply when patients on clozapine are receiving vaccines. However, it is crucial to acknowledge that data on the interaction between clozapine and vaccines remain limited.

Drug induced lupus associated with Trastuzumab emtansine in a patient with metastatic breast cancer.

INTRODUCTION: Ado-trastuzumab emtansine (T-DM1) is employed in the treatment of patients with HER2-positive breast cancer. The most common side effects are fatigue, diarrhoea, anaemia, transaminase elevation and drug-induced thrombocytopenia. This report describes a patient with metastatic breast cancer who developed drug-induced lupus due to T-DM1. CASE REPORT: A 54-year-old woman was diagnosed with breast cancer in March 2018. She underwent modified radical mastectomy and axillary lymph node dissection (pT2N1aM0). Following supraclavicular lymph node metastasis in May 2018, she received 8 cycles of docetaxel, trastuzumab, and pertuzumab. In December 2020, the patient presented with axillary and intra-abdominal lymph node metastases, along with bone metastases observed on PET/CT scan. Treatment with T-DM1 and zoledronic acid was initiated. After 18 months on T-DM1, she developed drug-induced lupus. Her symptoms resolved with hydroxychloroquine treatment and discontinuation of T-DM1. DISCUSSION: Drug-induced lupus is a clinical syndrome that shares similar features with systemic lupus erythematosus (SLE). The majority of patients present with symptoms such as arthralgia and myalgia. Hydralazine and procainamide are high-risk drugs for drug-induced lupus. Symptoms usually develop after months or years of use, but may also develop suddenly. Our patient also received TDM-1 treatment for 18 months. We present a case of TDM-1-associated drug-induced lupus in a patient with metastatic breast cancer. This is the first case of TDM-1-related drug-induced lupus reported in the literature.

Mirtazapine blood levels and antidepressant response.

OBJECTIVE: Therapeutic drug monitoring (TDM) is an important tool for treatment optimisation. Its usefulness has recently been demonstrated for some first-line antidepressants; however, few studies have been reported on the relationship between blood levels of mirtazapine and its antidepressant effects. The aim of this study was to investigate the association between blood concentration of mirtazapine and antidepressant response. METHODS: 59 outpatients treated with mirtazapine for depression were recruited and followed up for three months in a naturalistic setting. Hamilton Depression Rating Scale-21 (HAMD-21) was administered at baseline, month 1, and month 3 to assess antidepressant response. Mirtazapine serum concentration was measured at steady state. Linear regression analysis and nonlinear least-squares regression were used to estimate association between serum concentration of mirtazapine and antidepressant response. RESULTS: Our results showed no overall association between serum concentration of mirtazapine and symptom improvement at month 1 and month 3. A marginally significantly higher serum concentration of mirtazapine was found in responders vs non-responders at month 3. CONCLUSIONS: The study suggests that serum concentration of mirtazapine is not strongly associated with the antidepressant efficacy of mirtazapine. This is probably attributed to its pharmacodynamic profile, even though higher blood levels seem to be marginally more effective.

Mirtazapine plasma levels association with response is mild and do not follow the same curve of other antidepressantsMirtazapine higher plasma levels may show some benefit in a subgroup of patientsTherapeutic drug monitoring may help during antidepressant treatment.

Therapeutic Drug Monitoring for Biologic and Small-Molecule Therapies for Inflammatory Bowel Disease.

Background: Inflammatory bowel disease (IBD), encompassing ulcerative colitis and Crohn's disease, necessitates long-term medical therapy to manage symptoms and prevent complications. Therapeutic drug monitoring (TDM) has emerged as a strategy to optimize treatment efficacy, particularly with anti-tumour necrosis factor (anti-TNF) alpha drugs. This review explores the role of TDM for non-anti-TNF advanced therapies in IBD, focusing on vedolizumab, ustekinumab, tofacitinib, upadacitinib, risankizumab and ozanimod. Methods: The literature search, conducted through OVID (Medline) and PubMed, delves into proactive versus reactive TDM, timing of monitoring and methods for measuring drug levels and anti-drug antibodies. Results: While ustekinumab and vedolizumab exhibit exposure-response relationships, consensus on target levels and the role of TDM adjustments remains elusive. Limited data on risankizumab suggest a dose-dependent response, while for small molecule therapies (janus kinase inhibitors and ozanimod), the absence of real-world data and commercially available TDM tools pose challenges. Conclusion: At present, with the available data, there is a limited role for TDM in non-anti-TNF biologic and small-molecule therapies. This review underscores the need for further research to delineate the utility of TDM in guiding treatment decisions for these agents.

Population pharmacokinetics of gentamicin in acute lymphoblastic leukemia pediatric patients compared to non-oncology patients.

Understanding the pharmacokinetics of gentamicin is essential in special populations, such as pediatric patients with acute lymphoblastic leukemia (ALL), in light of previous studies indicating that ALL patients have a lower volume of distribution than non-ALL patients. Furthermore, validation of such results is needed to ensure their clinical application. Accordingly, this single-center, retrospective, cross-sectional study compares the pharmacokinetic parameters of volume of distribution and clearance (Cl) of gentamicin between ALL and non-ALL patients. Inclusion criteria were pediatric patients aged between 1 and 14 years with or without ALL and receiving intravenous gentamicin for treatment courses > 72 h. Patients' characteristics, such as age, sex, height, serum albumin, diagnosis, serum creatinine (Scr) concentration, dosing, and pharmacokinetic information, including peak and trough concentrations, were retrieved. The study scrutinized a total of 115 pediatric patients, comprising toddlers (15.7 %), children (76.5 %), and adolescents (7.8 %). All patients received gentamicin every 8 h, with an average dose of 2.50 (0.64) mg/kg. Patients were divided into two groups based on disease state, with 45.2 % (n = 52) in the non-ALL group and 54.8 % (n = 63) in the ALL group. Both groups had similar characteristics in terms of gender, weight, body surface area, and dose. The only significant covariates identified were weight and creatinine clearance (Clcr) for volume of distribution (Vd). A significant difference was found in Scr, Clcr, and blood urea nitrogen (BUN); however, no significant difference between ALL and non-ALL patients emerged in the volume of distribution or Cl. In conclusion, the study findings indicate that dosing requirements were similar between the two groups. Further prospective studies with larger sample sizes are warranted.