Imatinib plasma levels in patients with gastrointestinal stromal tumour under routine clinical practice conditions

OBJECTIVES

Imatinib is the first therapeutic option for the treatment of unresectable or metastatic gastrointestinal stromal tumours. Previous studies have shown an improvement in patient survival rates following the use of imatinib. Nevertheless, adequate plasma concentrations of imatinib are necessary to achieve such improvement in survival and limit the toxicity of the drug. This study aims to analyse the influence of imatinib plasma concentrations on efficacy and safety in the treatment of gastrointestinal stromal tumour.

MATERIALS AND METHODS

This descriptive, multicentre study analysed plasma levels of imatinib in patients diagnosed with gastrointestinal stromal tumour in the period 2019-2020. An optimal therapeutic range of 750-1500 ng/mL was established for the patient stratification based on their minimum plasma concentrations measured at the steady state.

RESULTS

This study included 11 patients with metastatic disease in total, among whom only 54.5% (n  =  6) had a minimum plasma concentrations measured at the steady state value within the therapeutic range. A median progression-free survival of 7.0 months was recorded for those patients with minimum plasma concentrations measured at the steady state < 750 ng/mL, while that median progression-free survival value remained unachieved for the group with minimum plasma concentrations measured at the steady state > 750 ng/mL (p  =  0.005). The toxicity rate was 25% and 14.3% for patients with minimum plasma concentrations measured at the steady state > 1500 ng/mL and minimum plasma concentrations measured at the steady state ≤1500 ng/mL, respectively (p  =  0.66).

CONCLUSIONS

The present study aims to describe the correlation between the toxicity and effectiveness of imatinib as a function of minimum plasma concentrations measured at the steady state under routine clinical practice conditions. The results described here show the usefulness of imatinib plasma concentrations monitoring as part of the standard daily routine in our hospitals.

Risk factors determining adherence to tyrosine kinase inhibitors in chronic myeloid leukaemia

OBJECTIVE

Tyrosine kinase inhibitors (TKIs) have successfully changed the natural course of chronic myeloid leukaemia (CML). Although they are highly effective drugs, their clinical benefit is conditioned by adherence. This study aims to analyse the adherence of CML patients treated with TKIs and to identify the main factors influencing their adherence to TKIs treatment.

MATERIAL AND METHODS

An 8-month prospective, observational, multicentre study which included patients diagnosed with CML on treatment with TKIs attending the outpatient departments (OPD) of the Pharmacy Services of the participating hospitals. Adherence was assessed using two methods: the Simplified Medication Adherence Questionnaire (SMAQ) and the register of treatment dispensations from the OPDs. To analyse the predictors of adherence, a questionnaire was developed to report demographic and socio-economic information on the patients.

RESULTS

A total of 130 patients enrolled in this study. Adherence rate was 56.9% (n = 74) among individuals, not conditioned by the type of drug used: imatinib (54.8%), nilotinib (63.6%) or dasatinib (54.3%) (p = 0.67). The patient educational level (p = 0.047) and employment status (p = 0.028) were predictors of non-adherence to treatment.

CONCLUSIONS

Adherence is one of the most relevant parameters affecting the effectiveness of highly effective chronic treatments. Approximately half of our patients showed inadequate adherence to treatment with TKIs, with employment status and the individual's level of education emerging as the determining factors.

Efficacy and Safety of Erenumab, Galcanezumab, and Fremanezumab in the Treatment of Drug-Resistant Chronic Migraine: Experience in Real Clinical Practice

BACKGROUND

Due to the recent introduction of new biologic drugs for chronic migraine, a global evaluation in real clinical practice is necessary.

OBJECTIVE

The objective was to evaluate the effectiveness and safety in real clinical practice of drugs targeting the calcitonin gene-related peptide receptor (CGRPr) in patients with chronic migraine.

METHODS

Single-center, restrospective study (2019-2022), including patients with chronic migraine treated with erenumab, galcanezumab, or fremanezumab. Effectiveness variables were recorded, namely, number of migraine headache days per month (MHD), Migraine Disability Assessment Scale (MIDAS) score, and Headache Impact Test-6 (HIT-6) score, assessing changes at week 12, 24 from baseline. Toxicity was recorded following the Common Terminology Criteria for Adverse Events (CTCAE) v5.0 criteria.

RESULTS

In all, 104 patients were included (46.2% erenumab, 41.3% galcanezumab, 12.5% fremanezumab). A reduction in MHD, MIDAS, and HIT-6 was achieved at weeks 12 and 24 with erenumab (p75% at week 24 than those intensified; P = 0.041). There was no difference in efficacy (P = 0.154) or improvement in quality of life (P = 0.783, P = 0.150), but there was greater toxicity (P < 0.001) among nonresponders with erenumab 70 mg versus erenumab 140 mg.

CONCLUSIONS

The results confirm the effectiveness and safety of anticalcitonin gene-related peptide (CGRP) drugs in real clinical practice. However, the study shows little benefit from erenumab intensification, with similar effectiveness and worse tolerability than the standard dose.

Definition of a therapeutic range for predicting long-term infliximab response in patients with inflammatory bowel disease

INTRODUCTION

Monitoring plasma levels of Infliximab plays an important role in optimising treatment in patients with inflammatory bowel disease (IBD). The aim of the following study has been to determine the predictive potential of monitoring infliximab plasma levels for sustained clinical response and evaluate its usefulness to improve treatment efficacy and symptom control, in patients with IBD.

METHODS

This single-centre retrospective study (2017-2019) included patients diagnosed with IBD treated with infliximab. Serum levels and the occurrence of drug-associated immunogenicity were analysed at Week 8 post-induction and 6, 12 and 24 months. Clinical parameters and inflammatory markers were recorded such as subjective global assessment (SGA), C-reactive protein (CRP) and faecal calprotectin (FC). Factors associated with early discontinuation and dose intensification of infliximab were determined.

RESULTS

Multivariate analysis determined that IFX concentrations>7μg/mL at week 8, and at 6 months, are associated with inflammatory remission (p=0.046, 0.045). IFX>7μg/mL at 12 months predicted remission at 18 months of treatment (p=0.006). IFX values>3μg/mL at 12 months are associated with stable SGA at 18 months (p=0.001). Such values at 18 months are associated with stable SGA at 24 months (p=0.044).

CONCLUSIONS AND RELEVANCE

The predictive potential of monitoring IFX plasma levels as a strategy to evaluate sustained long-term clinical response was confirmed. Our results highlight the importance of its introduction into routine clinical practice to enable early identification of non-responders, treatment optimisation, relapse prevention and improve long-term therapy maintenance.

Imatinib plasma levels in patients with chronic myeloid leukaemia under routine clinical practice conditions

INTRODUCTION

The addition of imatinib to the therapeutic arsenal for chronic myeloid leukaemia (CML) has changed the natural course of the disease, in such a way that it is now considered a chronic pathology. However, to achieve therapeutic success, it is necessary to reach adequate plasma concentrations to ensure efficacy and safety.In this study, we aimed to evaluate the plasma concentration of imatinib, analysing its influence on effectiveness and safety in patients with CML.

METHODS

We performed a descriptive, multicentre study in which imatinib plasma levels from patients diagnosed with CML between 2019-2020 were analysed. An optimal therapeutic range of 750-1500 ng/mL was established for the stratification of patients, according to their minimum plasma concentrations measured at steady state (Cssmin).

RESULTS

A total of 28 patients were included, of whom only 39.3% (n = 11) showed Cssmin within the therapeutic range. 100% of patients with Cssmin >750 ng/mL achieved an optimal molecular response, while only 50% of patients with Cssmin <750 ng/mL achieved an optimal molecular response (p = 0.0004). The toxicity rate was 36.4% for patients with Cssmin >1500 ng/mL and 5.9% for those with Cssmin <1500 ng/mL (p = 0.039).

CONCLUSIONS

This study aimed to describe the correlation between the toxicity and effectiveness of imatinib according to its Cssmin in routine clinical practice conditions. Based on our findings, it would be certainly justified to monitor patient plasma concentrations of imatinib on a daily routine basis in our hospitals.

Hepatitis C virus infection screening reduces mortality and is cost-effective independently of the intervention test

INTRODUCTION

Chronic infection due to hepatitis C virus (HCV) is frequently asymptomatic even in advanced stages of liver disease. Implementation of a screening program based on different HCV tests may enable an earlier diagnosis of HCV liver disease and subsequent application of highly effective treatment.

PATIENTS AND METHODS

A Markov model which compares three different screening strategies for hepatitis C versus no screening in low-risk prevalence (general population) and high-risk prevalence population (people who inject drugs or prison population) was designed, taking into account age at the start of screening and participation. The three strategies were: 1) serological detection of antibodies against the HCV, 2) dried blood spot test (DBS) to detect antibodies against HCV and 3) detection of RNA from HCV. Quality-adjusted life-years (QALY) were taken as a measurement of effectiveness. The incremental cost-effectiveness ratio (ICER) was calculated and a deterministic and probabilistic sensitivity analysis was performed.

RESULTS

All three screening strategies were found to be cost-effective with an ICER of €13,633, €12,015 and €12,328/QALY for AntiHCV, DBS-AntiHCV and DBS-RNA HCV, respectively. There was a decrease in mortality due to liver disease in comparison to no screening for AntiHCV (40.7% and 52%), DBS-AntiHCV (45% and 80%) and DBS-RNA HCV (45.2% and 80%) for low-prevalence and high-prevalence populations, respectively.

CONCLUSION

All test interventions for HCV screening are cost-effective for the early detection of HCV infection, also achieving a reduction in mortality. Thus, implementation of screening programs for HCV should not be halted by decisions on monetary policy.

Pharmacokinetics of Trastuzumab After Subcutaneous and Intravenous Administration in Obese Patients

Background: Subcutaneous trastuzumab (T-SC) administration does not allow the historical target concentration of 20 µg/mL for efficacy to be reached, from the start of treatment in patients with a body mass index (BMI) >30 kg/m². Objectives: To analyze the influence of the strategy of dosification (fixed vs adjusted patient's body weight dose) on the initial minimum plasma concentration (C_min) of trastuzumab in obese patients. Methods: This was an observational, prospective study, which included patients with HER2-positive nonmetastatic breast cancer treated with trastuzumab. The determination of the C_min of trastuzumab was performed on day +21 of the first cycle using the ELISA technique. Patients were stratified according to the strategy of dosification and BMI. Results: A total of 50 patients were included; 16 patients received the drug intravenously and 34 in a fixed dosage subcutaneous (T-SC) regimen. The proportion of patients who achieved an adequate plasma concentration since the beginning of treatment was significantly higher when the drug was administered intravenously (93.8% vs 67.6%, P = 0.042). These differences are especially greater in T-SC patients with BMI >30 kg/m², with only 20% of patients exceeding the pharmacokinetic target. Conclusion and Relevance: Our study suggests that trastuzumab SC fixed dose of 600 mg is not equivalent to IV administration, especially in obese patients. An adequate trastuzumab exposure in this population needs patient weight-adjusted IV dosage in the first administration. The clinical relevance of these findings remains to be elucidated, and further research, including larger controlled trials, is warranted.

Influence of Anthropometric Characteristics in Patients With Her2-Positive Breast Cancer on Initial Plasma Concentrations of Trastuzumab

Background: Plasma concentrations of trastuzumab <20 µg/mL in patients with gastric cancer are associated with reduced progression-free and overall survival. In breast cancer treatment, this relationship has not yet been studied, but a suboptimal pharmacodynamic exposure to trastuzumab could be a reason for therapeutic failure of treatment of HER2-positive breast cancer. Objective: The objective of the present study was to determine the proportion of nonmetastatic HER2-positive breast cancers that do not reach a minimum plasma concentration ( Cmin) of 20 µg/mL after first drug administration, established as therapeutically effective in clinical trials. The secondary objective was to identify the physiological and anthropometric characteristics that determine interindividual pharmacokinetic variability. Methods: Serum concentrations of trastuzumab were assessed by ELISA on day 1 of the second cycle before administration of the second dose ( Cmin). Results: Of 19 patients included, 9 (47.4%) had a mean Cmin of 19.0 µg/mL (±12.1) after the first administration. Body mass index (BMI) and weight was the main variable that determined the achievement of therapeutic levels after the first administration. Thus, the proportion of patients reaching the target concentration was 89% when BMI was ≤30 kg/m2 but only 11% when BMI was >30 kg/m2 ( P < 0.01). Conclusions: The standard dose of 600 mg subcutaneous trastuzumab did not ensure adequate pharmacodynamic exposure from the first administration in 52% of patients, with weight and BMI being related to the plasma levels obtained.

Cost-effectiveness of pemetrexed in combination with cisplatin as first line treatment for patients with advanced non-squamous non-small-cell lung cancer in Spain

INTRODUCTION

Lung cancer is the third most frequent neoplastic tumour in Spain, with around 27 000 new cases diagnosed per year; 80-95% of these are non-small-cell cancer (NSCLC), and the majority of cases are diagnosed in advanced stages of the disease, and for this reason it is one of the oncologic conditions with higher mortality rates (21.4% mean survival at 5 years). The main treatment regimens used for first-line treatment of NSCLC are: cisplatin/pemetrexed (cis/pem), cisplatin/gemcitabine/ bevacizumab (cis/gem/bev), and carboplatin/paclitaxel/ bevacizumab (carb/pac/bev). The objective of this study was to evaluate the cost-effectiveness ratio of antineoplastic 1st line NSCLC treatment regimens, from the point of view of hospital management.

METHODOLOGY

A cost-efficacy mathematical model was prepared, based on a decision tree. The efficacy variable was Progression Free Survival, obtained from the PARAMOUNT, AVAIL and SAIL Phase III clinical trials. The study was conducted from the perspective of the hospital management, considering only the direct costs of drug acquisition. A deterministic sensitivity analysis was conducted to confirm the robustness of outcomes.

RESULTS

The PFS obtained in clinical trials with cis/pem, cis/ gem/bev and carb/pac/bev was: 6.9, 6.7 and 6.2 months, respectively. Based on our model, the mean cost of treatment per patient for these regimens was: 19 942 €, 15 594 € and 36 095 €, respectively. The incremental cost-effectiveness ratio per month of additional PFS between cis/pem and cis/gem/bev was 19 303 €. Estimating a 30% reduction in acquisition costs for pemetrexed (Alimta®Eli Lilly Nederland B.V.), due to the forthcoming launch of generic medications, the cis/pem treatment would become the predominant alternative for 1st line treatment of NSCLC patients, by offering the best health results at a lower cost.

Reducing the degree of colonisation of venous access catheters by continuous passive disinfection

Introduction

The advent of Luer-type needleless venous access catheters has been accompanied by a growing number of catheter-related bloodstream infections. Our main objective was to compare rates of colonisation and phlebitis between our standard of care and the new passive disinfection system, using a Luer SwabCap bearing a sponge impregnated with 70% isopropyl alcohol.

Methods

We performed a prospective experimental study involving patients attending our day hospital oncology unit, with central venous (CV) or peripheral venous (PV) access lines with needleless connectors for antineoplastic treatment delivery. We assessed the colonisation rate by culture of the inside of the hubs (qualitative culture) and also assessed the possible appearance of phlebitis and the extra cost of introducing the new system in our oncology day hospital; nurse satisfaction was evaluated by a questionnaire. The effectiveness of the isopropyl alcohol disinfection cap was evaluated by analysing rates of catheter colonisation and phlebitis between two groups: group 1 comprised of patients receiving the standard disinfection method and group 2 comprised of patients receiving SwabCaps on any venous access connectors. Samples were taken from the catheter lumen through a sterile swab seeded in Luria Bertani-rich broth and cultivated for at least 48 h at 37°C. We also assessed the extra cost of introducing the new system in our oncology day hospital, and nurse satisfaction was evaluated by a questionnaire.

Results

29 patients were included (13 in group 1 and 16 in group 2). In group 1, 56% of the samples were taken from CV access connectors versus 40% in group 2. Bacterial growth was detected in 43.7% of group 1 samples versus 0% in group 2 (p=0.006). No differences in the degree of contamination were found between CV and PV access connectors. No cases of phlebitis were observed. Nurse satisfaction with the new system was 9.2 out of a maximum score of 10. The incremental cost of incorporating the new system in our oncology unit was estimated at €1.87 836.

Conclusion

Passive disinfection systems help reduce colonisation of venous access catheters without requiring large economic investment or special training of health personnel.