Quantitative assessment of the exposure-efficacy relationship of glucocerebrosidase using Markovian elements in Gaucher patients treated with enzyme replacement therapy.

AIMS: The aims of this study are (i) to develop a population pharmacokinetic model of enzyme activity in Gaucher-type 1 (GD1) patients after intravenous administration of enzyme replacement therapy (ERT), and (ii) to establish an exposure-efficacy relationship for bone marrow infiltration to propose dose adjustments according to patient covariate values. METHODS: A prospective follow-up, semi-experimental multi-centre study was conducted in four hospitals to evaluate the pharmacokinetics, efficacy and safety of ERT in GD1 patients. Twenty-five individuals with 266 glucocerebrosidase (GCase) observations in plasma and leukocytes and 14 individuals with 68 Spanish magnetic resonance imaging (S-MRI) observations were enrolled. RESULTS: A two concatenated compartment model with zero-order endogenous production and first-order distribution (CL1 = 3.85 × 10-1 L/d) and elimination (CL2 = 1.25 L/d) allowed GCase observations in plasma and leukocytes to be described, respectively. An exponential time dependency (kT = 6.14 × 10-1 d-1 ) effect on CL1 was incorporated. The final exposure-efficacy model was a longitudinal logistic regression model with a first-order Markov element. An Emax function (EC50 = 15.73 U/L and Emax = 2.33) linked steady-state concentrations of GCase in leukocytes to the probability of transition across the different S-MRI stages. CONCLUSION: A population pharmacokinetic model successfully characterized the leukocyte activity-time profiles of GCase following intravenous administration of ERT in GD1 patients together with an exposure-efficacy relationship in bone marrow using Markovian elements. The information obtained from this study could be of high clinical relevance in individualization of ERT in GD1 patients, as this could lead to anticipative decision-making regarding clinical response in bone and optimal dosing strategy.

Effectiveness, toxicity, and economic evaluation of ipilimumab for the treatment of patients with metastatic melanoma in the Spanish outpatient setting.

To evaluate the effectiveness and toxicity profile of ipilimumab treatment and to examine the cost-effectiveness relation in a real-world sample of patients with metastasic melanoma. This was a multicenter, observational, retrospective cohorts study. To assess the effectiveness and safety of ipilimumab treatment progression-free survival (PFS), overall survival (OS) and adverse events were registered. An economic evaluation was performed and cost-effectiveness ratios (CERs) were calculated. Eleven patients were included, mean age 59 (SD=11) years. The median PFS was 3.83 months (95% confidence interval 0.98-9.80) and the median OS was 5.15 months (95% confidence interval 1.70-8.48). None of the patients included in the study achieved an objective response. A stable disease was achieved in four (36%) patients. The most commonly reported analytical adverse event was anemia, with all patients developing anemia in any grade. The most severe adverse event was neutropenia (n=6; 55%), with three patients developing grade 4 neutropenia (3/11; 27%). The total cost of ipilimumab treatment was &OV0556;483 397, with a median of 43 033 (interquartile range=9555) euros per patient. The median-based CER was 136 675 (28 539-474 865) euros per progression-free year gained and the median-based CER was 100 112 (23 107-374 893) euros per life-year gained. PFS observed in real-world patients was higher than that reported in clinical trials and OS was lower. The incidence of adverse events was higher. The additional cost per progression-free year gained was ∼&OV0556;136 675. The data from this study fill an important need for information on the relative value of this treatment in terms of cost-effectiveness.

Effectiveness, toxicity, and economic evaluation of vinflunine for the treatment of patients with transitional cell carcinoma in the Spanish outpatient setting.

The aim of this study was to evaluate the effectiveness and toxicity profile of the vinflunine chemotherapy regimen and to examine the cost-effectiveness relation in a real-world sample of patients with transitional cell carcinoma of the bladder. This is a multicenter, observational, retrospective cohort study. To assess the effectiveness and safety of vinflunine treatment, progression-free survival, overall survival, and adverse events were registered. An economic evaluation was performed and cost-effectiveness ratios were calculated. A total of 37 patients were included in the study, with a mean age of 67 (SD=9) years. The median progression-free survival was 2.61 months (95% confidence interval 1.79-4.23) and the median overall survival was 5.72 months (95% confidence interval 3.34-10.35). An objective response was achieved in eight (22%) patients. Statistically significant differences were found between patients treated with vinflunine as a second-line therapy and those treated with vinflunine as a third-line therapy (P=0.036). The most commonly reported analytical adverse event was anemia (n=34; 92%), and the most severe was neutropenia (n=19; 51%), with nine patients developing grade 4 neutropenia (9/19; 47%). The total cost of vinflunine treatment was &OV0556;553 873, with a median of &OV0556;8524 (interquartile range, &OV0556;9220) per patient. The median-based cost-effectiveness ratio was &OV0556;44 789 (&OV0556;31 706-58 022) per progression-free year gained and &OV0556;22 750 (&OV0556;14 526-34 085) per life-year gained. The data from this study fill an important need for information on the relative value of this treatment in terms of cost-effectiveness and might help achieve an optimal quality healthcare system.

[Incidence, management and costs of adverse effects in chronic hepatitis C patients on triple therapy with telaprevir or boceprevir: first 12 weeks of treatment]. / Incidencia, manejo y coste de los efectos adversos hematológicos y dermatológicos durante las 12primeras semanas de tratamiento con triple terapia para hepatitisC.

INTRODUCTION: The aim of the study was to analyze the incidence, management and cost associated to hematological and dermatological adverse effects (AE) in chronic hepatitis C patients on triple therapy (TT) with telaprevir (TVR) or boceprevir (BOC). METHODS: An analysis was made on the data recorded on patients who started treatment with TVR or BOC associated with peginterferon alfa and ribavirin in a 12-week follow-up period. RESULTS: Fifty-three patients were included (TVR n=36; BOC n=17). Thrombocytopenia (83% TVR vs. 88% BOC) followed by neutropenia (89% TVR vs. 82% BOC) were the most common AE. Dermatological AE were observed in 32% of patients. Eleven patients required treatment discontinuation (all of them received TVR), and toxicity was the main reason for discontinuation (64%). The percentage of patients who required supportive treatment for management of AE was 66%. The most used supportive treatment was erythropoietin. Eight patients required emergency health care, and 2 were hospitalized due to AE. Total cost of additional supportive resources was 32,522€ (625 [SD=876]€/patient) (TVR 759 [SD=1,022]€/patient vs. BOC 349 [SD=327]€/patient; P>.05). Patients with gradeiii-iv toxicity required greater supportive care with higher costs, compared to patients with gradei-ii toxicity (849 [SD=1,143]€/patient vs. 387 [SD=397]€/patient; P=.053). CONCLUSION: The addition of new protease inhibitors to conventional treatment leads to a higher incidence of hematological AE in our study, compared to data described in clinical trials. The elevated incidence of AE involves the use of supportive care, increasing total costs of therapy.