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 (Cmin) 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 Cmin 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 / Coste-eficacia del pemetrexed en combinación con cisplatino como tratamiento de primera línea en pacientes con cáncer de pulmón avanzado no microcítico ni escamoso en España

Introduction: Lung cancer is the third most frequent neoplastic tumour in Spain, with around 27000 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: 19942 Euros, 15594 Euros and 36095 Euros, respectively. The incremental cost-effectiveness ratio per month of additional PFS between cis/pem and cis/gem/bev was 19303 Euros . 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 (AU)

Introducción: El cáncer de pulmón es la tercera neoplasia tumoral más frecuente en España, con unos 27.000 nuevos casos/ año, de los que el 80-85% son de etiología no microcítica (NSCLC) y en la mayoría de los casos diagnosticados en estadíos avanzados de la enfermedad, razón por la que es uno de los procesos oncológicos con mayores tasas de mortalidad (supervivencia media a los 5 años del 21,4%). Los principales esquemas de primera línea utilizados en el tratamiento del NSCLC son: cisplatino/pemetrexed (cis/pem), cisplatino/gemcitabina/ bevacizumab (cis/gem/bev), y carboplatino/paclitaxel/bevacizumab (carbo/pac/Bev). El objetivo del presente trabajo consistirá en realizar un análisis para estimar el ratio coste-eficacia de los esquemas antineoplásicos de primera línea en el tratamiento del NSCLC, desde la perspectiva de la gerencia hospitalaria. Métodos: Se elaboró un modelo matemático de coste-eficacia basado en un árbol de decisiones. Como variable de eficacia se utilizó la supervivencia libre de progresión, obtenida de los ensayos clínicos fase III PARAMOUNT, AVAIL y SAIL. El estudio se efectuó desde la perspectiva de la gerencia hospitalaria considerando únicamente los costes directos de adquisición de los fármacos. Se realizó un análisis de sensibilidad determinístico para comprobar la robustez de los resultados. Resultados: La SLP obtenida en los ensayos clínicos de los tratamientos cis/pem, cis/gem/bev y carb/pac/bev fue de: 6,9, 6,7 y 6,2 meses, respectivamente. En base a nuestro modelo, el coste medio del tratamiento por paciente para estos esquemas fue de 19.942 Euros, 15.594 Euros y 36.095 Euros, respectivamente. La razón coste-eficacia incremenal por mes de SLP adicional entre cis/pem y cis/gem/bev fue de 19.303 Euros. Estimando una reducción del 30% de los costes de adquisición de pemetrexed (Alimta®Eli Lilly Nederland B.V) ante su próxima incorporación al mercado de medicamentos genéricos, el tratamiento cis/pem se convertiría en la alternativa dominante en el tratamiento de primera línea de los pacientes con NSCLC, al ofrecer los mejores resultados en salud a un menor coste (AU)

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.

Introducción: El cáncer de pulmón es la tercera neoplasia tumoral más frecuente en España, con unos 27.000 nuevos casos/ año, de los que el 80-85% son de etiología no microcítica (NSCLC) y en la mayoría de los casos diagnosticados en estadíos avanzados de la enfermedad, razón por la que es uno de los procesos oncológicos con mayores tasas de mortalidad (supervivencia media a los 5 años del 21,4%). Los principales esquemas de primera línea utilizados en el tratamiento del NSCLC son: cisplatino/pemetrexed (cis/pem), cisplatino/gemcitabina/ bevacizumab (cis/gem/bev), y carboplatino/paclitaxel/bevacizumab (carbo/pac/Bev). El objetivo del presente trabajo consistirá en realizar un análisis para estimar el ratio coste-eficacia de los esquemas antineoplásicos de primera línea en el tratamiento del NSCLC, desde la perspectiva de la gerencia hospitalaria. Metodos: Se elaboró un modelo matemático de coste-eficacia basado en un árbol de decisiones. Como variable de eficacia se utilizó la supervivencia libre de progresión, obtenida de los ensayos clínicos fase III PARAMOUNT, AVAIL y SAIL. El estudio se efectuó desde la perspectiva de la gerencia hospitalaria considerando únicamente los costes directos de adquisición de los fármacos. Se realizó un análisis de sensibilidad determinístico para comprobar la robustez de los resultados. Resultados: La SLP obtenida en los ensayos clínicos de los tratamientos cis/pem, cis/gem/bev y carb/pac/bev fue de: 6,9, 6,7 y 6,2 meses, respectivamente. En base a nuestro modelo, el coste medio del tratamiento por paciente para estos esquemas fue de 19.942 €, 15.594 € y 36.095 €, respectivamente. La razón coste-eficacia incremenal por mes de SLP adicional entre cis/pem y cis/gem/bev fue de 19.303 €. Estimando una reducción del 30% de los costes de adquisición de pemetrexed (Alimta®Eli Lilly Nederland B.V) ante su próxima incorporación al mercado de medicamentos genéricos, el tratamiento cis/pem se convertiría en la alternativa dominante en el tratamiento de primera línea de los pacientes con NSCLC, al ofrecer los mejores resultados en salud a un menor coste.