Clinical and pharmacoeconomic impact of subgroup analysis in onco-hematological patients.

Subgroup analysis evaluates a health intervention in subpopulations according to a characteristic or factor. It can be useful for generating new hypotheses or conducting new studies. However, subgroup analysis presents several limitations and it should be considered cautiously. The development of new onco-hematological drugs is accelerating in recent years and the impact of subgroup analysis on clinical decision-making is increasing. The interpretation of subgroup analyses can be controversial in some cases, negatively affecting patients and healthcare systems. This work is a review of the clinical and pharmacoeconomic impact of subgroup analysis in onco-hematological patients. The study describes some illustrative examples of inadequate interpretations about subset analysis: combination of pembrolizumab plus chemotherapy in lung cancer, inhibitors of cyclin-dependent kinases in breast cancer, daratumumab-based regimens in newly diagnosed multiple myeloma, combination of nivolumab with ipilimumab in melanoma and docetaxel in prostate cancer. Subgroup analysis can have a significant impact on the data selection for the development of studies; efficacy, safety, and convenience of treatments in onco-hematological patients; efficiency of therapies in health systems; and therapeutic positioning of antineoplastic drugs. There is a strong need to establish homogeneous criteria for the assessment of subgroup analysis and to develop new tools for its consideration.

Use of docetaxel in low- and high-burden metastatic hormone-sensitive prostate cancer: A systematic review and assessment of subgroup analyses.

BACKGROUND: Use of docetaxel in low- and high-burden metastatic hormone-sensitive prostate cancer presents considerable controversy. There is literature suggesting lack of benefit for low-volume of metastases. OBJECTIVE: The study aims to develop a systematic review and methodological assessment of subset analysis about use of docetaxel in metastatic hormone-sensitive prostate cancer regarding volume of metastatic disease. METHODS: A systematic review in the Pubmed® database was conducted up to 25 September 2020. A reference tracking was also developed. Randomised clinical trials with subgroup analysis according volume of metastatic disease for overall survival were selected. Two methodologies were used. One of them considered statistical interaction of subsets (p(i) < 0.1), pre-specification, biological plausibility and consistency among subset results of similar randomised clinical trials. The second methodology was a two-part validated tool: preliminary questions to discard subset analysis without minimal relevance and a checklist The checklist provides recommendations for applicability of subgroup analysis in clinical practice. RESULTS: A total of 31 results were found in systematic reviews in the Pubmed® database. One result was identified in the reference tracking. Of the total of 32 results, four randomised clinical trials were included in the study. About first methodology, statistical interaction among subgroups was obtained in one randomised clinical trial. Subgroup analysis was pre-specified in two randomised clinical trials. Biological plausibility was reasonable. No external consistency among results of subgroup analyses in randomised clinical trials was observed. Preliminary questions of second methodology rejected applicability of subgroup analysis in three randomised clinical trials. A 'null' recommendation for applicability of subset results was obtained in the remaining randomised clinical trial. CONCLUSIONS: Patients with low- and high-burden metastatic hormone-sensitive prostate cancer would benefit from docetaxel therapy. No consistent differences for overall survival were observed in subgroup analyses regarding volume of metastatic disease.

Economic evaluation and budgetary burden of mepolizumab in severe refractory eosinophilic asthma.

OBJECTIVE: Mepolizumab is indicated as an additional treatment of severe refractory eosinophilic asthma. The observed differences in  population subgroups according to plasma eosinophil count, the  existence of patients with high levels of immunoglobulin E who are  candidates of omalizumab and mepolizumab, as well as mepolizumab's  economic impact, lead to make efficient economic studies for clinical  decision making. The aim was to analyze mepolizumab's cost-efficacy  and budget impact. METHOD: Cost comparison and the use of mepolizumab's budgetary  impact was performed, from the Spanish National Health System's  perspective. Among the assessed alternatives, inhaled systemic  corticosteroids, plus long acting beta agonist (ß2) and/or oral systemic  corticosteroids in patients with non immunoglobulin E-mediated severe  allergic asthma, and said treatment along with omalizumab in patients  with immunoglobulin E mediated eosinophilic allergic asthma were  included. Its efficacy was evaluated through avoided clinically relevant  exacerbations. The direct costs associated with exacerbation were  assessed. RESULTS: Mepolizumab's long run average incremental cost regarding omalizumab's is 797 euros per patient a year. Considering  omalizumab's alternative discounted price, including mepolizumab for  patients with immunoglobulin E mediated eosinophilic allergic asthma  would increase public spending from 2.3 to 4.6 million euros. Given  omalizumab's notified price, the gradual introduction of mepolizumab in  the Spanish National Health System would save 3.6 million euros in  three years. For non immunoglobulin E-mediated severe asthma  patients, the avoided cost/exacerbation by introducing mepolizumab is  15,085 euros, assuming a gradual market penetration of mepolizumab. In patients with ≥ 500 eosinophils/µL, this cost decreases to 7,767  euros per avoided exacerbation with a budgetary impact of 183.2 million  euros in three years with a progressive penetration of mepolizumab. CONCLUSIONS: The cost comparison between mepolizumab and  omalizumab in immunoglobulin E mediated eosinophilic asthma patients  suggests a use of the lower cost drug, promoting price competition.  Additionally, prioritizing its use among non immunoglobulin E-mediated  severe refractory eosinophilic asthma patients and ≥ 500 eosinophils/µL  plasma level patients, would improve its efficiency as well as  reducing its budgetary impact.

Objetivo: Mepolizumab está indicado como tratamiento adicional del asma eosinofílica refractaria grave. Las diferencias observadas en  subgrupos poblacionales según recuento eosinofílico plasmático,  existencia de pacientes con altos niveles de inmunoglobulina E  candidatos a omalizumab y mepolizumab, e impacto económico de  mepolizumab obligan a realizar estudios económicos para tomar  decisiones clínicas eficientes. El objetivo fue realizar un análisis de  coste/eficacia e impacto presupuestario de mepolizumab.Método: Se realizó la comparación de costes e impacto presupuestario del uso de mepolizumab desde la perspectiva del  Sistema Nacional de Salud. Las alternativas valoradas fueron  corticosteroides sistémicos inhalados + agonista ß2 de larga duración  y/o corticosteroides sistémicos orales en pacientes con asma alérgica  grave no mediada por inmunoglobulina E, y este tratamiento junto a  omalizumab en pacientes con asma eosinofílica alérgica mediada por  inmunoglobulina E. La eficacia se evaluó mediante exacerbaciones  clínicamente relevantes evitadas. Se valoraron los costes directos  asociados a exacerbación.Resultados: El coste incremental medio de mepolizumab respecto a omalizumab es de 797 euros por paciente y año. Considerando precio alternativo con descuento de omalizumab, incluir mepolizumab  para pacientes con asma eosinofílica alérgica y mediada por  inmunoglobulina E supondría incrementar el gasto público de 2,3 a 4,6  millones de euros. Teniendo en cuenta el precio notificado de  omalizumab, la introducción gradual de mepolizumab en el Sistema  Nacional de Salud supondría ahorrar 3,6 millones de euros en tres años.  Para pacientes con asma grave no mediada por inmunoglobulina  E, el coste/exacerbación evitada al añadir mepolizumab es de 15.085  euros, con un impacto presupuestario en tres años de 578,4 millones de  euros, asumiendo una penetración progresiva de mepolizumab en el  mercado. En los pacientes con ≥ 500 eosinófilos/µl, este coste  disminuye a 7.767 euros por exacerbación evitada, con un impacto  presupuestario de 183,2 millones de euros en tres años con penetración  progresiva de mepolizumab.Conclusiones: La comparación de costes entre mepolizumab y  omalizumab en pacientes con asma eosinofílica mediada por  inmunoglobulina E señala como razonable utilizar el fármaco de menor  coste, promoviendo competencia de precios. Asimismo, priorizar su uso  en pacientes con asma eosinofílica refractaria grave no mediada por  inmunoglobulina E y niveles plasmáticos ≥ 500 eosinófilos/µl permitiría  mejorar la eficiencia y disminuir el impacto presupuestario.