COST-EFFICACY ANALYSIS OF THE PHARMACOGENETICS TEST FOR THE TPMT IN ACUTE LYMPHOBLASTIC LEUKEMIA

• Published in: Value in health Vol. 20; no. 5; p. A112
• Main Authors: Gil, S García, Díaz, R Ramos, Sánchez, V Casañas, Sánchez, P Yanes, de la Fuente, G González, Casariego, GJ Nazco, Romero, MM Viña, Gómez, G Calzado, Rodríguez, J Ramos, Perera, I González, Nicolás, F Gutiérrez
• Format: Journal Article
• Language: English
• Published: Lawrenceville Elsevier Science Ltd 01.05.2017
• Subjects: 6-Mercaptopurine; Acute lymphoblastic leukemia; Blood; Children; Critical incidents; Deoxyribonucleic acid; DNA; Economic analysis; Efficacy; Extraction; Fluorescent indicators; Genetic diversity; Genetics; Genomics; Genotype & phenotype; Genotypes; Genotyping; Health care; Hospitalized; Islands; Leukemia; Leukopenia; Lymphatic leukemia; Methyltransferase; Myelosuppression; Patients; Pharmacogenetics; Population studies; Suffering; Toxicity; Variants
• ISSN: 1098-3015; 1524-4733
• DOI: 10.1016/j.jval.2017.05.005

OBJECTIVES: The potential impact of pharmacogenetics on healthcare are still uncertain. Toxicities derived from the use of 6-mercaptopurine can be prevented by the genotyping of the thiopurine-methyltransferase (TPMT) enzyme. The aim of this study is to elaborate a cost-efficacy analysis for the determination of TPMT genotype in children with Acute Lymphoblastic Leukemia(ALL) using an economic and simple method for the pharmacogenetic determination. METHODS: We perform this anlaysis using the Ramos(2015) method from a dried blood drop deposited in collection cards for the genomic-DNA extraction. Genetic variants of TPMT analyzed were: 2*,3A*,3B*,3C* and 4*. Polymorphisms determination was performed by PCR using fluorescent probe. The sensitivity of our method is 99% (data not show). The cost of each genetic determination was 1.16€. Therefore the genotyping of a patient was 4.64€.Leucopenia is the most severe adverse event(AE) associated with thiopurine treatment. For the economic analysis we considered that the frequency of occurrence of AE would be 3% (Sanderson-2004), and 1/3 of this AE are related to TPMT decreased activity (Marra (2002)). 2/3 of patients suffering significant leucopenia could be managed as out-patients, requiring two additional visits (132€). The mean hospital stay of a child with ALL with severe myelosuppression is 10 days (480€/day). The healht-costs were taken from the Official Bulletin of Canary-Islands, 2015. The cost-efficacy analysis was done for a hypothetical cohort of 2.000 children with ALL. RESULTS: For the study population are estimated 60 patients will develop severe myelosuppression. In 20 patients this AE are related to TPMT deficiency with a cost asociated: 7 hospitalized patients (70 days/33.600 €), 13 out-patients (1.716€).The TPMT genotyping costs for 2000 patients will be 9.280€. So the cost saving will be 26.036€. CONCLUSIONS: Our analysis indicates that TPMT genotyping could be considered as an integral part of healthcare prior to the initiation of therapy with thiopurine drugs.