Impact of Genetic Mutations and Health Plan Access to Therapies on Treatment Response and Drug Costs Related to Tyrosine Kinase Inhibitor Treatment Among Patients With Chronic Myelogenous Leukemia.

Abstract

This study assessed treatment responses and economic consequences of limiting access to the second-generation BCR-ABL1 tyrosine kinase inhibitors (2G-TKI), dasatinib and nilotinib, for treatment of chronic myelogenous leukemia, while taking into account frequencies of genetic mutations that exhibit different sensitivities to the 2G-TKIs. Frequencies of BCR-ABL1 mutations and the impact of mutations on responses to 2G-TKIs were obtained from published literature and used as inputs in a decision analytics model. Complete hematologic response (CHR) and major cytogenetic response (MCyR) were estimated after 12 months of 2G-TKI treatment. Total annual 2G-TKI drug costs per CHR and MCyR were estimated and compared among 3 2G-TKI access scenarios: (1) open access to both 2G-TKIs; (2) access restricted to dasatinib (DASA-only); and (3) access restricted to nilotinib (NILO-only). Among a hypothetical cohort of 1000 2G-TKI-treated chronic myelogenous leukemia patients, the percentage of patients with CHR and MCyR were greatest for the open access plan (CHR: 93%, MCyR: 56%), followed by DASA-only (88%, 53%) and NILO-only (67%, 47%). Compared with the 2G-TKI costs per CHR in open access ($120,706/CHR), the costs were 5% higher ($126,753/CHR) in DASA-only and 41% higher ($169,990/CHR) in NILO-only. Likewise, compared with the 2G-TKI costs per MCyR in open access ($198,284/MCyR), the costs were 6% higher ($209,259/MCyR) in DASA-only and 22% higher ($241,515/MCyR) in NILO-only. Open access to both 2G-TKIs is associated with improved clinical and economic outcomes: greater treatment response rates (CHR and MCyR) and lower drug costs compared with restricted access to 2G-TKIs.