AML-177 Treatment Adherence and Persistence of FLT3 Inhibitors as Post-Allogenic Hematopoietic Cell Transplant Maintenance Therapy in Patients With Acute Myeloid Leukemia in the United States: A Cohort Study Using Administrative Claims Data

• Published in: Clinical lymphoma, myeloma and leukemia Vol. 24; pp. S296 - S297
• Main Authors: Kennedy, Vanessa E., Touya, Maelys, Spalding, James, Young, Christopher, Cao, Lingtao Frank, Nimke, David, Block, Alana, Pednekar, Priti
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.09.2024
• Subjects: adherence; AML; FLT3-TKI; hemopoietic stem cell transplantation; post-alloHCT maintenance; AML; hemopoietic stem cell transplantation; post-alloHCT maintenance; FLT3-TKI; adherence
• ISSN: 2152-2650
• DOI: 10.1016/S2152-2650(24)01165-0

FMS-like tyrosine kinase 3 inhibitors (FLT3-TKIs) are recommended for post-allogeneic hematopoietic cell transplant (alloHCT) maintenance in patients with acute myeloid leukemia (AML) in the United States (US), but real-world data on patient adherence and persistence are limited. Evaluate adherence/persistence of FLT3-TKI as post-alloHCT maintenance in patients with AML with and without pre-alloHCT relapsed/refractory (R/R) disease. Observational study of US Inovalon Insights payer-sourced claims database. Eligible adult patients with AML received ≥1 alloHCT between 01/01/2016 and 06/30/2022; initiated gilteritinib, midostaurin, or sorafenib as maintenance ≤100 days post-alloHCT; and were followed from FLT3-TKI initiation to earliest post-alloHCT relapse, end of enrollment or study (adherence/persistence), or treatment end (persistence). Adherence (proportion of days covered [PDC] with FLT3-TKI in follow-up period ≥80%) and persistence (days of FLT3-TKI with <60 days treatment gap and without switching agents). Adjusted multivariate regression analyses were conducted. Patients (n=162; median age 52.0 [interquartile range: 39.0–60.0] years) received post-alloHCT FLT3-TKI maintenance; 65.4% (106/162) had pre-alloHCT R/R disease. Median PDC for gilteritinib, midostaurin, and sorafenib was 61.6%, 28.9%, 43.2% in patients without and 80.5%, 51.8%, 61.5% in those with pre-alloHCT R/R disease. Patients with pre-alloHCT R/R disease were less likely to be nonadherent than those without (P=0.009). Compared with gilteritinib, nonadherence was numerically greater for patients receiving midostaurin (odds ratio [OR]: 2.1; 95% CI, 0.9–5.0; P=0.097) or sorafenib (OR: 2.0; 95% CI, 0.9-4.7; P=0.099). Kaplan-Meier median days of persistence was 188 for gilteritinib, 51 midostaurin, and 113 sorafenib in patients without and 324, 127, and 155 in patients with pre-alloHCT R/R disease. Adjusted risk of discontinuation was 2.93 times higher for midostaurin (P=0.0003) and 1.75 times higher for sorafenib (P=0.0418) than for gilteritinib. At 18 months after FLT3-TKI initiation, 10.1% patients without and 13.9% with pre-alloHCT R/R disease continued treatment (gilteritinib: 25.6%, 31.9%; midostaurin: 7.6%, 6.5%; sorafenib: 8.6%, 11.4%, respectively). Overall real-world adherence to FLT3-TKI was modest, particularly among patients without pre-alloHCT R/R disease, and risk of discontinuation was lowest for gilteritinib regardless of R/R status. Additional studies exploring patient and disease-specific factors most predictive of adherence are warranted.