Treatment patterns and characteristics of acute promyelocytic leukemia (APL) patients receiving arsenic trioxide (ATO) therapy in a real-world setting.

Abstract

e18522 Background: Clinical trials have shown that low-risk APL patients had significantly better outcomes when receiving first-line all-trans retinoic acid (ATRA) + ATO compared with standard ATRA + chemotherapy. Few published studies have used real-world data to describe patients using ATO and their current treatment patterns. This study used United States (US) administrative claims data to describe treatment patterns and characteristics of patients receiving first-line ATO. Methods: This retrospective, observational cohort study used claims data from the MarketScan databases. As there is no ICD-9-CM diagnosis code for APL, ATO treatment was used as a surrogate for the diagnosis of APL since ATO is typically used only in APL patients. Patients were selected if they had ≥1 claims for ATO between January 1, 2000, and June 30, 2015. Date of first use was designated the index date. To identify first-line ATO initiation, patients with ATRA or other APL-indicated chemotherapy claims any time before the index date were excluded. Variable baseline and follow-up periods consisting of ≥3 months of pre-index and ≥30 days of post-index continuous enrollment in medical and pharmacy benefit were used. Results: In total, 331 patients were identified with a subset (n = 265) having ≥2 claims for ATO. The analysis focused on these 265 patients, 54% of whom were male. Mean age was 60.6 years; 45% were covered by Medicare. The most common comorbid conditions measured were diabetes (6%), chronic obstructive pulmonary disease (5%), and congestive heart failure (4%). The most commonly selected APL treatments administered during follow-up were ATRA (17%) and daunorubicin (9%) with the use of idarubicin, cytarabine, and mitoxantrone at less than 3%. Maintenance therapy with methotrexate or 6-mercaptopurine was observed in 7% and 6% of patients, respectively. Conclusions: This is one of the first studies to examine patient characteristics and treatment patterns for first-line ATO using real-world data. Further research is needed to evaluate outcomes for patients receiving ATO as first-line therapy and to re-evaluate treatment guidelines in light of these outcomes.