Healthcare Resource Utilization in Adult Patients with B-Cell Precursor Acute Lymphoblastic Leukemia in First Hematologic Complete Remission with and without Minimal Residual Disease
Authors: Rose Darya , Shah Shweta , Despiegel Nicholas , Tibrewala Shruti , Chawla Anita , Cong Ze 
Published: October 2019

Abstract
Introduction: B-cell precursor acute lymphoblastic leukemia (BCP ALL) is a rare and debilitating hematologic cancer. Among BCP ALL patients in hematologic complete remission (CR), minimal residual disease (MRD) is one of the most important prognostic factors predicting worse survival outcomes. However, to date, limited data in the U.S. have been available to characterize healthcare resource utilization (HRU) in BCP ALL patients with and without MRD. In the present study, a chart review was conducted to assess HRU as measured by the frequency of inpatient stays and outpatient visits among adult BCP ALL patients (MRD-positive and MRD-negative) in first hematologic CR. The chart review study was conducted across National Cancer Institute (NCI) designated cancer centers, academic and community hospitals, and integrated delivery systems.
Methods: U.S. hematologists and oncologists were invited to complete an 89-item online case report form, and provided data on patient demographic and disease characteristics, MRD assessment, and HRU over the study period. The study period was defined as the date of first hematologic CR (index date) until the earlier of 12 months post-CR, relapse, or death. Eligible patients were ≥ 18 years of age at diagnosis of BCP ALL, achieved first hematologic CR between April 1, 2015 and March 30, 2017, had no diagnoses for other cancer types, and had chart information available for the entire study period. Patients were characterized based on MRD history over the entire study period. This abstract reports HRU among patients who are in first hematologic CR with MRD, not including care associated with stem cell transplantation. The number of inpatient (IP)/emergency room (ER) days per month (mean) was calculated based on physician-reported dates of admission/discharge and the follow-up period (months) after the first MRD test. The number of outpatient (OP) visits per month was calculated based on the physician-reported number of acute care OP visits and the follow-up period (months) after the first MRD test.
Results: Sixty-six U.S. physicians completed the online questionnaire, providing data from a total of 126 patient charts meeting the eligibility criteria. Five patient charts were excluded from the analysis due to inconsistent or missing MRD assessment data. On average, the 63 physicians that provided eligible charts included in the analysis reported being in practice for 13.2 years and half of them have been treating ≥20 adult patients with BCP ALL in first hematologic CR in the last 12 months. At the index date, mean patient age was 48.5 years, 72.7% were male, 74.4% were Caucasian, and 25.6% were Philadelphia chromosome positive. Of the 121 patients included in the analysis, 82 patients were MRD-positive at the first MRD test (42 patients were persistent MRD-positive, 40 subsequently became MRD-negative). The number of IP/ER days per month (mean ± standard deviation [SD]) was 1.90 (± 4.92) vs. 0.52 (± 1.26) and the number of acute care OP visits per month was 0.13 (± 0.44) vs. 0.09 (± 0.37) for patients who were persistent MRD-positive vs. patients who subsequently became MRD-negative (Table 1).
Conclusions: This chart review study demonstrated that among adult BCP ALL patients in first hematologic CR with MRD, patients with persistent MRD had more inpatient stays and outpatient visits than those who subsequently became MRD-negative. New therapies that can eradicate MRD among adult ALL patients in hematologic CR may have some cost offsets from the decreased HRU associated with MRD-negative status.

Disclosures
Rose: Analysis Group, Inc.: Employment; Amgen, Inc.: Consultancy. Shah:Amgen, Inc.: Employment, Equity Ownership. Despiegel:Amgen, Inc.: Employment, Equity Ownership. Tibrewala:Analysis Group, Inc.: Employment; Amgen, Inc.: Consultancy. Chawla:Amgen, Inc.: Consultancy; Analysis Group, Inc.: Employment, Equity Ownership. Cong:Amgen, Inc.: Employment, Equity Ownership.