6MP adherence in a multiracial cohort of children with acute lymphoblastic leukemia: a Children's Oncology Group
Smita Bhatia1, Wendy Landier1, Lindsey Hageman1
1Department of Population Sciences, City of Hope, Duarte, CA;
Insights
Adherence to 6-mercaptopurine (6MP) in children with acute lymphoblastic leukemia (ALL) is lower in Asian American and African American children, impacting relapse risk. Race-specific factors influence adherence, highlighting the need for targeted interventions.
Area of Science:
- Pediatric Oncology
- Hematology
- Clinical Pharmacology
Background:
- Durable remissions in pediatric acute lymphoblastic leukemia (ALL) necessitate a 2-year maintenance phase involving daily oral 6-mercaptopurine (6MP).
- Adherence to oral 6MP in Asian American and African American children with ALL remains largely uncharacterized.
Purpose of the Study:
- To investigate adherence rates to oral 6MP in a multiracial cohort of children with ALL.
- To identify race-specific sociodemographic factors associated with 6MP adherence.
- To determine the relationship between 6MP adherence and relapse risk in pediatric ALL.
Main Methods:
- A cohort of 298 children with ALL (71 Asian Americans, 68 African Americans, 159 non-Hispanic whites) receiving oral 6MP maintenance therapy was enrolled.
- Electronic monitoring was used to assess adherence over 39,803 person-days.
- Statistical analyses examined adherence rates, sociodemographic correlates, and relapse risk.
Main Results:
- Overall adherence declined from 95.0% at month 1 to 91.8% at month 5.
- Significantly lower adherence rates were observed in Asian Americans (90.0%) and African Americans (87.1%) compared to non-Hispanic whites (95.2%).
- Poor adherence was linked to lower maternal education in African Americans and lower household income in Asian Americans. Adherence below 90% increased relapse risk (HR, 3.9; P = .01), with 20.5% of participants classified as nonadherent.
Conclusions:
- Race-specific determinants significantly influence 6MP adherence in children with ALL.
- Adherence rates below 90% are associated with a substantially higher risk of relapse.
- Identifying and addressing race-specific barriers to adherence is crucial for minimizing relapse risk in diverse pediatric ALL populations.
Abstract:
Durable remissions in children with acute lymphoblastic leukemia (ALL) require a 2-year maintenance phase that includes daily oral 6-mercaptopurine (6MP). Adherence to oral 6MP among Asian-American and African-American children with ALL is unknown. We enrolled 298 children with ALL (71 Asian Americans, 68 African Americans, and 159 non-Hispanic whites) receiving oral 6MP for the maintenance phase. Adherence was measured electronically for 39 803 person-days. Adherence declined from 95.0% (month 1) to 91.8% (month 5, P < .0001). Adherence rates were significantly (P < .0001) lower in Asian Americans (90.0% ± 4.9%) and African Americans (87.1% ± 4.4%), as compared with non-Hispanic whites (95.2% ± 1.3%). Race-specific sociodemographic characteristics helped explain poor adherence (African Americans: low maternal education [less than a college degree: 78.9%, vs at least college degree: 94.6%; P < .0001]; Asian Americans: low-income households [<$50 000: 84.5%, vs ≥$50 000: 96.7%; P = .04]; households without mothers as full-time caregivers [85.6%] vs households with mothers as full-time caregivers [97.2%; P = .05]). Adherence rate below 90% was associated with increased relapse risk (hazard ratio, 3.9; P = .01). Using an adherence rate <90% to define nonadherence, 20.5% of the participants were nonadherers. We identify race-specific determinants of adherence, and define a clinically relevant level of adherence needed to minimize relapse risk in a multiracial cohort of children with ALL. This trial was registered at www.clinicaltrials.gov as #NCT00268528.
