CAR-T effective for younger patients with leukemia, regardless of socioeconomic status
Click Here to Manage Email Alerts
Socioeconomic status had no impact on complete remission rates or overall survival among younger patients who received chimeric antigen receptor T-cell therapy for B-cell acute lymphoblastic leukemia, study results showed.
Data from the analysis published in Blood also revealed that children from higher-income households more likely received a referral for CAR-T with higher disease burden.
Background
Children living in poverty and those from historically underserved populations typically have inferior survival outcomes after front-line therapy for B-cell ALL, according to Haley Newman, MD, fellow in pediatric hematology/oncology at Children’s Hospital of Philadelphia (CHOP).
“We wanted to understand if [inferior survival outcomes are] mirrored in the relapsed or refractory setting so that we can begin to understand how we could intervene to improve disparities,” she told Healio.
Methodology
Newman and colleagues conducted a retrospective analysis of 206 patients (median age, 12.5 years; range, 1.4-29.1; 63.6white; 21.4% Hispanic) aged 29 years or younger who received CAR T-cell therapy for relapsed or refractory CD19-postive B-cell ALL or lymphoblastic lymphoma between April 2012 and December 2020 at CHOP. Investigators used outcomes data from patients who underwent treatment with CD19-directed CAR T cells with commercially available tisagenlecleucel (Kymriah, Novartis) or via a clinical trial.
The investigators used insurance type as a proxy for exposure to household poverty, with patients who received Medicaid only being defined as exposed to poverty. The census tract-based Childhood Opportunity Index based on patient addresses served as an indicator of neighborhood opportunity.
“In many studies, neighborhood metrics are proxied at the zip code level,” Newman said. “For our analysis, we utilized household addresses and mapped this to the U.S. census tract, which gives us a more detailed description of the neighborhoods these patients are coming from.”
Median follow-up was 46 months, with a data cutoff date of June 1, 2021.
Key findings
Overall, 35.9% of patients came from poverty-exposed households, with 24.9% living in low-opportunity neighborhoods.
Investigators noted a complete remission (CR) rate of 93%, with no significant differences for CR rates based on household poverty status or neighborhood opportunity.
Researchers reported no significant differences in relapse-free survival based on poverty exposure in either univariate or multivariate analyses (adjusted HR = 0.7, 95% CI, 0.4-1.3).
Likewise, 36-month OS did not differ significantly based on household poverty status or neighborhood opportunity.
Multivariate analysis showed no significant increase in hazard of death among patients from low-opportunity neighborhoods (adjusted HR = 1.2; 95% CI 0.6-2.4). However, multivariate analysis revealed that patients from low-opportunity neighborhoods had increased risk for disease relapse (adjusted HR = 2.3; 95% CI 1.3-4.1).
Results also showed a trend toward higher disease burden among CAR-T recipients from higher-income households, the investigators noted.
Clinical implications
“Among children treated at CHOP, [those] exposed to household poverty and lower neighborhood opportunity had equivalent overall survival and complete remission rates as children without these exposures,” Allison Leahy, MD, MSCE, assistant professor in the division of oncology at CHOP and innovation faculty at Penn Center for Cancer Care Innovation at University of Pennsylvania, told Healio.
“We did find that sicker patients — with higher disease burden — were more frequently from more advantaged households, which could indicate disparities in access,” she added.
This result surprised Leahy, who hypothesized that differences in referral patterns or economically advantaged families being more easily able to advocate for treatment with CAR-T may explain the results.
“We will need to perform future studies to see if this is replicated in other institutions and to uncover the drivers of this potential disparity,” she said.
Meanwhile, despite being a single-center study, Newman said she found the results “very reassuring” that younger patients who receive CAR-T for B-cell ALL can expect similar outcomes regardless of their socioeconomic status.
“We hope clinicians will broadly consider supporting families and advocate for access to CAR-T, and that we can partner with patients and families to consider interventions that would help improve access and outcomes,” she added.
For more information:
Allison Leahy, MD, MSCE, can be reached at Department of Pediatrics, Division of Oncology, Children’s Hospital of Philadelphia, 3500 Civic Center Blvd., Room 3548, Philadelphia, PA 19104; email: barza@chop.edu.
Haley Newman, MD, can be reached at Children’s Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104; email: newmanh@email.chop.edu.
Collapse
Click Here to Manage Email Alerts