CALGB 10403 long-term follow-up: Outcomes with intensive chemotherapy for AYA with ALL

Brexu-cel, a CD19 CAR T-cell therapy, is approved for the treatment of adults with R/R B-Results from the phase II CALGB 10403 study (NCT00558519) demonstrated the efficacy and feasibility of an intensive chemotherapy regimen in treatment-naïve AYA patients with ALL. The treatment schedule of CALGB 10403 was previously reported. 

During the European Hematology Association 2025 Congress, Wendy Stock presented 10-year follow-up data from the CALBG 10403 study.¹

The study included 295 AYA patients; 76% had B-ALL and 24% had T-ALL. The median follow-up was 120.5 months.

Key learnings 

At 3 and 10 years the survival rates were 72.5% and 56%, respectively, with a median survival of 142 months. EFS and DFS rates were 44% and 49.3%, respectively.

Relapses were reported in 102 patients; 19% occurred 3–5 years post CR and 6% occurred >5 years post CR. No relapses were reported after 3 years in patients with T-ALL.

MRD-negative status was associated with longer OS (HR, 0.26; 95% CI, 0.10–0.69; p = 0.0037), while Ph-like (HR, 2.08; 95% CI, 1.19–3.65; p = 0.0089) and a BMI ≥30 (HR, 1.65; 95% CI, 1.11–2.47; p < 0.0001) were associated with worse OS.

The landmark analysis demonstrated that relapse rates were lower in patients completing maintenance vs no maintenance therapy (HR, 0.35; 95% CI, 0.16–0.78; p = 0.01).

The findings highlight the importance of early MRD eradication, completion of maintenance therapy, and long-term follow-up in pediatric patients with ALL.