# AALL1331

Source: https://onco.cc/trials/aall1331/  
OnCo record `aall1331` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

AALL1331 tested swapping blocks of harsh chemotherapy for the antibody blinatumomab in children whose leukaemia had come back; the antibody caused far fewer serious infections, more patients survived in the higher-risk group, and children whose relapse was in the bone marrow did better in the low-risk group too.

## Summary

AALL1331 was a Children's Oncology Group phase 3 trial at 155 hospitals in the United States, Canada, Australia and New Zealand. All 669 patients received a four-week reinduction block and were then stratified. High- and intermediate-risk patients were randomised to two cycles of blinatumomab or two cycles of multi-agent chemotherapy, each followed by transplant. Low-risk patients were randomised to standard chemotherapy or chemotherapy with three blinatumomab blocks in place of some chemotherapy cycles. The primary endpoint in each stratum was disease-free survival.

In the high- and intermediate-risk randomisation, closed early on the monitoring committee's advice, two-year disease-free survival was 54.4 percent with blinatumomab against 39.0 percent with chemotherapy, a difference that did not reach the trial's threshold, while two-year overall survival was 71.3 against 58.4 percent and serious infections, sepsis and mucositis were far less common with blinatumomab. In the low-risk stratum the overall difference was not significant, but the two thirds of patients whose relapse involved the bone marrow had better disease-free and overall survival with blinatumomab, and the authors describe that as a new standard for them.

## Fields

- Kind: Trial
- Status: mixed
- Last checked: 2026-09-22
- Also known as: COG AALL1331
- Tags: soc-trials
- Registry id: NCT02101853
- Phase: 3
- Setting: Children, adolescents and young adults aged 1 to 30 with a first relapse of B-cell acute lymphoblastic leukaemia: after one block of reinduction chemotherapy, blinatumomab in place of intensive consolidation chemotherapy (high and intermediate risk, then transplant) or intercalated with chemotherapy (low risk)
- Sponsor: National Cancer Institute (NCI)
- Enrolled: 669
- Result: Blinatumomab consolidation gave two-year disease-free survival of 54.4 percent against 39.0 percent with chemotherapy in high- and intermediate-risk relapse (not statistically significant after early closure), with better overall survival and far less toxicity; in low-risk bone marrow relapse it improved disease-free and overall survival.
- Outcomes: Disease-free survival at 2 years, high- and intermediate-risk relapse: Blinatumomab consolidation then transplant 54.4% vs Chemotherapy consolidation then transplant 39%, HR 0.7; Overall survival at 2 years, high- and intermediate-risk relapse: Blinatumomab consolidation then transplant 71.3% vs Chemotherapy consolidation then transplant 58.4%, HR 0.62; Serious infection as an adverse event, high- and intermediate-risk relapse: Blinatumomab consolidation then transplant 15% vs Chemotherapy consolidation then transplant 65%; Disease-free survival at 4 years, low-risk relapse: Chemotherapy with blinatumomab blocks 61.2% vs Chemotherapy alone 49.5%; Overall survival at 4 years, low-risk relapse: Chemotherapy with blinatumomab blocks 90.4% vs Chemotherapy alone 79.6%; Disease-free survival at 4 years, low-risk relapse involving the bone marrow: Chemotherapy with blinatumomab blocks 72.7% vs Chemotherapy alone 53.7%

## Sources

- ClinicalTrials.gov NCT02101853: https://clinicaltrials.gov/study/NCT02101853

## Connected records

- cancers: [Acute lymphoblastic leukaemia](https://onco.cc/cancers/all-leukemia/), [Leukaemia (all types)](https://onco.cc/cancers/leukaemia/), [Relapsed and refractory acute lymphoblastic leukaemia in children](https://onco.cc/cancers/all-paediatric-relapsed/)
- technologies: [Bispecific antibodies](https://onco.cc/technologies/bispecific-antibody/), [T-cell engagers (bispecific)](https://onco.cc/technologies/t-cell-engager/)
- drugs: [Blinatumomab](https://onco.cc/drugs/blinatumomab/)
- institutions: [Children's Oncology Group (COG)](https://onco.cc/institutions/childrens-oncology-group/)
- key papers: [AALL1331: blinatumomab added to chemotherapy in low-risk first relapse of childhood B-ALL](https://onco.cc/key-papers/paper-aall1331-low-risk-hogan-jco-2023/), [AALL1331: blinatumomab versus chemotherapy consolidation in high- and intermediate-risk first relapse of childhood B-ALL](https://onco.cc/key-papers/paper-aall1331-brown-jama-2021/)

---
JSON: https://onco.cc/api/v1/entities/aall1331.json