Outcomes of children with T-cell acute lymphoblastic leukemia treated with the JACLS T-02 protocol
Hisashi Ishida1, Souichi Suenobu2, Toshihiko Imamura3
1Department of Pediatrics, Okayama University Hospital, Okayama, Japan.
Insights
Intensive chemotherapy for T-cell acute lymphoblastic leukemia (T-ALL) improved outcomes. The T-02 protocol showed a 70.9% event-free survival, but female patients with rapid response may benefit from tailored therapy.
Area of Science:
- Pediatric Oncology
- Hematology
- Clinical Trials
Background:
- T-cell acute lymphoblastic leukemia (T-ALL) historically had poorer outcomes than B-cell ALL.
- Intensive chemotherapy regimens have narrowed the outcome gap between T-ALL and B-cell ALL.
- The Japan Association of Childhood Leukemia Study (JACLS) ALL-02 study investigated a specific T-ALL protocol (T-02).
Purpose of the Study:
- To evaluate the efficacy and safety of the T-02 protocol for T-ALL patients.
- To determine the 2-year event-free survival (EFS) as the primary outcome.
- To identify prognostic factors influencing T-ALL patient outcomes.
Main Methods:
- Prospective study (ALL-02) involving 107 T-ALL patients from 2002-2008.
- All patients received uniform induction therapy; those with <25% bone marrow blasts at day 15 proceeded with the T-02 protocol.
- Event-free survival (EFS) and cumulative incidence of relapse were analyzed.
Main Results:
- 98% of enrolled T-ALL patients achieved complete remission (CR) after induction.
- Among 79 patients on the T-02 protocol, the 2-year EFS was 70.9%.
- A cumulative incidence of relapse was 29.1%, with no nonrelapse mortality observed. Female sex was a significant predictor of better EFS.
Conclusions:
- The T-02 protocol demonstrated acceptable outcomes for T-ALL, but excessive treatment reduction might negatively impact results.
- Female patients with a rapid early response to therapy may tolerate less intensive treatment.
- Further investigation in larger studies is warranted to explore tailored therapeutic approaches for specific T-ALL patient subgroups.
Abstract:
Historically, patients with T-cell acute lymphoblastic leukemia (ALL) had poorer outcomes than those with B-cell ALL. However, with intensive chemotherapy regimens, outcomes for both groups have become similar. From 2002 to 2008, the Japan Association of Childhood Leukemia Study (JACLS) conducted the prospective ALL-02 study, using a unique protocol for T-ALL (T-02). All T-ALL patients received the same induction therapy, and those who had < 25% bone marrow blasts at day 15 and achieved complete remission (CR) after induction continued on the T-02 protocol. Of the 107 T-ALL patients enrolled, 98 (91.6%) achieved CR after induction. Among 79 patients continuing on the T-02 protocol, the 2-year event-free survival (EFS), the study's primary outcome, was 70.9%, with a cumulative incidence of relapse of 29.1% and no observed nonrelapse mortality. Univariate analysis identified female sex as a significant predictor of better EFS. This study suggests that excessive treatment reduction may lead to poorer outcomes, although female patients with a rapid early response could potentially benefit from less-intensive therapy, warranting further investigation in a larger study.
![Dynamic Imaging of Chimeric Antigen Receptor T Cells with [18F]Tetrafluoroborate Positron Emission Tomography/Computed Tomography](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F62334.jpg&w=3840&q=50)
