Tisagenlecleucel Appears Effective in Babies With Advanced B-Cell Acute Lymphoblastic Leukemia

Children younger than 3 years of age who have advanced B-cell acute lymphoblastic leukemia (B-ALL) may benefit from treatment with tisagenlecleucel, a chimeric antigen receptor (CAR) T-cell therapy, according to research presented at the European Hematology Association (EHA) 2021 Virtual Congress.¹

Results from this retrospective study were presented by Sara Ghorashian, PhD, of UCL Great Ormond Street Institute of Child Health in London.

Prior results from the phase 2 ELIANA trial (ClinicalTrials.gov Identifier: NCT02435849) suggested that tisagenlecleucel may benefit pediatric and young adult patients with B-ALL.²

However, ELIANA did not include patients younger than 3 years of age. Dr Ghorashian and colleagues set out to determine the outcomes of tisagenlecleucel in this younger age group by analyzing data from patients treated at 15 centers.

Data from 30 patients were included in the analysis. The patients’ median age at diagnosis was 4.4 months. All patients had advanced disease, 24 had mixed-lineage leukemia (MLL)-rearranged B-ALL, 13 were refractory to 1 or more prior lines of treatment, and 21 had previously undergone stem cell transplant.

The patients’ median age at CAR T-cell infusion was 17.4 months. Of the 30 patients analyzed, 26 were evaluable for efficacy, and 27 were evaluable for safety.

Overall, 92% of patients (24/26) achieved a minimal residual disease-negative complete response (CR) or CR with incomplete hematologic recovery (CRi). Two patients had no response to tisagenlecleucel.

There were 6 patients who relapsed after achieving a CR/CRi, and 2 had CD19-negative relapses.

Five patients went on to stem cell transplant — 2 post-relapse, 2 due to early B-cell recovery, and 1 as a planned adjunctive procedure.

The overall survival rates at 6 months and 12 months were both 88%. Event-free survival rates at 6 months and 12 months, as defined by criteria from the ELIANA trial, were 67% and 58%, respectively.

Composite event-free survival rates at 6 months and 12 months were 59% and 49%, respectively. For this endpoint, an event was defined as molecular or frank relapse, further therapy, or death.

Rates of ongoing B-cell depletion at 6 months and 12 months were 77% and 68%, respectively.

Grade 3 or higher adverse events included cytokine release syndrome (10%), neurotoxicity (5%), and cytopenia (36%).

Dr Ghorashian noted that the outcomes in this study are similar to outcomes in the ELIANA trial.

“Overall, these data are very encouraging to support the use of tisagenlecleucel in this age group and in those with MLL-rearranged ALL, but longer follow-up is needed,” Dr Ghorashian said.

Disclosures: The presenter declared affiliations with UCLB and Novartis.

Reference

1. Ghorashian S, Jacoby E, De Moerloose B, et al. Outcomes of children aged under 3 years treated with tisagenlecleucel for B-ALL. Paper presented at: European Hematology Association 2021 Virtual Congress; June 2021; Abstract S116.
2. Maude SL, Laetsch TW, Buechner J, et al. Tisagenlecleucel in Children and Young Adults with B-Cell Lymphoblastic Leukemia. N Engl J Med. 2018;378(5):439-448. doi:10.1056/NEJMoa1709866.

This article originally appeared on Cancer Therapy Advisor