KTE-X19 Shows Promising Efficacy in Relapsed/Refractory B-Cell Acute Lymphoblastic Leukemia

The following article features coverage from the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting. Click here to read more of MPR‘s conference coverage.

KTE-X19, a chimeric antigen receptor (CAR) T-cell therapy, shows promising clinical activity among heavily pretreated patients with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL), according to research presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting.

KTE-X19 is an autologous anti-CD19 CAR T cell therapy that previously showed encouraging results in phase 1 study. For the phase 2 ZUMA-3 study (ClinicalTrials.gov Identifier: NCT02614066), researchers evaluated the safety and efficacy of the recommended phase 2 dose, which was determined to be 1 × 10⁶ CAR T cells/kg.

Overall, as of September 2020, a total of 55 patients were enrolled and received the experimental therapy. All patients had more than 5% bone marrow blasts at baseline and a performance status of 0 or 1.

The median follow-up period was 16.4 months (range, 10.3-22.1). The median patient age was 40 years (range, 19-84), the median baseline BM blasts were 65%, and 47% of patients had received at least 3 prior therapies.

The overall complete response (CR)/CR with incomplete hematological recovery rate was 71% (56% CRs vs 15% CRs with incomplete hematological recovery). Ongoing responses were noted in 31% of patients with a response; the median duration of response was 12.8 months (95% CI: 8.7-not estimable). Among patients with a CR/CR with incomplete hematological recovery, the minimal residual disease rate was 97%.

Median relapse free survival was 14.2 months; median overall survival was not reached.

Grade 3 or worse adverse events (AEs) were noted in 95% of patients, the most common of which were anemia (49%) and neutropenia (49%). Grade 3 or worse cytokine release syndrome was noted in 24% of patients, and grade 3 or worse neurologic events were noted in 25% of patients.

A total of 2 patients had a grade 5 treatment-related AE (brain herniation and septic shock, respectively).

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

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Reference

Shah BD, Ghobadi A, Oluwole OO, et al. Phase 2 results of the ZUMA-3 study evaluating KTE-X19, an anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, in adult patients (pts) with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL). J Clin Oncol. 2021;39:(suppl 15; abstr 7002). doi: 10.1200/JCO.2021.39.15_suppl.7002

This article originally appeared on Hematology Advisor