An observational study of Chinese adults with relapsed/refractory Philadelphia-negative acute lymphoblastic leukemia

Efficacy and safety of blinatumomab in Chinese adults with Ph-negative relapsed/refractory B-cell precursor acute lymphoblastic leukemia: A multicenter open-label single-arm China registrational study

OBJECTIVES

The prognosis for adults with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is poor. Blinatumomab is a CD3/CD19-directed BiTE® (bispecific T-cell engager) molecule approved globally for the treatment of BCP-ALL in adults and children. This multicenter open-label single-arm China registrational study evaluated the safety, efficacy, and pharmacokinetics of blinatumomab in Chinese adults with Philadelphia chromosome-negative (Ph-) R/R BCP-ALL (NCT03476239).

METHODS

Patients aged ≥ 18 years were treated with up to 5 cycles of blinatumomab. The primary objective was to evaluate the hematological response rate (complete remission/complete remission with partial hematological recovery [CR/CRh]) within 2 cycles of blinatumomab.

RESULTS

At the interim analysis (April 12, 2019), 90 patients (median age 31.5 years [range: 18-74]; 53.3% female; 77.8% with bone marrow blasts ≥ 50% at study entry) were enrolled at 23 study centers in China and had received blinatumomab. As of data cutoff, 43 patients (47.8%) continued the study. The CR/CRh rate within 2 cycles of blinatumomab was 45.6% (41/90 [CR, 37; CRh, 4]; 95% CI: 35.0-56.4). Median overall survival was 9.2 months (95% CI: 6.5-11.7); median relapse-free survival was 4.3 months (95% CI: 3.2-9.4). Mean serum concentration at steady-state and systemic clearance of blinatumomab in Chinese patients were within the range reported in adults from global clinical trials. No new safety risks were identified in Chinese patients.

CONCLUSIONS

The efficacy and safety of blinatumomab in these heavily pre-treated Chinese patients with Ph- R/R BCP-ALL is comparable to that for patients within global clinical trials.

Inotuzumab ozogamicin versus standard of care in Asian patients with relapsed/refractory acute lymphoblastic leukemia

Inotuzumab ozogamicin (InO) is a targeted treatment for adults with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL). InO was previously studied in INO-VATE, an international, open-label, randomized phase 3 trial comparing InO against standard of care (SoC). In the present subgroup analysis, we evaluated outcomes in the 55 Asian patients who were randomized in INO-VATE (31 InO and 24 SoC). Complete remission (CR) or CR with incomplete hematologic recovery (CRi) was achieved in 22/31 patients treated with InO versus 5/24 treated with SoC. In the InO arm, more of the patients achieving CR/CRi were minimal residual disease (MRD)-negative (17/22 versus 1/5), and more patients proceeded directly to hematopoietic stem cell transplantation (15/31 versus 3/24). Median overall survival for the respective arms was 5.8 versus 3.9 months (hazard ratio 0.67; 97.5% CI 0.28, 1.62). In the safety analysis (n = 51), the most common adverse events were hematologic. Sinusoidal obstruction syndrome was reported in five InO patients and one SoC patient. In conclusion, Asian patients with relapsed or refractory B-cell ALL experienced improved efficacy with InO versus SoC, with an efficacy and safety profile consistent with results of the overall INO-VATE population.Clinical trial registration: ClinicalTrials.gov identifier: NCT01564784.