TEST:

QXDx™ BCR-ABL %IS Kit

Both cdPCR and ddPCR demonstrated comparable performance in detecting BCR::ABL1 transcripts with high concordance in MR3 level or above. Choosing between platforms may depend on cost, workflow, and sensitivity requirements.

The assay demonstrated excellent clinical correlation with the comparator test using a Deming regression with a Pearson R of 0.99, slope of 1.037 and intercept of 0.1084. This data establishes that the QXDx™ BCR-ABL %IS Kit is an accurate, precise, and sensitive system for the diagnosis and monitoring of CML.

Twelve patients with ≥3 different time points were part of this cohort, and several patients showed MR (MR >2) or major MR (MR >3) after TKI initiation (imatinib, dasatinib, nilotinib). ddPCR and RT-qPCR are comparable methods, with ddPCR showing MR values that trended slightly higher than RT-qPCR, though this did not significantly change clinical status. Both assays also showed sensitive MRD detection in patients with CML.

ddPCR may be most useful where other TFR predictive factors including BCR-ABL1 transcript type and halving time are not available. In-kind support was received from Bio-Rad for this study.