TEST:

Xpert® BCR-ABL Ultra

Using an IQCP approach, our lab has established a quality control plan that uses weekly QC with the Xpert BCR-ABL assay. Regular review of this weekly QC data shows that this assay continues to perform well with minimal deviations in QC results during our first 18 months of patient testing.

The validation demonstrated the Xpert P190 BCR-ABL Real-Time RT-PCR assay was very accurate and precise. The assay will be used to confirm p190 BCR::ABL transcripts in whole-blood samples and to quantitate the levels in patients undergoing treatment.

Excellent concordance was seen between the Xpert BCRABL Ultra p210 and p190 assays compared to our institutional RT-qPCR assay in PB/BM samples. The Xpert BCR-ABL Ultra p190 and p210 assays showed distinct benefits, including near full automation, quick setup time without laborious RNA extraction, and fast turnaround time. These advancements allow us to assess PB/BM samples for p190 and p210 transcripts with high sensitivity and specificity for diagnostic and therapeutic monitoring purposes.

Objective: To assess the most mutation in 2 genes: ABL ( T315I) and ASXL1 (c.1934dupG), in Tunisian patients with CML and imatinib resistance... Our findings suggest that both mutations are uncommon in Tunisian patients with CML and TKI resistance. A comprehensive mutational analysis of other genes and epigenetic factors is mandatory to elucidate the molecular mechanisms that lead to kinase inhibitor resistance.

Less than 2-fold difference was observed in %BCR-ABL p190/ABL1 reporting between delta Ct-based and CN-based approaches. Conclusion & Significance: A BCR-ABL p190 copy number estimator for Xpert ® BCR-ABL Ultra p190 test was established, which will provide helpful information for diagnosis and prognosis of diseases relating to BCR-ABL p190.

Hanfstein B, Lauseker M, Hehlmann R, Saussele S, Erben P, Dietz C (2014) Distinct characteristics of e13a2 versus e14a2 BCR-ABL1 driven chronic myeloid leukemia under first-line therapy with imatinib... A %CN e13a2/ABL and e14a2/ABL reporting method with known CN of IVT-RNAs has been successfully established in Xpert BCR-ABL Ultra. Both WHO IS and %CN showed very minor differences between e13a2 and e14a2 for % reporting. %CN method demonstrated comparable %reporting to WHO IS in Xpert BCR-ABL Ultra.

To the best of our knowledge this is the first study to investigate ASXL1 mutation in -TKI-resistant CML patients in Tunisia. Despite the limits of our study, our finding highlights that this truncating ASXL1 mutation may be a potential biomarker for predicting therapeutic efficacy, and a treatment strategy for CML with ASXL1 mutation should be established. Moreover, future studies need to comprehensively identify the landscape and clinical relevance of genetic and epigenetic alterations in CML, which can be used to develop novel therapeutic strategies or to prognosticate treatment response.

Current results are promising and show high molecular response rates in Tunisian Ph+ALL, though follow-up is still too short to determine their impact on remission duration and long-term survival. A larger study is mandatory to elucidate prognosis impact of TKI in the management of Ph+ALL.

Statistical analysis of the data obtained with the two systems and on the three different types of material demonstrated a good correlation at all different levels of disease. The CEPHEID cartridge system could therefore be considered as an alternative to the analysis systems currently validated within the Italian network CML LabNet.

A %CN e13a2/ABL and e14a2/ABL reporting method with known CN of IVT-RNAs has been successfully established in Xpert BCR-ABL Ultra. Both WHO IS and %CN showed very minor differences between e13a2 and e14a2 for % reporting. %CN method demonstrated comparable %reporting to WHO IS in Xpert BCR-ABL Ultra.

Bland-Altman Plot showing minimal bias between venous and capillary measurements (BCR::ABL1 %). Values are log10 transformed.

In conclusion, we observed slightly higher MR values with the Cepheid assay compared to our current TaqMan-based qPCR assay, but within acceptable range. The Xpert BCR-ABL Ultra assay showed similar performance to our current clinical assay, but had faster turnaround and less hands-on time in our lab.

The Cepheid Xpert p190 RUO assay demonstrated excellent laboratory performance on both clinical and contrived materials as compared to the laboratory test of record. The simplicity of the assay also allows for decreased turnaround, less hands-on time, and fewer required technical skills which may enable increased laboratory efficiencies over conventional methods.

The synthetic BCR/ABL1 p190 external control demonstrated reproducible and robust performance when tested on Xpert BCR-ABL Ultra p190 assay. These controls are beneficial for routine monitoring of p190 BCRABL1/ABL1 assay performance.

Sokal and ELTS scores had no influence on FIT since 44.4% (4pts) of intermediate, 33.3% (3pts) of low and 2 of high risk relapsed vs 37.5% (6pts) of intermediate, 25% (4pts) of low and 4 of high risk in FIT, an influence of gender since 77.7% of relapses were men, age and even depth of MMR are all potential factors for cessation but the results in our cohort. The results in our cohort do not confirm their influence since 88.8% of our relapses were in MMR4.5 with a median age of 45 years (42-69) Conclusion : The A-STIM and EURO-SKI studies demonstrate that the depth of response before stopping does not play a prognostic factor for a good FIT, which is confirmed by our study; therapeutic impregnation is the only factor ensuring the maintenance of the FIT found in the studies less in our cohort, hence the factors ensuring the maintenance of the FIT in CML are still to be determined, in order to select the eligible patients.

Conclusion Despite the limit of our study, it underscores the importance of MiR-199a expression, as potential marker of optimal molecular evolution in patients under TKI therapy. Data from a larger number of patients are needed to reveal the clinical relevancy of MiR-199a expression in CML Tunisian patients.

Despite the limit of our study (duration and size), the available real-life molecular responses with TKI therapy should be considered to identify potentially CML patients eligible for discontinuation of TKI therapy.

BCRABL1 testing of peripheral blood, bone marrow, and extracted RNA using the Cepheid Xpert BCR-ABL Ultra p210 assay is sufficient to measure molecular remission (0.003% IS, 4.5log reduction) at >95% sensitivity and specificity. BCR-ABL1 testing of peripheral blood, bone marrow, and extracted RNA using the Cepheid Xpert BCR-ABL Ultra p190 assay is sufficient to measure ≤0.1% of cells at >95% sensitivity and specificity. This assay provides a combined benefit of highly accurate results and ease of use.

Our study highlights that TKidiscontinuation was safe and effective in CML patients who are in sustained deep molecular response with longer TKitreatment duration. A larger study is mandatory for a comprehensive analysis of molecular recurrence in CML patients.

Among 149 patients with sustained DMR; 14 (8.6%) CML patients have discontinued TKI therapy. Conclusion Despite the limit of our study (duration and size), the available real-life molecular responses with TKI therapy should be considered to identify potentially CML patients eligible for discontinuation of TKI therapy.

No abstract available

Del6q23 by FISH in previously untreated CLL represents an uncommon abnormality. When compared to patients without del6q23, patients with del6q23 tend to have more adverse clinical and cytogenetic profiles at baseline, which likely confer a worse prognosis as reflected by shorter TTFT compared to patients without this abnormality.

No abstract available

In our series, 13 patients and one discontinued imatinib and second-generation TKIs, respectively... Despite the limit of our study, these results highlight the importance of sustained deep molecular responses to safely suspend therapy and attempt treatment-free remission (TFR).