Digital PCR improves the quantitation of DMR and the selection of CML candidates to TKIs discontinuation

In conclusion, dPCR resulted in an improved recognition of stable DMR and of candidates to TKI discontinuation. AbstractTreatment ‐free remission (TFR) by tyrosine kinase inhibitors (TKI) discontinuation in patients with deep molecular response (DMR) is a paramount goal in the current chronic myeloid leukemia (CML) therapeutic strategy. The best DMR level by real‐time quantitative PCR (RT‐qPCR) for TKI discontinuation is still a matter of debate. To compare the accuracy of digital PCR (dPCR) and RT‐qPCR forBCR ‐ABL1 transcript levels detection, 142 CML patients were monitored for a median time of 24  months. Digital PCR detectedBCR ‐ABL1transcripts in the RT ‐qPCR undetectable cases. The dPCR analysis of the samples, grouped by the MR classes, revealed a significant difference between MR4.0 and MR4.5 (P = 0.0104) or MR5.0 (P = 0.0032). The clinical and hematological characteristics of the patients grouped according to DMR classes (MR4.0 vs MR4.5 ‐5.0) were superimposable. Conversely, patients with dPCR values<0.468BCR ‐ABL1 copies/ µL (as we previously described) showed a longer DMR duration (P = 0.0220) and mainly belonged to MR4.5 ‐5.0 (P = 0.0442) classes compared to patients with higher dPCR values. Among the 142 patients, 111 (78%) discontinued the TKI treatment; among the 111 patients, 24 (22%) lost the MR3.0or MR4.0. RT ‐qPCR was not able to discriminate patients with higher risk of MR loss after discontinuation (P = 0.8100). On the...
Source: Cancer Medicine - Category: Cancer & Oncology Authors: Tags: ORIGINAL RESEARCH Source Type: research