BCR-ABL1 M351T

Highly polymorphic BCR-ABL kinase domains have been reported to harbor more than a hundred mutations, and among these, 40-60% have been identified as influencers of imatinib mesylate (IM) resistance...A haplotype frequency distribution pattern analysis of ABL1 loci further identified the CGC haplotype as an independent predictor for IM resistance. As such the study highlights the importance of patient characteristics, genotype distribution, and haplotype frequency distribution in predicting the response to IM treatment and clinical outcomes of CML patients.

The present study demonstrated that a half of baseline conc ABPIs in combination with ASC is as effective as other ABPIs not just in WT but also in other ABL1 KDM CML cell lines. Different CML cell lines harboring different ABL KDM has different treatment spectrum on optimal ABPI drug as well as optimal drug conc. This result will be useful to design future clinical trial of dual blockade of ASC with other ABPIs considering the ABL KDM profiles.

ASCEMBL trial showed superior efficacy of ASC to Bosutinib (BOS) with a higher molecular response rate, and a lower rate of discontinuation due to lack of efficacy (24.2% vs 35.5% at week 96)...A phase 1 study attempted to determine appropriate dose of ASC in combination with fixed dose of ABPIs including Imatinib (IMA), Dasatinib (DAS) and Nilotinib (NIL)...Each cell lines does have its inherent resistance level to double blockades, which needs to be further explored. A phase 1 study with reduced dose of ABPI in combination with fixed dose ASC is strongly warranted to define an optimal dose for combination.

Y253F mutation was not seen in the present study sample. In the present cohort of 83 patients, 29 (35%) cases were positive for single mutation, 12 (14%) had two mutations and 3 (4%) had three mutations.

Although dasatinib and nilotinib have been approved as second-line therapies that could overcome some of these mutants, the most prevalent gatekeeper T315I mutant remains unconquered. CHMFL-48 also exhibited great anti-leukemic efficacies in vivo in K562 cells and p210-T315I-transformed BaF3 cell-inoculated murine models. This discovery extended the pharmacological diversity of BCR-ABL kinase inhibitors and provided more potential options for anti-CML therapies.

P, N=200, Recruiting, Wuhan Union Hospital, China

In patient #6, G645delinsGWfs was found at the diagnosis and on the 3rd line nilotinib treatment...In patient #3, the CSF3R mutation A593V was found at diagnosis and confirmed 14 months after the imatinib initiation...Despite the clonal hematopoiesis with somatic mutations is considered as age-related phenomenon, in AYA CML patients, it may represent a critical problem in achieving sustained molecular response on solo TKI therapy, or even worse, it may result in higher risk of therapy failure and disease progression. Supported by MZCR 00023736