BCR-ABL1 Y253H

Flumatinib-based regimens demonstrated high efficacy and tolerable toxicity in Ph+ ALL, which was comparable to other second-generation TKIs. T315I and Y253H mutations were key drivers of relapse. Although allo-HSCT enhanced survival, longer follow-up period and prospective trials are warranted to validate these findings.

Mutational analysis is recommended to identify patients at risk of disease progression. Therefore, early detection of such mutations may allow timely treatment intervention to prevent or overcome resistance.

Compared with Sanger sequencing, fluorescence quantitative PCR has higher sensitivity and can screen for low-frequency ABL1 kinase mutations in the early stage. Moreover, it can also perform relative quantitative analysis, so the method has good clinical application prospects for detecting ABL1 mutation.

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.

This study shows us that there are more mutations associated with therapeutic failure in patients with CML in addition to those in the ABL domain. Knowing these mutations can support the diagnosis, prognosis, establish target therapies and even guide the decision of a bone marrow transplant. Studies with larger populations are required to corroborate the data presented here to generate correlations the clinical and prognostic relevance of myeloid mutations, both at the time of treatment failure and perhaps at diagnosis.

Dasatinib in combination with a two-week vincristine and glucocorticoids regimen were administered, followed by sequential infusions of CD19 and CD22 CAR-T cells. Conclusions Dasatinib in combination with CAR-T cell therapy has enabled chemotherapy-free treatment in newly diagnosed Ph-positive ALL. This treatment is characterized by high complete molecular response, high long-term survival, low toxicity and short treatment cycles.

ABL1 is subject to auto-inhibition mediated by myristoylation-triggered conformational change, which can be exploited to overcome resistance, as validated by allosteric inhibitors such as GNF2, GNF5 and asciminib. Furthermore, TGRX-678 and ponatinib synergize to overcome the clinically challenging resistance conferred by T315M or T315I-inclusive compound mutations. This data warrant further clinical investigation of TGRX-678 for the treatment of resistant or refractory CML patients.

In summary, our newly developed assay can be used for kinase domain mutation analysis from clinical samples and with very good sensitivity of 2%, which is in a well-acceptable range of 1% to 3% and is available on commonly used the Ion Torrent platform. This ability of the assay in detecting low-level variants and even compound variants makes it very important for selection of appropriate TKIs for CML patients.

As a result, cells expressing different forms of BCR/ABL were recruited for the present study, including K562 (human wild-type) or TCCY-T315I (human imatinib-resistant) and the Ba/F3-(T315I/E279K/Y253H) (mouse BCR/ABL point mutation-transfected cells)...The results demonstrated that the ethyl acetate and chloroform fractions were more effective than the n-hexane and water fractions. It is thus concluded that AVM inhibits the activity of BCR/ABL and their subsequent molecular signals, including AKT and MAPK, resulting in cytotoxicity via apoptosis.

It has been demonstrated better efficacy compared to imatinib in clinical trials of CML, but few reports are available in ALL...Once the diagnosis is confirmed, combination of flumatinib (600mg/day) and VIP-based chemotherapy regimen (Vincristine/Idarubicin/Prednisone) is administered promptly...Central nervous system (CNS) prophylaxis is regularly performed by intrathecal injection of methotrexate, cytarabine, and dexamethasone after remission induction course...Conclusion The combination of the second-generation TKI flumatinib and chemotherapy is quite effective and safe in Chinese adult pts with newly diagnosed Ph/BCR-ABL1+ ALL. This clinical trial is still ongoing, and the long-term follow-up data will be further investigated.

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.