ABL1 T315I

This project highlights the application of creative and robust methods of molecular diagnostics for LMICs, allowing for the treatment and monitoring of patients with previously limited access to assays and medications widely available in Western industrialized countries.

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.

Asciminib has also been shown to have no clinically relevant effect on cardiac repolarization. Here, we review the clinical pharmacology data available to date for asciminib that supported its clinical development program and regulatory applications.

The primary treatment for chronic myeloid leukemia (CML) involves first- and second-generation tyrosine kinase inhibitors (TKIs), such as imatinib, nilotinib, bosutinib, and dasatinib. It includes in silico calculations, such as the octanol/water partition coefficient (cLogP) via SwissAdme, and 2D maps of intermolecular interactions through molecular docking. This approach enhances understanding for both specialists and those interested in medicinal chemistry and pharmacology, while also contextualizing future directions for further optimizations of ponatinib, facilitating the development of new analogs of this crucial inhibitor for the treatment of CML and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL).

We report the case of a 63-year-old woman with a history of CML with poor response to imatinib who progressed to myeloid BP-CML, driven by the acquisition of t(8;21)(q22;q22)/RUNX1::RUNX1T1. The patient received intensive chemotherapy and dasatinib, followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT)...Ponatinib and azacitidine were started as salvage treatment, allowing for the achievement of complete remission with deep molecular response after five cycles. Advances in the knowledge of disease biology and clonal evolution are crucial for optimal treatment selection, which ultimately translates into better patient outcomes.

Overall, our findings indicate the prevalence and impact of new ABL1 KD mutations in BCR::ABL1-positive ALL patients, highlighting the necessity for effective therapies targetingthese mutations.

Currently, ponatinib is the only approved tyrosine kinase inhibitor (TKI) that is effective for Ph-positive ALL with the T315I mutation...is a retrospective observational study, it offers prospects for the efficacy of chemotherapy combined with the novel third-generation TKI, olverembatinib, in these conditions, which may be validated in future prospective clinical trials...Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19804.

The safety profile was generally manageable. This study suggests that olverembatinib-based therapy is another promising option for BCR::ABL1-positive ALL in addition to ponatinib, especially for patients with MRD-positive disease and a single T315I mutation.

P=N/A, N=31, Not yet recruiting, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine; Ruijin Hospital, Shanghai Jiao Tong University School of Medicine

Coadministration with rifampin decreased these same variables by 61.27%, 74.21%, and 75.19%, respectively. These results confirm that olverembatinib is primarily metabolized by CYP3A4 in humans, suggesting that caution should be exercised with concurrent use of olverembatinib and strong CYP3A4 inhibitors or inducers.

Five (10.4%) patients experienced AEs leading to discontinuation, including 2 who discontinued asciminib and died due to COVID-19; these were the only deaths reported. These results show asciminib's effectiveness, including in almost 50% of ponatinib pretreated patients, and confirm its risk-benefit profile, supporting its use as a treatment option for T315I-mutated CML-CP.

Ponatinib-based therapy also resulted in significantly better outcomes in frontline Ph-positive ALL compared with prior TKIs and is becoming a new standard of care in this setting. As the clinical development of third-generation TKIs and their rational combinations progresses, we envision further transformative changes in the treatment of CML and Ph-positive ALL.

The safety profile of ponatinib was comparable with imatinib. ClinicalTrials.gov Identifier: NCT03589326.

BCR::ABL1 plays an essential role in the laminin adhesion of Ph-positive ALL cells through upregulation of CD49f.

We identified six genes that were consistently upregulated in the fly CML model and validated in adult and pediatric CML patients and in a mouse cell line expressing BCR::ABL1T315I. This study provides a comprehensive analysis of gene signatures in BCR::ABL1p210 and BCR::ABL1T315I, laying the groundwork for targeted investigations into the role of these genes in CML pathogenesis.

Y139D and T315I mutations are extremely resistant to asciminib. Ponatinib and omacetaxine show potential for treating asciminib-resistant chronic myeloid leukemia.

P1/2, N=68, Active, not recruiting, Takeda | Trial completion date: Aug 2027 --> Jan 2027 | Recruiting --> Active, not recruiting

T315I mutations have a high incidence in Ph-positive ALL patients even if the course of disease is short. In molecular biology, T315I mutation detection is indicated for CML patients not in remission.

Overall survival (OS) of the patients with BCR-ABL1 mutations was significantly lower comparing to the patients with no mutation (p < 0.05) and 8 patients with T315I mutation presented OS of 0%. T315I was the most commonly identified BCR-ABL1 mutation in TKI-resistant CML patients of Azerbaijani origin, being associated with disease progression and poor OS.

The T315I mutation is the most common mechanism for disease resistance, being targetable to ponatinib. Blinatumomab, a bispecific antibody, has shown significant synergy with TKIs in treating this disease. It serves as an excellent salvage therapy, aside from achieving outstanding results when incorporated into the frontline.

Myeloablative conditioning regimens with total body irradiation (fractionated, total 10 Gy) /etoposide (200mg/m 2 x 3) /fludarabine (30mg/m 2 x 5) or cyclophosphamide (1...Cyclosporine, mycophenolate mofetil and short-term methotrexate were employed for graft-versus-host disease (GVHD) prophylaxis... Our results indicate that CAR-T bridging to allo-HSCT is safe and effective for patients with r/r ph+ ALL. The 2 years OS and LFS both reach to 78. 6%.

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.

Its efficacy and safety profile in patients with chronic-phase chronic myeloid leukaemia (CML) have been shown in the Phase 3 ASCEMBL study, comparing asciminib 40 mg twice daily versus bosutinib 500 mg once daily...All had received prior chemotherapy in combination with a TKI (imatinib, N=3; dasatinib, N=5; ponatinib, N=5), with 3 patients having undergone allogeneic haematopoietic stem cell transplantation (allo-HSCT)...ConclusionAsciminib demonstrated promising clinical efficacy with satisfactory tolerance in this cohort of Ph+ leukaemias failing multiple lines of therapy. Further investigation of its therapeutic role in Ph+ ALL is warranted.

Background ASCEMBL trial has demonstrated superior efficacy of Asciminib (ASC) over Bosutinib in terms of molecular response, and event-free survival. These findings contribute valuable insights to the understanding of ASC and PON treatments in pts with specific disease characteristics and may have implications for personalized therapy decisions in the absence of clinical trials comparing these drugs. Our aim is to expand our PSM cohort.

2% at week 24) and a favorable safety profile compared with bosutinib 500 mg once daily (qd) in adult patients with Ph+ CML-CP in the phase 3 ASCEMBL study (NCT03106779). The study is still recruiting. This study will determine a pediatric dose for asciminib and support a strategy of full extrapolation from adult data to use in the pediatric patients with CML-CP.

Also, with >2 years of follow-up, ASC demonstrated superior efficacy and better safety and tolerability compared with bosutinib in pts with CML-CP without the T315I mutation after ≥2 prior TKIs in the phase 3 ASCEMBL study (NCT03106779)...In addition to pts receiving ASC as their 2L TKI, a separate cohort of newly diagnosed pts will be included, and these pts may receive up to 4 weeks of prior treatment with imatinib or an approved second-generation TKI (Table)...Dose escalation of ASC in 2L and 1L is another treatment strategy and results from ASC2ESCALATE will add to the growing body of evidence for using ASC to treat pts with CML-CP. Recruitment for pts using ASC as their 2L TKI began November 2022, and as of July 10, 2023, 5 pts have been enrolled in this cohort; Up to 92 and 90 pts are estimated to enroll in the 2L and 1L cohorts, respectively, across 90 sites.

First-line therapy was available for 16 pts and was imatinib for 11 pts, nilotinib for 2 pts, dasatinib for 3 pts. Our data confirmed the efficacy of ponatinib in second or later lines of treatment. All pts, including those treated for resistance, achieved optimal responses at 3 mos. We also showed that TFR may be feasible for some pts treated in second or subsequent lines, not only for intolerance.

T315I mutation in ABL KD confers broad-spectrum resistance to all 1st- and 2nd-generation ABPIs including Imatinib (IMA), Dasatinib (DAS), Nilotinib (NIL) and Bosutinib (BOS). This result suggests synergistically enhanced inhibitory activity of dual blockade using AXI combined with ASC specifically for T315I mutant CML. This approach will be promising against CML cells carrying compound mutation with T315I mutation, which is highly resistant even to Ponatinib or Asciminib.

As for the 23-year-old female pt with CML-LBP, dasatinib was switched to olverembatinib when T315I, E255K, and E255V mutations were detected...At present, the patient maintained in CR, and blinatumomab will be used for MRD clearance before allo-HSCT...In addition, bridging allo-HSCT after deeper molecular remission could further improve survival. The safety profiles were manageable, but there is still a need to explore the optimal dose in elderly pts.

It has shown better efficacy compared to imatinib in clinical trials of CML, but few reports are available in ALL...Once the diagnosis is confirmed, the combination of flumatinib (600mg/day) and VIP-based chemotherapy regimen (Vincristine/Idarubicin/Prednisone) is given promptly...Blinatumomab is allowed to administer for MRD clearance before allo-HSCT...Achieving MRD flow negativity or CMR at 3 months and bridging allo-HSCT could further improve survival. The long-term follow-up data will be disclosed soon.

The 15 R/R patients (11, Ph + ALL; 4, CML-BP) received olverembatinib 30 or 40 mg on alternate days combined with VP (vindesine 4 mg once per week for 4 weeks and prednisone 1 mg/kg for 3 weeks and tapered at the fourth)...Among the 16 patients with molecular resistance to TKI-based chemotherapy (imatinib [n = 4]; dasatinib [n = 9]; flumatinib [n = 3]), 2 received olverembatinib monotherapy, 7 olverembatinib plus VP, and 7 hyper-CVAD, of whom 8 received subsequent allogeneic transplantation...Treatment-related nonhematologic severe adverse events were observed in 3 patients, including (each) stable angina pectoris, severe pneumonia, and fatal Klebsiella sepsis. Conclusions Olverembatinib-based chemotherapy is effective and safe in patients with R/R and molecular resistant Ph + ALL or CML-LBP.

A similar pattern was also observed when olverembatinib was combined with doxorubicin. ConclusionsOlverembatinib, a novel, third-generation TKI, in combination with chemotherapeutic agents vincristine or doxorubicin decreased MCL-1, BCL-2, and BCL-xL and increased BAX and PUMA in a dose-dependent manner, the combinations have demonstrated synergistic antitumor effects by enhancing apoptosis and antiproliferation in Ph⁺ ALL cells, which may provide an alternative approach for treatment of patients with Ph⁺ ALL.

The Olverembatinib involving regimen included: Olverembatinib and Venetoclax in combination with VP based low intensive chemotherapy (Vindesine /Prednisone), Olverembatinib+Blinatumomab, Olverembatinib + INO. ConclusionThis work suggests that Olverembatinib showed a profound response rate and was well tolerated in MRD clearance prior to allo-HSCT in Ph+ALL with disease recurrence and persistently MRD positive. Larger prospective studies are needed.

Recently, such pts have new hope with the wide application of a novel third-generation TKI Olverembatinib developed in China and Blinatumomab（CD19 antibody,BITE）and INOTUZUMAB OZOGAMICIN(CD22 antibody,Ino. For heavily treated RR ABL1+B ALL pts,including those after treatment with ponatinib and other TKICART and HSCT, Olverembatinib combined with monoclonal antibodies is effective and safe. In my cases, it is particularly noteworthy that one pts ,Ph like ALL with ABL1 FG, received Olverembatinib combination BITE and achieved a surprising response, so Olverembatinib may also be effective and safe for such pts. In addition, venetoclax may be used as a sensitizer for TKI or other antitumor drugs.

P1, N=62, Recruiting, Ascentage Pharma Group Inc. | Trial primary completion date: Jan 2023 --> Jan 2024

CV toxicity was consistent with clinical trials and other real-world registries. Older age, hypercholesterolemia and a SCORE risk >2% were significantly associated with higher risk of AOEs. Controlling CV risk factors and reducing doses at optimal time points may help to optimize ponatinib use in daily practice.

The recent update of the ASCEMBL study demonstrated a superior efficacy with a good tolerability of Asc compared to bosutinib in chronic phase chronic myeloid leukemia (CP-CML) patients (pts) intolerant or refractory to ≥2 TKIs (Rea et al., 2022) Here we present the real-world clinical outcomes of 77 3rd + line Italian CP-CMLpts who received Asc through a Managed Access Program (MAP) approved by Novartis in 41 Italian institutions...Forty-three pts (55.8%) had a prior exposure to ponatinib and 38 of them (88.4%) had ponatinib as last TKI before switching to Asc...In this heavily pre-treated population of CML pts most of whom with a high comorbidity burden, Asc demonstrated fast and sustained responses. Collectively, these results continue to confirm that Asc has a promising role as standard of care in pts with CP-CML treated with ≥2 prior TKI.

17 (30.4%) patients were pretreated with third-generation TKI (ponatinib). As of the data cutoff date, 37 (66.1%) patients continued on treatment and 19(33.9%) discontinued because of disease progression, intolerance, loss to follow-up or death. Conclusion Olverembatinib-based therapy showed strong efficacy and tolerable toxicity in advanced Ph+ leukemia.

Background: In patients (pts) with CML, the BCR::ABL1 T315I gatekeeper mutation confers treatment resistance to all approved ATP-competitive tyrosine kinase inhibitors (TKIs) except ponatinib and olverembatinib; thus pts harboring this mutation have limited treatment options. Asciminib demonstrated effectiveness in pts with CML and the T315I mutation in routine medical practice, including ponatinib pre-treated pts, a population with limited available treatment options. Effectiveness estimates were consistent with those observed in clinical trials. Although the number of pts was small, this global study reports on one of the largest cohorts of pts with CML and the T315I mutation.