ABL1 T315I

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%.

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.

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.

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.

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.

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.

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.

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.

Furthermore, regarding AOE, no expression levels exceeding the results of the clinical trial were confirmed. However, patients with advanced age and who have predisposing factors for AOEs should be closely monitored for possible adverse vascular events.

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.

These results pave the way for a new era in the treatment of adult Ph+ ALL patients. Vignetti et al, Blood 2007 Foà et al, Blood 2011 Chiaretti et al, Haematologica 2016 Chiaretti et al, Haematologica 2021 Martinelli et al, Blood Advances 2022 Foà et al, N Engl J Med 2020 Foà & Chiaretti, N Engl J Med 2022

The upfront use of third generation TKI ponatinib has improved the frequency of complete molecular response (CMR) and the overall survival rate to a greater extent...They received three cycles of OVP regimen(for 28 days each cycle :olverembatinib 40mg qod d1-28,Vindesine 4mg d1,8,15,22,Prednisone1mg/Kg/d d1-21,0.5mg/kg/dd22-28). Twelve intrathecal injections of cytarabine alternating with methotrexate were designed as central nervous system prophylaxis in the following therapy after the diagnosis...The trial is ongoing. we need more time to observe.

Furthermore, through analyzing patients who received TKI treatment, we observed that 3G TKIs like olverembatinib exhibited advantages in prognosis, including achieving deep molecular response, rapid remission reduction, and decreased relapse probability, for both newly diagnosed and relapsed Ph+ ALL patients...The promising outcomes observed with 3G TKIs suggest their potential as a treatment option for both newly diagnosed and relapsed Ph+ ALL patients, offering advantages in terms of molecular response depth, rapid remission, and reduced relapse risk. Further investigations are warranted to explore the clinical significance of unreported ABL1 KD mutations and validate the effectiveness of 3G TKIs against them.

INTRODUCTION: ATP-competitive tyrosine kinase inhibitors (TKIs) have extended the life expectancy of pts with CML. ASC in combination with ATP-competitive TKIs, while associated with a higher AE burden vs ASC monotherapy, demonstrated rapid efficacy in the enrolled pt population. The MTD for ASC + IMA was reached at ASC 60 mg QD + IMA 400 mg QD (Table); the MTD for ASC + NIL or DAS was not reached. ASC 40 or 60 mg QD + IMA 400 mg QD, ASC 40 mg BID + NIL 300 mg BID, and ASC 80 mg QD + DAS 100 mg QD were recommended doses for expansion.

Introduction This was a multicenter, randomized, registrational phase 2 study to assess the efficacy and safety of olverembatinib compared with BAT in pts with CML-CP who were resistant and/or intolerant to 3 TKIs (imatinib [I], dasatinib [D], nilotinib [N]) in China...Pts were randomized 2:1 to investigational olverembatinib (40 mg QOD) or the BAT arm, which could be one of the following per investigator choice: TKIs (I, D, or N), interferon (IFN), hydroxyurea (HU), and homoharringtonine (HHT)...Olverembatinib was observed to be better tolerated and more effective than BAT in treating these pts. Internal study (CT.gov) numbers: HQP1351CC203 (NCT04126681).

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.

With >2 years of follow-up in the phase 3 ASCEMBL study, asciminib (ASC) has continued to demonstrate superior efficacy vs bosutinib (BOS) in pts with CML-CP after ≥2 prior TKIs, and analysis of cancer gene somatic mutations in this population has the potential to reveal additional insights into pts' response to study treatments or characteristics of the disease in later lines of therapy... Adults with CML-CP previously treated with ≥2 TKIs with intolerance of their last TKI or lack of efficacy per 2013 European LeukemiaNet recommendations and without BCR::ABL1 T315I or V299L mutations were randomized 2:1 to ASC 40 mg twice daily or BOS 500 mg once daily... ASXL1 mutations are most frequently detected at CML diagnosis and were enriched at BL in this study of pts with CML-CP previously treated with ≥2 TKIs, which is consistent with a role in TKI resistance. RUNX1 and IKZF1 mutations, which are associated with progression to accelerated or blast phase in CML, were very rare in this pt population, supporting their role in CML disease progression. The high frequency of co-occurrence of BCR::ABL1 mutations and blood cancer gene mutations in CML-CP is an important finding since cancer gene mutations could modify response to TKIs in individual pts.

In the combination cohort, pts with Ph+ B-cell precursor (BCP) ALL or lymphoid CML-BP (CML-LBP) resistant to at least 1 TKI were enrolled and received olverembatinib (30 or 40 mg) QOD in combination with blinatumomab. Internal study identifier: HQP1351-CU101. Clinicaltrials.gov identifier: NCT04260022.

Background: Therapy choice in chronic myeloid leukemia (CML) patients (pts) with ≥2 lines of tyrosine kinase inhibitors (TKIs) failure or in pts with T315I mutation is a relevant problem. ASC shows effectiveness and good safety profile in pts after prior failure to TKIs and those with T315I mutation. The CIF of any response was higher in ponatinib-naive pts at any dose. Different mutational subclones evolution was observed, including emergence of myristoyl-site mutation in 1 pt.

Use of TKIs prior to asciminib included dasatinib (85.6%), imatinib (63.9%), bosutinib (61.9%), nilotinib (53.6%), and ponatinib (15.5%). This is the first real-world study describing treatment patterns and clinical outcomes among patients with Ph+ CML-CP treated with asciminib in the US. The findings of real-world treatment efficacy based on achieving BCR::ABL1 ≤0.1% were consistent with the ASCEMBL trial. Patients who initiated asciminib after 2 previous TKIs had higher persistence and treatment response rates than those initiated on asciminib after ≥3 previous TKIs.

The four patients loosing MMR after ponatinib cessation resumed low dose ponatinib (≤ 15 mg QD) for 2 and asciminib (80 mg BID) for 2, three patients regained MMR (one non evaluable with too short follow-up). TFR attempt represents a strategy that can be applied to ponatinib patients in the setting of heavily pretreated CP-CML in a similar way as of less advanced CP-CML patients, with high success rates and no disease progression. If those data are confirmed by further studies and longer follow-up, TFR strategies might have to be considered also in previously heavily pre-treated patients.

Induction (IND) w/ corticosteroids (CS) and dasatinib (DAS) alone results in morphologic complete response (mCR) rates approaching 100% but low rates of measurable residual disease (MRD) negativity; addition of intensive chemotherapy to TKIs adds risks of myelosuppression...Pts received CS pre-phase w/ prednisone (PRED) or dexamethasone (DEX) followed by modified GIMEMA LAL1205 IND (DEX + DAS 140 mg/d w/ DAS dose adjustments or TKI change per protocol) w/ intrathecal methotrexate (IT MTX) d22, 43 and bone marrow (BM) MRD assessments including FACS and BCR::ABL1 PCR...All began DAS 140 mg/d as initial TKI; 4 changed TKI for DAS intolerance per protocol (bosutinib, n=2; ponatinib [PON], n=2) and remained on study; TKI was changed to PON in 1 other pt to optimize BCR::ABL1 transcript suppression pre-allogeneic transplant (alloHCT) and that pt was withdrawn from study... DAS + CS IND w/ addition of BLIN to TKI in mCR leads to high rates of deep molecular response w/ low risk of early relapse and low rates of severe regimen-related toxicity in pts w/ ND Ph+ ALL. Use of PON (vs DAS) as initial TKI w/ BLIN may further suppress resistant clones. Further f/u is needed to confirm durability of CMR w/ BLIN + TKI CONSOL ± MAINT in absence of alloHCT and whether pts w/ persistent BCR::ABL1 PCR positivity and no malignant clonal IgHR by NGS exhibit similar outcomes to those in CMR.