Project description:Tyrosine kinase inhibitors (TKIs) have significantly changed the treatment of chronic myeloid leukemia (CML) and improved outcomes for patients with CML in chronic phase (CML-CP) and accelerated phase (AP). Now armed with numerous effective therapeutic options, clinicians must consider various patient- and disease-specific factors when selecting the most appropriate TKI across lines of therapy. While most patients with CML expected to have a near-normal life expectancy due to the success of TKIs, emphasis has expanded beyond response and survival to include factors like quality of life, tolerability, and long-term toxicity management. Importantly, a subset of patients can achieve sustained deep molecular response and can attain treatment-free remission. Despite these successes, unmet needs remain related to CML treatment, including the persistent challenge of treatment resistance and intolerance, broadening treatment options for patients with resistance mutations or serious comorbidities, and focus on specific populations such as children and young adults. In particular, the only previously available treatments for patients with CML-CP with the T315I mutation were ponatinib, olverembatinib (exclusively approved for use in China at the time of this writing), omacetaxine, and hematopoietic stem cell transplantation. Asciminib has entered the CML treatment landscape as a new option for adult patients with CML-CP who have received ≥2 prior TKIs or those with the T315I mutation. Asciminib's unique mechanism of action, Specifically Targeting the ABL Myristoyl Pocket, sets it apart from traditional adenosine triphosphate-competitive TKIs. While asciminib may overcome unmet needs for patients with CML-CP and continues to be studied in other novel settings, guidance on how to integrate asciminib in treatment algorithms is needed. This review focuses on clinical data and how asciminib can overcome current unmet needs, discusses how to individualize patient selection, and highlights future directions to investigate asciminib in earlier lines of therapy and in children and adolescents.
Project description:Background and objectiveAsciminib is approved in patients with Philadelphia chromosome-positive chronic myeloid leukemia in chronic phase (Ph+ CML-CP) treated with ≥ 2 prior tyrosine kinase inhibitors. Here, we aimed to demonstrate similarity in efficacy/safety of asciminib 80 mg once daily (q.d.) versus 40 mg twice daily (b.i.d.) in patients with CML-CP without T315I mutation and support the use of the 200-mg b.i.d. dosage in patients harboring T315I, using model-informed drug development.MethodsData were collected from 199 patients in the phase I (NCT02081378; 10-200 mg b.i.d. or 10-400 mg q.d.) and 154 patients in the phase III (NCT03106779; 40 mg b.i.d.) studies. Evaluations were based on population pharmacokinetics (PopPK) and exposure-response (efficacy/safety) analyses.ResultsPopPK showed comparable exposure (area under the curve, AUC0-24h) for 40 mg b.i.d. and 80 mg q.d. (12,638 vs 12,646 ng*h/mL); average maximum and minimum plasma concentrations for 80 mg q.d. were 1.61- and 0.72-fold those of 40 mg b.i.d., respectively. Exposure-response analyses predicted similar major molecular response rates for 40 mg b.i.d. and 80 mg q.d. (Week 24: 27.6% vs 24.8%; Week 48: 32.3% vs 30.6%). Results also established adequacy of 200 mg b.i.d. in patients with T315I mutation (Week 24: 20.7%; Week 48: 23.7%), along with a similar safety profile for all dose regimens.ConclusionsSimilarity between 40 mg b.i.d. and 80 mg q.d. regimens was investigated, demonstrating similar and substantial efficacy with well-tolerated safety in patients without T315I mutation. The 200-mg b.i.d. dose was deemed safe and effective for patients with T315I mutation.
Project description:BCR-ABL1 is a fusion protein as a result of a unique chromosomal translocation (producing the so-called Philadelphia chromosome) that serves as a clinical biomarker primarily for chronic myeloid leukemia (CML); the Philadelphia chromosome also occurs, albeit rather rarely, in other types of leukemia. This fusion protein has proven itself to be a promising therapeutic target. Exploiting the natural vitamin E molecule gamma-tocotrienol as a BCR-ABL1 inhibitor with deep learning artificial intelligence (AI) drug design, this study aims to overcome the present toxicity that embodies the currently provided medications for (Ph+) leukemia, especially asciminib. Gamma-tocotrienol was employed in an AI server for drug design to construct three effective de novo drug compounds for the BCR-ABL1 fusion protein. The AIGT's (Artificial Intelligence Gamma-Tocotrienol) drug-likeliness analysis among the three led to its nomination as a target possibility. The toxicity assessment research comparing AIGT and asciminib demonstrates that AIGT, in addition to being more effective nonetheless, is also hepatoprotective. While almost all CML patients can achieve remission with tyrosine kinase inhibitors (such as asciminib), they are not cured in the strict sense. Hence it is important to develop new avenues to treat CML. We present in this study new formulations of AIGT. The docking of the AIGT with BCR-ABL1 exhibited a binding affinity of -7.486 kcal/mol, highlighting the AIGT's feasibility as a pharmaceutical option. Since current medical care only exclusively cures a small number of patients of CML with utter toxicity as a pressing consequence, a new possibility to tackle adverse instances is therefore presented in this study by new formulations of natural compounds of vitamin E, gamma-tocotrienol, thoroughly designed by AI. Even though AI-designed AIGT is effective and adequately safe as computed, in vivo testing is mandatory for the verification of the in vitro results.
Project description:ABL tyrosine kinase inhibitor (TKI) therapy has improved the survival of patients with Philadelphia (Ph) chromosome-positive leukemia. However, ABL TKIs cannot eradicate leukemia stem cells. Therefore, new therapeutic approaches for Ph-positive leukemia are needed. Aberrant activation of phosphoinositide 3-kinase (PI3K) signaling is important for the initiation and maintenance of human cancers. Copanlisib (BAY80-6946) is a potent inhibitor of PI3Kα and PI3K-δ. Here we investigated the efficacy of combination therapy of copanlisib with an ABL TKI (imatinib, nilotinib, or ponatinib) using BCR-ABL-positive cells. Although the effects of the ABL TKI treatment were reduced in the presence of the feeder cell line, HS-5, copanlisib inhibited cell growth. Upon combining ABL TKI and copanlisib, cell growth was reduced. Ponatinib and copanlisib combined therapy reduced tumor volume and increased survival in mouse allograft models, respectively. These results indicate that the PI3Kα and -δ inhibitors overcame the chemoprotective effects of the feeder cells and enhanced ABL TKI cytotoxicity. Thus, co-treatment with ABL TKI and copanlisib may be a powerful strategy against ABL TKI-resistant cells, including those harboring the related T315I mutation.
Project description:Abelson murine leukemia viral oncogene homolog (ABL) tyrosine kinase inhibitors (TKIs) have been shown to be effective for treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia patients. However, resistance to ABL TKIs can develop as a result of breakpoint cluster region-ABL point mutations. Aurora kinases regulate many processes associated with mitosis. In this study, we investigated whether inhibiting Aurora kinase can reduce the viability of Ph+ leukemia cells. Treatment with the Aurora kinase A inhibitor alisertib blocked Ph+ leukemia cell proliferation and Aurora kinase A phosphorylation; it also induced G2/M-phase arrest and increased the intracellular levels of reactive oxygen species. Combined treatment of Ph+ cells with ABL TKIs and alisertib was cytotoxic, with the fraction of senescent cells increasing in a time- and dose-dependent manner. Aurora A gene silencing suppressed cell proliferation and enhanced ABL TKI efficacy. In a mouse xenograft model, co-administration of ponatinib and alisertib enhanced survival and reduced tumor size; moreover, the treatments were well tolerated by the animals. These results indicate that inhibiting Aurora kinase can enhance the cytotoxic effects of ABL TKIs and is, therefore, an effective therapeutic strategy against ABL TKI-resistant cells, including those with the T315I mutation.
Project description:BackgroundResistance to tyrosine kinase inhibitors in patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) is frequently caused by mutations in the BCR-ABL kinase domain. Ponatinib (AP24534) is a potent oral tyrosine kinase inhibitor that blocks native and mutated BCR-ABL, including the gatekeeper mutant T315I, which is uniformly resistant to tyrosine kinase inhibitors.MethodsIn this phase 1 dose-escalation study, we enrolled 81 patients with resistant hematologic cancers, including 60 with CML and 5 with Ph-positive ALL. Ponatinib was administered once daily at doses ranging from 2 to 60 mg. Median follow-up was 56 weeks (range, 2 to 140).ResultsDose-limiting toxic effects included elevated lipase or amylase levels and pancreatitis. Common adverse events were rash, myelosuppression, and constitutional symptoms. Among Ph-positive patients, 91% had received two or more approved tyrosine kinase inhibitors, and 51% had received all three approved tyrosine kinase inhibitors. Of 43 patients with chronic-phase CML, 98% had a complete hematologic response, 72% had a major cytogenetic response, and 44% had a major molecular response. Of 12 patients who had chronic-phase CML with the T315I mutation, 100% had a complete hematologic response and 92% had a major cytogenetic response. Of 13 patients with chronic-phase CML without detectable mutations, 100% had a complete hematologic response and 62% had a major cytogenetic response. Responses among patients with chronic-phase CML were durable. Of 22 patients with accelerated-phase or blast-phase CML or Ph-positive ALL, 36% had a major hematologic response and 32% had a major cytogenetic response.ConclusionsPonatinib was highly active in heavily pretreated patients with Ph-positive leukemias with resistance to tyrosine kinase inhibitors, including patients with the BCR-ABL T315I mutation, other mutations, or no mutations. (Funded by Ariad Pharmaceuticals and others; ClinicalTrials.gov number, NCT00660920.).
Project description:A major drawback of tyrosine kinase inhibitor (TKI) treatment in chronic myeloid leukemia (CML) is that primitive CML cells are able to survive TKI-mediated BCR-ABL inhibition, leading to disease persistence in patients. Investigation of strategies aiming to inhibit alternative survival pathways in CML is therefore critical. We have previously shown that a nonspecific pharmacological inhibition of autophagy potentiates TKI-induced death in Philadelphia chromosome-positive cells. Here we provide further understanding of how specific and pharmacological autophagy inhibition affects nonmitochondrial and mitochondrial energy metabolism and reactive oxygen species (ROS)-mediated differentiation of CML cells and highlight ATG7 (a critical component of the LC3 conjugation system) as a potential specific therapeutic target. By combining extra- and intracellular steady state metabolite measurements by liquid chromatography-mass spectrometry with metabolic flux assays using labeled glucose and functional assays, we demonstrate that knockdown of ATG7 results in decreased glycolysis and increased flux of labeled carbons through the mitochondrial tricarboxylic acid cycle. This leads to increased oxidative phosphorylation and mitochondrial ROS accumulation. Furthermore, following ROS accumulation, CML cells, including primary CML CD34(+) progenitor cells, differentiate toward the erythroid lineage. Finally, ATG7 knockdown sensitizes CML progenitor cells to TKI-induced death, without affecting survival of normal cells, suggesting that specific inhibitors of ATG7 in combination with TKI would provide a novel therapeutic approach for CML patients exhibiting persistent disease.
Project description:The Philadelphia chromosome (Ph) resulting from the t(9;22) translocation generates the oncogenic BCR::ABL1 fusion protein that is most commonly associated with chronic myeloid leukemia (CML) and Ph-positive (Ph+) acute lymphoblastic leukemia (ALL). There are also rare instances of patients (≤1%) with newly diagnosed acute myeloid leukemia (AML) that harbor this translocation (Paietta et al., Leukemia 12: 1881 [1998]; Keung et al., Leuk Res 28: 579 [2004]; Soupir et al., Am J Clin Pathol 127: 642 [2007]). AML with BCR::ABL has only recently been provisionally classified by the World Health Organization as a diagnostically distinct subtype of AML. Discernment from the extremely close differential diagnosis of myeloid blast crisis CML is challenging, largely relying on medical history rather than clinical characteristics (Arber et al., Blood 127: 2391 [2016]). To gain insight into the genomic features underlying the evolution of AML with BCR::ABL, we identified a patient presenting with a high-risk myelodysplastic syndrome that acquired a BCR::ABL alteration after a peripheral blood stem cell transplant. Serial samples were collected and analyzed using whole-exome sequencing, RNA-seq, and ex vivo functional drug screens. Persistent subclones were identified, both at diagnosis and at relapse, including an SF3B1p.Lys700Glu mutation that later cooccurred with an NRASp.Gly12Cys mutation. Functional ex vivo drug screening performed on primary patient cells suggested that combination therapies of ABL1 with RAS or PI3K pathway inhibitors could have augmented the patient's response throughout the course of disease. Together, our findings argue for the importance of genomic profiling and the potential value of ABL1 inhibitor-inclusive combination treatment strategies in patients with this rare disease.
Project description:Opinion statementWith the introduction of tyrosine kinase inhibitors (TKIs) in the management of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), the prognosis of patients has improved dramatically. Currently, the standard of care in the frontline setting for fit patients is TKI in combination with chemotherapy. Age-adjusted chemotherapy or corticosteroids alone have been used with TKIs in elderly patients with comorbidities with modest long-term benefit. The primary goal of treatment is the achievement of early deep molecular remission as the achievement of complete molecular remission (CMR) at 3 months has been demonstrated to be predictive of higher long-term survival. The probability of attaining this goal by a more potent TKIs like dasatinib or ponatinib is higher, thus we recommend the use of second- or third-generation TKIs over imatinib. Clinicians should be aware of possible fatal cardiovascular events mainly related to ponatinib. Allogeneic hematopoietic stem cell transplantation (alloHSCT) should still be considered in first remission, especially for younger patients treated with imatinib combination therapy. A subset of patients achieving CMR at 3 months may be able to continue consolidation and maintenance with chemotherapy and TKI without the need for alloHSCT. Because of higher risk of relapses in the central nervous system, intrathecal chemoprophylaxis is mandatory for all patients. New strategies incorporating novel agents, such as antibody-drug conjugates, bispecific monoclonal antibodies, potent TKIs, and CAR T cells are under investigation.
Project description:The introduction of agents targeted at specific molecular events is changing the treatment paradigms in a number of malignancies. Historically, we have relied entirely on DNA-interactive, cytotoxic drugs for treating patients with leukemia. Increased understanding of the leukemic cell biology and pathogenesis, and the ways they evade the immune surveillance mechanisms, will likely lead to the development of more effective agents, and regimens less reliant on chemotherapy, able to achieve deep levels of disease eradication. In Philadelphia chromosome-positive acute lymphoblastic leukemia, the introduction of increasingly potent tyrosine kinas inhibitors (TKIs) has revolutionized therapy. These drugs have been established as the cornerstone of any therapeutic strategy in this disease, and a number of trials have better defined the best ways to incorporate them into the established paradigms. Despite using TKIs, we have continued to remain reliant on cytotoxic chemotherapy regimens and allogeneic hematopoietic cell transplant to achieve the best long-term outcomes. However, with the introduction of more potent TKIs and other novel agents, as well as better methods for monitoring minimal/measurable residual disease, we are entering an era where we hope to diminish our reliance on transplantation and cytotoxic chemotherapy in this disease.