Computer-aided design of imatinib derivatives: Overcoming drug-resistance in chronic myeloid leukemia.
Chronic myeloid leukemia (CML) is a hematologic condition characterized by the overexpression of stem blood cells in the bone marrow. The Philadelphia chromosome encodes the oncogenic tyrosine kinase BCR-ABL, which is a hallmark of CML. Imatinib, a phenylamino pyrimidine derivative, was the first tyrosine kinase inhibitor (TKI) approved in 2001 for CML. Despite launching a new era in cancer targeted therapy, acquired resistance occurred due to the point mutation of a gatekeeper residue (Thr315Ile) at the BCR-ABL catalytic pocket. There are no approved medications for Thr315Ile-BCR-ABL harboring CML patients. Present study was aimed at the in silico identification of synthetically accessible imatinib derivatives that are likely to bind a frequent Thr315Ile-BCR-ABL and overcome drug resistance. 4-((4-benzylpiperazin-1-yl) methyl)-N-(4-methyl-3-(4-(pyridine-3-yl) pyrimidine-2-amino) phenyl) benzamide (SCHEMBL12127861) and 4-(methoxy (methyl) amino)-N-(3-methyl-5-(pyrido[3,4-b] pyrazin-2-yl thio) phenyl) benzamide (18) were revealed as top-binders. Molecular dynamics simulations and free energy calculations conferred stable binding features Thr315Ile-BCR-ABL. A new binding model was suggested for 18 that resided outside the kinase domain (∼15 Å from Ile315). Considering stability and binding energy compared to imatinib, the intended binding model may be the subject of further evaluations to overwhelm drug resistance. SCHEMBL12127861 had appropriate and more buried accommodation than imatinib near the DFG motif and P-loop of the kinase domain. Hydrogen bonds, π-cation interaction, salt bridge, and a vdW cooperative contacts mediated the complex stability. Although validation of proposed models is to be achieved, this study identified synthetically accessible in silico hits with tight binding to the clinically frequent mutant BCR-ABL phenotypes in Thr315Ile-positive CML patients.
Gholizadeh S
，Panahi N
，Razzaghi-Asl N
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Nilotinib versus imatinib for the treatment of patients with newly diagnosed chronic phase, Philadelphia chromosome-positive, chronic myeloid leukaemia: 24-month minimum follow-up of the phase 3 randomised ENESTnd trial.
Nilotinib has shown greater efficacy than imatinib in patients with newly diagnosed Philadelphia chromosome-positive chronic myeloid leukaemia (CML) in chronic phase after a minimum follow-up of 12 months. We present data from the Evaluating Nilotinib Efficacy and Safety in clinical Trials-newly diagnosed patients (ENESTnd) study after a minimum follow-up of 24 months.
ENESTnd was a phase 3, multicentre, open-label, randomised study. Adult patients were eligible if they had been diagnosed with chronic phase, Philadelphia chromosome-positive CML within the previous 6 months. Patients were randomly assigned (1:1:1) to receive nilotinib 300 mg twice a day, nilotinib 400 mg twice a day, or imatinib 400 mg once a day, all administered orally, by use of a computer-generated randomisation schedule, using permuted blocks, and stratified according to Sokal score. Efficacy results are reported for the intention-to-treat population. The primary endpoint was major molecular response at 12 months, defined as BCR-ABL transcript levels on the International Scale (BCR-ABL(IS)) of 0·1% or less by real-time quantitative PCR in peripheral blood. This study is registered with ClinicalTrials.gov, number NCT00471497.
282 patients were randomly assigned to receive nilotinib 300 mg twice daily, 281 to receive nilotinib 400 mg twice daily, and 283 to receive imatinib. By 24 months, significantly more patients had a major molecular response with nilotinib than with imatinib (201 [71%] with nilotinib 300 mg twice daily, 187 [67%] with nilotinib 400 mg twice daily, and 124 [44%] with imatinib; p<0·0001 for both comparisons). Significantly more patients in the nilotinib groups achieved a complete molecular response (defined as a reduction of BCR-ABL(IS) levels to ≤0·0032%) at any time than did those in the imatinib group (74 [26%] with nilotinib 300 mg twice daily, 59 [21%] with nilotinib 400 mg twice daily, and 29 [10%] with imatinib; p<0·0001 for nilotinib 300 mg twice daily vs imatinib, p=0·0004 for nilotinib 400 mg twice daily vs imatinib). There were fewer progressions to accelerated or blast phase on treatment, including clonal evolution, in the nilotinib groups than in the imatinib group (two with nilotinib 300 mg twice daily, five with nilotinib 400 mg twice daily, and 17 with imatinib; p=0·0003 for nilotinib 300 mg twice daily vs imatinib, p=0·0089 for nilotinib 400 mg twice daily vs imatinib). At 24 months, survival was comparable in all treatment groups, but fewer CML-related deaths had occurred in both the nilotinib groups than in the imatinib group (five with nilotinib 300 mg twice daily, three with nilotinib 400 mg twice daily, and ten with imatinib). Overall, the only grade 3 or 4 non-haematological adverse events that occurred in at least 2·5% of patients were headache (eight [3%] with nilotinib 300 mg twice daily, four [1%] with nilotinib 400 mg twice daily, and two [<1%] with imatinib) and rash (two [<1%], seven [3%], and five [2%], respectively). Grade 3 or 4 neutropenia was more common with imatinib than with either dose of nilotinib (33 [12%] with nilotinib 300 mg twice daily, 30 [11%] with nilotinib 400 mg twice daily, and 59 [21%] with imatinib). Serious adverse events were reported in eight additional patients in the second year of the study (four with nilotinib 300 mg twice daily, three with nilotinib 400 mg twice daily, and one with imatinib).
Nilotinib continues to show better efficacy than imatinib for the treatment of patients with newly diagnosed CML in chronic phase. These results support nilotinib as a first-line treatment option for patients with newly diagnosed disease.
Novartis.
Kantarjian HM
，Hochhaus A
，Saglio G
，De Souza C
，Flinn IW
，Stenke L
，Goh YT
，Rosti G
，Nakamae H
，Gallagher NJ
，Hoenekopp A
，Blakesley RE
，Larson RA
，Hughes TP
... -
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Novel ABL1 mutation in a Moroccan CML patient with Imatinib resistance.
Tyrosine Kinase Inhibitors (TKI), such as Imatinib, are known for their effectiveness in achieving complete remission from Chronic Myeloid Leukemia (CML), a malignancy caused by a reciprocal translocation between the terminal fragments of the long arms of chromosomes 9 and 22 that leads to the famous chimeric BCR::ABL1 gene. Mutations in this fusion gene may induce resistance to TKI treatment, which requires prescribing a second-, or third-generation TKI medication. We report here a case of a Moroccan CML patient with secondary resistance to the frontline TKI treatment (Imatinib), in which, BCR::ABL1 cDNA sequencing reveals the novel mutation p.K375M at the ABL1 Kinase Domain. In-silico prediction tools confirm the pathogenicity of the p.K375M substitution. Homology analysis indicated that the residue is highly conserved and located in a stable region. This potentially pathogenic mutation is likely to disrupt the BCR::ABL1-Imatinib binding, leading to the observed resistance. To overcome the treatment resistance, Imatinib should be substituted with a second-generation TKI medication, such as Dasatinib, Bosutinib, or Nilotinib. The present study further widens the spectrum of TKI resistance mutations and emphasizes particularly the crucial role of molecular investigation in personalizing treatment for CML patients, ensuring efficient follow-up and appropriate healthcare.
El Bouchikhi I
，Azami Idrissi H
，Lazraq A
，El Makhzen B
，Ahakoud M
，Berrady R
，Ouldim K
，Bouguenouch L
，El-Azami-El-Idrissi M
... -
《Cancer Genetics》
Circumventing Imatinib resistance in CML: Novel Telmisartan-based cell death modulators with improved activity and stability.
Drug resistance presents a significant challenge in cancer therapy, which has led to intensive research in resistance mechanisms and new therapeutic strategies. In chronic myeloid leukemia (CML), the introduction of Imatinib, the first tyrosine kinase inhibitor (TKI), drastically changed the outcome for patients. However, complete remission still cannot be achieved in a large number of patients in the long term. Therefore, there is a great interest in the design of new drugs to target TKI-resistant cancer cells. A promising approach to enhance the efficacy of Imatinib is the simultaneous application of cell death modulators derived from the Angiotensin II type 1 receptor blocker Telmisartan. The methyl ester (3a) of 4'-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1'-biphenyl]-2-carboxylic acid (LEAD-acid (4)), which is the structural core of Telmisartan, has already been shown to abolish the resistance of Imatinib in TKI-insensitive CML cells at a concentration of 5 μM. As the ester was expected to be unstable in a biological environment, this study attempted to increase the stability through structural modifications. The methyl group was exchanged for longer (3b (ethyl), 3c (propyl), 3d (butyl) and branched (3e (isopropyl), 3f (tert-butyl)) alkyl chains as well as a phenyl (3g) and 4-phenoxyphenyl (3h) group. Furthermore, the esters were bioisosterically replaced with a respective substituted carboxamide (5a-h). The LEAD-amides (5a-h) showed high stability against esterases, while amidases cleaved only the carboxamides with short alkyl chains to a small extent. Esterases hydrolyzed the LEAD-alkylesters (3a-d) dependent on the chain length with τ½ = 55-82 min. Esters with branched alkyl chains were stable and introduction of the aromatic rings mentoined above increased the half-life to τ½ = 280 min and 360 min. In cell culture medium, only 3a-d degraded to 67-78 % after 72 h. However, the uptake studies showed that approximatly 80 % of the esters accumulated in the cell within the first 1-3 h of incubation. Therefore, it can be concluded that the intact LEAD-esters and LEAD-amides caused the biological effects. The compounds were non-cytotoxic and efficiently sensitized KD225 (K562-resistant) CML cells to Imatinib at a half-maximal sensitizing concentration (SC50) of 1.5-2.9 μM (ester derivatives) and 1.3-11.2 μM (amide derivatives).
Gebhart M
，Alilou M
，Gust R
，Salcher S
... -
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ResearchGate
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