Dasatinib

Dasatinib is a small-molecule inhibitor of multiple tyrosine kinases, including BCR-ABL, SRC, c-KIT, ephrin A receptor and platelet-derived growth factor-beta receptor kinases, at nanomolar concentrations. In vitro, dasatinib is 325-fold more potent than imatinib against cells expressing wild-type BCR-ABL. The efficacy and tolerability of oral dasatinib has been established in the START phase II trials in adults with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) who were intolerant or resistant to imatinib, and optimal dasatinib dosage regimens were identified in phase III randomized trials. In patients with chronic phase CML, the major cytogenetic response rate in the START-C trial (median follow-up 15.2 months) was 59% with dasatinib, and in the randomized START-R trial (median follow-up 15 months), was greater with dasatinib than with high-dose imatinib (52% vs 33%). Major hematologic response rates with dasatinib were 63% in patients with accelerated phase CML (follow-up > or =9 months; START-A trial), 34% in patients with myeloid blast phase CML and 35% in those with lymphoid blast phase CML (follow-up > or =12 months; START-B and START-L trials), and 41% in patients with Ph-positive ALL (follow-up > or =12 months; START-L trial). Based on phase III results, a once-daily dasatinib regimen is considered optimal in chronic phase CML (starting dosage 100 mg once daily), while a twice-daily regimen continues to be recommended in accelerated phase, myeloid blast phase or lymphoid blast phase CML and Ph-positive ALL (starting dosage 70 mg twice daily). Adverse events were frequent in patients treated with dasatinib, but most were mild to moderate in severity. Grade 3/4 adverse events were uncommon and were clinically manageable.     

Dasatinib attenuated bleomycin-induced pulmonary fibrosis in mice

Abstract

Anti-fibrotic effect of dasatinib, a platelet-derived growth factor receptor (PDGFR) and Src-kinase inhibitor, was tested on pulmonary fibrosis (PF). Adult mice were divided into four groups: mice dissected 21?d after the bleomycin (BLM) instillation (0.08?mg/kg in 200?µl) (I) and their controls (II), and mice treated with dasatinib (8?mg/kg in 100?µl, gavage) for one week 14?d after BLM instillation and dissected 21?d after instillation (III) and their controls (IV). The fibrosis score and the levels of fibrotic markers were analyzed in lungs. BLM treatment-induced cell proliferation and increased the levels of collagen-1, alpha smooth muscle actin, phospho (p)-PDGFR-alpha, p-Src, p-extracellular signal-regulated kinases1/2 and p-cytoplasmic-Abelson-kinase (c-Abl) in lungs, and down-regulated PTEN expression. Dasatinib reversed these alterations in the fibrotic lung. Dasatinib limited myofibroblast activation and collagen-1 accumulation by the inhibition of PDGFR-alpha, and Src and c-Abl activations. In conclusion, dasatinib may be a novel tyrosine and Src-kinase inhibitor for PF regression in mice.     

Dasatinib suppresses invasion and induces apoptosis in nasopharyngeal carcinoma

Dasatinib, an orally available tyrosine kinas inhibitor (TKI), potently inhibits SRC which was found to activate RTKs that induce trastuzumab de novo and acquired resistance. To evaluate the potential of Dasatinib in the treatment of Nasopharyngeal Carcinoma, we used a variety of assays to measure its effects on cell proliferation, apoptosis, and migration. This work aimed to test the antitumor effects of the inhibitor in vitro to determine whether in vivo analyses were warranted. Cell growth rate and 50% inhibitory concentration was calculated by MTT assay. Dasatinib-induced apoptotic cells were investigated by Annexin V/PI staining. Proteins from cell extracts were analyzed by Western blot. Cell motility was investigated by Transwell. Our study showed that Dasatinib significantly inhibited CNE2 proliferation and induced apoptosis in vitro. Phospho-AKT, phospho-MEK, phospho-ERK expression was significantly reduced when treated with dasatinib which means the downregulated RAS/RAF/MEK/ERK and PI3K/AKT pathway activity. Dasatinib significantly inhibited the motility of CNE2 as well as Phospho-FAK expression. Dasatinib exhibit antitumor effects of nasopharyngeal carcinoma by downregulating MAPK and PI3K/AKT pathways activity and FAK phosphorylation. This suggests that dasatinib would have therapeutic activity against NPC.     

Spotlight on Dasatinib in Chronic Myeloid Leukemia and Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemiay

Dasatinib (Sprycel?) is an orally administered small molecule inhibitor of multiple tyrosine kinases, including BCR-ABL and SRC family kinases, which is indicated for the treatment of adults with newly diagnosed chronic-phase chronic myeloid leukemia (CML), CML (chronic-, accelerated- or blast-phase) with resistance or intolerance to prior therapy, including imatinib, or Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) with resistance or intolerance to prior therapy. Dasatinib is ≈325-fold more active than imatinib in inhibiting wild-type BCR-ABL kinase in vitro and is active against a wide variety of imatinib-resistant BCR-ABL mutants, except for T315I. This article reviews the efficacy and tolerability of dasatinib in the treatment of patients with newly diagnosed chronic-phase CML or imatinib-resistant or -intolerant CML or Ph+ ALL, as well as summarizing its pharmacologic properties. In clinical trials, oral dasatinib was effective in achieving major or complete cytogenetic responses in both newly diagnosed and imatinib-resistant or -intolerant chronic-phase CML. Dasatinib was likewise effective in achieving major or overall hematologic responses in imatinib-resistant or -intolerant, accelerated- or blast-phase CML, or Ph+ ALL. Responses were rapidly achieved within 1-3 months and were durable over 1-5 years of follow-up. The majority of adverse events with dasatinib were of mild or moderate severity. Fluid retention (including pleural effusion) was the most common adverse event. Hematologic abnormalities were common and cytopenias were the most common grade 3/4 adverse events. Dasatinib 100?mg administered once daily was as effective as dasatinib 70?mg administered twice daily, and was better tolerated, being associated with lower incidences of pleural effusion and grade 3/4 thrombocytopenia, in particular. Dasatinib was more effective than high-dose imatinib in the treatment of patients with imatinib-resistant chronic-phase CML and was more effective than standard dosages of imatinib, as well as being associated with less frequent fluid retention, in patients with newly diagnosed chronic-phase CML. Dasatinib was generally equally effective in patients with or without BCR-ABL mutations at baseline. Therefore, oral dasatinib is a highly effective, once-daily therapy for the first-line treatment of newly diagnosed patients with chronic-phase CML, as well as for the treatment of patients with imatinib-resistant or -intolerant chronic- and advanced-phase CML or Ph+ ALL.     

Dasatinib: A Guide to Its Use in Chronic Myeloid Leukemia in the EU

Oral dasatinib (Sprycel^®) is effective in the treatment of patients with newly diagnosed chronic-phase chronic myeloid leukemia (CML) or imatinib-resistant or imatinib-intolerant chronic-phase, accelerated-phase, or blast-phase CML. In particular, dasatinib is associated with better and faster responses than imatinib in patients with newly diagnosed chronic-phase CML. The response to dasatinib appears to be maintained in the longer-term. Dasatinib has an acceptable tolerability profile; it is associated with myelosuppression, with fluid retention being the most common nonhematologic adverse event. Thus, dasatinib is a highly effective, once-daily therapy for the first-line treatment of patients with chronic-phase CML and for the second-line treatment of imatinib-resistant or imatinib-intolerant CML.     

Dasatinib as salvage therapy for steroid refractory and imatinib resistant or intolerant sclerotic chronic graft-versus-host disease

Sclerotic chronic graft-versus-host disease (scGVHD) is a severe form of this disease that resembles systemic sclerosis and has limited and disappointing treatment options. Tyrosine kinase inhibitors (TKI) targeting up-regulated profibrotic pathways, such as imatinib mesylate, have been proposed as a potential therapeutic approach for patients with scGVHD. Dasatinib, a second-generation TKI with a well-established safety and efficacy profile in chronic myeloid leukemia patients, who are refractory or intolerant to imatinib, has also shown potent antifibrotic effects. We present here the first direct clinical evidence, from 3 patients treated in a small single-center series, suggesting that dasatinib can be a therapeutic option for patients with severe scGVHD resistant or intolerant to imatinib. All patients achieved partial response, with improvement in scGHVD target organs severity, joint mobility, lung impairment, and deep fibrotic lesions. This clinical response has remained stable or continued to improve after a median of 22 months (20-25) on dasatinib treatment, with very good tolerance. In addition, corticosteroids could be discontinued or significantly reduced in all patients. This clinical evidence suggests that dasatinib could be a safe and effective alternative for scGVHD patients refractory to corticosteroids and resistant or intolerant to imatinib. Based on these preliminary findings, and in order to address appropriate patient selection, time of intervention, and choice of drug, future larger studies should more formally establish the efficacy and safety of second-generation TKI for the treatment of scGVHD.     

Dasatinib prevent hepatic fibrosis induced by carbon tetrachloride (CCl4) via anti-inflammatory and antioxidant mechanism

Objectives: Dasatinib, a potent and broad-spectrum tyrosine kinase inhibitor, is approved for the treatment of imatinib-resistant chronic myelogenous leukemia. The aim of this study was to evaluate the anti-fibrotic, anti-inflammatory and antioxidant effects of this agent against CCl₄-induced hepatic fibrosis and oxidative status.

Materials and methods: Experimental fibrosis was induced in Wistar male rats by 12 weeks of CCl₄ administration (i.p.). During the last 8 weeks of injection, rats were gavaged daily with Dasatinib (10?mg/kg). To evaluate anti-inflammatory and anti-fibrotic effects of Dasatinib, histopathological examination of liver tissue was performed and serum ALT and AST activities, oxidant, antioxidant parameters and hepatic tumor necrosis factor alpha (TNF-α) were examined. Moreover, transforming growth factor (TGF-β₁), platelet derived growth factor (PDGF) and TNF-α mRNA expressions were also evaluated by real time polymerase chain reaction.

Results: Dasatinib administration induced a significant reduction of ALT and AST activities (p?4 injected rats (p?1 and PDGF were increased due to CCl₄ intoxication (p?p?p?4 administration which was significantly attenuated by Dasatinib (p?Discussion and conclusion: Our findings indicate that Dasatinib can be cautiously an anti-fibrotic, anti-inflammatory and anti-oxidative agent in clinical setting.     

Activity and Safety of Dasatinib as Second-Line Treatment or in Newly Diagnosed Chronic Phase Chronic Myeloid Leukemia Patients

Dasatinib is an oral dual tyrosine kinase inhibitor active against ABL1 and SRC family kinases. The US FDA approved it for the treatment of chronic myeloid leukemia (CML) patients in chronic, accelerated, or blastic phase with resistance or intolerance to imatinib therapy. Dasatinib is also indicated for the treatment of adults with Philadelphia chromosome-positive acute lymphoblastic leukemia who have become resistant to or intolerant of other treatments. The agent is now also approved for newly diagnosed chronic phase (CP) patients. This article reviews the pharmacokinetic and pharmacodynamic properties of dasatinib as well as clinical data limited to CP-CML patients. Four-year follow-up of a phase III dose-optimization trial confirmed that better progression-free survival (66%) and overall survival (82%) were obtained with a dose of 100 mg once daily (od) than with the standard 70 mg twice daily dosing (65% and 75%, respectively). The 100 mg od dosing schedule was also associated with the highest benefit-risk ratio for CP patients with resistant, intolerant, or suboptimal response. Recent results of a phase III trial in newly diagnosed patients demonstrated that dasatinib 100 mg od has superiority in terms of confirmed cytogenetic and molecular responses, with faster responses and high activity in high Sokal risk patients compared with standard-dose imatinib.