Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

One-hundred, twenty-eight patients with Hodgkin's disease in remission or who had failed a mechlorethamine, vincristine, procarbazine and prednisone (MOPP), a doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) and/or lomustine, etoposide and prednimustine (CEP) regimens have been treated with a high-dose therapy (HDT) containing cyclophosphamide, etoposide, carmustine (CVB) and autologous bone marrow transplantation (ABMT). Forty patients were treated while they were in resistant or progressive disease states using alternating MOPP/ABVD protocol; 15 patients received ABMT in first relapse; 51 patients had a complete remission (CR) with first-line therapy but later relapsed and then received conventional salvage therapy; 16 achieved no response or progression ("resistant relapse" patients) and 35 responded partially or completely ("sensitive-relapse" patients). The other 22 patients received ABMT in remission. Following HDT, 56 patients (52.8%) achieved CR and 23 patients (21.6%) achieved a partial remission for an overall response rate of 74.4%. Sixteen patients failed to respond and died in progressive disease 1 to 10 months (median 6 months) after ABMT. High-dose therapy produced severe toxicity including vomiting (100%), mucositis (75%) and liver enzymes and alkaline phosphatase elevations (51%). There were 10 treatment-related deaths. A multivariate analysis identified poor performance status and resistant-relapse patients as very important adverse risk factors for survival immediately after ABMT. These results, while validating this procedure for inducing remissions in advanced highly-treated patients, at the same time confirm the need of employing this approach in first relapse or in second complete remission after standard therapy and before ABMT or, in first complete remission in very high risk Hodgkin's disease patients. Our experience in 15 very poor prognosis Hodgkin's disease patients transplanted in first CR demonstrated to be much significant.
Leukemia 1991
PMID:Nine years' experience with ABMT in 128 patients with Hodgkin's disease: an Italian study group report. 189 Aug 70

Limited-extent small-cell lung carcinoma (SCLC) remains a therapeutic problem with little improvement in complete response (CR) rates and long-term survival in the past 5 years. From June 1984 through January 1985, 56 patients with limited-extent SCLC were enrolled in a Cancer and Leukemia Group B (CALGB) phase II study using five cycles of cyclophosphamide (500 mg/m2 intravenously [IV] day 1), etoposide (80 mg/m2 IV days 1 to 3), and cisplatin (33 mg/m2 IV days 1 to 3) administered at 3-week intervals (CEP), with radiation therapy (50 Gy to chest and 30 Gy to brain) administered concomitant with cycles 4 and 5, followed by three cycles of cyclophosphamide (500 mg/m2 IV day 1), etoposide (80 mg/m2 IV days 1 to 3), and doxorubicin (50 mg/m2 IV day 1). Of 49 patients evaluable for response, the overall response rate was 88%, with 57% CRs. The median overall survival was 14 months; the median duration of CR was 10 months, and nine CRs remain disease free at a median follow-up of 23 months. Toxicity was significant: 56% patients experienced WBC less than 1,000 microL, 32% platelets less than 25,000 microL and 10% hemoglobin less than 7 g/dL. There was one treatment-related septic death. These results are as good as the best previous CALGB study of SCLC, despite a reduction in duration of treatment from 18 to 5 months. We are currently using a variant of this multimodality treatment approach as our standard management for patients with limited-extent SCLC.
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PMID:A phase II trial of cyclophosphamide, etoposide, and cisplatin with combined chest and brain radiotherapy in limited small-cell lung cancer: a Cancer and Leukemia Group B Study. 282 9

Constitutively activating internal tandem duplication (ITD) and point mutations of the receptor tyrosine kinase FLT3 are present in up to 41% of patients with acute myeloid leukemia (AML). These FLT3/ITD mutations are likely to be important because their presence is associated with a poor prognosis. Both types of mutations appear to activate the tyrosine kinase activity of FLT3. We describe here the identification and characterization of the indolocarbazole derivative CEP-701 as a FLT3 inhibitor. This drug potently and selectively inhibits autophosphorylation of wild-type and constitutively activated mutant FLT3 in vitro in FLT3/ITD-transfected cells and in human FLT3-expressing myeloid leukemia-derived cell lines. We demonstrate that CEP-701 induces a cytotoxic effect on cells in a dose-responsive fashion that parallels the inhibition of FLT3. STAT5 and ERK1/2, downstream targets of FLT3 in the signaling pathway, are inhibited in response to FLT3 inhibition. In primary leukemia blasts from AML patients harboring FLT3/ITD mutations, FLT3 is also inhibited, with an associated cytotoxic response. Finally, using a mouse model of FLT3/ITD leukemia, we demonstrate that the drug inhibits FLT3 phosphorylation in vivo and prolongs survival. These findings form the basis for a planned clinical trial of CEP-701 in patients with AML harboring FLT3- activating mutations.
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PMID:A FLT3-targeted tyrosine kinase inhibitor is cytotoxic to leukemia cells in vitro and in vivo. 1201 Jul 85

Constitutively activating mutations of FMS-like tyrosine kinase 3 (FLT3) occur in approximately one third of patients with acute myeloid leukemia (AML) and are associated with poor prognosis. Altered FLT3 signaling leads to antiapoptotic and proliferative signaling pathways. We recently showed that these mutations can also contribute to the differentiation arrest that characterizes leukemia. In this report we investigated the mechanism by which internal tandem duplication (ITD) mutation of FLT3 signaling blocks differentiation. Normally, myeloid differentiation requires the induction of CCAAT/enhancer-binding protein alpha (C/EBPalpha) and PU.1 expression. Expression of both genes was repressed by FLT3/ITD signaling in 32Dcl3 (32D) cells and this repression was overcome by treatment with a FLT3 inhibitor, allowing differentiation to proceed. We also observed increased expression of C/EBPalpha and PU.1 accompanied by signs of differentiation in 2 of 3 primary AML samples from patients with FLT3/ITD mutations receiving a FLT3 inhibitor, CEP-701, as part of a clinical trial. Forced expression of C/EBPalpha was also able to overcome FLT3/ITD-mediated differentiation block, further proving the importance of C/EBPalpha in this process.
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PMID:Internal tandem duplication mutation of FLT3 blocks myeloid differentiation through suppression of C/EBPalpha expression. 1459 41

Acute myeloid leukemia is the most common type of leukemia in adults, yet it continues to have the lowest survival rate of all leukemias. Prognosis for the elderly in particular continues to be dismal. This review examines the currently available literature on the epidemiology, etiology, diagnosis and management of acute myeloid leukemia. New therapies and therapeutic strategies must be found to improve survival, especially as the worldwide population ages. Gemtuzumab ozogamicin (Mylotarg) for the treatment of patients with CD33-positive acute myeloid leukemia, selective FLT3 inhibitors currently in advanced development (e.g., SU11248, PKC412, CT53518 and CEP-710) and other targeted compounds (e.g., farnesyl transferase inhibitors, BCL-2 inhibitors and interleukin-2) may present initial opportunities to achieve improved outcomes.
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PMID:Epidemiology and clinical burden of acute myeloid leukemia. 1459 92

Activating mutations of FMS-like tyrosine kinase 3 (FLT3) are present in approximately 30% of patients with de novo acute myeloid leukemia (AML) and are associated with lower cure rates from standard chemotherapy-based treatment. Targeting the mutation by inhibiting the tyrosine kinase activity of FLT3 is cytotoxic to cell lines and primary AML cells harboring FLT3 mutations. Successful FLT3 inhibition can also improve survival in mouse models of FLT3-activated leukemia. CEP-701 is an orally available, novel, receptor tyrosine kinase inhibitor that selectively inhibits FLT3 autophosphorylation. We undertook a phase 1/2 trial to determine the in vivo hematologic effects of single-agent CEP-701 as salvage treatment for patients with refractory, relapsed, or poor-risk AML expressing FLT3-activating mutations. Fourteen heavily pretreated AML patients were treated with CEP-701 at an initial dose of 60 mg orally twice daily. CEP-701-related toxicities were minimal. Five patients had clinical evidence of biologic activity and measurable clinical response, including significant reductions in bone marrow and peripheral blood blasts. Laboratory data confirmed that clinical responses correlated with sustained FLT3 inhibition to CEP-701. Our results show that FLT3 inhibition is associated with clinical activity in AML patients harboring FLT3-activating mutations and indicate that CEP-701 holds promise as a novel, molecularly targeted therapy for this disease.
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PMID:Single-agent CEP-701, a novel FLT3 inhibitor, shows biologic and clinical activity in patients with relapsed or refractory acute myeloid leukemia. 1472 87

Patients with acute myeloid leukemia (AML) harboring internal tandem duplication mutations of the FLT3 receptor (FLT3/ITD mutations) have a poor prognosis compared to patients lacking such mutations. Incorporation of FLT3 inhibitors into existing chemotherapeutic regimens has the potential to improve clinical outcomes in this high-risk group of patients. CEP-701, an indolocarbazole-derived selective FLT3 inhibitor, potently induces apoptosis in FLT3/ITD-expressing cell lines and primary leukemic blasts. We conducted a series of in vitro cytotoxicity experiments combining CEP-701 with chemotherapy using the FLT3/ITD-expressing cell lines MV4-11 and BaF3/ITD as well as a primary blast sample from a patient with AML harboring a FLT3/ITD mutation. CEP-701 induced cytotoxicity in a synergistic fashion with cytarabine, daunorubicin, mitoxantrone, or etoposide if used simultaneously or immediately following exposure to the chemotherapeutic agent. In contrast, the combination of pretreatment with CEP-701 followed by chemotherapy was generally antagonistic, particularly with the more cell cycle-dependent agents such as cytarabine. This effect appears to be due to CEP-701 causing cell cycle arrest. We conclude that in FLT3/ITD-expressing leukemia cells, CEP-701 is synergistic with standard AML chemotherapeutic agents, but only if used simultaneously with or immediately following the chemotherapy. These results should be considered when designing trials combining chemotherapy with each of the FLT3 inhibitors currently in clinical development.
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PMID:In vitro studies of a FLT3 inhibitor combined with chemotherapy: sequence of administration is important to achieve synergistic cytotoxic effects. 1512 17

Internal tandem duplication mutations of the FLT3 gene (FLT3/ITD mutations) are the most frequent molecular abnormality in acute myeloid leukemia (AML) and are associated with a poor overall survival. While the normal FLT3 receptor is expressed in early hematopoietic progenitor cells, it has not been determined whether FLT3 mutations are present in the leukemic stem cells. In this study, we sorted primary AML samples into stem cell-enriched CD34+/CD38- fractions and then analyzed the sorted and unsorted cells for the FLT3 mutant-wild-type ratio. In each case, the FLT3 mutant-wild-type ratio was not changed by selection of CD34+/CD38- cells, implying that the mutations are present in the leukemic stem cells. We used the stem cell-enriched fraction to engraft nonobese diabetic-severe combined immunodeficient (NOD-SCID) mice and then confirmed that the FLT3/ITD mutation was present in the resultant engrafted marrow. As a final test of the importance of FLT3/ITD signaling in this engraftment model, we used a small molecule FLT3 inhibitor, CEP-701, to inhibit engraftment of FLT3/ITD stem cells. Taken together, these experiments establish that the FLT3/ITD mutations are present in leukemia stem cells, and that FLT3 inhibitors may have activity against these cells.
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PMID:Internal tandem duplications of the FLT3 gene are present in leukemia stem cells. 1579 98

Mixed lineage leukemia (MLL) rearrangements occur in 80% of infants and 5% of older children with acute lymphoblastic leukemia (ALL). These cases have a poor prognosis with current therapy. The FLT3 kinase is overexpressed and constitutively activated in MLL-rearranged ALL cells. The FLT3 inhibitor CEP-701 selectively kills these cells, but is unlikely to be curative if used as monotherapy. To identify potentially synergistic combination strategies, we studied CEP-701 and six standard chemotherapeutic agents in three sequences of exposure (S1: chemotherapy followed by CEP-701, S2: simultaneous exposure to both; and S3: CEP-701 followed by chemotherapy) using MLL-rearranged ALL cell lines and patient bone marrow samples. MTT cytotoxicity and annexin V binding apoptosis assays were used to assess antileukemic effects. Combination indices (CI) were calculated for each combination (CI<0.9 - synergistic; CI 0.9-1.1 - additive; CI>1.1 - antagonistic). A striking pattern of sequence-dependent synergy was observed: S1 was markedly synergistic (mean CI=0.59+/-0.10), S2 was additive (mean CI=0.99+/-0.09) and S3 was antagonistic (mean CI=1.23+/-0.10). The sequence dependence is attributable to the effect of CEP-701 on cell cycle kinetics, and is mediated specifically by FLT3 inhibition, as these effects are not seen in control cells without activated FLT3.
Leukemia 2006 Aug
PMID:Combinations of the FLT3 inhibitor CEP-701 and chemotherapy synergistically kill infant and childhood MLL-rearranged ALL cells in a sequence-dependent manner. 1676 Oct 17

We have developed a useful surrogate assay for monitoring the efficacy of FLT3 inhibition in patients treated with oral FLT3 inhibitors. The plasma inhibitory activity (PIA) for FLT3 correlates with clinical activity in patients treated with CEP-701 and PKC412. Using the PIA assay, along with in vitro phosphorylation and cytotoxicity assays in leukemia cells, we compared PKC412 and its metabolite, CGP52421, with CEP-701. While both drugs could effectively inhibit FLT3 in vitro, CEP-701 was more cytotoxic to primary samples at comparable levels of FLT3 inhibition. PKC412 appears to be more selective than CEP-701 and therefore less effective at inducing cytotoxicity in primary acute myeloid leukemia (AML) samples in vitro. However, the PKC412 metabolite CGP52421 is less selective than its parent compound, PKC412, and is more cytotoxic against primary blast samples at comparable levels of FLT3 inhibition. The plasma inhibitory activity assay represents a useful correlative tool in the development of small-molecule inhibitors. Our application of this assay has revealed that the metabolite CGP52421 may contribute a significant portion of the antileukemia activity observed in patients receiving oral PKC412. Additionally, our results suggest that nonselectivity may constitute an important component of the cytotoxic effect of FLT3 inhibitors in FLT3-mutant AML.
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PMID:Plasma inhibitory activity (PIA): a pharmacodynamic assay reveals insights into the basis for cytotoxic response to FLT3 inhibitors. 1685 87


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