Biomedical subjects

Dimitris Voliotis

Publications and source records attributed to Dimitris Voliotis.

5 recordsLinked to original sources

PubMed2005

Final report of the efficacy and safety of gemtuzumab ozogamicin (Mylotarg) in patients with CD33-positive acute myeloid leukemia in first recurrence.

BACKGROUND: In this study, the authors analyzed the efficacy and safety of gemtuzumab ozogamicin (GO) (Mylotarg), an antibody-targeted chemotherapy for CD33-positive acute myeloid leukemia (AML). METHODS: Patients with CD33-positive AML in first recurrence were entered in 3 open-label, single-arm, Phase II studies. Patients received monotherapy with GO 9 mg/m(2) as a 2-hour intravenous infusion in 2 doses separated by 2 weeks. Patients were evaluated for remission, survival, and treatment-emergent adverse events. RESULTS: Two hundred seventy-seven patients (median age, 61 yrs) were treated with GO, and 71 patients (26%) achieved remission, which was defined as < or = 5% blasts in the bone marrow without leukemic blasts in the peripheral blood, neutrophil recovery to > or = 1500/microL, hemoglobin > or = 9 g/dL, and independence from red blood cell and platelet transfusions. Complete remission (CR) with platelet recovery (> or = 100,000/microL) or without full platelet recovery (< 100,000/microL) (CRp) was observed in 35 patients (13%) and 36 patients (13%), respectively. The median recurrence-free survival was 6.4 months for patients who achieved CR and 4.5 months for patients who achieved CRp. Although expected incidences of Grade 3 or 4 neutropenia (98%) and thrombocytopenia (99%) were observed, the incidence of Grade 3 or 4 sepsis (17%) and pneumonia (8%) was relatively low. Grade 3 or 4 hyperbilirubinemia and hepatic aspartate aminotransferase and alanine aminotransferase elevations were reported in 29%, 18%, and 9% of patients, respectively; 0.9% of patients who did not undergo prior or subsequent hematopoietic stem cell transplantation developed hepatic venoocclusive disease after GO treatment. CONCLUSIONS: When it was administered to patients with CD33-positive AML in first recurrence, single-agent GO induced a 26% remission rate with a generally acceptable safety profile.

Adult↗

PubMed2005

The Raf kinase inhibitor BAY 43-9006 reduces cellular uptake of platinum compounds and cytotoxicity in human colorectal carcinoma cell lines.

Raf kinase plays a central role in oncogenic signaling and acts as a downstream effector of Ras in the extracellular signal-regulated (ERK) kinase pathway. BAY 43-9006 (BAY) is a novel signal transduction inhibitor that prevents tumor cell proliferation and angiogenesis through blockade of the Raf/MEK/ERK pathway at the level of Raf kinase and the receptor tyrosine kinases vascular endothelial growth factor receptor-2 and platelet-derived growth factor receptor-beta. The present study evaluates the effects of combining BAY and platinum derivatives on human colorectal cancer cells using different incubation protocols. Our data show that the combination of oxaliplatin or cisplatin with BAY results in marked antagonism irrespective of the used application schedule. Furthermore, BAY abrogates the cisplatin-induced G2 arrest as well as the G1 arrest induced by oxaliplatin. BAY alone arrests cancer cells in their current cell cycle phase and affects cell cycle regulative genes. Specifically, BAY reduced the protein expression of p21Cip1 as well as cyclin D1, and inhibits the expression of cdc2 (cdk1). Utilizing atom absorption spectrometry, BAY significantly reduced cellular uptake of platinum compounds and thereby the generation of DNA adducts. Taken together, co-incubation with BAY results in reduced cellular uptake of platinum compounds and consecutively reduced generation of DNA adducts, and eventually decreased cellular cytotoxicity in human colorectal cancer cells. Our results indicate that the Raf kinase inhibitor BAY 43-9006 might also directly or indirectly interact with platinum transporter proteins in vitro.

Antineoplastic Agents↗

PubMed2004

Phase I clinical and pharmacokinetic study of the Novel Raf kinase and vascular endothelial growth factor receptor inhibitor BAY 43-9006 in patients with advanced refractory solid tumors.

PURPOSE: BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor inhibitor that inhibits tumor cell proliferation and angiogenesis. This study established the safety and pharmacokinetics of BAY 43-9006 in 69 patients with advanced refractory solid tumors. PATIENTS AND METHODS: BAY 43-9006 (50 to 800 mg) was administered once or twice daily on a varying weekly schedule. Pharmacokinetic sampling was performed in all patients; preliminary tumor response was also assessed. The effect of BAY 43-9006 on phorbol myristate acetate-stimulated ERK phosphorylation in peripheral blood lymphocytes was studied using flow cytometry. RESULTS: Mild to moderate diarrhea was the most common (55%) treatment-related adverse event. The maximum-tolerated dose was 400 mg bid continuous. Dose-limiting toxicities were grade 3 diarrhea and fatigue at 800 mg bid, and grade 3 skin toxicity at 600 mg bid. BAY 43-9006 pharmacokinetics were highly variable for single and multiple dosing, and toxicity did not appear to be dose dependent. Significant decreases of phorbol myristate acetate-stimulated ERK phosphorylation (P < .01) were identified at doses >/= 200 mg bid continuous. Forty-five patients were assessable for efficacy; one patient had a partial response (hepatocellular carcinoma at 400 mg bid continuous), 25 patients had stable disease, with eight lasting > 6 months and five for >12 months. Eighteen patients had progressive disease, and tumor response could not be evaluated in one patient. CONCLUSION: Oral BAY 43-9006 was well tolerated and appeared to provide some clinical benefits. Based on the results of this study, BAY 43-9006 at 400 mg bid continuous is recommended for ongoing and future studies.

Adolescent↗

PubMed2002

Leading prognostic relevance of the BCR-ABL translocation in adult acute B-lineage lymphoblastic leukemia: a prospective study of the German Multicenter Trial Group and confirmed polymerase chain reaction analysis.

The BCR-ABL fusion, the molecular equivalent of the Philadelphia translocation, gains importance for treatment stratification in adult acute lymphoblastic leukemia (ALL). In this prospective study, samples from 478 patients with CD10(+) B-cell precursor ALL (c-ALL and pre-B ALL) underwent BCR-ABL reverse transcription-polymerase chain reaction (RT-PCR) analysis with double testing of positive samples. Patients were stratified according to the PCR result and treated in 2 German Multicenter Trials of Adult ALL. The outcome was followed and the prognostic impact of BCR-ABL was compared to clinical risk features. Of the 478 samples, 432 had an evaluable BCR-ABL result. Thirty-seven percent of the c-ALL and pre-B ALL patients were BCR-ABL(+) (p190, 77%; p210, 20%; simultaneous p190/p210, 3%). BCR-ABL positivity was associated with the high-risk features of older age (45 years versus 30 years median age; P =.0001) and higher white blood cell counts (23 500/microL versus 11 550/microL; P =.0001). Univariate and multivariate analyses revealed BCR-ABL as the leading factor for a poor prognosis (P =.0001) in comparison to clinical risk criteria. Irrespective of the breakpoint, presence of any BCR-ABL transcript predicted a lower chance of initial treatment response (68.4% versus 84.6%; P =.001) and a lower probability of disease-free survival at 3 years (0.13 versus 0.47; P =.0001). This bad outcome was not influenced by postinduction high-dose treatment stratifications. The results show a high prevalence of BCR-ABL fusion transcripts with predominance of p190. BCR-ABL RT-PCR is confirmed as a sensitive, rapid method to diagnose t(9;22), and p190 and p210 are unequivocally demonstrated as the most important predictors of poor long-term survival despite intensified chemotherapy.

Adolescent↗

PubMed2002

Challenges in treating hematologic malignancies.

During the past 40 years substantial progress has been made in the treatment of hematologic malignancies, particularly in some subgroups of patients. Today, cure is attainable for patients with Hodgkin's disease and a considerable proportion of patients with high-grade non-Hodgkin's lymphoma. Prognosis is improving in patients with acute promyelocytic leukemia and, to some extent, those with acute lymphoblastic and myeloid leukemias. However, the majority of patients who suffer from a hematologic malignancy live with incurable disease. In CLL, outside the setting of a clinical trial, it is advisable to postpone treatment until the manifestation of clinical symptoms. It is yet to be determined whether treatment strategies based on new prognostic parameters such as cytogenetics can change the course of disease. In indolent lymphomas, cure is not attainable for the vast majority of patients; the median survival of 9 to 10 years has remained unchanged for several decades. Nevertheless, there has been a dramatic change in therapeutic paradigms in the past few years. For the first time, with the use of new cytostatic drugs and recombinant monoclonal antibodies, it is possible to achieve molecular remissions. Whether this will translate into cure or prolonged survival is still to be determined. In Hodgkin's disease, which is curable when treated with radiotherapy, chemotherapy, or combined therapy, depending on the stage of disease, the focus of future studies must be on prevention of early relapse and on primary resistant disease, both of which present a very poor prognosis. Finally, regardless of underlying malignancy and prognosis, the preservation of quality of life is of major consideration in the setting of hematologic malignancies.

Anemia↗