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Susan O'Brien

Publications and source records attributed to Susan O'Brien.

At least 73 records · Page 4Linked to original sources
PubMed2005

Activity of selective fully human agonistic antibodies to the TRAIL death receptors TRAIL-R1 and TRAIL-R2 in primary and cultured lymphoma cells: induction of apoptosis and enhancement of doxorubicin- and bortezomib-induced cell death.

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) is a death protein that preferentially kills tumour cells while sparing normal cells. TRAIL has four exclusive receptors, two of which (TRAIL-R1, TRAIL-R2) are death receptors. Both TRAIL/Apo2L and agonistic antibodies to the TRAIL death receptors are currently being explored for cancer therapy. Although the activity of TRAIL/Apo2L in a variety of haematological malignancies has been examined, the activity of anti-TRAIL receptor agonistic antibodies in primary and cultured lymphoma cells has not. Using two fully human selective agonistic monoclonal antibodies to the TRAIL death receptors TRAIL-R1 (HGS-ETR1) and TRAIL-R2 (HGS-ETR2) this study demonstrated that both monoclonal antibodies activated caspase-8 and induced cell death in five of nine human lymphoma cell lines, and induced >10% cell death in 67% and 70%, respectively, of 27 primary lymphoma cells, and >20% cell death in at least one-thirds of the samples. HGS-ETR1 and HGS-ETR2 demonstrated comparable activity in the fresh tumour samples, which was independent of TRAIL receptor surface expression, Bax, cFLIP, or procaspase-8 expression, or exposure to prior therapy. Furthermore, both antibodies enhanced the killing effect of doxorubicin and bortezomib. Our data demonstrate that HGS-ETR1 and HGS-ETR2 monoclonal antibodies can induce cell death in a variety of cultured and primary lymphoma cells, and may have therapeutic value in lymphoma.

Analysis of Variance↗
PubMed2005

Alemtuzumab.

Alemtuzumab is a humanized monoclonal antibody against CD52, a small glycosylphosphatidylinositol-anchored glycoprotein that is highly expressed on normal T- and B-lymphocytes, and on a large proportion of malignant lymphoid cells, but not on hematopoietic progenitor cells. Over the past several years, a number of clinical trials have demonstrated the clinical activity of alemtuzumab in treating patients with chronic lymphocytic leukemia, T-cell malignancies such as T-prolymphocytic leukemia and cutaneous T-cell lymphoma, as well as in the prevention and therapy of graft-versus-host disease in the setting of allogeneic stem cell transplantation. Its application in a number of autoimmune disorders is currently under investigation. The most significant side effect of alemtuzumab is predisposition to infections related to the associated profound lymphopenia. Despite this, and with appropriate and more effective antibiotic prophylaxis, it is likely that we will witness an expansion of the role of alemtuzumab in the future.

Alemtuzumab↗
PubMed2005

Monoclonal antibodies in the treatment of leukemia.

MoAb-based therapies are evolving into the first broad-spectrum class of targeted anti-leukemic therapy. Developments in many areas, including computer modeling of receptors and ligands, and increasing sophistication in recombinant technologies may result in a rapid increase in the number and complexity of MoAb's available. We can anticipate an increase in the number of safer conjugates being delivered to leukemia cells. Further understanding of the in vitro mechanisms involved in tumor cell killing by MoAb will be important in maximizing the efficacy of this approach.

Alemtuzumab↗
PubMed2005

T-cell prolymphocytic leukemia: a single-institution experience.

BACKGROUND: T-cell prolymphocytic leukemia is an uncommon, aggressive, mature T-cell leukemia characterized by proliferation of T-cell lymphocytes. The recent availability of modern immunophenotypic and molecular tools has allowed a better distinction of this disorder from its B-cell counterpart and other mature T-cell leukemias. PATIENTS AND METHODS: The clinical, pathologic, and cytogenetic features of 57 patients with T-PLL who were evaluated at the Department of Leukemia, M. D. Anderson Cancer Center (MDACC) from 1986 to 2004 were examined. RESULTS: The most common cytogenetic abnormality was inv(14)(q11;q32), which was present in 7 patients. In all 7 patients, this abnormality was associated with other chromosomal aberrations. Patients treated with alemtuzumab at MDACC had a significantly better response rate (P = 0.02) and survival rate (P = 0.002). There were no significant differences in survival based on Tcl-1 expression or different patterns of CD4 and CD8 expression. CONCLUSION: Treatment with alemtuzumab results in higher response rates and a better survival rate in patients with T-cell prolymphocytic leukemia.

Adult↗
PubMed2005

Chronic lymphoid leukemias other than chronic lymphocytic leukemia: diagnosis and treatment.

The World Health Organization classification divides lymphoid malignancies into precursor B-cell and T-cell neoplasms as well as mature B-cell and T-cell neoplasms. Mature B-cell neoplasms comprise more than 85% of non-Hodgkin lymphomas worldwide and can be further subclassified according to the postulated cell of origin by using specific morphologic, immunophenotypic, and molecular characteristics. Similarly, the more uncommon mature T-cell neoplasms have been better characterized to include numerous distinct entities with widely varying natural histories. The distinction between lymphoma and leukemia is somewhat arbitrary and is based on variable involvement of the bone marrow, peripheral blood, and lymphatic system. In this article, we review the diagnostic and clinical features of mature B-cell and T-cell lymphoproliferative disorders that commonly have a leukemic presentation.

Diagnosis, Differential↗
PubMed2004

Long-term follow-up results of hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD), a dose-intensive regimen, in adult acute lymphocytic leukemia.

BACKGROUND: Modern intensive chemotherapy regimens have improved the prognosis for patients with adult acute lymphocytic leukemia (ALL). With these regimens, the complete response rates are now reported to be > 80%, and the long-term survival rates range from 30% to 45%. The current analysis updated the long-term results with the original hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (Hyper-CVAD) program, with a median follow-up time of 63 months. METHODS: Between 1992 and 2000, 288 patients were treated with Hyper-CVAD. The median age of the patients was 40 years, and 59 patients (20%) were > or = age 60 years. The incidence of Philadelphia chromosome (Ph)-positive ALL was 17%, and the incidence of of T-cell ALL was 13%. RESULTS: A complete response (CR) was achieved in 92% of patients. The induction mortality rate was 5% (2% if the patient's age was < 60 years, and 15% if the patient's age was > or = 60 years). With a median follow-up time of 63 months, the 5-year survival rate was 38% and the 5-year CR duration rate was 38%. Multivariate analysis of prognostic factors for CR duration identified the following adverse factors: age > or = 45 years, leukocytosis > or = 50 x 10(9)/L, poor performance status (an Eastern Cooperative Oncology Group score of 3-4), Ph-positive disease, French-American-British L2 morphology, > 1 course to achieve CR, and Day 14 bone marrow blasts > 5%. Patients were divided into low-risk (risk score 0-1; 37%), intermediate risk (risk score 2-3; 36%), and poor-risk groups (risk score > or = 4; 27%) with 5-year CR duration rates of 52%, 37%, and 10%, respectively. CONCLUSIONS: Compared with the previous VAD regimens, Hyper-CVAD was associated with significantly better CR rates, CR duration, and survival. The long-term follow-up results of Hyper-CVAD were favorable. Comparison of Hyper-CVAD with other established adult ALL regimens is warranted.

Adolescent↗
PubMed2004

Imatinib mesylate therapy may overcome the poor prognostic significance of deletions of derivative chromosome 9 in patients with chronic myelogenous leukemia.

Deletions of derivative chromosome 9 [der(9)] can be identified by fluorescence in situ hybridization (FISH) in 10% to 15% of patients with chronic myeloid leukemia (CML). Patients with der(9) deletions have been reported to have an adverse outcome when treated with chemotherapy, interferon, and possibly imatinib mesylate. We investigated the frequency and prognostic significance of der(9) deletions among 352 patients with CML treated with imatinib mesylate at our institution, in whom a deletion status of der(9) was determined. Thirty-three patients (9%; 95% CI 0.07, 0.13) (30 in chronic phase, 3 in accelerated phase) had der(9) deletions. The rates of major (82% vs 79%, P = 0.82) and complete cytogenetic response (76% vs 66%, P = .33) with imatinib mesylate therapy were similar in patients with and without der(9) deletions, respectively. After a median follow-up of 28 months, there was no difference in overall survival (P = .30) or response duration (P = .49) in patients with and without deletions. In a multivariate analysis, der(9) deletions had no significant impact on response, survival, or response duration. We conclude that treatment with imatinib mesylate overcomes the adverse prognostic significance of der(9) deletions in patients with CML.

Adolescent↗
PubMed2004

Results of a phase 1-2 study of clofarabine in combination with cytarabine (ara-C) in relapsed and refractory acute leukemias.

Clofarabine (2-chloro-2'-fluoro-deoxy-9-beta-D-arabinofuranosyladenine) is a second-generation nucleoside analog with activity in acute leukemias. As clofarabine is a potent inhibitor of ribonucleotide reductase (RnR), we hypothesized that clofarabine will modulate ara-c triphosphate accumulation and increase the antileukemic activity of cytarabine (ara-C). We conducted a phase 1-2 study of clofarabine plus ara-C in 32 patients with relapsed acute leukemia (25 acute myeloid leukemia [AML], 2 acute lymphoblastic leukemia [ALL]), 4 high-risk myelodysplastic syndrome (MDS), and 1 blast-phase chronic myeloid leukemia (CML).(1) Clofarabine was given as a 1-hour intravenous infusion for 5 days (days 2 through 6) followed 4 hours later by ara-C at 1 g/m(2) per day as a 2-hour intravenous infusion for 5 days (days 1 through 5). The phase 2 dose of clofarabine was 40 mg/m(2) per day for 5 days. Among all patients, 7 (22%) achieved complete remission (CR), and 5 (16%) achieved CR with incomplete platelet recovery (CRp), for an overall response rate of 38%. No responses occurred in 3 patients with ALL and CML. One patient (3%) died during induction. Adverse events were mainly less than or equal to grade 2, including transient liver test abnormalities, nausea/vomiting, diarrhea, skin rashes, mucositis, and palmoplantar erythrodysesthesias. Plasma clofarabine levels generated clofarabine triphosphate accumulation, which resulted in an increase in ara-CTP in the leukemic blasts. The combination of clofarabine with ara-C is safe and active. Cellular pharmacology data support the biochemical modulation strategy.

Acute Disease↗
PubMed2004

Free circulating soluble CD52 as a tumor marker in chronic lymphocytic leukemia and its implication in therapy with anti-CD52 antibodies.

BACKGROUND: The CD52 antigen is a glycoprotein anchored on the cell membrane of mature B and T lymphocytes, monocytes, and eosinophils. Alemtuzumab (CAMPATH-1H; anti-CD52) is currently approved for the treatment of patients with refractory chronic lymphocytic leukemia (CLL). The authors investigated the possibility that CD52 may be shed from cells and, once soluble, may bind to injected alemtuzumab, forming immune complexes. METHODS: The authors used Western blot analysis, immunoprecipitation, and enzyme-linked immunoadsorbent assay to investigate the presence of soluble CD52 (sCD52) in the plasma specimens of 117 patients with CLL. They also used in vitro mixing experiments to examine the ability of sCD52 to compete with cells and sequester therapeutic alemtuzumab. RESULTS: The authors detected high levels of sCD52 in the plasma specimens of patients with CLL. sCD52 can compete with cells in vitro for binding to alemtuzumab, and can form complexes in patients receiving alemtuzumab. Plasma levels of sCD52 were found to be correlated (r)with Rai stage (P = 0.0001), beta-2-microglobulin (beta-2M) levels (P = 0.00002), soluble CD23 levels (r = 0.42, P < 0.001), and immunoglobulin mutation status (P = 0.003). In the multivariate analysis adjusted for beta-2M level, patients with sCD52 levels > 2336 nM/L had a nearly 4-fold increase in risk of death. Higher levels of plasma alemtuzumab were achieved when levels of sCD52 were lower. CONCLUSIONS: These data not only demonstrated that sCD52 was detectable and useful in the staging and monitoring of patients with CLL, but also showed that sCD52 formed immune complexes with alemtuzumab and may influence the efficacy and toxicity of alemtuzumab therapy.

Adult↗
PubMed2004

Imatinib mesylate therapy reduces bone marrow fibrosis in patients with chronic myelogenous leukemia.

BACKGROUND: Reticulin-stained bone marrow fibrosis is associated with a poor prognosis in patients with chronic myelogenous leukemia (CML). Resolution of fibrosis with therapy may improve patient outcome. METHODS: The effect of imatinib therapy on bone marrow fibrosis was evaluated in 40 patients with chronic-phase CML who were treated after interferon-alpha failure. RESULTS: Thirty-one patients (78%) had severe (Grade 3 or 4) reticulin fibrosis prior to therapy. After imatinib therapy was administered for 3 to > 24 months, fibrosis was reduced by at least 2 grades in 19 of the 31 patients (61%) and by at least 1 grade in 34 patients (85%). There was no correlation noted between reduction of fibrosis and cytogenetic response. However, a reduction in fibrosis was found to correlate with a reduction in bone marrow megakaryocytosis (P = 0.002). CONCLUSIONS: Treatment with imatinib mesylate appears to reduce CML-associated bone marrow fibrosis in most patients who are treated during the chronic phase of disease. This effect may be independent of the degree of suppression of Philadelphia chromosome-positive cells, and may improve prognosis in patients with CML.

Adult↗
PubMed2004

Fludarabine and mitoxantrone for patients with chronic lymphocytic leukemia.

BACKGROUND: The objective of the current study was to assess the efficacy of combination therapy with fludarabine and mitoxantrone in patients with B-cell chronic lymphocytic leukemia (CLL). METHODS: Eighty-eight patients were treated with fludarabine 30 mg/m(2) intravenously daily for 3 days and mitoxantrone 10 mg/m(2) on Day 1 (FN). Patients were divided into four groups based on expected response to single-agent fludarabine. These four groups included previously untreated patients, patients who previously were treated with alkylating agents, patients who were successfully treated with alkylating agents and fludarabine but who developed recurrent disease, and patients whose disease was refractory to fludarabine with or without alkylating agents. RESULTS: The overall response rate was 66%. The response rates were 83% in previously untreated patients, 87% in patients previously treated with alkylating agents, 50% in patients whose disease was not refractory to fludarabine at the start of therapy, and 25% in patients whose disease was refractory to fludarabine. The complete remission (CR) rate was 20% for previously untreated patients, which was not significantly different from the CR rate for a group of historical control patients who were treated with single-agent fludarabine. The median follow-up was 8 years for surviving patients. The median progression free survival was 24 months for all patients and 34 months for previously untreated patients. The median overall survival was 40 months, and the median survival of previously untreated patients was 88 months. The most common toxicities were myelosuppression and infection. Eleven patients (12.5%) developed a second malignancy after a median of 62 months. CONCLUSIONS: The FN regimen did not have a significant advantage over fludarabine alone in the treatment of patients with CLL.

Adult↗
PubMed2004

Granulocyte-colony-stimulating factor (filgrastim) may overcome imatinib-induced neutropenia in patients with chronic-phase chronic myelogenous leukemia.

BACKGROUND: Imatinib mesylate administration has become standard treatment for patients with chronic myelogenous leukemia (CML). Although the safety profile of imatinib is favorable, Grade > or = 3 neutropenia (according to the National Cancer Institute Common Toxicity Criteria) occurs in 35-45% of patients with CML in chronic phase who receive standard-dose imatinib. Myelosuppression results in treatment interruptions, which may compromise responses to imatinib. The authors investigated the ability of granulocyte-colony-stimulating factor (filgrastim) to reverse imatinib-associated neutropenia, thereby allowing for more continuous imatinib administration. METHODS: Thirteen patients with chronic-phase CML and Grade > or = 3, imatinib-induced neutropenia were treated with filgrastim. Treatment with filgrastim was initiated after a median of 22 months from the start of imatinib. Eleven patients received filgrastim 5 microg/kg 1-3 times weekly, and 2 patients received filgrastim 5 microg/kg daily; doses were titrated to maintain an absolute neutrophil count (ANC) > or = 10(9)/L. RESULTS: Seven of 11 patients (64%) who began treatment with an ANC < 1.5 x 10(9)/L had responses (i.e., their ANC improved to > or = 2 x 10(9)/L within 21 days); the other 4 patients experienced slower recovery but were able to continue receiving imatinib uninterrupted. Before filgrastim administration was initiated, patients did not receive imatinib (due to neutropenia-related treatment interruptions) for an average of 21% of the total time since the start of imatinib. This figure decreased to 6% after the start of filgrastim treatment (P = 0.0008). Before filgrastim treatment was initiated, only one patient had achieved a major (partial) cytogenetic response. After the start of filgrastim treatment, five patients had major cytogenetic responses (including two complete responses). CONCLUSIONS: The authors concluded that filgrastim may overcome imatinib-associated neutropenia and allow improved delivery of imatinib. Some patients may experience improvements in their responses to therapy as a result.

Adult↗
PubMed2004

Long-term survival benefit and improved complete cytogenetic and molecular response rates with imatinib mesylate in Philadelphia chromosome-positive chronic-phase chronic myeloid leukemia after failure of interferon-alpha.

We reviewed 261 patients with chronicphase chronic myelogenous leukemia (CML) after interferon-alpha (IFN-alpha) failure treated with imatinib mesylate 400 mg daily. With a median follow-up time of 45 months, the major cytogenetic response rate was 73% and the complete cytogenetic response rate 63%. The estimated 4-year survival rate was 86%. Multivariate analysis for survival identified hematologic resistance to IFN-alpha (P =.01), splenomegaly (P =.03), and lack of any cytogenetic response after 3 months of therapy (P =.01) to have independent poor prognostic significance. Patients could be divided into good (no adverse factors), intermediate (1 adverse factor), and poor-risk groups (2 or 3 adverse factors; 12% of patients) with estimated 4-year survival rates of 96%, 86%, and 49%, respectively (P <.00001). The 4-year cumulative major molecular response (quantitative reverse transcriptase-polymerase chain reaction [Q-PCR] = BCR-ABL/ABL less than 0.05%) rate was 43% and complete molecular response rate (BCR-ABL undetectable) 26%. Compared with a historical group of 251 similar patients treated with nonimatinib therapies, imatinib mesylate was associated with a better 4-year survival rate (86% versus 43%; P <.0001); the survival advantage was confirmed by multivariate analysis (hazard ratio, 0.19; P <.0001).

Aged↗
PubMed2004

Outcome with the hyper-CVAD regimens in lymphoblastic lymphoma.

Therapy of lymphoblastic lymphoma (LL) has evolved with use of chemotherapy regimens modeled after those for acute lymphocytic leukemia (ALL). We treated 33 patients with LL with the intensive chemotherapy regimens hyper-CVAD (fractionated cyclophosphamide, vincristine, Adriamycin, and dexamethasone) or modified hyper-CVAD used for ALL at our institution. Induction consolidation was administered with 8 or 9 alternating cycles of chemotherapy over 5 to 6 months with intrathecal chemotherapy prophylaxis, followed by maintenance therapy. Consolidative radiation therapy was given to patients with mediastinal disease at presentation. No consolidation with autologous or allogeneic stem cell transplantation was performed. At diagnosis, 80% were T-cell immunophenotype, 70% were stages III to IV, 70% had mediastinal involvement, and 9% had central nervous system (CNS) disease. Of the patients, 30 (91%) achieved complete remission, and 3 (9%) achieved partial response. Within a median of 13 months, 10 patients (30%) relapsed or progressed. Estimates for 3-year progression-free and overall survival for the 33 patients were 66% and 70%, respectively. Estimates for the patients with known T-cell immunophenotype were 62% and 67%, respectively. No parameters (eg, age, stage, serum lactate dehydrogenase [LDH], beta(2) microglobulin) appeared to influence outcome except for CNS disease at presentation. Modification of the hyper-CVAD regimen with anthracycline intensification did not improve outcome. Other modifications of the program could include incorporation of monoclonal antibodies and/or nucleoside analogs, particularly for slow responders or those with residual mediastinal disease.

Adolescent↗
PubMed2004

Erythropoietin is effective in improving the anemia induced by imatinib mesylate therapy in patients with chronic myeloid leukemia in chronic phase.

BACKGROUND: Myelosuppression occurs in up to 50% of patients with chronic myeloid leukemia (CML) who are treated with imatinib and > or = Grade 3 myelosuppression is reported in approximately 10% of patients. METHODS: The authors investigated the prognostic significance of anemia occurring during therapy with imatinib in patients with CML in chronic phase. RESULTS: Of 338 patients treated with imatinib (150 patients after interferon failure and 188 patients with newly diagnosed CML), 230 (68%) developed anemia. In a multivariate analysis, factors associated with an increased probability of developing anemia were a starting hemoglobin level < 12 g/dL, age > or = 60 years, female gender, higher imatinib dose, and intermediate or high Sokal risk group. Of these 230 patients, 102 patients received treatment with 40,000 U of recombinant human erythropoietin administered subcutaneously once weekly. An increase in the hemoglobin level of > or = 2 g/dL was achieved in 69 patients (68%) and 22 patients (22%) had an increase of 1-1.9 g/dL. Patients who developed anemia had a trend toward a lower probability of complete cytogenetic remission compared with patients without anemia (68% vs. 77%; P = 0.14), as well as a trend for inferior survival. Patients with anemia and other manifestations of myelosuppression were found to have a significantly worse outcome than those with isolated anemia. CONCLUSIONS: The authors concluded that erythropoietin is safe and effective in patients in chronic-phase CML who develop anemia with imatinib therapy.

Anemia↗
PubMed2004

The clinical significance of large cells in bone marrow in patients with chronic lymphocytic leukemia.

BACKGROUND: Patients with chronic lymphocytic leukemia (CLL) that transforms to Richter syndrome (RS) frequently show atypical lymphocytes in bone marrow; however, a diagnosis of RS requires confirmation of the presence of sheets of large cells in bone marrow or lymph nodes. METHODS: In this study, the authors evaluated the clinical significance of scattered large cells in bone marrow. They assessed the possibility of predicting transformation to RS in bone marrow smears by counting the percentages of prolymphocytes and large cells in 78 patients with CLL and 29 patients with lymph node biopsy-confirmed RS. RESULTS: The percentage of large cells was found to be correlated with decreasing survival in a continuous fashion (P = 0.006). It is interesting to note that patients who had > 7% large cells in the bone marrow and elevated beta(2)-microglobulin (beta(2)-M) levels (> 5 mg/L) had a survival duration identical to that of patients with RS, and these factors together were a strong predictor of RS (P < 0.001). CONCLUSIONS: Patients with CLL who had bone marrow that contained > 7% large cells and who had beta(2)-M levels > 5 mg/L had a disease that was similar to RS, and the combination of large cells and beta(2)-M can be used as a surrogate marker for RS.

Adult↗