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Biomedical subjects

G A Omura

Publications and source records attributed to G A Omura.

At least 19 recordsLinked to original sources
PubMed2001

Dose-escalated cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (CHOPE) chemotherapy for patients with diffuse lymphoma: Cancer and Leukemia Group B studies 8852 and 8854.

BACKGROUND: To address the feasibility and outcome of moderate dose intensification with granulocyte-colony stimulating factor (G-CSF) for patients with aggressive non-Hodgkin lymphoma (NHL), the Cancer and Leukemia Group B (CALGB) conducted two studies evaluating dose-escalated cyclophosphamide and etoposide in the cyclophosphamide, doxorubicin, vincristine, prednisone, etoposide (CHOPE) regimen. METHODS: Eligibility criteria included histologically documented, diffuse small cleaved, diffuse mixed, diffuse large cell, or immunoblastic lymphoma, Stage III--IV or bulky Stage II disease, and an ECOG performance status of 0--1. CALGB 8852, a group-wide study, accrued 227 patients: 120 patients in the pilot study to determine the maximum tolerated dose (MTD) without G-CSF and 107 in the pilot study of dose-escalated CHOPE with G-CSF. CALGB 8854, a limited-institution, Phase I study, enrolled 38 patients and determined the MTD of CHOPE with G-CSF to be used in CALGB 8852. The MTD in both studies was defined as the dose at which 50% of patients had 1) Grade 4 neutropenia or thrombocytopenia lasting 7 days or more, or 2) Grade 3--4 hemorrhage or nonhematologic toxicity (excluding alopecia, nausea, and emesis), or 3) were prevented from receiving 100% of drug on Day 22. RESULTS: The MTD of CHOPE without G-CSF was cyclophosphamide 1000 mg/m(2) on Day 1 and etoposide 100 mg/m(2) on Days 1--3 with doxorubicin 50 mg/m(2) on Day 1, vincristine 1.4 mg/m(2) (maximum, 2 mg) on Day 1, and prednisone 100 mg on Days 1--5. With the addition of G-CSF at 200 microg/m(2) on Days 5--19, the MTD was cyclophosphamide 1500 mg/m(2) and etoposide 160 mg/m(2) on Days 1-3 with standard doses of doxorubicin, vincristine, and prednisone. Increasing the dose of G-CSF from 200 microg/m(2) to 400 microg/m(2) did not allow for further dose escalation. The primary toxicity in all cohorts was neutropenia. Four toxic deaths occurred on CALGB 8852. The 5-year failure free survival (FFS) and overall survival (OS) rates for eligible patients on CALGB 8852 were 31% (95% confidence interval [95%CI], 23--39) and 48% (95%CI, 40--57), respectively. The 5-year FFS and OS rates for eligible patients on CALGB 8854 were 34% (95%CI, 17--52) and 51% (95%CI, 33--70), respectively. CONCLUSIONS: Moderate dose escalation with G-CSF is feasible. However, response and survival rates of patients who receive dose-escalated CHOPE, even with the addition of G-CSF, appear similar to the rates reported with standard-dose CHOP.

Adult↗
PubMed2001

A phase III, randomized, double-blind, placebo-controlled study of peldesine (BCX-34) cream as topical therapy for cutaneous T-cell lymphoma.

BACKGROUND: The purine nucleoside phosphorylase inhibitor peldesine is a new agent being evaluated as a T-cell inhibitor. OBJECTIVE: We attempted to determine the efficacy of peldesine (BCX-34) in a 1% dermal cream formulation as a treatment for cutaneous T-cell lymphoma (CTCL). METHODS: Ninety patients with patch and plaque phase CTCL, histologically confirmed by a referee dermatopathologist, were enrolled in a randomized, double-blind, placebo-controlled study. BCX-34 dermal cream 1% or the vehicle cream (as a placebo control) was applied twice daily to the entire skin surface for up to 24 weeks. Efficacy of the topical therapy was assessed in terms of complete or partial (> or = 50%) clearing of patches and plaques. RESULTS: Of the 89 patients able to be examined, 43 received BCX-34 and 46 received the placebo vehicle cream. One patient withdrew early and was not analyzed. The two groups were well balanced for potential prognostic factors. A total of 28% (12/43) of the patients treated with BCX-34 showed a response, but 24% (11/46) of patients who received vehicle also responded (P =.677). CONCLUSION: Although BCX-34 dermal cream 1% was not significantly better than the control as therapy for patch and plaque-phase CTCL, this appears to be the first published placebo-controlled trial evaluating treatment for CTCL. Whether the vehicle cream has more than a placebo therapeutic effect is unclear. The relatively high (24%) placebo response rate should be kept in mind in assessing other treatments for early-stage CTCL.

Administration, Cutaneous↗
PubMed2001

Cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (CHOPE) for advanced-stage Hodgkin's disease: CALGB 8856.

Successful treatment of advanced-stage Hodgkin's disease (HD) may critically depend on dose intensity. Because mechlorethamine, Oncovin, procarbazine, and prednisone (MOPP), and Adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) are not suitable for major dose escalation, we evaluated the activity and toxicity of combined cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (CHOPE) in advanced HD, here used at conventional dose intensity, as a preparatory study prior to using this regimen at higher dose intensity. Ninety-two patients were treated with CHOPE (cyclophosphamide, 750 mg/m2, day 1; doxorubicin, 50 mg/m2, day 1; vincristine, 1.4 mg/m2, days 1 and 8; prednisone, 100 mg/day, days 1-5; and etoposide, 80 mg/m2, days 1, 2, and 3) every 21 days. All had advanced HD with no prior chemotherapy with 46% stage IV, 63% with B symptoms, and 57% with bulky disease (> 5 cm). Radiation and growth factor support were not permitted. Full-dose vincristine (not capped at maximum 2 mg/dose) was used in the first 33 patients. An initial cohort of 41 patients was treated with four cycles of CHOPE to evaluate safety and efficacy followed by four cycles of ABVD. A second cohort of 51 patients was treated with 6-8 cycles of CHOPE alone. Toxicity was generally acceptable and primarily hematologic, with neutrophils < 500 in 63% of cohort I and 90% of cohort II, and platelets < 25,000 in 7% of cohort I and 8% of cohort II. The long-term neurotoxicity of full-dose, high-intensity vincristine was acceptable and largely reversible. In cohort I, 92% of patients achieved a complete response (CR) or partial response (PR) with four cycles of CHOPE and 85% were in CR after four additional cycles of ABVD. In cohort II, 77% achieved a CR with 6-8 cycles of CHOPE alone. FFS was 76% in cohort I and 59% in cohort II, with a median follow-up of 8.2 and 5.7 years, respectively. CHOPE, at conventional dose intensity as used here, is an effective first-line regimen for the treatment of advanced-stage HD and may warrant evaluation using higher doses of cyclophosphamide and etoposide with granulocyte colony stimulating factor (G-CSF) support.

Adult↗
PubMed2001

Arsenic therapy.

Explore the source record for details and available documents.

Arsenicals↗
PubMed2000

Pharmacokinetics and pharmacodynamics of peldesine (BCX-34), a purine nucleoside phosphorylase inhibitor, following single and multiple oral doses in healthy volunteers.

The pharmacokinetic parameters of peldesine (BCX-34) were investigated after single and multiple oral doses in two groups of healthy adult volunteers. The pharmacodynamic elevation of endogenous inosine and 2'-deoxyguanosine was simultaneously monitored. The first group of 8 subjects received an intravenous dose (18 mg/m2) and five oral doses (30, 63, 108, 144, and 192 mg/m2) of drug. A second group of 12 subjects received 160 mg/m2 in four and in six divided doses orally. Serial blood samples and total urine outputs were collected during dosing and for at least 24 hours after the last dose was administered. One set of samples was analyzed using high-pressure liquid chromatography/ultraviolet (LC/UV) methods, validated for intact drug in human plasma and urine samples. Another set of samples was analyzed for the biomarkers, inosine and 2'-deoxyguanosine, using high-pressure LC with either mass spectrometry (MS) or electrochemical detection (EC) methods. The pharmacokinetic parameters of inosine and 2'-deoxyguanosine were calculated using noncompartmental methods and correlated against the pharmacokinetic parameters of BCX-34. For the single-dose study, the results exhibited linear pharmacokinetics over the dose range from 30 to 144 mg/m2. The calculated terminal half-life was 3.5 +/- 1.0 h, and the absolute bioavailability of the oral formulation was approximately 51%. Analysis of urine in the first 24 hours of collection accounted for approximately 82% of the absorbed intact drug. Evaluation of the multiple-dose pharmacokinetics indicated that steady-state blood concentrations were achieved by 24 hours when the drug was administered four or six times a day. A drug dose-related elevation of plasma 2'-deoxyguanosine was observed. This phenomenon was not seen with plasma inosine levels. However, analysis of urine samples showed an increase in inosine output with an increase in the drug dose. The calculated terminal half-life of inosine and 2'-deoxyguanosine was 15.3 +/- 1.8 h and 1.3 +/- 0.1 h, respectively.

Administration, Oral↗
PubMed2000

Inhibitors of the enzyme purine nucleoside phosphorylase as potential therapy for psoriasis.

Purine nucleoside phosphorylase (PNP) is one of the enzymes comprising the purine salvage pathway , and is responsible for the catalysis of the reversible phosphorolytic cleavage of purine ribonucleosides and 2'-deoxyribonucleosides. The pivotal role of PNP in T-cell proliferation has been demonstrated in patients with inherited PNP deficiency, where T-cell levels may be 1-3% of normal. This observation helped establish the critical role of PNP in T-cells and provided a rationale for developing inhibitors of PNP. Inhibitors of PNP may be useful for treating a variety of T-cell related autoimmune diseases including psoriasis, rheumatoid arthritis and Crohn s disease and T-cell cancers. In this manuscript, the x-ray crystal structure of the PNP enzyme is described. Results of a structure-based drug design program aimed at designing small-molecule inhibitors of PNP are also described. Of the many classes of compounds synthesized, studied and reviewed, only one, the 3-pyridinylmethyl-9-deazaguanine (BCX-34, 39) analog has been used in clinical trials. Both topical and oral formulations of BCX-34 were studied in psoriatic patients and the results of these clinical trials are described.

Drug Design↗
PubMed1998

A phase I study of paclitaxel, doxorubicin, and cisplatin in patients with previously untreated epithelial ovarian cancer.

OBJECTIVE: Although doxorubicin is not currently popular as a primary agent in ovarian cancer, overviews of previous studies suggest that the inclusion of doxorubicin may have improved outcome. The purpose of this phase I study was to determine the maximal dose of doxorubicin that could be added to standard doses of paclitaxel and cisplatin with G-CSF support. METHODS: Women with FIGO stage III or IV epithelial ovarian cancer were primarily treated with escalating doses of doxorubicin in combination with paclitaxel (135 mg/m2 over 24 h) and cisplatin (75 mg/m2) every 3 weeks. Doxorubicin was started at 30 mg/m2 and escalated by 10 mg/m2 per treatment level. All patients received G-CSF support. RESULTS: Eleven patients were treated at two dose levels. Dose limiting toxicity (DLT) was reached at the 40 mg/m2 dose of doxorubicin. All patients experienced grade 4 neutropenia although none required hospitalization. DLT included renal toxicity and prolonged thrombocytopenia. Despite vigorous antiemetic regimens 60% of patients experienced severe nausea and vomiting. Nine patients were assessable for response. Eight patients have had a complete clinical response (89%). Of the five patients undergoing second-look laparotomy two were negative. CONCLUSIONS: The maximum tolerated dose of doxorubicin in this three-drug regimen is 30 mg/m2 with standard doses of paclitaxel and cisplatin. Hematologic toxicity is manageable using G-CSF. Doxorubicin appears to increase the renal toxicity of cisplatin which may be exaggerated by marked nausea and vomiting. This is an active but toxic regimen and alternative sequences and strategies should be evaluated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Randomized trial of cisplatin versus cisplatin plus mitolactol versus cisplatin plus ifosfamide in advanced squamous carcinoma of the cervix: a Gynecologic Oncology Group study.

PURPOSE: Cisplatin, mitolactol (dibromodulcitol), and ifosfamide have been the most active single agents in squamous carcinoma of the cervix identified so far by the Gynecologic Oncology Group (GOG). Combinations of cisplatin plus ifosfamide and cisplatin plus mitolactol are prospectively compared with cisplatin alone. PATIENTS AND METHODS: Patients were randomized to receive cisplatin 50 mg/m2 or the same dose of cisplatin plus mitolactol (C + M) 180 mg/m2 orally on days 2 to 6, or cisplatin plus ifosfamide (CIFX) 5 g/m2 given as a 24-hour infusion plus mesna 6 g/m2 during and for 12 hours after the ifosfamide infusion, every 3 weeks for up to six courses. Of 454 patients entered, 438 were eligible and analyzed for response and survival. RESULTS: CIFX had a higher response rate (31.1% v 17.8%, p = .004) and longer progression-free survival (PFS) time (P = .003) compared with cisplatin alone. The median times to progression or death were 4.6 and 3.2 months, respectively. C + M showed no significant improvement in these parameters compared with cisplatin alone. Survival was associated with initial performance score (PS; 0 was more favorable; P < .001) and with age (younger was unfavorable, P = .025). There was no significant difference in overall survival between cisplatin and either of the combinations. Leukopenia, renal toxicity, peripheral neurotoxicity, and CNS toxicity were more frequent with CIFX (P < .05). CONCLUSION: CIFX improved the response rate and PFS duration in advanced cervix cancer compared with cisplatin alone, but at the cost of greater toxicity and with no improvement in survival.

Adult↗
PubMed1996

A randomized, double-blind comparison of single-dose and divided multiple-dose dolasetron for cisplatin-induced emesis.

PURPOSE: Intravenous dolasetron has been shown to be an effective antiemetic agent in patients receiving high-dose cisplatin-containing chemotherapy. Previous studies have suggested that 1.8 mg/kg is an optimal dose for achieving control of emesis and nausea. The objective of this study was to compare the efficacy and safety of a single intravenous (IV) dose of dolasetron with an equal divided multiple dose. METHODS: In this randomized, double-blind, parallel-group, multicenter study, the efficacy and safety of a single 1.8-mg/kg dose of dolasetron given 30 min prior to high-dose cisplatin ( > or = 80 mg/m2) chemotherapy was compared with the same total amount of dolasetron administered in three separate doses (0.6 mg/kg each) over a 12-h interval commencing 30 min prior to beginning chemotherapy and ending 11.5 h later. Antiemetic efficacy, safety, and tolerability were compared in 55 patients with various malignancies during the 24 h following the initiation of chemotherapy. The number of emetic episodes was the primary efficacy parameter. RESULTS: A single IV dose of dolasetron was generally more effective than a multiple-dose regimen in all measures of efficacy. There was a larger proportion of complete responders in the single-dose group compared with the multiple-dose group (48% vs 23%), although this difference did not reach statistical significance. Compared with the multiple-dose group, patients who received a single dose of dolasetron had a significantly (P = 0.034) longer median time to the first emetic episode (10.1 h vs > 24 h, respectively). Overall, 53% of patients had either a complete response or a major response to dolasetron, and only 40% of the total patient population received escape antiemetic medication in the 24 h after cisplatin administration. Except for headache, adverse events were similar with both regimens and were generally of mild or moderate intensity; no serious adverse events occurred. Neither dolasetron treatment regimen was associated with any clinically important events, trends in laboratory variables, or differences in safety profile. CONCLUSIONS: single-dose dolasetron was well tolerated and effectively controlled emesis and nausea in patients who received highly emetogenic, high-dose cisplatin chemotherapy. The greater antiemetic efficacy of a single prophylactic dose of dolasetron offers both convenience and potential cost savings, compared with a multiple-dose schedule of administration.

Aged↗
PubMed1996

Chemotherapy for stage IVB or recurrent cancer of the uterine cervix.

Numerous drugs and drug combinations have been evaluated, largely in phase II trials, for the treatment of carcinoma of the uterine cervix. There clearly is a need for effective chemotherapy for this disease, but the results to date have unfortunately not met that need. Cisplatin is active but overrated. Drug combinations have not shown a consistent advantage and require careful study, with the initial focus on maximizing the complete response rate in women with no or minimal prior chemotherapy and with adequate sample size to have confidence about the results. The patient populations under treatment need to be carefully defined with respect to potential prognostic factors for response and survival, so that results will be more reproducible. The few large, randomized trials completed so far have failed to show a survival benefit with combination chemotherapy; in fact, there does not appear to have been a comparison of chemotherapy with best supportive care. Systemic therapy of cervical cancer remains experimental.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Clinical pharmacology of cytarabine in patients with acute myeloid leukemia: a cancer and leukemia group B study.

The pharmacokinetics of cytarabine (ara-C) were determined in 265 patients with acute myeloid leukemia (AML) receiving ara-C (200 mg/m2 per day for 7 days as a continuous infusion) and daunorubicin during induction therapy. The mean (standard deviation) ara-C concentration at steady-state (Css) and systemic clearance (Cl) were 0.30 (0.13) microM and 134 (71) l/h per m2 respectively. Males had a significantly faster ara-C Cl (139 vs 131 l/h per m2, P = 0.025) than females. Significant correlations were noted between ara-C Cl and the pretreatment, peripheral white blood cell count (P = 0.005) and pretreatment blast count (P = 0.020). No significant differences in ara-C Css or Cl were noted in patients achieving complete remission compared with those failing therapy (P = 0.315, P = 0.344, respectively). No significant correlations were observed between ara-C pharmacokinetic parameters and several indices of patient toxicity. Our findings indicate that variability in ara-C disposition in plasma at this dosage level does not correlate with remission status or toxicity in patients with AML receiving initial induction therapy with ara-C and daunorubicin.

Acute Disease↗
PubMed1995

Preliminary analysis of the behavior of stage I ovarian serous tumors of low malignant potential: a Gynecologic Oncology Group study.

PURPOSE: From December 1983 through February 1992, a prospective study designed to determine the clinical course of patients with ovarian tumors of low malignant potential (LMP) was conducted by the Gynecologic Oncology Group (GOG). MATERIALS AND METHODS: This protocol was developed to evaluate the following (1) the biologic behavior of ovarian LMP tumors, (2) the effectiveness of melphalan chemotherapy in patients with clinically detectable residual disease after surgical staging and in patients whose tumors progress or recur after surgical therapy, and (3) the response rate to cisplatin in those who failed to respond to melphalan therapy. The study group consisted of 146 assessable patients with stage I serous LMP tumors. All of these women had the affected ovary (or ovaries) removed, and a complete staging operation was performed in each case. While 123 patients had a total abdominal hysterectomy (TAH) and bilateral salpingo-oophorectomy (BSO), 21 retained the uterus and one normal-appearing ovary and fallopian tube. No adjuvant chemotherapy or radiation therapy was administered to any patients in the stage I study group. RESULTS: The median follow-up time was 42.4 months (range, 1.6 to 108). Thus far, no patient with a stage I ovarian serous LMP tumor has developed recurrent disease. CONCLUSION: Stage I ovarian serous LMP tumors rarely, if ever, recur. Limited resection, after meticulous surgical exploration, is adequate therapy for women of reproductive age.

Adult↗
PubMed1995

Long-term follow-up of a randomized post-induction therapy trial in acute myelogenous leukemia (a Southeastern Cancer Study Group trial).

A phase III clinical trial was designed to determine if more intensive induction and consolidation therapy for acute myeloblastic leukemia increases the remission rate and prolongs survival. A minor objective was to determine if the use of non-cross resistant drugs was more effective than the same drugs used for induction. Patients with untreated leukemia between the ages of 15 and 50 were given daunorubicin 45 mg/m2 for the first 3 days of a 10-day continuous infusion of cytosine arabinoside, initially at a dose of 2000 mg/m2 but reduced to 100 mg/m2 because of toxicity. Those under 36 achieving a complete remission and with an histocompatible donor were assigned to a transplant arm. The rest were randomized to receive one of three consolidation arms: A, cytosine arabinoside, 200 mg/m2 daily for 7 days and daunorubicin 45 mg/m2 daily for 3 days for three courses; B, one course as in Arm A followed by amsacrine, 120 mg/m2 daily for 5 days followed by a 5-day continuous infusion of azacytidine, 150 mg/m2/day; C, thioguanine and cytosine arabinoside, 100 mg/m2 every 12 h and daunorubicin 10 mg/m2 daily for 5 days for three courses followed by four maintenance courses of cytosine arabinoside, 100 mg/m2 daily for 5 days and daunorubicin, 45 mg/m2 for 2 days every 13 weeks. From 1981 to 1986, 398 eligible patients were enrolled and 219 achieved a complete remission. The initial induction dose of cytosine arabinoside was reduced after five of 29 patients exhibited fatal gastrointestinal toxicity. Only 11 patients were assigned to the transplant arm. There were no significant differences in the consolidation arms. The 5 year disease-free survivals were 38, 31 and 27% in arms A, B, and C respectively. Intensive consolidation therapy with the same or different drugs used in induction was as effective as lower dose consolidation followed by maintenance therapy.

Adolescent↗
PubMed1994

Intensive postremission chemotherapy in adults with acute myeloid leukemia. Cancer and Leukemia Group B.

BACKGROUND: About 65 percent of previously untreated adults with primary acute myeloid leukemia (AML) enter complete remission when treated with cytarabine and an anthracycline. However, such responses are rarely durable when conventional postremission therapy is administered. Uncontrolled trials have suggested that intensive postremission therapy may prolong these complete remissions. METHODS: We treated 1088 adults with newly diagnosed AML with three days of daunorubicin and seven days of cytarabine and randomly assigned patients who had a complete remission to receive four courses of cytarabine at one of three doses: 100 mg per square meter of body-surface area per day for five days by continuous infusion, 400 mg per square meter per day for five days by continuous infusion, or 3 g per square meter in a 3-hour infusion every 12 hours (twice daily) on days 1, 3, and 5. All patients then received four courses of monthly maintenance treatment. RESULTS: Of the 693 patients who had a complete remission, 596 were randomly assigned to receive postremission cytarabine. After a median follow-up of 52 months, the disease-free survival rates in the three treatment groups were significantly different (P = 0.003). Relative to the 100-mg group, the hazard ratios were 0.67 for the 3-g group (95 percent confidence interval, 0.53 to 0.86) and 0.75 for the 400-mg group (95 percent confidence interval, 0.60 to 0.94). The probability of remaining in continuous complete remission after four years for patients 60 years of age or younger was 24 percent in the 100-mg group, 29 percent in the 400-mg group, and 44 percent in the 3-g group (P = 0.002). In contrast, for patients older than 60, the probability of remaining disease-free after four years was 16 percent or less in each of the three postremission cytarabine groups. CONCLUSIONS: These data support the concept of a dose-response effect for cytarabine in patients with AML who are 60 years of age or younger. The results with the high-dose schedule in this age group are comparable to those reported in similar patients who have undergone allogeneic bone marrow transplantation during a first remission.

Acute Disease↗
PubMed1994

Prognostic factor analysis of central nervous system relapse in adult acute lymphoblastic leukemia. A Southeastern Cancer Study Group report.

A randomized clinical trial in adult ALL has previously shown a benefit for central nervous system prophylaxis (intrathecal methotrexate plus cranial irradiation) with respect to CNS relapse-free interval, and the long-term follow-up revealed that about 20% of the patients in this multicenter trial were long survivors, probably cured. Questions that were not addressed in the earlier reports concern the time to CNS relapse as the initial site of relapse and the prognostic factors associated with initial CNS relapse. Further analysis of the 62 evaluable randomized patients has shown that in every case with CNS relapse, time to any relapse and time to CNS relapse as the first event were the same. Multivariate analysis showed that, although CNS prophylaxis is a significant favorable prognostic factor with respect to CNS relapse over time, race (nonwhite is unfavorable) and splenomegaly (unfavorable) are more significant, albeit not well explained. Future trials should examine race and splenomegaly as well as other clinical and biologic features as potential prognostic factors for CNS relapse in adult ALL.

Adolescent↗