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Biomedical subjects

E M Bonnem

Publications and source records attributed to E M Bonnem.

At least 19 recordsLinked to original sources
PubMed1996

Randomized trial of recombinant platelet factor 4 versus protamine for the reversal of heparin anticoagulation in humans.

BACKGROUND: Protamine reverses heparin anticoagulation, but it can have important side effects. We compared the safety and effectiveness of intravenous recombinant platelet factor 4 (rPF4) as an alternative to protamine in a randomized blinded trial. METHODS AND RESULTS: In 81 patients having diagnostic cardiac catheterization, baseline hemodynamics were measured after a 5000-U bolus of heparin. Repeat measurements were obtained at the end of the procedure, and the anticoagulation status was determined by an activated coagulation time (ACT) and activated partial thromboplastin time (aPTT). Patients then received either protamine (50 mg IV over 10 minutes) or rPF4 (1.0 mg/kg IV over 2 minutes) in a blinded fashion. Serial measurements of hemodynamic and clotting functions were performed 5, 10, 20, and 30 minutes after drug administration. Follow-up measurements and clinical assessments were made at 1, 4, 6, and 24 hours later and after 7 days. Before drug administration, ACTs, aPTTs, and hemodynamics were similar among the groups. After drug infusion, there was no difference in ACT between the protamine and rPF4 patients. At 20 and 30 minutes after drug infusion, ACT and aPTT were slightly higher in those receiving rPF4, but these changes were small and of no clinical significance. There were no clinically meaningful differences in any of the hemodynamic variables between the groups, and there were no serious side effects in any patient. CONCLUSIONS: At the dose used in this study, rPF4 was well tolerated and reversed the anticoagulant effect of heparin. These data support its continued evaluation as an alternative to protamine after cardiac surgery.

Adult↗
PubMed1996

Phase I trial of recombinant platelet factor 4 (rPF4) in patients with advanced colorectal carcinoma.

BACKGROUND: Recombinant platelet factor 4 (rPF4) is a naturally occurring protein found in platelet alpha granules that can inhibit angiogenesis. METHODS: In this Phase I trial, 9 patients with metastatic colorectal cancer who had failed 5-FU treatment received rPF4 at doses ranging from 0.3 to 3.0 mg/kg via 30-minute infusion. Three additional patients were treated with the 3 mg/kg dose over a 6-hour period of infusion. RESULTS: The only toxicity encountered was mild leg twitching in 2/3 patients treated with the 6-hour infusion. One patient with a history of phlebitis developed a lower extremity deep venous thrombosis after the first dose of rPF4. A mild rise in fibrinogen level was noted in several patients. Of the 11 evaluable patients, there were no clinical responses to treatment. CONCLUSIONS: rPF4 is well tolerated at the doses and schedules tested. No clinical responses were observed. Prolonged infusion schedules should be investigated.

Adult↗
PubMed1995

Reversal of heparin anticoagulation by recombinant platelet factor 4 in humans.

BACKGROUND: Protamine is used to reverse the anticoagulant effects of heparin, but it can have important side effects. Platelet factor 4 (PF4) is a protein found in platelet alpha granules that binds to and thereby neutralizes heparin. We evaluated the safety and effectiveness of intravenous recombinant PF4 to neutralize heparin anticoagulation after cardiac catheterization in a phase 1, open-label trial. METHODS AND RESULTS: The study group consisted of 18 patients having diagnostic cardiac catheterization. Heparin (5000 U) was given after vascular access was obtained. In the first 12 patients, additional heparin was given at the conclusion of the procedure so that all patients had activated coagulation times > 300 seconds before rPF4 was given. Three patients each received 0.5, 1.0, 2.5, or 5.0 mg/kg rPF4 over a period of 3 minutes at the conclusion of the catheterization procedure. In 6 additional patients, extra heparin was not given at the conclusion of the procedure, and 1.0 mg/kg rPF4 was given. Hemodynamic measurements, cardiac output, and serial blood tests were performed 5, 10, 20, and 30 minutes after rPF4 and then into the next 24 hours. There were no serious side effects in any patient, despite transient rPF4 levels as high as 14,870 ng/mL in the patients receiving 5.0 mg/kg. One patient receiving 2.5 mg/kg had a slight transient rise in liver enzymes possibly related to the rPF4. There were no important hemodynamic effects of rPF4 administration at any dose used. Doses of 2.5 and 5.0 mg/kg were uniformly effective in reversing the anticoagulant effect of heparin. At lower doses, rPF4 neutralized the effects of heparin in most but not all patients. Pharmacokinetic analysis suggested a monophasic and one-compartment clearance of the PF4-heparin complex. No neutralizing factors to rPF4 were detected in the samples collected 7 days after dosing. CONCLUSIONS: rPF4, in doses ranging from 0.5 to 5.0 mg/kg over 3 minutes, had no serious side effects. Given in sufficient amounts, rPF4 can completely and rapidly reverse the anticoagulant effects of heparin.

Cardiac Catheterization↗
PubMed1992

Granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjunct to autologous hemopoietic stem cell transplantation for lymphoma.

OBJECTIVE: To determine the hemopoietic effects of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients having autologous hemopoietic stem cell transplantation for Hodgkin or non-Hodgkin lymphoma. DESIGN: Placebo or GM-CSF was administered after bone marrow or peripheral blood stem cell transplantation or both in a randomized, double-blind phase III trial by daily intravenous infusion (10 micrograms/kg body weight) until absolute neutrophil counts reached greater than or equal to 1000/mm3 on 3 consecutive days. SETTING: Bone marrow transplantation unit in a university hospital. PATIENTS: Sixty-nine consecutive patients with Hodgkin or non-Hodgkin lymphoma received GM-CSF (36 patients) or placebo (33 patients). MEASUREMENTS AND MAIN RESULTS: Patients who received GM-CSF achieved absolute neutrophil counts greater than or equal to 500/mm3 (median, 12 compared with 16 days, P = 0.02) and absolute neutrophil counts greater than or equal to 1000/mm3 (median, 15 compared with 24 days, P less than 0.001) more quickly than patients who received placebo. Multivariate analysis indicated that use of GM-CSF, peripheral blood stem cells, and unpurged bone marrow were the strongest predictors for early neutrophil recovery greater than 500/mm3. Bacterial infections were significantly reduced in the GM-CSF group (P = 0.04). Delayed engraftment (neutrophils less than 500/mm3 at day 30) occurred in 26% and 17% of the placebo and GM-CSF groups, respectively, and correlated with the absence of detectable myeloid progenitor cells (colony-forming units-granulocyte macrophage, CFU-GM) (P less than 0.001) in marrow aspirate specimens obtained on day 15. Time to platelet independence, duration of hospital stay, severe adverse reactions, relapse, and disease-free survival rates did not differ significantly between the two groups. CONCLUSIONS: Administration of GM-CSF after autologous hemopoietic stem cell transplantation in patients with lymphoma resulted in accelerated myeloid recovery, particularly in patients who received peripheral blood stem cells and nonpurged bone marrow, and was associated with a decreased incidence of bacterial infections.

Actuarial Analysis↗
PubMed1991

alpha Interferon: the potential drug of adjuvant therapy: past achievements and future challenges.

This paper aims to summarize current experience with alpha interferon and provide direction for future study. There are four areas in which alpha interferon has proven or potential activity: antiviral, premalignant, adjuvant and advanced disease settings. The three main viral diseases in which interferon alfa-2b has been shown to have activity are chronic viral hepatitis, acquired immunodeficiency syndrome, and human papilloma virus infections. In vitro studies suggest that alpha interferon may inhibit transformation of some premalignant conditions into malignant disease; e.g., vaginal intraepithelial neoplasia. In the adjuvant setting, it is possible that a biological response modifier, such as alpha interferon, may have a role in helping the immune system to destroy residual tumour cells following tumour bulk reduction with radiation or chemotherapy. A higher response rate has been seen in patients with small tumour bulk compared to those with large tumour bulk (e.g., malignant melanoma, ovarian carcinoma), and in patients with early, rather than late, disease (e.g., chronic myelogenous leukaemia, hairy cell leukaemia, multiple myeloma, non-Hodgkin's lymphoma). This may be due to efficacy in a small tumour bulk setting or due to an immunoadjuvant role. In advanced disease, the question is how best to exploit the possible synergistic effects between alpha interferon and other therapeutic modalities. The optimum dose, schedule and patient populations for combined treatment have yet to be determined. The major objective of this paper is to determine how best to capitalize upon the current state of knowledge to build for future trials of alpha interferon, and to determine whether the existing data suggest an adjuvant role for interferon after initial tumour regression.

Combined Modality Therapy↗
PubMed1989

Subcutaneous granulocyte-macrophage colony-stimulating factor in patients with myelodysplastic syndrome: toxicity, pharmacokinetics, and hematological effects.

The toxicity, pharmacokinetics, and hematologic effects of granulocyte-macrophage colony-stimulating (GM-CSF) were studied in a phase I/II trial of 16 patients with myelodysplastic syndrome (MDS). The GM-CSF was administered subcutaneously (SC) daily so as to achieve prolonged blood levels and to establish an outpatient treatment regimen. Four dose levels were administered for ten days: 0.3 microgram/kg/d (three patients), 1.0 microgram/kg/d (three), 3.0 micrograms/kg/d (four), and 10.0 micrograms/kg/d (six). The most common toxicities were fever and a flu-like syndrome, which were dose-dependent. The maximum-tolerated dose was 10.0 micrograms/kg/d, which induced severe rigors (two patients), fever greater than 40 degrees C (one), severe bronchospasm (one), and WBC 60,000 (one). In one patient, refractory anemia with excess blasts in transformation (RAEB-T) progressed to acute nonlymphocytic leukemia after two doses of GM-CSF, and the patient died of leukemia that did not respond to chemotherapy. After doses of 3.0 and 10.0 micrograms/kg, serum GM-CSF levels peaked at 3.8 to 6.3 hours, and persisted for 14 and 24 hours, respectively. Circulating granulocytes (neutrophils and bands) increased in a dose-dependent manner, as 11 of 13 patients who received greater than or equal to 1.0 microgram/kg/d responded with a two- to 194-fold increase. Although the neutrophils usually returned to pretreatment levels shortly after stopping GM-CSF, two patients continue to exhibit an elevation of neutrophils for 6 months. Dose-related increases in circulating monocytes and eosinophils were also noted. Transient increases in platelet and reticulocyte counts were observed in two and three patients, respectively. Five of the 16 patients later received maintenance GM-CSF at 3 micrograms/kg/d for 2 to 9 weeks. All showed a dramatic increase in neutrophils after 2 weeks. Thereafter, despite continued therapy, the neutrophil count in four patients declined markedly. In conclusion, GM-CSF is well tolerated by the SC route and induces striking, but usually temporary, improvement in the neutropenia of MDS. Larger prospective phase III trials will determine the duration of hematologic responses and the impact on infection, morbidity, and mortality.

Adolescent↗
PubMed1987

Subcutaneous recombinant gamma interferon in cancer patients: toxicity, pharmacokinetics, and immunomodulatory effects.

Recombinant gamma interferon (r gamma-IFN) was administered s.c. daily to 26 patients with advanced cancer. Patients were assigned to one of six doses: 0.5, 1, 2, 4, 6, or 8 million units (MU)/m2 per d. The major toxicities were an influenza-like syndrome and fever, seen in all patients. Dose limiting toxicity occurred in 4 of 4 patients treated at 8 MU/m2. One patient with nodular poorly differentiated lymphocytic lymphoma had a mixed response, and two patients with renal cell cancer have had stabilization of disease for greater than 10 and greater than 12 months. Pharmacokinetic analysis, by radioimmunoassay, revealed mean serum r gamma-IFN concentrations up to 17 ng/ml, with maximal serum levels noted 6 to 13 h after injection. In vivo immunomodulation was assessed by natural killer (NK) cytotoxicity, monocyte activation as determined by cell surface expression of HLA-Dr, and peripheral blood mononuclear cell phenotype analysis by flow cytometry. The mean T4/T8 ratio increased from 2.1 pretreatment to 4.1 after 24 h of treatment, but returned to baseline after 7 and 28 days of treatment. Augmentation of NK function was noted after 7 days of treatment. Monocyte cell surface expression of HLA-Dr increased after 28 days of treatment at the three lowest doses. In conclusion, daily s.c. r gamma-IFN can be easily administered on an outpatient basis with minimal local skin toxicity, results in prolonged serum levels, and is associated with immunological changes of potential antitumor significance. Further study of the in vivo immunomodulatory effects induced by r gamma-IFN is indicated to help define the optimal treatment regimen.

Adult↗
PubMed1987

Alpha interferon: a look to the future.

The alpha-interferons have been explored in a wide variety of clinical applications in cancer. Significant activity has been demonstrated in AIDS-related Kaposi's sarcoma, ovarian carcinoma, bladder carcinoma, malignant glioma, non-Hodgkin's lymphoma, chronic granulocytic leukemia, the carcinoid syndrome and hairy cell leukemia. Although these leads are promising, the research has only just begun.

Alkylating Agents↗
PubMed1987

A phase I clinical trial of recombinant DNA gamma interferon.

Recombinant gamma interferon (r-GIFN) demonstrates in vitro and in vivo characteristics that contrast with those of alpha and beta interferons. It has relatively weak antiviral properties, yet relatively potent immunomodulatory effects. A phase I trial was performed with r-GIFN (specific activity 2.6 X 10(6) IU/mg protein), administered as a continuous intravenous (IV) infusion over 24 hours for five days (Cl X 5) and repeated every 28 days. This schedule was chosen based on the short half-life of r-GIFN in animal systems and the in vitro augmentation of biologic effects with continuous exposure to interferons. Twenty-one patients with refractory solid tumors received 46 evaluable courses of therapy. The dose-limiting toxicities included fever, flu-like symptoms, cardiovascular toxicity, and neurotoxicity. The cardiovascular toxicity included hypotension and one episode of cardiac ischemia with chest pain. Neurotoxicity consisted of lethargy and confusion. These toxicities were reversible, and although dose-limiting, occurred sporadically throughout all dosage levels. Mild to moderately severe non-dose-limiting toxicities included nausea and vomiting, leukopenia, and liver function abnormalities. Other infrequent toxicities included hypocalcemia, diarrhea, constipation, and alopecia. The maximally tolerated dose of r-GIFN on this schedule is 0.5 X 10(6) IU/m2/d. Partial responses were seen in one patient with metastatic melanoma and in one patient with renal cell carcinoma. Toxicity and antitumor activity were seen at doses where interferon serum levels could not be detected by radioimmunoassay. In addition, the toxicity and antitumor activity seen were at much lower doses than previously described for shorter infusion schedules of other recombinant gamma interferon preparations. Differences in biologic activity of interferon preparations and/or differences in scheduling may account for this variability. Although this study defines a recommended phase II dose of r-GIFN based on the maximally tolerated dose, the optimal therapeutic index may exist at a lower dosage level.

Adult↗
PubMed1987

Gamma-interferon: physiology and speculation on its role in medicine.

Gamma-interferon appears to be a pivotal molecule in the immune system. Recombinant DNA technology has permitted the cloning and expression of the gene for gamma-interferon (gamma-IFN), leading to an exponential increase in the level of knowledge both in vitro and in vivo. Laboratory evidence suggests a clinical role for gamma-IFN in collagen vascular disease, chronic granulomatous infectious diseases, hematology, and medical oncology. Phase I trials have identified the toxicities; these toxicities are primarily clinical and include fever, fatigue, flu-like symptoms, and hypotension. Antitumor activity has been noted in the early development of the drug.

Animals↗
PubMed1987

Alfa interferon: combinations with other antineoplastic modalities.

Early laboratory work demonstrated synergism from the combination of various cytotoxic agents and alfa interferon against various cell lines. In conjunction with anecdotal clinical reports of this synergism, multiple clinical trials were initiated to determine the tolerance and toxicity of the alfa interferons in conjunction with other antineoplastic agents/modalities. Phase I-II studies have been completed with alfa interferon and melphalan/prednisone, vincristine, vinblastine, etoposide (VP-16), cyclophosphamide, and radiation. In general, it may be stated that the toxicities are nonoverlapping and not unexpected. The tolerable doses of the interferons (IFNs) have generally been low. The future of research with interferon may be divided into three areas: Efforts must be made to determine how best to translate the in vitro synergy into clinically meaningful terms; in order to exploit the fullest potential of IFN, research is moving toward using this agent earlier in disease either as an adjuvant after tumor debulking or after initial diagnosis; the medical community must rethink the natural history of some diseases, because the fullest potential of the biologic agents will most likely manifest itself when these agents are used together.

Alkylating Agents↗
PubMed1987

A trial of recombinant alpha 2 interferon in the myelodysplastic syndromes: I. Clinical results.

Interferon has been reported to have differentiation promoting effects in certain model systems. Because of this and other potentially beneficial effects, a trial of recombinant alpha 2 interferon was undertaken in myelodysplastic syndromes. The study population consisted of 14 patients, subclassified as two refractory anemia (RA), one RA with ring sideroblasts (RARS), nine RA with excess blasts (RAEB), and two chronic myelomonocytic leukemia (CMMoL). The planned dosage schedule was 2.0 MU/M2 t.i.w. sc x 2 weeks q 4 weeks for at least two cycles. No patient achieved the prospective remission criteria, which included sustained blood count improvements. Transient improvements of platelet counts of greater than 50% in baseline were noted in six patients, and a transient antileukemic effect was noted in one patient with CMMoL. Myelodysplastic syndrome patients were found to be sensitive to the count suppressing effects of alpha 2 interferon with greater than 25% suppression of granulocytes, platelets, or reticulocytes transiently noted in 11 patients and decreasing bone marrow cellularity noted in two while on treatment. Because of these effects, dosage adjustments were frequently instituted in the RA, RARS, and RAEB patients. The average dosages and durations of treatment received were thus 1.48 MU/M2 x 19.4 injections for patients with RA, RARS, and RAEB and 2.25 MU/M2 x 27 injections for the CMMoL patients. Progression to acute myeloid leukemia or RAEB in transformation was noted in five patients, and increasing leukocytosis was noted in one CMMoL patient while on protocol. It cannot be determined at this time whether these transformations were accelerated by alpha 2 interferon or represent selection bias in this study population. Although some evidence of beneficial effects was noted, alpha 2 interferon in this dosage and schedule is not a useful treatment for myelodysplastic syndromes.

Bone Marrow↗
PubMed1987

Sequential evaluation of alpha-2b-interferon treatment in 128 patients with hairy cell leukemia.

This multicenter study reports on 128 patients with hairy cell leukemia (HCL) who were treated subcutaneously with alfa-2b interferon (Intron A, Schering Corp, Kenilworth, NJ), three times a week at a dosage of 2 megaunits/m2. Five patients (4%) had a complete response (CR) with virtual eradication of hairy cells from the bone marrow, 98 (77%) showed a partial response (PR), defined as hematologic normalization of all three blood counts associated with decreased hairy cells in the bone marrow, and nine (7%) showed a minor response (MR) that included improvement in at least one measurement of the blood count. Sixteen persons (12%) did not respond. Thirteen of the 128 had had neither a splenectomy nor a CR. Responders who completed 12 months of interferon therapy were randomized to either an additional 6 months of therapy or to observation only. Relapses occurred in six of 35 (18%) randomized to observation alone and in two of 29 (7%) who continued interferon therapy. The relapses are too few to draw conclusions; however, 27 responders have remained off interferon treatment for greater than 6 months; cessation of interferon therapy does not result in a rapid deterioration of peripheral blood counts. In HCL, interferon therapy produced a large percentage of durable objective responses in the majority of patients. The exact duration of this response and the results of retreatment are yet undetermined.

Adult↗