Search

Introduction: Studies measuring the effectiveness of risk minimization measures (RMMs) submitted by pharmaceutical companies to the European Medicines Agency are part of the post-authorization regulatory requirements and represent an important source of data covering a range of medicinal products and safety-related issues. Their objectives, design, and the associated regulatory outcomes were reviewed, and conclusions were drawn that may support future progress in risk minimization evaluation., Methods: Information was obtained from risk management plans, study protocols, clinical study reports, and assessment reports of 157 medicinal products authorized for cardiovascular, endocrinology, and metabolic indications. We selected observational studies measuring, as outcomes of interest, the relationship between the RMMs in place and (1) implementation measures, such as clinical knowledge or physicians` compliance to recommendations contained in the RMMs; and (2) occurrence or reduced severity of the adverse drug reactions for which the RMMs were required., Results: Of 59 eligible studies (24 completed, 35 ongoing), 44 assessed implementation measures, whereas only 15 assessed safety outcomes (1 study as a single endpoint and 14 studies with other endpoints). Fifty-one studies used non-experimental designs and 25 studies employed electronic healthcare databases for analysis. Of the 24 completed studies, 17 were considered satisfactory and supported immediate regulatory decision making, 6 were considered inconclusive and required new evaluations, and 1 was terminated early because new safety restrictions were required, thereby necessitating a new evaluation. Compliance with agreed deadlines was considered acceptable in 21 of 24 completed studies; the average time for a submission was 37 months (standard deviation ± 17), with differences observed by type of data source employed., Conclusions: Three important gaps in the evaluation plans of RMMs were identified: lack of early feedback on implementation, limited evaluation of safety outcomes, and inability to provide information on the effectiveness from an integrated measurement of different elements of a set of risk minimization tools. More robust evidence is needed to advance regulatory science and support more rapid adjustment of risk minimization strategies as needed.

Background: Risks that are potentially associated with long-term therapies should be assessed., Objective: The present analyses were performed to determine the risk of malignancy in patients with multiple sclerosis (MS) receiving subcutaneous (sc) interferon (IFN) beta-1a, using pooled safety data from key clinical trials and data from the Merck Serono Global Drug Safety database., Methods: The standard Medical Dictionary for Regulatory Activities query "malignancies" was used to retrieve relevant cases from each data set. The incidence of malignancies per 1000 patient-years was calculated using the pooled safety data from clinical trials. The reporting rates of malignancy types were calculated for the post-marketing setting based on sales volume. Malignancies were grouped by organ localization and classified as medically confirmed or not medically confirmed according to the source of each report. The number of reported cases of each type was compared with the expected number in the general population., Results: Analysis of pooled safety data from 12 key clinical trials did not show an increased incidence of malignancy per 1000 patient-years with sc IFN beta-1a (4.0; 95% confidence interval (CI): 2.9-5.5) compared with placebo (6.4; 95% CI: 3.3-11.2). Analysis of the database shows that among the medically confirmed cases, reported to expected ratios ranged from 1 : 6 to 1 : 18 for solid tumours and from 1 : 2 to 1 : 9 for lymphohaematopoietic tumours., Conclusion: Safety data from both clinical trial and post-marketing settings suggest that treatment with sc IFN beta-1a does not increase the risk of malignancy in patients with MS.

Background: Women with multiple sclerosis (MS) are advised to discontinue interferon-beta therapy before trying to conceive. Unplanned pregnancies occur and risks related to exposure remain unclear., Methods: To determine pregnancy outcomes following interferon-beta therapy, we examined pregnancies from a global drug safety database containing individual case safety reports received in the post-marketing setting and safety data from clinical trials of subcutaneous interferon beta-1a in MS., Results: One thousand and twenty-two cases of exposure to subcutaneous interferon beta-1a during pregnancy were retrieved; 679 had a documented outcome. In cases for which exposure duration was available (n  = 231), mean time of foetal exposure to subcutaneous interferon beta-1a before treatment discontinuation was 28 days; most pregnancies (199/231; 86.1%) were exposed for ≤ 45 days. To avoid bias, only outcomes for prospective data (n  = 425) in pregnancies exposed to interferon beta-1a in utero were analysed further. Of these, 324 (76.2%) resulted in normal live births and four (0.9%) in live births with congenital anomalies (3 [0.7%] were 'major'). Four (0.9%) pregnancies resulted in stillbirths (1 [0.2%] with foetal defects). There were 5 (1.2%) ectopic pregnancies, 49 (11.5%) spontaneous abortions and 39 (9.2%) elective terminations. Most pregnancies exposed to subcutaneous interferon beta-1a in utero were associated with normal live births. The rates of spontaneous abortion and major congenital anomalies in live births were in line with those observed in the general population., Conclusions: These data should be taken into account when considering options for women with MS who become pregnant or who are planning pregnancy while on treatment with subcutaneous interferon beta-1a.

Introduction: Interferon-beta-1a (Rebif) is an established treatment for relapsing-remitting multiple sclerosis (MS) and haematological changes are commonly reported in clinical trials of this agent. The combined clinical trial and postmarketing safety database for subcutaneous interferon-beta-1a (Rebif) allows a comprehensive, retrospective assessment of both common and infrequent haematological effects associated with interferon-beta therapy., Methods: Haematological laboratory abnormalities were analysed from six randomised, controlled clinical trials of subcutaneous interferon-beta-1a in MS, five of which were placebo-controlled. Treatment data were collected from 2482 patients for up to 6 months, 1178 patients for up to 2 years and 786 patients for up to 6 years. Total interferon-beta-1a doses ranged from 22 microg once weekly to 44 microg three times weekly. Postmarketing surveillance data were also analysed., Results: Treatment with interferon-beta-1a led to asymptomatic dose-related reductions in all cell lineages under investigation, predominantly white blood cells. The greatest differences between interferon-beta-1a therapy and placebo were seen for total leucocyte and neutrophil counts. At least two-thirds of patients affected by cytopenia experienced the onset of cytopenia within the first 6 months of therapy. The majority of events were mild and generally resolved within 3--4 months, while continuing therapy. Dose reductions were uncommon and only a small proportion (6 of 727; 0.8%) of patients stopped treatment over 2 years because of haematological abnormalities when receiving the highest dose of interferon-beta-1a, 44 microg three times weekly. Postmarketing safety reports were similarly related to asymptomatic cytopenias, although one case of potentially related autoimmune haemolytic anaemia was reported., Conclusion: Although haematological abnormalities are common and dose-related in patients with MS receiving interferon-beta-1a, the events are mainly mild and transient, with little impact on adherence to therapy. Haematological events are rarely of clinical significance and do not adversely affect the benefit-to-risk ratio that favours high-dose interferon-beta-1a therapy.

Background: Hepatic dysfunction, manifested as liver enzyme elevations, occurs frequently in patients who are treated with interferon, however, data for patients with multiple sclerosis are limited., Objective: To retrospectively assess the safety profile of interferon-beta-1a therapy with respect to liver function during clinical trials and postmarketing surveillance in the treatment of multiple sclerosis., Patients and Methods: Adverse effects and laboratory abnormalities were analysed from six randomised, controlled clinical trials (five of which were placebo-controlled) that assessed the use of interferon-beta-1a in patients with multiple sclerosis. Treatment data were collected for 2819 patients for up to 12 months, of whom 1995 received interferon-beta-1a (337 [12%] received Avonex intramuscular therapy, and 1658 [59%] received Rebif subcutaneous therapy), and 824 (29%) received placebo. Data for 2 years were collated for 1178 patients (from two studies). Total weekly interferon doses were 22-132 microg. Postmarketing surveillance data were also analysed., Results: In patients receiving interferon-beta-1a, there were significant elevations of alanine aminotransferase (ALT) levels, of all grades of severity, in up to 59% of patients at 6 months, up to 64% of patients at 12 months and up to 67% of patients at 24 months; ALT elevations were asymptomatic and dose related. More than 50% of elevations in liver enzymes occurred during the first 3 months of treatment, and more than 75% occurred during the first 6 months. Elevated enzyme levels resolved spontaneously or with dosage adjustment. Although the overall incidence of liver enzyme elevation was high during the early months of therapy, after 2 years, the proportion of patients with abnormal liver enzyme levels was 11% of those receiving Rebif 44 microg three times weekly compared with 6% of placebo-treated patients. Only 0.4% of patients discontinued interferon-beta-1a treatment because of hepatic adverse effects. Serious symptomatic interferon-related hepatic toxicity occurs, but is uncommon. Concomitant medication use was not associated with increased risk., Conclusion: Asymptomatic hepatic dysfunction is common in patients with multiple sclerosis who are treated with interferon-beta-1a, and is dose related. Adverse effects are mainly mild and transient, with little impact on adherence to therapy, although rare serious events can occur. Regular liver function monitoring during the first 6 months is recommended.

Cephalosporins in aqueous solutions generate degradation products that inhibit in vitro HIV-1 replication in cell lines, as well as in primary cells (lymphocytes and macrophages). This effect is observed at concentrations that do not interfere with the normal functions of these cells. Upon chromatographic fractionation of an aqueous solution of hydrolysed ceftazidime, a high molecular weight fraction (MW 8000) with antiviral activity was isolated. The exact chemical nature of the active component responsible for the anti-HIV activity in vitro appears to be complex and is currently unknown. Inhibition of HIV-1 reverse transcriptase and RNase H activity was observed, however, higher concentrations than those needed to inhibit HIV replication were required. The inhibitory action of the hydrolysed ceftazidime was manifested during the early phase of the HIV-1 life-cycle. Despite a lack of a direct effect of the CD4/gp120 interaction, HIV-1 mediated cell fusion was inhibited by the hydrolysed ceftazidime, suggesting that the active principle acts in a very early stage of the viral life-cycle.

In vitro exposure of human blood monocyte-derived macrophages to T-cell tropic human immunodeficiency virus (HIV) isolates fails to establish a productive viral infection. Several studies have shown that such preferential HIV-1 replication in T cells or in mononuclear phagocytes (HIV tropism) may be determined by distinct viral characteristics. In the present study it was demonstrated that transforming growth factor-beta (TGF-beta), a factor known to be produced by platelets, macrophages, and other cells present at a wound site, can act as a mediator in overcoming the lymphocytotropic restriction of several well-characterized viral isolates of HIV-1 (i.e., LAV, Z84, pLAI, NY5). Macrophages infected with these isolates show cytopathic changes comparable to those seen upon infection with the monocytotropic isolate ADA. To achieve this effect with TGF-beta, the factor must be present after the infection period. The emerging virus retains its original cellular tropism. Based on these observations the authors propose a role for TGF-beta in the establishment and progression of HIV infection and disease.

TGF-beta at physiological concentrations, when added to monocyte-derived macrophages following HIV1 infection, has an enhancing effect upon the rate of virus production. This effect is observed with the monocytotropic isolate ADA, as well as with HIV1 IIIB, which poorly replicates in macrophages.

Cultured monocyte-derived macrophages were productively infected with human immunodeficiency virus in vitro. Treatment of these cells shortly after infection and several times thereafter with the free form of MTP-PE had an inhibitory effect on virus production. When the liposomal formulation of MTP-PE was used, higher levels of protection were achieved. The drug was not only effective when added to cells immediately after infection, but it also reduced virus production by cells with an established infection. When the liposomal formulation of MTP-PE was used only one treatment was required to achieve maximal effects. During these studies it was noted that the placebo liposomes had some effect in reducing the reverse transcriptase levels found in the supernatants of infected cells. This reduction could not be explained by direct cytotoxic effect. Both free and liposomal MTP-PE lipid significantly prevented formation of giant cells during the course of infection as well as reduced the cell associated viral antigen.

An assay for the evaluation of antiviral and immunomodulator potency was developed using pure populations of cultured human monocytes. The assay involved culturing of human monocytes until they were fully susceptible (15-20 days) to lytic infection with HSV-1. When susceptible cells were cultured with recombinant interferon-alpha or a synthetic interferon inducer such as polyinosinic:polycytidylic acid prior to infection, a significant enhancement in resistance to the cytopathic effects of HSV-1 was observed. Likewise, a dose dependent reduction in cell lysis was observed when acyclovir was added immediately after virus infection. Monocyte resistance to HSV-1 was determined by the retention of pinocytic activity as determined by the uptake of neutral red dye. Relative pinocytic activity was quantitated using a simple colorimetric procedure. This antiviral assay can be completed in 48 h; is easy to perform, highly sensitive and reproducible.

The monokines interleukin-1 beta and alpha (IL-1) play a central role in the connective tissue destruction of many chronic inflammatory diseases. A high capacity screening assay for the detection of inhibitors of IL-1 biosynthesis has been established. Normal human monocytes were obtained by leukapheresis and elutriation. IL-1 beta and alpha biosynthesis was stimulated with LPS, and cell-associated and secreted IL-1 beta and IL-1 alpha were measured by specific immunoassays (ELISA). The mean total IL-1 beta (cell-associated and secreted) production in 18 different donors was 11 ng/10(6) cells (range 1.2-28.8). Secreted IL-1 beta represented 31 to 86% of the total IL-1 beta. More IL-1 alpha than IL-1 beta was produced but, unlike IL-1 beta, IL-1 alpha was poorly secreted. The steroids prednisolone and dexamethasone, gold (sodium aurothiomalate) and chloroquine were potent inhibitors of the IL-1 production. Mean IC50 values of 180 nM (range 2.5 nM-1 microns), 10 microM (range 6-20 microM) and of 75 microM were found for prednisolone, gold and chloroquine, respectively. Above 5 microM, the non-steroidal anti-inflammatory compounds indomethacin and BW755C increased IL-1 beta biosynthesis. Nordihydroguaiaretic acid inhibited the level of the secreted form of IL-1 beta, but tended to increase the cell-associated level. D-Penicillamine (up to 6 mM), cyclosporin A (up to 1 microM) and methotrexate (up to 12 microM) inhibited neither cell-associated nor secreted IL-1 beta levels. This high capacity assay, which is insensitive to classical NSAIDs, may serve in the detection and characterization of new classes of anti-inflammatory compounds.

Analogues of staurosporine were synthesized and their ability to inhibit protein kinases was examined. Staurosporine is a potent but non-selective inhibitor of in vitro protein kinase C(PKC) activity (IC50 6.0 nM). The derivative CGP 41 251 had reduced PKC activity with an IC50 of 50 nM but showed a high degree of selectivity when assayed for inhibition of cyclic AMP-dependent protein kinase (IC50 2.4 microM), S6 kinase (IC50 5.0 microM) and tyrosine-kinase-specific activity of epidermal growth factor receptor (IC50 3.0 microM). Staurosporine and CGP 41 251 exerted growth inhibition in the human bladder carcinoma line T-24, human promyelocytic leukemia line HL-60 and bovine corneal endothelial cells at concentrations which correlated well with in vitro PKC inhibition. In addition, both compounds inhibited the release of H2O2 from human monocytes pre-treated with 12-O-tetradecanoyl-phorbol-13-acetate at non-toxic concentrations. In vivo anti-tumor activity was examined in T-24 human bladder carcinoma xenografts in athymic nude mice. Tumor growth inhibition tests revealed significant anti-tumor activity (2p less than 0.001) at 1/10 of the maximum tolerated doses for both compounds. By contrast, a closely related derivative of staurosporine (CGP 42 700) was inactive at concentrations of over 100 microM in all in vitro enzyme and anti-proliferative assays as well as in animal tumor models. Our data suggest an association between PKC inhibition and anti-proliferative and anti-tumor activity.