摘要:

Graft versus host disease (GVHD) remains the main barrier to successful allogeneic bone marrow transplant outcomes. Depletion of graft T cells is an effective way of reducing the incidence of acute and chronic GVHD, and a variety of methods have been used to achieve this depletion. Donor CD8+ T cells seem to be the critical effector cells; GVHD is reduced when the depletion process eliminates these cells, but not when CD4 cells are targeted alone. However, despite the successful reduction in GVHD, transplant outcomes are usually inferior with T-cell depleted transplants, because of increased graft failure, infections and relapse. Alternative approaches are needed.In vivoT-cell depletion, using antithymocyte globulin (ATG) as part of the conditioning regimen, seems an attractive option. Pre-transplant ATG lingers in the bone marrow to deplete engrafting donor T cells, but also depletes host T cells to prevent graft rejection and allow de-escalation of the conditioning regimen. It also avoids the need for graft manipulation with its associated costs, need for expertise and CD34+ cell loss. The efficacy of pre-transplant horse ATG remains anecdotal but it has been reported to modestly lower GVHD in single arm studies. Rabbit ATG has been studied in prospective randomised trials. There is evidence of a dose-response effect in reducing GVHD; however, there was no improvement in outcome, because of increased mortality associated with infection. In contrast, pre-transplant alemtuzumab (campath-1H) or an earlier version of this molecule (campath-1G), which target CD52+ cells, do appear to be effective in reducing both acute and chronic GVHD. There is speculation that this is not solely due to the effect of campath on T cells but that it may also be due to the elimination of host antigen-presenting cells (APC), which seem to be important in GVHD pathogenesis. Host APC are more efficient at expressing endogenous and exogenous host antigens on class I MHC to donor CD8+ cells than donor APC, which need to cross-prime exogenous antigen. Campath-1G eliminates host dendritic cells by the time of graft infusion, supporting this as a possible mechanism of action. Pre-transplant alemtuzumab has not yet been studied in a prospective randomised study, and this is required to quantify any benefit on outcome; despite this, published studies do show cause for optimism.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Gangliosides, sialic acid-containing glycosphingolipids, have engendered great interest for more than 20 years in the search for target molecules of relevance for tumour growth and formation of metastases and as potential targets for immunotherapy. These molecules show large quantitative and structural variability, which is related to cell type and developmental stage. Their potential role in the formation of tumour metastases was suggested from data supporting that they are involved in cell growth regulation and in cell-cell and cell-matrix adhesion. Moreover, gangliosides are expressed on the cell surface and thereby are accessible for antibodies or other ganglioside-binding molecules to induce cell death, inhibit cell growth and/or inhibit formation of tumour metastasis.All tumours exhibit aberrant ganglioside expression. This includes overexpression of normal ganglioside constituents, which appears to be common among various tumours, and expression of gangliosides not found in normal adult tissue but often found during fetal development. The ganglioside composition of melanoma cells has been found to correlate with their metastatic potential and also to be selectively expressed in cells of a tumour mass and invading tumour cells. Passive immunotherapy using murine or murine/human chimeric monoclonal antiganglioside antibodies in their native form or combined with various effector molecules has been investigated. However, the vaccination strategy using native or structurally modified tumour-associated gangliosides in combination with adjuvants is currently the dominant method in clinical trials. The outcomes reported so far vary between type of tumour and treatment strategies. However, we believe that targeting gangliosides is as promising as any other immune therapeutic strategy, and basic research as well as clinical trials utilising new aspects is encouraged.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Riboviruses and retroviruses have been shown to spontaneously mutate at an extraordinarily high rate. While this genetic diversity allows viral subpopulations to escape conventional antivirals, it also has a cost. Indeed, this high mutation rate results in the synthesis of many defective virions. Stealth nucleosides are nucleoside analogues that are designed to increase the already high spontaneous mutation rate of viruses to the point where the virus cannot further replicate, a process known as ‘lethal mutagenesis’. Rather than causing chain termination and attempting to immediately halt viral replication, as with conventional nucleoside reverse transcriptase inhibitors (NRTI), stealth nucleosides are incorporated into the viral genome during replication and, by mispairing, cause mutations to the viral genome. These mutations affect all viral proteins and cumulatively, over a number of replication cycles, are lethal to the virus. There are two distinct stealth nucleoside platforms: DNA stealth nucleosides and RNA stealth nucleosides. DNA stealth nucleosides are currently being screened for activity against HIV and may have activity against hepatitis B virus and smallpox virus, with the clinical lead DNA stealth nucleoside demonstrating activity in the low nanomolar range. In addition, DNA stealth nucleosides have been shown to be able to effectively treat NRTI-resistant HIV strainsin vitro, which is not surprising given that the two principal modes of resistance (low affinity of reverse transcriptase for a modified sugar or pyrophosphorolysis) should not be applicable to DNA stealth nucleosides. RNA stealth nucleosides are being developed for the treatment of ribovirus infections, and particularly hepatitis C virus infection. RNA stealth nucleosides are selected for their broad spectrum of antiviral activity, and current lead RNA stealth nucleosides have potency in the same range as ribavirin.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Inflammatory bowel disease (IBD) is characterised by a chronic dysregulation of the inflammatory response in the gastrointestinal tract. While the pathogenesis is unclear, studies have demonstrated that the gastrointestinal tracts of patients with IBD are populated with increased levels of adherent and pathogenic bacteria. This evidence, combined with growing data accumulated from genetic studies as well as animal models of IBD, indicates that an aberrant response to altered enteric flora plays a significant role in the disease process.Current therapies for IBD have been directed towards the development of anti-inflammatory agents and immunomodulators to attenuate the inflammatory response in the gastrointestinal tract. Antibiotics are also partially effective in the treatment of IBD, presumably by altering the bowel flora. However, it is clear from clinical trials that immunomodulators and antibiotics are not effective in a large proportion of patients with IBD and other therapeutic alternatives need to be pursued.Probiotics are microbial supplements capable of recolonising the bowel with non-pathogenic strains of bacteria or yeast. Probiotics have long been shown to be beneficial in both infectious and non-infectious digestive disorders. Growing evidence indicates that probiotics may be effective in the treatment of specific clinical IBD conditions. This article addresses the current evidence for the role of enteric flora in the pathogenesis of IBD and the clinical evidence supporting the use of probiotics in specific clinical IBD conditions.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Psoriatic arthritis (PsA) is a partly debilitating disease that may affect small and large joints and the spine. Patients with PsA are divided into different subgroups according to joint involvement and their disease may be classified as part of the spectrum of spondyloarthritides or seronegative rheumatoid arthritis. Traditional treatment comprises nonsteroidal anti-inflammatory drugs, systemic and intra-articular corticosteroids and disease-modifying antirheumatic drugs such as sulfasalazine, methotrexate and cyclosporin. On the basis of the very recent studies performed in the US and Germany, patients with severe disease can be treated with anti-tumour necrosis factor (TNF) therapy. Biologicals such as etanercept and infliximab have been used successfully to treat PsA. While etanercept is a 75kD TNF receptor fusion protein that binds to TNFα and TNFβ, infliximab is a chimeric monoclonal antibody that binds to TNFα both in its soluble form in the serum and on the cell membrane. Adalimumab is a fully humanised antibody recognising TNFα that has not been tested in PsA to date. Another biological agent, alefacept, is directed against the adhesion molecule lymphocyte function-associated antigen (LFA)-2, which is known to interfere with T-cell activation. Alefacept has been shown to be efficacious in a limited number of patients with PsA. Taken together, there has been definite recent progress in the treatment of PsA. Severely affected patients may especially have substantial benefit from therapy with biologicals directed against TNFα and other targets.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

BackgroundAlpha-interferon (α-IFN) is the treatment of choice for chronic hepatitis C but most patients experience adverse effects which sometimes lead to the suspension of therapy. Recently, higher doses of α-IFN or prolonged therapy have increased the number of cases of intolerance.End of treatment responders were patients in whom hepatitis C virus (HCV)-RNA had been eradicated from the blood by the end of treatment, sustained responders were those patients who maintained negative HCV-RNA at the end of follow-up, and the remaining patients were considered non-responders. Adverse effects were monitored by interviews, laboratory and clinical examinations.Study DesignIn this open study we evaluated the efficacy and safety of leucocyte interferon-alpha (IFNα) [6MU three times a week] in 43 patients with chronic hepatitis C who had been intolerant to previous treatment courses with recombinant or lymphoblastoid IFNα. All patients were treated for 6 months and followed-up for an additional 6 months.End of treatment responders were patients in whom hepatitis C virus (HCV)-RNA had been eradicated from the blood by the end of treatment, sustained responders were those patients who maintained negative HCV-RNA at the end of follow-up, and the remaining patients were considered non-responders. Adverse effects were monitored by interviews, laboratory and clinical examinations.ResultsFive patients (11.6%) discontinued the treatment, four due to the reappearance of previous adverse effects, and one due to anex novoadverse effect. In six patients the dose had to be halved. At the end of treatment 11 patients (25.6%) had negative serum HCV-RNA. After discontinuation of therapy, disease flared in four patients, thus seven patients were sustained responders.ConclusionsThis study shows that leucocyte IFNα at a dose of 6MU three times a week is well tolerated in patients previously intolerant to recombinant or lymphoblastoid IFNα, allowing a high percentage of them to complete a course of treatment in terms of duration and dose.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Glatiramer acetate (Copaxone®) is a synthetic copolymer composed of a random mixture of four amino acids that modifies the immune response that results in the CNS inflammation, demyelination and axonal loss characteristic of relapsing-remitting multiple sclerosis (RRMS).In three randomised, double-blind trials in patients with RRMS, subcutaneous glatiramer acetate 20 mg/day was significantly more effective than placebo for the primary outcome measure of each trial (mean relapse rate, proportion of relapse-free patients and number of gadolinium-enhancing lesions on magnetic resonance imaging [MRI] scans). The mean relapse rate was significantly reduced at endpoint (approximately one-third less) in the two larger trials (the US pivotal trial [primary endpoint] and the European/Canadian study [tertiary endpoint]) in patients receiving glatiramer acetate compared with those receiving placebo. The rate was 78% less for glatiramer acetate than placebo patients in the pilot trial that investigated a slightly different patient population. Glatiramer acetate significantly decreased disease activity and burden of disease, as assessed in the European/Canadian study using a range of MRI measures. Patients with RRMS treated with glatiramer acetate in the US trial were significantly more likely to experience improved disability (whereas placebo recipients were more likely to experience worsening disability) and their overall disability status was significantly improved compared with placebo recipients. Data from the active-treatment extension of the US trial suggest that glatiramer acetate has sustained clinical benefits up to 8 years.Glatiramer acetate was generally well tolerated; the most commonly reported treatment-related adverse events were localised injection-site reactions and transient post-injection systemic reactions. Both reactions were generally mild and self limiting but were responsible for the majority of withdrawals from treatment (up to 6.5% and 3.5%, respectively). Glatiramer acetate is not associated with the influenza-like syndrome or neutralising antibodies that are reported in patients treated with interferon-β for RRMS.The cost effectiveness of glatiramer acetate has yet to be definitively determined as assessment of available data is confounded by very different models, data sources and assumptions.In conclusion, glatiramer acetate has shown efficacy in well controlled clinical trials in patients with RRMS; it reduces relapse rate and decreases MRI-assessed disease activity and burden. It is generally well tolerated and is not associated with the influenza-like symptoms and formation of neutralising antibodies seen with the interferons-β. Based on available data and current management guidelines, glatiramer acetate is a valuable first-line treatment option for patients with RRMS.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

All drugs appearing in the Adis Profile Summary table have been selected based on information contained inR&D Insight™1, a proprietary product of Adis International. The information in the profiles is gathered from the world’s medical and scientific literature, at international conferences and symposia, and directly from the developing companies themselves. The emphasis of this section inBioDrugsis on the clinical potential of new drugs, and selection of agents for inclusion is based on products in late phase clinical development that have recently had a significant change in status.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Abetimus [Abetimus sodium, LJP 394, Rentol™, Riquent™] is a synthetic Toleragen®molecule consisting of four double-stranded oligodeoxyribonucleotides attached to nonimmunogenic polyethylene glycol, a proprietary carrier platform.1It was originated by La Jolla Pharmaceuticals.Abetimus is an immunomodulating agent that induces tolerance in B cells directed against double-stranded DNA (dsDNA). It does this by cross-linking surface antibodies. These antibodies are thought to be responsible for lupus nephritis, a chronic kidney disease that develops in patients with systemic lupus erythematosus. A phase III trial of abetimus was completed in December 2002. La Jolla Pharmaceuticals previously established two licensing agreements for abetimus, which have since been terminated. One of the agreements was with Leo Pharmaceutical Products of Denmark. The company was licensed rights to abetimus covering Europe and the Middle East. The other agreement was with Abbott Laboratories. Abbott returned all rights to abetimus to La Jolla Pharmaceuticals in September 1999 based on the results of an analysis of the phase II/III trial of abetimus in lupus patients with a history of renal disease.A phase III trial, named ‘PEARL’ (Program Enabling Antibody Reduction in Lupus), has been conducted in the US in patients with lupus nephritis. It enrolled 317 patients with a history of lupus who were treated with a weekly dose of abetimus 100mg or placebo. The trial was completed in December 2002 and preliminary results were reported in February 2003.[1]PEARL was designed to determine whether abetimus can significantly delay renal flares and delay the need for treatment with high-dose corticosteroids and/or cyclophosphamide in patients with high affinity IgG antibodies to the double-stranded oligonucleotide epitope in abetimus. Patients with high-affinity antibodies, were selected using a surface plasmon resonance (SPR)-based pharmacoproteonomics assay provided by Biacor International.Following the completion of PEARL in December 2002, La Jolla Pharmaceuticals initiated an on-going, open-label, follow-on trial. All patients who had completed PEARL were eligible to enrol and receive weekly treatment with abetimus.[1]However, in April 2003, La Jolla Pharmaceuticals announced that it was closing this trial, which was designed to collect additional long-term safety data, to conserve resources for the continued development of the drug.[2]Previously, La Jolla Pharmaceuticals and Abbott initiated a phase II/III trial of abetimus in more than 200 patients with lupus nephritis. However, this trial was discontinued in May 1999 because the primary end-point (time to renal flare) was much shorter than expected. After the trial was halted, further analysis of trial data using a new blood test to measure the strength of the binding between abetimus and a patient's antibodies to dsDNA was conducted. The additional analysis showed that the number of renal flares in the high-affinity patients (responders) treated with abetimus was less than half of the number of renal flares in high-affinity patients treated with placebo. Responders also showed a significant reduction in the use of high-dose corticosteroids and cyclophosphamide. Being able to screen patients to identify those likely to respond to therapy lead La Jolla Pharmaceuticals to initiate PEARL after Abbott's withdrawal from the drug. It is believed that screening patients will help increase the cost-effectiveness of clinical development.In September 2000, the US FDA granted orphan drug status for abetimus in the treatment of lupus nephritis. The European Commission followed suit in November 2001, granting orphan drug status for abetimus in the EU.[3,4]

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS

摘要:

Introgen's adenoviral p53 gene therapy [INGN 201, ADVEXIN®] is in clinical development for the treatment of various cancers.1The p53 tumour suppressor gene is deleted or mutated in many tumour cells and is one of the most frequently mutated genes in human tumours. INGN 201 has been shown to kill cancer cells directly.In August 2002, Introgen announced plans to file an application for INGN 201 with the European Agency for the Evaluation of Medicinal Products (EMEA) for the treatment of head and neck cancer; the European filing will be submitted simultaneously with the previously scheduled (planned for 2004) submission of a Biologics License Application (BLA) for ADVEXIN®to the US FDA. On 20 February 2003, INGN 201 received orphan drug designation from the US FDA for head and neck cancer.[1]INGN 201 is available for licensing although Introgen favours retaining partial or full rights to the therapy in the US.Introgen Therapeutics and its collaborative partner for the p53 programme, Aventis Gencell, have been developing p53 gene therapy products. The agreement was originally signed by Rhône-Poulenc Rorer's Gencell division, which became Aventis Gencell after Rhône-Poulenc Rorer merged with Hoechst Marion Roussel to form Aventis Pharma. According to the original agreement, Introgen was responsible for phase I and preclinical development in North America, while Aventis Gencell was responsible for clinical trials conducted in Europe and for clinical trials in North America beyond phase I.In April 2001, Aventis Gencell and Introgen restructured their existing collaboration agreement for p53 gene therapy products. Aventis Gencell indicated that p53 research had suffered from internal competition for resources and was pulling back from its development agreement with Introgen for p53 gene therapy products. Introgen will assume responsibility for worldwide development of all p53 programmes and will obtain exclusive worldwide commercial rights to p53-based gene therapy products. Aventis Gencell will increase its equity stake in Introgen by investing $US20 million in non-voting preferred shares of Introgen that will be convertible to Introgen common shares at a premium to the market price. Introgen will also receive a 5% equity stake in Aventis Gencell. Introgen intends to use the proceeds of Aventis Gencell's investment to fund the commercialisation of the p53 gene therapy product and to begin building its internal sales and marketing division to support the products anticipated market introduction.In April 2001, Aventis Pharma announced that it intended to spin off its gene therapy division, Aventis Gencell, as a separate operating company.In mid-2002, Aventis Pharma was still attempting to spin off Aventis Gencell but negotiations with venture capital partners had failed. Gene Logic (formerly OncorMed) of the US was contracted by Introgen to perform the p53 status testing for RPR/INGN 201 phase I clinical trials.In February 2003, Introgen announced it will streamline its phase III clinical trials for head and neck cancer to reduce spending, and that INGN 201 received Orphan Drug Status for head and neck cancer in the US.According to results (published in January 2003) of Introgen's phase II study of non-metastatic patients with non-small cell lung cancer (ineligible to receive surgery or combination therapy with radiation and cancer chemotherapy) treated with INGN 201 combined with radiation therapy, approximately 60% of patients' primary tumours regressed or disappeared after the combination therapy, as assessed by both biopsies and by CT scans 3 months after treatment. Investigators commented that further randomised trials are needed to follow-up on these observations.In February 2003, Introgen announced that it will move ahead with the development of registration plans for a non-small cell lung cancer indication for INGN 201, and is now including support for lung cancer registration in partnering discussions.RPR/INGN 201 is undergoing phase I trials for the potential treatment of lung, breast, ovarian, bladder, liver and brain cancers. Introgen and Aventis Pharma had signed a Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute (NCI). NCI will sponsor clinical trials to evaluate and develop RPR/INGN 201 as a potential anticancer agent for these cancer indications. The trials conducted under a NCI-sponsored IND will evaluate RPR/INGN 201 alone and in combination with other anticancer agents. This agreement was originally signed by Rhône-Poulenc Rorer's Gencell.Introgen has completed three phase I clinical trials with INGN 201 in patients with bronchioalveolar cell lung carcinoma, ovarian cancer and recurrent glioblastomas, respectively. Intratumoural injection of RPR/INGN 201 in patients with recurrent glioblastomas was well tolerated and resulted in expression of the p53 protein. Direct administration of RPR/INGN 201 to the lower airways of patients with bronchioalveolar cell lung carcinoma resulted in symptomatic improvement and improved lung function in some patients.In February 2003, Introgen announced that the US Patent and Trademark Office has issued to The Board of Regents of The University of Texas System, patent No. 6,511,847 entitled ‘Recombinant p53 Adenovirus Methods and Compositions’. Introgen Therapeutics is the exclusive licensee of this patent. The patent covers any adenoviral DNA molecules that encode the p53 gene positioned under the control of a promoter. Such a DNA molecule forms the genetic core of Introgen's ADVEXIN®cancer therapy.Introgen's ADVEXIN®therapy is now covered by up to ten separate US patents relevant to the product including compositions, therapeutic methods of administering the product in virtually any form, alone and in conjunction with the most widely used chemotherapeutic and radiation treatments, as well as its production.[2]Introgen has a number of US patents that relate to the clinical use of ADVEXIN®in cancer as monotherapy or in combination with one or more chemotherapeutic drugs, radiation therapies, or other agents that have a damaging effect on the DNA or survival of (i.e. 2-methoxyestradiol, patent No. 6,410,029) cancer cells.In July 2002, the US Patent and Trademark Office issued to The Board of Regents of The University of Texas System US patent No. 6,410,010. The patent broadly covers all adenoviral p53 compositions (including ADVEXIN®), therapeutic and otherwise, that express adequate p53 in amounts sufficient to suppress the growth of or kill cancer cells in patients. The patent also covers adenoviral p53 that incorporates a specific type of promoter that helps cells to express the p53 tumour suppressor gene. Introgen is the exclusive licensee of this composition of matter patent covering ADVEXIN®.In December 2002, Aventis Pharmaceuticals was issued US patent No. 6,262,032 B1 entitled ‘Method of Destroying Hyperproliferative Cells by Combining p53 and Taxoid Treatment’. Introgen has an exclusive license to this patent and is using this type of combination therapy in its breast cancer trial.Introgen expects to realise $US2.5–3 million from sales of INGN 201.

ISSN:1173-8804    

出版商:ADIS    

年代:2003

数据来源: ADIS