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Biomedical subjects

Keith Dredge

Publications and source records attributed to Keith Dredge.

12 recordsLinked to original sources
PubMed2005

Orally administered lenalidomide (CC-5013) is anti-angiogenic in vivo and inhibits endothelial cell migration and Akt phosphorylation in vitro.

The thalidomide analogue and immunomodulatory drug (IMiD) lenalidomide (CC-5013, REVLIMID) is emerging as a useful treatment for a number of cancers and has recently entered phase III trials for multiple myeloma. It has been suggested that the anti-tumor effect of lenalidomide is related to its anti-angiogenic potency. In this regard, we have previously shown that lenalidomide inhibits angiogenesis in both rat and human in vitro models but does not affect endothelial cell proliferation. We now show that oral administration of lenalidomide attenuates growth factor-induced angiogenesis in vivo; the rat mesenteric window assay was utilized to show that lenalidomide significantly inhibits vascularization in a dose-dependent manner. We also found that lenalidomide significantly inhibits growth factor-induced endothelial cell migration. This correlates with the inhibitory effect of lenalidomide on growth factor-induced Akt phosphorylation, thereby providing a potential mechanism for its anti-migratory and subsequent anti-angiogenic effects. These data further support the use of lenalidomide as an orally administered drug for the effective treatment of angiogenesis-dependent conditions, including cancer, and suggest a potential mechanism of action.

Administration, Oral↗
PubMed2005

CC-1088 Celgene.

CC-1088, a thalidomide analog inhibitor of phosphodiesterase 4, was being developed by Celgene for the potential treatment of inflammatory diseases and myelodysplastic syndromes, and had undergone clinical trials. By April 2005, however, the company was no longer developing CC-1088, with CC-10004 presumed to be the preferred compound.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2004

AE-941 (AEterna).

AEterna is developing AE-941, an angiogenesis inhibitor derived from the ultrafiltration of liquid shark cartilage, with matrix metalloprotease (MMP)-2, MMP-9 and vascular endothelial growth factor inhibitory properties, for the potential treatment of non-small-cell lung cancer.

Animals↗
PubMed2003

A novel subclass of thalidomide analogue with anti-solid tumor activity in which caspase-dependent apoptosis is associated with altered expression of bcl-2 family proteins.

Thalidomide is clinically useful in a number of cancers. Antitumor activity may be related to a number of known properties, including anti-tumor necrosis factor (TNF)-alpha and T-cell costimulatory and antiangiogenic activities. However, it may also involve direct antitumor effects. A series of second generation thalidomide analogues have been separated into two distinct groups of compounds, each with enhanced therapeutic potential, i.e., SelCIDs, which are phosphodiesterase (PDE) type IV inhibitors, and IMiDs, which have unknown mechanism(s) of action. We report here our efforts to determine direct antitumor effects of thalidomide and compounds from both groups. We found that one of the SelCID analogues (SelCID-3) was consistently effective at reducing tumor cell viability in a variety of solid tumor lines but had no effect on non-neoplastic cells. The antitumor activity was independent of known PDE4 inhibitory activity and did not involve cAMP elevation. Growth arrest was preceded by the early induction of G(2)-M cell cycle arrest, which led to caspase 3 mediated apoptosis. This was associated with increased expression of pro-apoptotic proteins and decreased expression of antiapoptotic bcl-2. Furthermore, extensive apoptosis in vivo was detected during SelCID-3-mediated inhibition of tumor growth in a murine xenotransplantation cancer model. Our results suggest that SelCID-3 represents a novel antitumor agent distinct from thalidomide and from previously characterized analogues with therapeutic potential against a range of solid tumors. This effect appears to be mediated via alterations in the expression of bcl-2 family proteins.

Animals↗
PubMed2003

Thalidomide analogs as emerging anti-cancer drugs.

Recently, it has been demonstrated that a number of novel thalidomide analogs possess anti-cancer properties due to their T cell co-stimulatory, anti-angiogenic and/or anti-inflammatory effects. Based on such effects, a class of thalidomide analogs known as Immunomodulatory Drugs (IMiDs) have recently entered into phase I clinical trials for the treatment of a number of cancers. The lead IMiD CC-5013 (referred to clinically as REVIMID) is now entering phase III clinical trials for multiple myeloma and metastatic melanoma, while CC-4047 (ACTIMID) is currently under investigation in phase I/II and II trials for multiple myeloma and prostate cancer, respectively. The other group of compounds, classified as Selective Cytokine Inhibitory Drugs (SelCIDs), do not co-stimulate T cells, but have anti-inflammatory and anti-angiogenic properties. Moreover, a subset of SelCIDs has been found to possess direct anti-tumor activity both in vitro and in vivo. This minireview highlights the various mechanisms of action associated with these compounds and their subsequent clinical development. The enhanced efficacy and lower side-effect profiles of the analogs in comparison to thalidomide make the use of these agents very attractive as novel anti-cancer agents.

Adjuvants, Immunologic↗
PubMed2003

Thalidomide derived immunomodulatory drugs (IMiDs) as potential therapeutic agents.

Thalidomide is known to be effective in the treatment of a number of conditions, including leprosy and various cancers. The exact mechanisms of action remain unclear although these are known to include anti-tumour necrosis factor (TNF)-alpha, T cell costimulatory, anti-angiogenic and anti-tumour activities. However, thalidomide is being superceded by novel structural derivatives which have been designed to have improved immunomodulatory activity and side effect profiles. These are currently being characterised and some are entering the clinic in phase I/II studies. One novel group of structural analogues are classified as the Immunomodulatory Drugs (IMiDs). This review describes the emerging immunological, anti-angiogenic and direct anti-tumour properties of thalidomide and the characterisation and clinical application of its IMiD analogues. We describe the laboratory studies which have led to the characterisation and development of IMiDs into potentially clinically relevant drugs. Early trial data suggests that these compounds may themselves become established therapies, particularly in certain cancers. Furthermore, ongoing studies will determine how best to apply these compounds to the appropriate clinical settings. We will describe the various clinical studies of lead compounds that are in progress and speculate as to the potential and future development of these exciting compounds.

Adjuvants, Immunologic↗
PubMed2003

Angiogenesis inhibitors in cancer therapy.

The formation of new blood vessels is essential for tumor growth and progression. Angiogenesis inhibitors have been demonstrated to block tumor growth and/or metastasis. Although initial clinical data have been disappointing, new strategies to increase the efficacy of these drugs have ensured their ongoing clinical development. This review highlights the broad spectrum of angiogenesis inhibitors under investigation in both preclinical and clinical studies. From 'natural' inhibitors to thalidomide analogs, the number of compounds in development is extensive. Elucidating the mechanisms of action will enable their use in conjunction with existing/other novel therapies, thereby maximizing the potential efficacy of angiogenesis inhibitors to fulfill their promise in patients with cancer.

Angiogenesis Inhibitors↗
PubMed2002

Adjuvants and the promotion of Th1-type cytokines in tumour immunotherapy.

Immunotherapy includes both active and passive mechanisms that have the potential to treat many tumour types. Whereas monoclonal antibodies may kill cells by merely binding to them, 'cancer vaccines' involve the induction of an active immune response. The activation of tumour antigen-specific T-helper and cytotoxic T lymphocytes or non-specific macrophages and natural killer (NK) cells using immunotherapeutic approaches may lead to the subsequent destruction of tumour tissue. Administration of a tumour antigen alone is often not sufficient to stimulate an appropriate immune response. However, incorporating an immunological adjuvant into a vaccine regime often improves anti-tumour immunity. There are various types of adjuvants used in immunotherapy, ranging from microbial, chemical, and cellular components to proteins and cytokines. Previous reports have demonstrated that the induction of Th1-promoting cytokines, using specific adjuvants, can enhance anti-tumour immunity and can reduce or even prevent tumour growth. There is also increasing evidence that many adjuvants induce Th1-type cytokines, which correlates with the induction anti-tumour immunity. Th1-type responses which comprise cell-mediated immunity are characterised by the secretion of interferon-gamma by T cells, which is induced by antigen-presenting cell (APC)-derived IL-12. This review describes immunoadjuvants that are currently undergoing preclinical investigation, and emerging clinical data revealing that adjuvants which induce Th1-type responses can improve the efficacy of cancer vaccines. Therefore, the use of Th1-inducing adjuvants may provide an essential strategy for the future success of immunotherapy.

Adjuvants, Immunologic↗
PubMed2002

Protective antitumor immunity induced by a costimulatory thalidomide analog in conjunction with whole tumor cell vaccination is mediated by increased Th1-type immunity.

Thalidomide and its novel T cell costimulatory analogs (immunomodulatory drugs) are currently being assessed in the treatment of patients with advanced cancer. However, neither tumor-specific T cell costimulation nor effective antitumor activity has been demonstrated in vivo. In this study, we assessed the ability of an immunomodulatory drug (CC-4047/ACTIMID) to prime a tumor-specific immune response following tumor cell vaccination. We found that the presence of CC-4047 during the priming phase strongly enhanced antitumor immunity in the vaccinated group, and this correlated with protection from subsequent live tumor challenge. Protection was associated with tumor-specific production of IFN-gamma and was still observed following a second challenge with live tumor cells 60 days later. Furthermore, CD8(+) and CD4(+) splenocyte fractions from treated groups secreted increased IFN-gamma and IL-2 in response to tumor cells in vitro. Coculture of naive splenocytes with anti-CD3 mAb in the presence of CC-4047 directly costimulated T cells and increased Th1-type cytokines. Our results are the first to demonstrate that a costimulatory thalidomide analog can prime protective, long-lasting, tumor-specific, Th1-type responses in vivo and further support their ongoing clinical development as novel anti-cancer agents.

Adjuvants, Immunologic↗
PubMed2002

Recent developments in antiangiogenic therapy.

The use of antiangiogenic therapy is gaining momentum as a novel treatment for a number of conditions, ranging from cancer to psoriasis. This has stemmed from research in the early 1970s showing that the formation of new blood vessels by pre-existing endothelial cells is essential in tumour growth and progression. However, although antiangiogenic therapy was hailed as a new avenue of treatment for cancer, initial clinical data have been disappointing. This has led to the reassessment of antiangiogenic therapy for cancer, and new strategies have been proposed to increase the efficacy of these agents in this setting. Angiogenesis has also been implicated in other conditions that are notoriously difficult to treat, such as arteriosclerosis, arthritis, psoriasis and diabetic retinopathy. Increased understanding of the angiogenic process, the diversity of its inducers and mediators, appropriate drug schedules and the use of these agents with other modalities may lead to radically new treatment regimens for many of these conditions. The role of angiogenesis in different pathological settings, and emerging antiangiogenic agents currently in preclinical and clinical studies are discussed in this review. However, while potential benefits are profound, limitations of antiangiogenic therapy have also been identified, suggesting that there is also a need for caution in applying these compounds to the clinical setting.

Angiogenesis Inhibitors↗
PubMed2002

Immunological effects of thalidomide and its chemical and functional analogs.

Thalidomide has recently shown considerable promise in the treatment of a number of conditions, such as leprosy and cancer. Its effectiveness in the clinic has been ascribed to wide-ranging properties, including anti-TNF-alpha, T-cell costimulatory and antiangiogenic activity. Novel compounds with improved immunomodulatory activity and side effect profiles are also being evaluated. These include selective cytokine inhibitory drugs (SelCIDs), with greatly improved TNF-alpha inhibitory activity, and immunomodulatory drugs (IMiDs) that are structural analogs of thalidomide, with improved properties. A third group recently identified within the SelCID group, with phosphodiesterase type 4-independent activity, is in the process of being characterized in laboratory studies. This review describes the emerging immunological properties of thalidomide, from a historical context to present-day clinical applications, most notably in multiple myeloma but also in other cancers, inflammatory disease, and HIV. We also describe the laboratory studies that have led to the characterization and development of SelCIDs and IMiDs into potentially clinically relevant drugs. Early trial data suggest that these novel immunomodulatory compounds may supercede thalidomide to become established therapies, particularly in certain cancers. Further evidence is required, however, to correlate the clinical efficacy of these compounds with their known immunomodulatory, antiangiogenic, and antitumor properties.

Adjuvants, Immunologic↗