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Jason TLH, Koropatnick J, Berg RW. Toxicology of antisense therapeutics. Toxicol Appl Pharmacol 2004; 201:66-83. [PMID: 15519609 DOI: 10.1016/j.taap.2004.04.017] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2003] [Accepted: 04/28/2004] [Indexed: 12/24/2022]
Abstract
Targeting unique mRNA molecules using antisense approaches, based on sequence specificity of double-stranded nucleic acid interactions should, in theory, allow for design of drugs with high specificity for intended targets. Antisense-induced degradation or inhibition of translation of a target mRNA is potentially capable of inhibiting the expression of any target protein. In fact, a large number of proteins of widely varied character have been successfully downregulated using an assortment of antisense-based approaches. The most prevalent approach has been to use antisense oligonucleotides (ASOs), which have progressed through the preclinical development stages including pharmacokinetics and toxicological studies. A small number of ASOs are currently in human clinical trials. These trials have highlighted several toxicities that are attributable to the chemical structure of the ASOs, and not to the particular ASO or target mRNA sequence. These include mild thrombocytopenia and hyperglycemia, activation of the complement and coagulation cascades, and hypotension. Dose-limiting toxicities have been related to hepatocellular degeneration leading to decreased levels of albumin and cholesterol. Despite these toxicities, which are generally mild and readily treatable with available standard medications, the clinical trials have clearly shown that ASOs can be safely administered to patients. Alternative chemistries of ASOs are also being pursued by many investigators to improve specificity and antisense efficacy and to reduce toxicity. In the design of ASOs for anticancer therapeutics in particular, the goal is often to enhance the cytotoxicity of traditional drugs toward cancer cells or to reduce the toxicity to normal cells to improve the therapeutic index of existing clinically relevant cancer chemotherapy drugs. We predict that use of antisense ASOs in combination with small molecule therapeutics against the target protein encoded by the antisense-targeted mRNA, or an alternate target in the same or a connected biological pathway, will likely be the most beneficial application of this emerging class of therapeutic agent.
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Affiliation(s)
- Tracey L H Jason
- Cancer Research Laboratories, London Regional Cancer Centre, London, Ontario, Canada N6A 4L6
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Villarreal EC. Current and potential therapies for the treatment of herpes-virus infections. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2003; 60:263-307. [PMID: 12790345 DOI: 10.1007/978-3-0348-8012-1_8] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Human herpesviruses are found worldwide and are among the most frequent causes of viral infections in immunocompetent as well as in immunocompromised patients. During the past decade and a half a better understanding of the replication and disease-causing state of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella zoster virus (VZV), and human cytomegalovirus (HCMV) has been achieved due in part to the development of potent antiviral compounds that target these viruses. While some of these antiviral therapies are considered safe and efficacious (acyclovir, penciclovir), some have toxicities associated with them (ganciclovir and foscarnet). In addition, the increased and prolonged use of these compounds in the clinical setting, especially for the treatment of immunocompromised patients, has led to the emergence of viral resistance against most of these drugs. While resistance is not a serious issue for immunocompetent individuals, it is a real concern for immunocompromised patients, especially those with AIDS and the ones that have undergone organ transplantation. All the currently approved treatments target the viral DNA polymerase. It is clear that new drugs that are more efficacious than the present ones, are not toxic, and target a different viral function would be of great use especially for immunocompromised patients. Here, an overview is provided of the diseases caused by the herpesviruses as well as the replication strategy of the better studied members of this family for which treatments are available. We also discuss the various drugs that have been approved for the treatment of some herpesviruses in terms of structure, mechanism of action, and development of resistance. Finally, we present a discussion of viral targets other than the DNA polymerase, for which new antiviral compounds are being considered.
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Affiliation(s)
- Elcira C Villarreal
- Eli Lilly and Company, Lilly Centre for Women's Health, Indianapolis, IN 46285, USA.
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Villarreal EC. Current and potential therapies for the treatment of herpesvirus infections. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; Spec No:185-228. [PMID: 11548208 DOI: 10.1007/978-3-0348-7784-8_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Human herpesviruses are found worldwide and are among the most frequent causes of viral infections in immunocompetent as well as in immunocompromised patients. During the past decade and a half a better understanding of the replication and disease causing state of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), and human cytomegalovirus (HCMV) has been achieved due in part to the development of potent antiviral compounds that target these viruses. While some of these antiviral therapies are considered safe and efficacious (acyclovir, penciclovir), some have toxicities associated with them (ganciclovir and foscarnet). In addition, the increased and prolonged use of these compounds in the clinical setting, especially for the treatment of immunocompromised patients, has led to the emergence of viral resistance against most of these drugs. While resistance is not a serious issue for immunocompetent individuals, it is a real concern for immunocompromised patients, especially those with AIDS and the ones that have undergone organ transplantation. All the currently approved treatments target the viral DNA polymerase. It is clear that new drugs that are more efficacious than the present ones, are not toxic, and target a different viral function would be of great use especially for immunocompromised patients. Here, we provide an overview of the diseases caused by the herpesviruses as well as the replication strategy of the better studiedmembers of this family for which treatments are available. We also discuss the various drugs that have been approved for the treatment of some herpesviruses in terms of structure, mechanism of action, and development of resistance. Finally, we present a discussion of viral targets other than the DNA polymerase, for which new antiviral compounds are being considered.
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Affiliation(s)
- E C Villarreal
- Eli Lilly and Company, Infectious Diseases Research, Lilly Research Laboratories, Indianapolis, IN 46285, USA.
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4
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Abstract
A variety of ocular disease processes have been identified in HIV-antibody positive persons, especially in people with AIDS. The most common sight-threatening disease in this population is cytomegalovirus (CMV) retinitis. Effective therapies are available to treat CMV retinitis. However, such therapies carry potentially challenging toxicities. Highly active antiretroviral therapy (HAART) has improved immune system functioning in many of its adherents, decreasing the incidence and improving the clinical course of CMV retinitis. However, a recent phenomenon associated with HAART, immune recovery uveitis (IRU), has been noted with additional, often problematic ocular manifestations in many persons with CMV retinitis. Periodic ophthalmic examination is prudent for all persons with HIV and especially for people with AIDS.
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Villarreal EC. Current and potential therapies for the treatment of herpesvirus infections. PROGRESS IN DRUG RESEARCH. FORTSCHRITTE DER ARZNEIMITTELFORSCHUNG. PROGRES DES RECHERCHES PHARMACEUTIQUES 2001; 56:77-120. [PMID: 11417115 DOI: 10.1007/978-3-0348-8319-1_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
Human herpesviruses are found worldwide and are among the most frequent causes of viral infections in immunocompetent as well as in immunocompromised patients. During the past decade and a half a better understanding of the replication and disease causing state of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), varicella-zoster virus (VZV), and human cytomegalovirus (HCMV) has been achieved due in part to the development of potent antiviral compounds that target these viruses. While some of these antiviral therapies are considered safe and efficacious (acyclovir, penciclovir), some have toxicities associated with them (ganciclovir and foscarnet). In addition, the increased and prolonged use of these compounds in the clinical setting, especially for the treatment of immunocompromised patients, has led to the emergence of viral resistance against most of these drugs. While resistance is not a serious issue for immunocompetent individuals, it is a real concern for immunocompromised patients, especially those with AIDS and the ones that have undergone organ transplantation. All the currently approved treatments target the viral DNA polymerase. It is clear that new drugs that are more efficacious than the present ones, are not toxic, and target a different viral function would be of great use especially for immunocompromised patients. Here, we provide an overview of the diseases caused by the herpesviruses as well as the replication strategy of the better studied members of this family for which treatments are available. We also discuss the various drugs that have been approved for the treatment of some herpesviruses in terms of structure, mechanism of action, and development of resistance. Finally, we present a discussion of viral targets other than the DNA polymerase, for which new antiviral compounds are being considered.
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Affiliation(s)
- E C Villarreal
- Eli Lilly and Company, Infectious Diseases Research, Drop Code 0438, Lilly Research Laboratories, Indianapolis, IN 46285, USA.
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Sensibilidad del citomegalovirus frente a fármacos antivíricos en pacientes infectados por el virus de la inmunodeficiencia humana con coriorretinitis en España. Enferm Infecc Microbiol Clin 2001. [DOI: 10.1016/s0213-005x(01)72704-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Chiou SH, Liu JH, Wong WW, Chan YJ, Chang YC, Wang JJ, Liu CY, Liu WT, Chen SC, Hsu WM. Detection of human cytomegalovirus retinitis and monitoring of ganciclovir treatment using conjunctival swab with polymerase chain reaction in AIDS patients. Int J STD AIDS 2000; 11:85-91. [PMID: 10678475 DOI: 10.1177/095646240001100204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This report studies the accuracy of conjunctival swab polymerase chain reaction (CS-PCR) for the diagnosis of human cytomegalovirus retinitis (HCMV) in AIDS patients. PCR and virus culture were used for the detection of HCMV in conjunctival swab, serum, and urine specimens from 38 AIDS patients between April 1996 and April 1998. The clinical utility of the identification of HCMV retinitis by these 6 different methods was demonstrated by their prediction power to estimate AIDS patients at risk of contracting HCMV retinitis. The sensitivity, specificity, positive predictive value, and negative predictive value of CS-PCR for the detection of HCMV retinitis were 91.5%, 80.9%, 60.8%, and 92.7%, respectively; for serum PCR were 74.3%, 81.7%, 57.2%, and 90.3%; for urine PCR were 100%, 17.3%, 20.4%, and 100%; for conjunctival swab culture were 22.7%, 100%, 100%, and 86%; for serum culture were 27.3%, 98.1%, 75%, and 86.4%; and for urine culture were 90.9%, 44.2%, 25.6%, and 95.8%.
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Affiliation(s)
- S H Chiou
- Department of Ophthalmology, Veterans General Hospital, Taipei, Taiwan, Republic of China
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Abstract
Ophthalmic abnormalities are common in HIV-infected patients. Serious ophthalmic diseases often result from opportunistic infections and can cause blindness in the absence of prompt diagnosis and therapy. We review recent advances in the diagnosis and management of HIV-associated ocular disease, including cytomegalovirus retinitis, the leading cause of vision loss in HIV-infected patients. The widespread use of highly active antiretroviral therapy (HAART) over the past 3 years has reduced the morbidity and mortality associated with HIV infection. HAART has dramatically altered the incidence and natural history of many opportunistic infections, and we discuss the impact of HAART on ophthalmic disease.
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Affiliation(s)
- M R Robinson
- National Institutes of Health, National Eye Institute, Bethesda, Maryland 20892-1863, USA.
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Morin NJ, Delorme C, Gourde P, Omar RF, Désormeaux A, Tremblay MJ, Beauchamp D, Rousseau A, Bergeron MG. Reducing chorioretinal viral counts with intravitreal foscarnet injections in a rabbit model of Herpes simplex virus type-1 retinitis. J Ocul Pharmacol Ther 1999; 15:465-77. [PMID: 10530708 DOI: 10.1089/jop.1999.15.465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The efficacy of intravitreal foscarnet injections was evaluated in a rabbit model of Herpes simplex virus type-1 (HSV-1) retinitis. In untreated infected animals, viral titration revealed that the optic chiasm, vitreous and chorioretina were positive for HSV-1. On the other hand, foscarnet treatment significantly decreased the viral count in the chorioretina when compared to the untreated group. Immunolocalization of HSV in untreated infected animals clearly showed infected cells in the outer and inner layers of the retina and also in the ciliary body of the eye. Clinical examination by indirect ophthalmoscopy indicated an absence of optic nerve congestion and a lower level of vitritis in foscarnet treated animals compared to the untreated group. It is concluded that intravitreal injections of foscarnet reduced the viral titer in the chorioretina in a rabbit model of HSV-1 retinitis. This route of administration might be valuable for the treatment of CMV retinitis in AIDS patients with sight threatening lesions or intolerance to intravenous anti-CMV drugs.
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Affiliation(s)
- N J Morin
- Centre de Recherche en Infectiologie, Centre Hospitalier, Universitaire de Québec, Canada
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Field AK. Human cytomegalovirus: challenges, opportunities and new drug development. Antivir Chem Chemother 1999; 10:219-32. [PMID: 10574177 DOI: 10.1177/095632029901000501] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the age of highly active antiretroviral therapy, the incidence of human cytomegalovirus (HCMV) retinitis in AIDS patients has decreased substantially. However, this change does not indicate that HCMV disease in AIDS patients and other immunocompromised patients has abated and is no longer a concern. On the contrary, HCMV disease in graft recipients, newborns, and even in AIDS patients still accounts for considerable morbidity, and drug resistance to the anti-HCMV compounds is a major problem. Furthermore, HCMV may have a role in metabolic diseases, such as atherosclerosis. Fortunately there are novel and potentially very effective new compounds undergoing pre-clinical and clinical evaluation. These developments point the way toward new therapies and also to a clearer understanding of the biology of HCMV replication, infection and disease.
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Affiliation(s)
- A K Field
- Department of Pharmacology and Molecular Toxicology, University of Massachusetts Medical Center, North Wales, PA 19454, USA.
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Abstract
UNLABELLED Cidofovir is an antiviral nucleotide analogue with significant activity against cytomegalovirus (CMV) and other herpesviruses. The drug is indicated for the treatment of CMV retinitis, a sight-threatening condition, in patients with AIDS. Cidofovir has a long intracellular half-life which allows for a prolonged interval (2 weeks) between maintenance doses. In contrast, other intravenous treatment options for patients with CMV retinitis (i.e. ganciclovir and foscarnet) must be administered on a daily basis. The efficacy of intravenous cidofovir has been demonstrated in patients with AIDS and previously untreated CMV retinitis in multicentre randomised trials, and in a dose-finding study of cidofovir in patients with AIDS and previously treated relapsing CMV retinitis. Clinical trials have been relatively small (n < or = 100 patients) and no studies have been conducted directly comparing intravenous cidofovir with the more established intravenous agents, ganciclovir or foscarnet. Indirect comparisons of clinical trial data suggest that intravenous cidofovir may have similar efficacy to intravenous ganciclovir or foscarnet in delaying progression of CMV retinitis. However, such comparisons must be made with caution because of potential differences in patient populations, data analysis techniques and interobserver variability in the masked assessment of retinal photographs. Nevertheless, intravenous cidofovir offers a less intrusive administration regimen than intravenous ganciclovir or foscarnet because of its prolonged dosage interval. Since therapy is life-long, patients receiving daily intravenous ganciclovir or foscarnet (but not cidofovir) usually require an indwelling central venous catheter and are therefore at increased risk of serious infection. The relatively long dosage interval for cidofovir may also have favourable implications in terms of overall treatment costs and patient quality of life, although specific data are very limited. Potentially irreversible nephrotoxicity is the major treatment-limiting adverse event associated with intravenous cidofovir in patients with AIDS-related CMV retinitis. Anterior uveitis/iritis has been reported frequently with intravenous cidofovir in postmarketing reports and a small number of patients have developed hypotony. Other treatment options for CMV retinitis are also associated with serious adverse events, and selection of pharmacotherapy will depend on a number of factors including retinitis lesion characteristics, patient quality-of-life issues and efficacy and tolerability profiles of available therapies. CONCLUSION Although the extent of its use may be limited by its adverse event profile, cidofovir offers a useful addition to the limited number of drugs available for the treatment of CMV retinitis in patients with AIDS.
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Affiliation(s)
- G L Plosker
- Adis International Limited, Auckland, New Zealand.
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