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Cottrell ML, Kashuba ADM. Topical microbicides and HIV prevention in the female genital tract. J Clin Pharmacol 2014; 54:603-15. [PMID: 24664786 DOI: 10.1002/jcph.292] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/19/2014] [Indexed: 11/05/2022]
Abstract
Worldwide, HIV disproportionately affects women who are often unable to negotiate traditional HIV preventive strategies such as condoms. In the absence of an effective vaccine or cure, chemoprophylaxis may be a valuable self-initiated alternative. Topical microbicides have been investigated as one such option. The first generation topical microbicides were non-specific, broad-spectrum antimicrobial agents, including surfactants, polyanions, and acid buffering gels, that generally exhibited contraceptive properties. After extensive clinical study, none prevented HIV infection, and their development was abandoned. Second generation topical microbicides include agents with selective mechanisms of antiviral activity. Most are currently being used for, or have previously been explored as, drugs for treatment of HIV. The most advanced of these is tenofovir 1% gel: the first topical agent shown to significantly reduce HIV infection by 39% compared to placebo. This review summarizes the evolution of topical microbicides for HIV chemoprophylaxis, highlights important concepts learned, and offers current and future considerations for this area of research.
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Affiliation(s)
- Mackenzie L Cottrell
- University of North Carolina at Chapel Hill, UNC Eshelman School of Pharmacy, Chapel Hill, NC, USA
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Mauck CK, Lai JJ, Weiner DH, Chandra N, Fichorova RN, Dezzutti CS, Hillier SL, Archer DF, Creinin MD, Schwartz JL, Callahan MM, Doncel GF. Toward early safety alert endpoints: exploring biomarkers suggestive of microbicide failure. AIDS Res Hum Retroviruses 2013; 29:1475-86. [PMID: 23885658 DOI: 10.1089/aid.2012.0345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Several microbicides, including nonoxynol-9 (N-9) and cellulose sulfate (CS), looked promising during early trials but failed in efficacy trials. We aimed to identify Phase I mucosal safety endpoints that might explain that failure. In a blinded, randomized, parallel trial, 60 healthy premenopausal sexually abstinent women applied Universal HEC placebo, 6% CS or 4% N-9 gel twice daily for 13½ days. Endpoints included immune biomarkers in cervicovaginal lavage (CVL) and endocervical cytobrushes, inflammatory infiltrates in vaginal biopsies, epithelial integrity by naked eye, colposcopy, and histology, CVL anti-HIV activity, vaginal microflora, pH, and adverse events. Twenty women enrolled per group. Soluble/cellular markers were similar with CS and placebo, except secretory leukocyte protease inhibitor (SLPI) levels decreased in CVL, and CD3(+) and CD45(+) cells increased in biopsies after CS use. Increases in interleukin (IL)-8, IL-1, IL-1RA, and myeloperoxidase (MPO) and decreases in SLPI were significant with N-9. CVL anti-HIV activity was significantly higher during CS use compared to N-9 or placebo. CS users tended to have a higher prevalence of intermediate Nugent score, Escherichia coli, and Enterococcus and fewer gram-negative rods. Most Nugent scores diagnostic for bacterial vaginosis were in N-9 users. All cases of histological inflammation or deep epithelial disruption occurred in N-9 users. While the surfactant N-9 showed obvious biochemical and histological signs of inflammation, more subtle changes, including depression of SLPI, tissue influx of CD45(+) and CD3(+) cells, and subclinical microflora shifts were associated with CS use and may help to explain the clinical failure of nonsurfactant microbicides.
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Affiliation(s)
| | - Jaim Jou Lai
- FHI 360 (formerly Family Health International), Research Triangle Park, North Carolina
| | - Debra H. Weiner
- FHI 360 (formerly Family Health International), Research Triangle Park, North Carolina
| | - Neelima Chandra
- CONRAD, Eastern Virginia Medical School (EVMS), Norfolk, Virginia
| | - Raina N. Fichorova
- Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Charlene S. Dezzutti
- University of Pittsburgh and Magee-Womens Research Institute, Pittsburgh, Pennsylvania
| | - Sharon L. Hillier
- University of Pittsburgh and Magee-Womens Research Institute, Pittsburgh, Pennsylvania
| | - David F. Archer
- CONRAD, Eastern Virginia Medical School (EVMS), Norfolk, Virginia
| | | | - Jill L. Schwartz
- CONRAD, Eastern Virginia Medical School (EVMS), Arlington, Virginia
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Pirrone V, Passic S, Wigdahl B, Krebs FC. Application and removal of polyanionic microbicide compounds enhances subsequent infection by HIV-1. Virol J 2012; 9:33. [PMID: 22281044 PMCID: PMC3295645 DOI: 10.1186/1743-422x-9-33] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 01/26/2012] [Indexed: 04/05/2023] Open
Abstract
Background Continued efforts are being directed toward the development of microbicides that will be used to reduce or eliminate the risk of HIV-1 sexual transmission. Unfortunately, clinical trials involving polyanion-containing microbicide formulations, including Carraguard (λ-carrageenan [LC]) and Ushercell (cellulose sulfate [CS]) demonstrated that these products were ineffective and may have, in some circumstances, increased the risk of HIV-1 infection. These findings prompted reassessments of the in vitro activities of these agents to determine whether variables that can affect agent safety and efficacy had been overlooked during preclinical testing. One such variable is product retention and loss following topical application. Results In the present studies involving an HIV-1-susceptible cell line and primary human immune cells, product loss was mimicked by introducing and then removing polyanionic compounds prior to HIV-1 infection. In these in vitro "washout" experiments, LC and CS significantly enhanced HIV-1 infection, despite potent antiviral activity when introduced simultaneously with the virus. The presence and magnitude of this effect were dependent on compound identity and concentration; target cell; interval between compound removal and virus challenge; and coreceptor usage. Levels of enhancement (relative to controls) were considerable, exceeding a 200% increase (CS) in P4-R5 MAGI cells and a 300% increase (LC) in human peripheral blood mononuclear cells. Conclusions These studies, which demonstrate significant increases in HIV-1 infection subsequent to application and removal of LC and CS, support plausible explanations for the failures of microbicides formulated from these compounds. Detailed studies are now underway to determine the mechanism responsible for this enhancement effect and to assess the potential contribution of this effect to the clinical failures of these agents.
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Affiliation(s)
- Vanessa Pirrone
- Department of Microbiology and Immunology, and Center for Molecular Therapeutics and Resistance, Center for Sexually Transmitted Disease, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA 19102, USA
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Ariën KK, Jespers V, Vanham G. HIV sexual transmission and microbicides. Rev Med Virol 2011; 21:110-33. [PMID: 21412935 DOI: 10.1002/rmv.684] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 01/25/2011] [Accepted: 01/26/2011] [Indexed: 12/12/2022]
Abstract
Pathogens often rely on the contacts between hosts for transmission. Most viruses have adapted their transmission mechanisms to defined behaviours of their host(s) and have learned to exploit these for their own propagation. Some viruses, such as HIV, the human papillomavirus (HPV), HSV-2 and HCV, cause sexually transmitted infections (STIs). Understanding the transmission of particular viral variants and comprehending the early adaptation and evolution is fundamental to eventually inhibiting sexual transmission of HIV. Here, we review the current understanding of the mechanisms of sexual transmission and the biology of the transmitted HIV. Next, we present a timely overview of candidate microbicides, including past, ongoing and future clinical trials of HIV topical microbicides.
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Affiliation(s)
- Kevin K Ariën
- Virology Unit, Department of Microbiology, Institute of Tropical Medicine, Antwerpen, Belgium.
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Microbicide excipients can greatly increase susceptibility to genital herpes transmission in the mouse. BMC Infect Dis 2010; 10:331. [PMID: 21087496 PMCID: PMC2996397 DOI: 10.1186/1471-2334-10-331] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Accepted: 11/18/2010] [Indexed: 01/05/2023] Open
Abstract
Background Several active ingredients proposed as vaginal microbicides have been shown paradoxically to increase susceptibility to infection in mouse genital herpes (HSV-2) vaginal susceptibility models and in clinical trials. In addition, "inactive ingredients" (or excipients) used in topical products to formulate and deliver the active ingredient might also cause epithelial toxicities that increase viral susceptibility. However, excipients have not previously been tested in susceptibility models. Methods Excipients commonly used in topical products were formulated in a non-toxic vehicle (the "HEC universal placebo"), or other formulations as specified. Twelve hours after exposure to the excipient or a control treatment, mice were challenged with a vaginal dose of HSV-2, and three days later were assessed for infection by vaginal lavage culture to assess susceptibility. Results The following excipients markedly increased susceptibility to HSV-2 after a single exposure: 5% glycerol monolaurate (GML) formulated in K-Y® Warming Jelly, 5% GML as a colloidal suspension in phosphate buffered saline, K-Y Warming Jelly alone, and both of its humectant/solvent ingredients (neat propylene glycol and neat PEG-8). For excipients formulated in the HEC vehicle, 30% glycerin significantly increased susceptibility, and a trend toward increased HSV-2 susceptibility was observed after 10% glycerin, and 0.1% disodium EDTA, but not after 0.0186% disodium EDTA. The following excipients did not increase susceptibility: 10% propylene glycol, 0.18%, methylparaben plus 0.02% propylparaben, and 1% benzyl alcohol. Conclusions As reported with other surfactants, the surfactant/emulsifier GML markedly increased susceptibility to HSV-2. Glycerin at 30% significantly increased susceptibility, and, undiluted propylene glycol and PEG-8 greatly increased susceptibility.
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Schwartz JL, Poindexter A, Wheeless A, Mauck CK, Callahan MM. Safety evaluation of 1% tenofovir gel in healthy men. Int J STD AIDS 2009; 20:384-6. [PMID: 19451321 DOI: 10.1258/ijsa.2008.008309] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study was conducted to determine the safety of tenofovir (TFV) gel, a potential microbicide, following seven consecutive daily penile applications. Eighteen circumcised and 18 uncircumcised healthy men were randomly assigned to TFV gel versus K-Y Jelly in a 2:1 ratio within circumcision group. TFV gel or K-Y Jelly was applied onto the penis at bedtime and washed off 6-10 hours later. Safety was assessed by reported symptoms, findings and laboratory tests. Three of 24 (13%) men in the TFV group reported mild genital symptoms compared with two of 11 (18%) men in the K-Y group. Few mild genital findings were observed and no significant systemic toxicities were reported or observed. TFV gel applied to the penis for seven days was well tolerated locally and systemically and it is unlikely that male partners exposed to small amounts of TFV gel will experience significant genital or systemic toxicity.
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Affiliation(s)
- J L Schwartz
- Department of Obstetrics and Gynecology, CONRAD, Eastern Virginia Medical School, Arlington, VA 22209, USA.
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Cutler B, Justman J. Vaginal microbicides and the prevention of HIV transmission. THE LANCET. INFECTIOUS DISEASES 2008; 8:685-97. [PMID: 18992405 DOI: 10.1016/s1473-3099(08)70254-8] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Worldwide, nearly half of all individuals living with HIV are now women, who acquire the virus largely by heterosexual exposure. With an HIV vaccine likely to be years away, topical microbicide formulations applied vaginally or rectally are being investigated as another strategy for HIV prevention. A review of preclinical and clinical research on the development of microbicides formulated to prevent vaginal HIV transmission yielded 118 studies: 73 preclinical and 45 clinical. Preclinical research included in-vitro assays and cervical explant models, as well as animal models. Clinical research included phase I and II/IIb safety studies, and phase III efficacy studies. Whereas most phase I and phase II clinical trials have found microbicide compounds to be safe and well tolerated, phase III trials completed to date have not demonstrated efficacy in preventing HIV transmission. Topical microbicides are grouped into five classes of agents, based on where they disrupt the pathway of sexual transmission of HIV. These classes include surfactants/membrane disruptors, vaginal milieu protectors, viral entry inhibitors, reverse transcriptase inhibitors, and a fifth group whose mechanism is unknown. The trajectory of microbicide development has been toward agents that block more specific virus-host cell interactions. Microbicide clinical trials face scientifically and ethically complex issues, such as the choice of placebo gel, the potential for viral resistance, and the inclusion of HIV-infected participants. Assessment of combination agents will most likely advance this field of research.
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Affiliation(s)
- Blayne Cutler
- Department of Medicine, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
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Microbicide acceptability research: recent findings and evolution across phases of product development. Curr Opin HIV AIDS 2008; 3:581-6. [DOI: 10.1097/coh.0b013e32830aba00] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Van Damme L, Govinden R, Mirembe FM, Guédou F, Solomon S, Becker ML, Pradeep BS, Krishnan AK, Alary M, Pande B, Ramjee G, Deese J, Crucitti T, Taylor D. Lack of effectiveness of cellulose sulfate gel for the prevention of vaginal HIV transmission. N Engl J Med 2008; 359:463-72. [PMID: 18669425 DOI: 10.1056/nejmoa0707957] [Citation(s) in RCA: 333] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Women make up more than 50% of adults living with human immunodeficiency virus (HIV) infection or the acquired immunodeficiency syndrome (AIDS) in sub-Saharan Africa. Thus, female-initiated HIV prevention methods are urgently needed. METHODS We performed a randomized, double-blind, placebo-controlled trial of cellulose sulfate, an HIV-entry inhibitor formulated as a vaginal gel, involving women at high risk for HIV infection at three African and two Indian sites. The primary end point was newly acquired infection with HIV type 1 or 2. The secondary end point was newly acquired gonococcal or chlamydial infection. The primary analysis was based on a log-rank test of no difference in the distribution of time to HIV infection, stratified according to site. RESULTS A total of 1398 women were enrolled and randomly assigned to receive cellulose sulfate gel (706 participants) or placebo (692 participants) and had follow-up HIV test data. There were 41 newly acquired HIV infections, 25 in the cellulose sulfate group and 16 in the placebo group, with an estimated hazard ratio of infection for the cellulose sulfate group of 1.61 (P=0.13). This result, which is not significant, is in contrast to the interim finding that led to the trial being stopped prematurely (hazard ratio, 2.02 [corrected]; P=0.05 [corrected]) and the suggestive result of a preplanned secondary (adherence-based) analysis (hazard ratio, 2.02; P=0.05). No significant effect of cellulose sulfate as compared with placebo was found on the risk of gonorrheal infection (hazard ratio, 1.10; 95% confidence interval [CI], 0.74 to 1.62) or chlamydial infection (hazard ratio, 0.71; 95% CI, 0.47 to 1.08). CONCLUSIONS Cellulose sulfate did not prevent HIV infection and may have increased the risk of HIV acquisition. (ClinicalTrials.gov number, NCT00153777; and Current Controlled Trials number, ISRCTN95638385.)
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Doh AS, Ngoh N, Roddy R, Lai JJ, Linton K, Mauck C. Safety and acceptability of 6% cellulose sulfate vaginal gel applied four times per day for 14 days. Contraception 2007; 76:245-9. [PMID: 17707724 DOI: 10.1016/j.contraception.2007.05.083] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 05/04/2007] [Accepted: 05/15/2007] [Indexed: 11/18/2022]
Abstract
BACKGROUND Six percent cellulose sulfate (CS) is a vaginal gel that has been in development as a microbicide. STUDY DESIGN This was a single-center, multi-dose, Phase I, placebo-controlled, randomized, fully masked study conducted in Yaoundé, Cameroon, and involving sexually active women at low risk for sexually transmitted infections (STIs). METHODS The study assessed the effect of CS and K-Y Jelly applied vaginally four times per day, for 14 consecutive days, on genital epithelial disruption, candidiasis and bacterial vaginosis (BV). Acceptability of the products was also assessed. Twenty-seven women were enrolled in each treatment group. RESULTS Two (7.4%) of the women in each group developed genital epithelial disruption. One (3.7%) of the women in each group developed candidiasis, and one (3.7%) of the K-Y users developed BV. One (3.7%) of the CS users said she would not buy her product for pregnancy prevention but would for STI prevention. All the remaining women indicated they would buy their product for both indications. CONCLUSION The results suggest that the safety and acceptability of 6% CS gel are comparable to that of K-Y Jelly.
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Affiliation(s)
- Anderson S Doh
- l'Hôpital Gynéco Obstétrique et Pédiatrique de Yaoundé, Yaoundé, Cameroon
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