Condyloma
Miranda A. Farage, Howard I. Maibach in The Vulva, 2017
Imiquimod is a topical, at home, patient-applied medication that is thought to act as an immunomodulatory, stimulating an inflammatory and cytolytic response, and it comes in a 5% and 3.5% cream. It requires an intact immune system to be most effective. The 5% cream is applied three times a week with at least 1 day in between each application for up to 16 weeks. It is normally applied at night and then washed off 6–10 hours later. For the 5% cream, the clearance rate is 40%–70%, with a recurrence rate of 9%–19% (42). The 3.5% cream is applied once daily and washed off 6–10 hours later for up to 8 weeks. The 3.5% cream clearance rate is 28% and the recurrence rate is 15%. The nightly application has been shown to have a higher compliance rate at the cost of a lower clearance rate (45).
Virus Wars
Satya Prakash Gupta in Cancer-Causing Viruses and Their Inhibitors, 2014
Today, aside from recombinant type I IFNs (Multiferon and PEGintron/PEGasys), at least toll-like receptor (TLR)-7 agonist and type I IFN inducer Aldara (Imiquimod) have been approved for clinical use in the United States and in Europe. Imiquimod is applied topically to combat certain skin conditions (keratosis)—superficial basal cell carcinoma as well as morbidities of oncogenic viral etiology—including papilloma and genital warts. It must be noted, however, that although Imiquimod acts through TLR7, it may inhibit cancer cell proliferation through induction of opioid growth factor receptor expression rather than via type I IFN (Zagon et al. 2008). In the case of papilloma, the respective roles of type I IFN, opioid growth factor receptor, or other hitherto undiscovered mechanisms of virus inhibition by Imiquimod have not been elucidated in detail.
Depigmenting Agents
Vineet Relhan, Vijay Kumar Garg, Sneha Ghunawat, Khushbu Mahajan in Comprehensive Textbook on Vitiligo, 2020
Imiquimod is a novel imidazoquinolinone immune response modifier frequently used for topical treatment of anogenital warts and basal cell carcinomas [32]. Imiquimod increases production of proinflammatory cytokines, mainly interferon (IFN)-α, tumor necrosis factor (TNF)-α, and IL-6, IL-8, IL-10, and IL-12, all of which augment the type 1 helper T-cell (TH1) response which is found to be prominent in the pathogenesis of vitiligo [4]. Imiquimod also stimulates CD8 cells to become cytotoxic, and enhances antigen presentation [33]. Recently, it was reported that human melanocytes express toll-like receptor 7 (TLR7). When applied topically, imiquimod binds to TLR7, followed by stimulation of various cytokines which induce the previously-mentioned T lymphocytic response [34]. Imiquimod also has a direct action on melanocytes via apoptosis of melanocytes. This action is related to reduction of expression of Bcl-2 and/or an increase in the proapoptotic stimulus (cytotoxic T lymphocytes, natural cytotoxic T cells/killer cells, granzyme B, Fas, TNF, Bax, etc.) [35]. Imiquimod (5%) application may be followed by erythema, which gradually turns to depigmented patches over a period of 3 months. No repigmentation has been seen until 6 months after the depigmentation. Also, depigmentation did not extend to areas that had not been treated with imiquimod [36]. The most common side effects of imiquimod are burning, itching, pain, erythema, erosions, and scabbing/crusting at the target site, which occur more frequently with twice-daily application [4].
Efficacy and safety of imiquimod 5% cream for basal cell carcinoma: a meta-analysis of randomized controlled trial
Published in Journal of Dermatological Treatment, 2020
Hong-Xia Jia, Yan-Ling He
With the growing incidence in BCC worldwide, there are several treatment options that are used available for BCC, which include surgery and non-surgical treatments. Surgery is considered as the gold standard for patients with low-risk BCC (6), and it is largely done by dermatologists and plastic surgeons. However, non-surgical treatment modalities like photodynamic therapy (PDT) and imiquimod have been used as good alternatives for surgery in superficial BCC (sBCC) (6–8). As a first-line treatment by international consensus for sBCC (8), PDT is less invasive, and also has other advantages like the good cosmetic outcome according to evaluation by physicians (9). Imiquimod is a new topical treatment, and is effective in assisting in the removal of a tumor without causing collateral structural damage. Previous studies related to BCCs of the trunk or extremities have suggested that imiquimod is as effective as surgical treatment in clinical cure rates and it achieves good to excellent cosmetic outcomes (10,11). However, there was one randomized controlled trial (RCT) that reported different results, which showed that imiquimod was inferior to surgery in the treatment of low-risk sBCC (12). In order to evaluate the effects of imiquimod, we conducted this meta-analysis of RCTs to compare the efficacy and safety between imiquimod and other treatments in patients with BCC.
Intravenous delivery of the toll-like receptor 7 agonist SC1 confers tumor control by inducing a CD8+ T cell response
Published in OncoImmunology, 2019
Fulvia Vascotto, Jutta Petschenka, Kerstin C. Walzer, Mathias Vormehr, Magdalena Brkic, Stefan Strobl, Roman Rösemann, Mustafa Diken, Sebastian Kreiter, Özlem Türeci, Ugur Sahin
Various synthetic TLR7 agonists, including the imidazoquinolines imiquimod (R837), 852A, and resiquimod (R848), are being studied as immunotherapy drugs and have strong anti-tumor activity.9-11 So far only imiquimod is approved for human use. Repetitive intravenous (i.v.) administration of imiquimod at a systemically effective IFNα-inducing dose level is associated with dose-limiting adverse reactions.12,13 As a consequence, imiquimod is registered as a cream formulation for topical use in localized diseases such as basal cell carcinoma, genital warts, and bladder cancer.14 Similarly, repeat-dose i.v. regimens of other TLR7 agonists in development, e.g. R848 and 852A, are not well tolerated limiting the clinical use of these compounds to the treatment of localized disease and requiring their combination with other active drugs.15-17 We and others hypothesized that the unfavorable safety profile may be attributable to the release of a broader array of proinflammatory cytokines on top of the intended type 1 IFN induction.18,19
Asiatic acid exerts an anti-psoriatic effect in the imiquimod-induced psoriasis model in mice
Published in Immunopharmacology and Immunotoxicology, 2022
Osman Kukula, Seda Kırmızıkan, Emre Soner Tiryaki, Mustafa Nusret Çiçekli, Caner Günaydın
Imiquimod-induced psoriasis is a frequently used model to mimic psoriasis pathology in murine. Imiquimod is a toll-like receptor-7/8 agonist and is currently used to treat actinic keratosis, genital warts, and superficial basal cell carcinoma [17]. Recent studies demonstrated that imiquimod mimics psoriasis-like dermatitis by activating IL-23/IL-17 pathway [18]. Imiquimod-induced psoriasis model is accepted as the closest murine model that imitates human plaque-type psoriasis with inflammatory infiltration, redness, thickening, and skin scaling. Therefore, imiquimod is a valuable pharmacological tool to investigate compounds that might protect against psoriasis. In this study, we used the imiquimod-induced psoriasis model due to the properties mentioned above. In line with previous studies, imiquimod caused psoriasis-like dermatitis and increased serum levels of IL-17A and IL-23, which indicates its successful model development according to the previous studies [19]. However, several treatment options present in the clinics, their serious side effects and intolerance because of long-term treatment deter their use and show the urgent need for novel treatment options with fewer side effects. So, compounds derived from natural sources are accepted as ideal candidates. Therefore, we investigated the effect of asiatic acid, a well-known compound present in the Centella Asiatica. The recent works that showed wound healing and anti-inflammatory properties of Centella Asiatica and its ingredients led us to think that asiatic acid might be an effective natural compound to alleviate psoriasis pathology [20,21].
Related Knowledge Centers
- Actinic Keratosis
- Biological Response Modifier
- Genital Wart
- Interleukin 6
- Cytokine
- Medication
- Basal-Cell Carcinoma
- Squamous-Cell Carcinoma
- Organ Transplantation
- Toll-Like Receptor 7