Scientists at 3M's pharmaceuticals division discovered the drug and 3M obtained the first FDA approval in 1997. As of 2015, imiquimod is generic and is available worldwide under many brands. In 2021, it was the 290th most commonly prescribed medication in the United States, with more than 600,000 prescriptions.[5][6]
Imiquimod 5% cream is indicated for the topical treatment of:
external genital and perianal warts (condylomata acuminata) in adults;[10]
small superficial basal-cell carcinomas (sBCCs) in adults;[10]
clinically typical, non-hyperkeratotic, non-hypertrophic actinic keratoses (AKs) on the face or scalp in immunocompetent adults when size or number of lesions limit the efficacy and / or acceptability of cryotherapy and other topical treatment options are contraindicated or less appropriate.[10]
Imiquimod 3.75% cream is indicated for the topical treatment of clinically typical, non-hyperkeratotic, non-hypertrophic, visible or palpable actinic keratosis of the full face or balding scalp in immunocompetent adults when other topical treatment options are contraindicated or less appropriate.[11]
Side effects include local inflammatory reactions, such as blisters, a burning sensation, skin redness, dry skin, itching, skin breakdown, skin crusting or scabbing, skin drainage, skin flaking or scaling, skin ulceration, sores, swelling, as well as systemic reactions, such as fever, "flu-like" symptoms, headache, and tiredness.[9][12]
People who have had an organ transplant and are taking immune-suppressing drugs should not use imiquimod.[9]
Imiquimod exerts its effect by increasing levels of the opioid growth factor receptor (OGFr). In experiments, blocking OGFr function with siRNA technology resulted in loss of any antiproliferative effect of imiquimod.[18]
Scientists at 3M's pharmaceutical division discovered imiquimod as part of a program to discover inhibitors of herpes simplex virus replication based on a known adenine derivative.[19]: 369–372 3M obtained the first FDA approval for it in 1997 as a treatment for external genital and perianal warts under the brand "Aldara".[20] In 2004, 3M obtained FDA approval to market imiquimod as a treatment for superficial basal cell carcinoma.[21]
In 2006, 3M sold its pharmaceutical business in the Americas to Graceway Pharmaceuticals, its European pharmaceutical business to Meda AB, and its pharmaceutical business in other territories to two private equity firms.[22]
Graceway declared bankruptcy in 2011, after the expiration of the patents on imiquimod, and its assets, including the rights to imiquimod branding and approvals in the Americas, were purchased by Medicis Pharmaceutical.[23]
Imiquimod 5% was approved for medical use in the European Union in September 1998.[10] Imiquimod 3.75% was approved for medical use in the European Union in August 2012.[11]
As of 2015, imiquimod is generic and is available worldwide under many brands.[1]
One randomized double-blind Phase III clinical study found clearance of genital warts (an FDA-approved indication) improved from 9% with placebo to 24.9% with 3.75% imiquimod cream applied for up to eight weeks.[24]
Imiquimod has been tested for treatment of molluscum contagiosum. Two large randomized controlled trials, however, found no evidence of effectiveness of imiquimod in treating children with molluscum contagiosum, and concerning adverse effects were also noted.[25] These disprove earlier anecdotal claims and smaller, less reliable studies.[26][27][28][29]
Imiquimod has also been tested for treatment of vulvar intraepithelial neoplasia,[30]vaginal intraepithelial neoplasia,[31]common warts (a 2012 Cochrane review found no randomized controlled trials),[32]plantar warts,[33] warts in people with suppressed immune systems,[34] flat warts on face and neck,[33] and warts under and around fingernails and toenails.[33] As of 2014, insufficient evidence exists to recommend treatment of warts (other than genital warts) with imiquimod, due to the small size of and lack of controls in existing studies.[35][33]
^"FDA Approval for Imiquimod". U.S. Food And Drug Administration. 1 January 2011. Archived from the original on 6 April 2015. Retrieved 19 October 2012. Imiquimod should be used for treatment of [superficial basal cell carcinoma] only when surgery is medically less appropriate
^"Imiquimod Cream". Guide To Cancer Drugs. American Cancer Society. Archived from the original on 7 February 2015. Retrieved 28 April 2014.
^ abMiller RL, Gerster JF, Owens ML, Slade HB, Tomai MA (January 1999). "Imiquimod applied topically: a novel immune response modifier and new class of drug". International Journal of Immunopharmacology. 21 (1): 1–14. doi:10.1016/s0192-0561(98)00068-x. PMID10411278.
^Zagon IS, Donahue RN, Rogosnitzky M, McLaughlin PJ (August 2008). "Imiquimod upregulates the opioid growth factor receptor to inhibit cell proliferation independent of immune function". Experimental Biology and Medicine. 233 (8): 968–979. doi:10.3181/0802-RM-58. PMID18480416. S2CID35164284.
^Randall L. Halcomb. TLR-7 Agonists for the Treatment of Viral Hepatitis. Chapter 10 in Successful Strategies for the Discovery of Antiviral Drugs. Issue 32 of RSC drug discovery series. Eds Manoj C. Desai and Nicholas A. Meanwell. Royal Society of Chemistry, 2013. ISBN9781849736572
^Theos AU, Cummins R, Silverberg NB, Paller AS (August 2004). "Effectiveness of imiquimod cream 5% for treating childhood molluscum contagiosum in a double-blind, randomized pilot trial". Cutis. 74 (2): 134–8, 141–2. PMID15379366.
^Bayerl C, Feller G, Goerdt S (November 2003). "Experience in treating molluscum contagiosum in children with imiquimod 5% cream". The British Journal of Dermatology. 149 (Suppl 66): 25–29. doi:10.1046/j.0366-077x.2003.05631.x. PMID14616342. S2CID23728783.
^Harwood CA, Perrett CM, Brown VL, Leigh IM, McGregor JM, Proby CM (January 2005). "Imiquimod cream 5% for recalcitrant cutaneous warts in immunosuppressed individuals". The British Journal of Dermatology. 152 (1): 122–129. doi:10.1111/j.1365-2133.2005.06322.x. PMID15656812. S2CID42369353.
^Ahn CS, Huang WW (October 2014). "Imiquimod in the treatment of cutaneous warts: an evidence-based review". American Journal of Clinical Dermatology. 15 (5): 387–399. doi:10.1007/s40257-014-0093-5. PMID25186654. S2CID26624740.
