An exploratory, prospective, open-label trial of ingenol mebutate gel 0.05% for the treatment of external anogenital warts

Immunothrombotic Mechanisms Induced by Ingenol Mebutate Lead to Rapid Necrosis and Clearance of Anogenital Warts

Ingenol mebutate (IM) is highly effective in the treatment of human papillomavirus (HPV)-induced anogenital warts (AGW) leading to fast ablation within hours. However, the exact mode of action is still largely unknown. We performed dermoscopy, in vivo confocal microscopy (CLM), histology, immunohistochemistry, and immunofluorescence to gain insights in mechanisms of IM treatment in AGW. In addition, we used in vitro assays (ELISA, HPV-transfection models) to further investigate in vivo findings. IM treatment leads to a strong recruitment of neutrophils with thrombosis of small skin vessels within 8 h, in a sense of immunothrombosis. In vivo and in vitro analyses showed that IM supports a prothrombotic environment by endothelial cell activation and von Willebrand factor (VWF) secretion, in addition to induction of neutrophil extracellular traps (NETosis). IM superinduces CXCL8/IL-8 expression in HPV-E6/E7 transfected HaCaT cells when compared to non-infected keratinocytes. Rapid ablation of warts after IM treatment can be well explained by the observed immunothrombosis. This new mechanism has so far only been observed in HPV-induced lesions and is completely different from the mechanisms we see in the treatment of transformed keratinocytes in actinic keratosis. Our initial findings indicate an HPV-specific effect, which could be also of interest for the treatment of other HPV-induced lesions. Larger studies are now needed to further investigate the potential of IM in different HPV tumors.

Ingenol Mebutate Gel 0.05% in the Treatment of Anogenital Warts: A Prospective Controlled Trial Comparing It With Topical Podophyllin Solution 25

BACKGROUND

Anogenital warts (AGWs) are a common therapeutic challenge. All therapies are associated with burning, pain, and frustrating high rate of recurrence. The search for a new alternative continues. Recently, a diterpene ester extracted from the Euphorbia peplus plant (ingenol mebutate [IM]) has been shown to possess activity against AGWs.

OBJECTIVE

This study aimed to compare and evaluate the therapeutic efficacy and safety of topical 0.05% ingenol gel with another herbal extract medication (topical 25% podophyllin solution) in treatment of AGWs.

METHODS

This was a comparative single blinded nonrandomized, 2-arm trial of ingenol 0.05% gel versus podophyllin solution 25% administered up to 6 times to patients with AGWs. To evaluate the therapeutic efficacy, the complete clearance rate and recurrence rate were assessed 1 and 12 weeks after last treatment, respectively. Safety was assessed by occurrence and severity of pain and local skin reaction (LSR).

RESULTS

Of 31 and 36 patients in the IM group and podophyllin group who completed the study, initial complete resolution was observed in 20 (64.5%) and 14 (38.9%) patients, respectively (P = 0.03). The initial clearance was faster in the IM group (2.00 ± 0.91 weeks) compared with the podophyllin group (4.21 ± 1.05 weeks, P = 0.00). After 3 months, recurrence was seen in 13 (65.0%) of 20 patients in the IM group and 6 (42.8%) of 14 in the podophyllin group (P = 0.20). The number of patients with complete resolution after 3 months was not different between the 2 groups (7/31 in the IM group and 8/36 in the podophyllin group, P = 0.97). The mean ± SD severity scores for LSR and pain in the IM group were 6.65 ± 1.76 and 6.13 ± 2.57, respectively, which was significantly higher than their scores (3.39 ± 1.57 and 2.58 ± 1.38) in the podophyllin group (P = 0.00).

CONCLUSION

Ingenol mebutate 0.05% gel is effective as podophyllin 25% solution in treating AGWs, with further benefit of being much more rapid. However, high recurrence rate, sever pain, and LSR limit its use.

Ingenol mebutate for the management of cryotherapy-resistant anogenital warts

Ingenol mebutate (IM), as an active compound, is derived from the sap of the Euphorbia peplus, which is an FDA-approved plant for the treatment of actinic keratosis. Some reports have demonstrated that the IM gel 0.05% is safe and effective in the treatment of external anogenital warts (AGWs) but the efficacy of the drug on the recalcitrant AGWs is not clear. This article assesses the efficacy and safety of the IM gel 0.05% for cryotherapy -resistant AGWs. Totally, 15 cryotherapy-resistant patients with AGWs (including 8 men and 7 women) and a mean age of 34 years old (age range of 23-50 years old) were enrolled in this study. IM gel 0.05% was applied carefully on the AGWs every two weeks for a maximum of three cycles. The complete clearance rate and recurrence rate were assessed 1 week and 3 months after the last treatment, respectively. Safety was assessed by the occurrence of local skin reaction and the severity of pain was evaluated using the 10-point Visual Analogue Scale. Initially, the AGWs were cleared completely in 10 (66%) patients while 4 (40%) and all of (100%) the patients experienced a recurrence in the 3- and 12-months follow-ups, respectively. All the 15 patients experienced some degrees of pain and local adverse reactions. The mean score of the reported pain was equal to 5.87 ± 2.39. The use of IM gel 0.05% in the treatment of the difficult-to-treat cases of AGWs is associated with a high recurrence rate despite the initial rapid and effective clearance of the lesions. Also, the high level of local adverse reactions and severe pain are other prohibitive factors in the treatment of recalcitrant AGWs with the IM.

Successful treatment of condylomata acuminata at the urethral meatus with high-dose ingenol mebutate gel: Report of two cases

Condylomata acuminata (CA), or anogenital warts, is the most common sexually transmitted infection. Treatments for CA generally have suboptimal recurrence rates, which results in a need for repeated treatments and adds to the already negative impact on the patients’ quality of life. CA can present at the urethral meatus, which is a particularly challenging anatomic location from a therapeutic perspective. We report two cases of CA at the urethral meatus successfully treated with topical application of high-dose ingenol mebutate gel.