FIT-039

Human papilloma viruses (HPVs) infect squamous epithelial cells and form verrucous lesions, or warts. Besides the psychosocial problems caused by the disfiguring warts, a subset of HPVs can be the primary etiologic agent for malignancies such as cervical cancer. However, there is no curative antiviral therapy for HPV infection. We recently found that the viral RNA transcription of DNA viruses requires cyclin dependent kinase 9 (CDK9) in the host cells, and that FIT039, a specific inhibitor of CDK9, suppressed the proliferation of DNA viruses such as herpes simplex virus 1 (HSV-1), HSV-2, human adenovirus, human cytomegalovirus, hepatitis virus B, and HPVs. Here, we describe a protocol to evaluate the safety and antiviral effect of FIT039 on common warts in human skin.

A multi-institutional, single-blind, placebo-controlled randomized phase I/II clinical trial was designed to evaluate the safety and efficacy of FIT039 on common warts on the extremities. A total of 44 adults with a primary diagnosis of verruca vulgaris on the extremities without serious comorbidities will be randomized into either the intervention group with an FIT039-releasing transdermal patch or a control group for a duration of 14 days. Outcomes will be assessed at baseline and postintervention. Participants will be further assessed at 2 months follow-up. The primary endpoint for efficacy is the resolution of the warts. The safety endpoint is the incidence of adverse events and adverse drug reactions. The secondary endpoints are changes in the dimensions of the wart, the cross-sectional area of the wart, and the number of clots within the area of the wart.

This study is the first to assess the efficacy of FIT039 and will contribute to the development of antiviral agents that can cure refractory common warts in immunocompromised patients.

UMIN Clinical Trials, UMIN000029695 . Registered on 1 November 2017.

Cutaneous warts are caused by human papilloma virus (HPV) infection. FIT039, a specific inhibitor of CDK9, suppresses the proliferation of DNA viruses in vitro.

We evaluated the safety, plasma concentrations, and efficacy of FIT039 delivered by single application of an adhesive skin patch on normal back skin and cutaneous warts.

In this placebo-controlled, dose-escalation, open-label, two-cohort phase I/II clinical trial, after a single administration of a 1% FIT039 patch, 3% FIT039 patch, or placebo on back skin, patients with cutaneous warts were treated with cryotherapy followed by a 1% FIT039 patch for 24 h in the first cohort. In the second cohort, cutaneous warts were treated with cryotherapy followed by a 3% FIT039 patch for 24 h. Adverse events and adverse drug reactions, the concentrations of FIT039, and surface area of cutaneous warts were evaluated.

Neither irritant reactions nor symptoms related to FIT039 occurred when the FIT039 patches were applied to patients' backs or on warts in ten patients. The concentrations of FIT039 were under 0.1 ng/ml at every time point. The median wart surface area at 1 week after application of the 1% FIT039 patch was similar to baseline, while that of the 3% FIT039 patch was smaller than baseline.

The FIT039 patch showed no topical or systemic adverse reactions when applied on normal skin or cutaneous warts. The safety and good adherence of the FIT039 patch are encouraging and support further studies to evaluate the efficacy of FIT039 in patients with cutaneous warts.