The efficacy of a cyclin dependent kinase 9 (CDK9) inhibitor, FIT039, on verruca vulgaris: study protocol for a randomized controlled trial

BACKGROUND: 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. METHODS AND DESIGN: 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. DISCUSSION: 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. TRIAL REGISTRATION: UMIN Clinical Trials, UMIN000029695. Registered on 1 November 2017. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3570-6) contains supplementary material, which is available to authorized users.