A Phase 3 interventional study of Cantharidin in Common Warts (Verruca Vulgaris), Common Warts and Human Papilloma Virus (HPV), sponsored by Verrica Pharmaceuticals Inc.. Recruiting at 12 sites in 2 countries. Open to participants aged 2 Years and older. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by Verrica Pharmaceuticals Inc. · Phase 3, Interventional, and Treatment
People who participated in either the COVE-2 or COVE-3 study for common warts, may be eligible to enroll into this Long Term Follow Up (LTFU) study COVE-4. The main question(s) to answer in this LTFU study are:
Participants with eligible common warts present will receive YCANTH (VP-102/TO-208) with an interval of 21 (± 4) days between applications until there is a wart count of zero (ie, completed clearance has been achieved) or a maximum of 4 additional treatments. Participants with complete clearance will attend Observation Visits at intervals of 42 (± 4) days without treatment. Participants who develop a new wart after having a wart count of zero will resume Treatment Visits every 21 (± 4) days for a maximum of 4 additional treatments. All subjects will attend visits until the End-of-Study (EOS) Visit, which is on Day 378 (0/+ 8 days).
If participants still have warts present after 4 additional treatments of YCANTH (VP-102/TO-208) the wart(s) will be discontinued from study and participants will be allowed to seek treatment but should be limited to destructive therapy such as cryosurgery and warts cannot be within 10 mm of any warts that receive(d) study drug treatment . The exact interval of Treatment Visits will be determined by evaluation of the treatment site, taking into account any ongoing local skin reactions (LSRs), which are defined as temporary application site:
vesiculation, pain, pruritus, scabbing, erythema, discoloration, dryness, edema and erosion that is expected and consistent with historical treatment with YCANTH (VP-102/TO-208). Participants may receive treatment until all treatable common warts are clear, up to a maximum of 4 treatment sessions, or until Day 357, whichever occurs first.
Treatment:
For participants with warts present at the time of study entry, the first treatment application may occur on the same day as transition from the parent study. All required parent study assessments must be complete, including the final evaluation of response to treatment (ERT; as defined in Assessments and procedures).
In addition, eligibility for participation in the LTFU study must have been determined, and informed consent/assent for participation in this LTFU study obtained. YCANTH (VP-102/TO-208) will be applied by the Investigator or qualified member of the research team to treatable common warts, including an approximate 1 to 2 mm margin of healthy, surrounding skin. After YCANTH (VP-102/TO- 208) is applied, warts are to be covered with occlusive tape (occlusive tape with similar properties should be used across all clinical sites) that will remain in place overnight and should be removed 24 hours after application of study drug and just before a 24-hour ERT. Before application of study drug, wart paring, if necessary, will be completed with a sharp surgical instrument (eg, scalpel or flexible medical blade) to remove any adherent thick scale from a treatable common wart. Wart paring is required to be performed at any treatment visit when adherent thick scale is present, and the Investigator feels paring can be safely performed. Paring should be conducted by a trained practitioner and in compliance with any local regulations and should be discontinued if it results in punctate bleeding or significant pain. Not all treatable common warts may require paring. If adherent scale is not present, study drug can be applied without paring. The assessment for complete clearance may be made once all treatable common warts are evaluable and not obscured by an ongoing LSR. If the Investigator is unable to evaluate or treat 1 or more warts due to ongoing LSRs, no warts should be treated, and the visit will be documented as an Unscheduled Visit. The timing of the next treatment visit will be determined by resolution of the LSRs. The research team will be in contact with the Participant until all LSRs are resolved. Once LSRs have resolved, a Treatment Visit will be scheduled within 21 (± 4) days of the previous treatment application, noting it may be longer than 21 (± 4) days depending on the length of time until LSR resolution. All treatable common warts that are not completely clear should undergo treatment with study drug. Study duration from Days 84, 105, or 147 of the parent study (COVE-2 or COVE-3) through the final EOS visit of this LTFU study (Day 378) is approximately 294 days.
171 studies on the registry are indexed under Warts; 35 are open to participants now.
This study's planned enrollment of 250 is above the median of 70 across 155 interventional studies indexed under Warts.
Browse Warts studies →Verrica Pharmaceuticals Inc. is the lead sponsor of 10 studies on the registry; 3 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 6 (100%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Oct 22, 2026. See what changed
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Candidates will be included in the study if they:
Meet ≥ 1 of the following criteria:
Agree not to use any wart-removing product (prescription or over-the-counter) other than the study drug during the course of the study with the exception of circumstances for excluded wart types. Excluded warts include common warts located in excluded areas that will not be treated or evaluated during the study as well as genital, plantar, or anal warts:
a. If treatment of these excluded wart types is required during the study, it should be limited to destructive therapy such as cryosurgery and warts cannot be within 10mm of any warts that are under study.
Exclusion Criteria:
Candidates will be excluded from the study if they:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Excipients
The other ingredients in a medicine besides the active drug, such as fillers, colours or preservatives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Combination Product: Cantharidin
Combination Product: Cantharidin
A single-use applicator and applied in sufficient quantity to cover the entirety of each treatable common wart, including approximately a 1 to 2 mm margin of surrounding, healthy skin. The contents of no more than 2 applicators may be applied at each treatment visit. Each applicator contains 0.45 mL of 0.7% w/v cantharidin. Occlusive tape (occlusive tape with similar properties should be used across all clinical sites) will be applied to warts that have been treated. Once applied, the occlusive tape should be gently rubbed to maximize adherence to the treated area.
Incidence and severity of AEs including LSRs.
To assess the safety of YCANTH (VP-102/TO-208) by assessing adverse events (AEs), including expected local skin reactions (LSRs).
Time frame: Day of transition to this LTFU study to End of Study Visit Day 378.
Change from baseline in vital signs (body temperature)
To assess the safety of YCANTH (VP-102/TO-208) by assessing the change from baseline body temperature.
Time frame: Day of transition to this LTFU study to End of Study Visit Day 378.
Change from baseline in vital signs (pulse)
To assess the safety of YCANTH (VP-102/TO-208) by assessing the change in baseline in vital signs (pulse).
Time frame: Day of transition to this LTFU study to End of Study Visit Day 378.
Concomitant medication use
To assess the safety of YCANTH (VP-102/TO-208) by assessing concomitant medication use.
Time frame: Day of transition to this LTFU study to End of Study Visit Day 378.
Proportion of subjects achieving clearance (reduction to zero) at the Day 378 EOS Visit of all treatable warts present at Baseline*
To evaluate the efficacy of continued dermal application of YCANTH (VP-102/TO-208) when applied to each common wart once every 21 days for a maximum of 4 additional treatments. \*Baseline in the study will be either 1) Treatment Visit 1 (Day 1) of the parent study for subjects who received YCANTH (VP-102/TO-208) during the parent study; 2) the first Treatment Visit of this study for subjects who received Vehicle in the parent study; or 3) Treatment Visit 1 of the parent study for subjects who received Vehicle in the parent study and did not receive YCANTH (VP-102/TO-208) during this study.
Time frame: Baseline* to End of Study Visit Day 378.
Proportion of subjects achieving clearance of all treatable warts at each Treatment Visit after transition to this LTFU study.
To evaluate the efficacy of YCANTH (VP-102/TO-208) by assessing the proportion of subjects achieving clearance (reduction to zero) of all treatable warts at each Treatment Visit after transition to the long-term follow-up (LTFU) study and by the Day 378 EOS Visit.
Time frame: Each Treatment Visit in this study (up to 4) and by the End of Study visit Day 378
Mean percent change from baseline in the number of treatable warts present at the Day 378 EOS Visit.
To evaluate the efficacy of YCANTH (VP-102/TO-208) by assessing the change from baseline to the Day 378 EOS Visit in the number of treatable warts. \*Baseline in the study will be either 1) Treatment Visit 1 (Day 1) of the parent study for subjects who received YCANTH (VP-102/TO-208) during the parent study; 2) the first Treatment Visit of this study for subjects who received Vehicle in the parent study; or 3) Treatment Visit 1 of the parent study for subjects who received Vehicle in the parent study and did not receive YCANTH (VP-102/TO-208) during this study.
Time frame: Baseline to End of Study Visit Day 378.
Plan to share: No
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Cantharidin
Verrica Pharmaceuticals Inc.