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5% KOH Solution vs. Placebo and Diclofenac Gel for the Treatment of Actinic Keratosis

Prospective, Three-armed, Randomised, Double-blind Study to Evaluate the Efficacy and Safety of the Treatment of Mild and Moderate Actinic Keratosis With a 5% Potassium Hydroxide Solution (Solcera, Medical Device) Versus Placebo and Investigator-blinded Comparison With 3% Diclofenac Gel (Solaraze, Medicinal Product) (Regulated by the Laws for Both Medical Devices and Medicinal Products)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT04552327
Acronym
KOHDIAK
Enrollment
631
Registered
2020-09-17
Start date
2020-10-14
Completion date
2023-01-24
Last updated
2024-03-05

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Actinic Keratosis

Keywords

Actinic Keratosis, Solcera, Prospective, Multicentric, Monitored, Efficacy, Safety, Potassium Hydroxide, Randomized, Double-Blind

Brief summary

The KOHDIAK study is a prospective, three-armed, randomised, double-blind study to evaluate the efficacy and safety of the treatment of mild and moderate actinic keratosis with a 5% potassium hydroxide solution (Solcera, medical device) versus placebo and investigator-blinded comparison with 3% diclofenac gel (Solaraze, medicinal product). It is performed in accordance with both the laws in force for clinical trials with medical devices and those with medicinal products.

Interventions

DRUGSolaraze

Twice daily application for a duration of 60 days

DEVICEPlacebo

Twice daily application for a duration of 4 weeks followed by another 4 weeks without treatment (up to 2 potential repetitions of this 8-week cycle)

DEVICESolcera

Twice daily application for a duration of 4 weeks followed by another 4 weeks without treatment (up to 2 potential repetitions of this 8-week cycle)

Sponsors

Gesellschaft für Therapieforschung mbH
CollaboratorINDUSTRY
Infectopharm Arzneimittel GmbH
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Age ≥ 18 years and \< 90 years * Actinic keratosis grade I (mild) or II (moderate) according to the definition by Olsen with palpable or clinically/dermatoscopically apparent keratosis * Either lesions being well accessible/treatable by the patient or presence of a second person to do the daily applications * Written informed consent by the patient

Exclusion criteria

* Number of initial lesions to be treated ≥ 6 * Overall size of the area to be treated \> 25 cm2 * Size (maximum diameter) of single lesion to be treated \> 20 mm * Lesions in close proximity to the eyes, eyelids, nostrils, mouth or mucosal tissue * Need for topical treatment of cancerous area * Presence of a relapsing, persistent, indurated, thickened, painful, bleeding, ulcerated and/or rapidly growing lesion * Existing skin cancer (all forms of skin cancer incl. basal-cell carcinoma and squamous cell carcinoma) in the area to be treated in this study * Dermal injuries, skin infection or exfoliative dermatitis in the area to be treated in this study * Other skin diseases in the area to be treated in this study that affect the diagnostic assessment * Pharmacological or physical local therapy of actinic keratosis (or application of the active ingredients used in the pharmacological therapy) in the area to be treated in this study during the last 4 weeks * Primary or secondary immunodeficiency * Treatment with interferons, interferon inducers, immunomodulators or systemic corticosteroids during the last 4 weeks * Treatment with oral isotretinoin during the last 6 months * Intracranial bleeding in the medical history or generally increased primary bleeding tendency * Known intolerance/hypersensitivity to one of the ingredients of the investigational products, especially to diclofenac, parabens or benzyl alcohol as well as to NSAIDs, in particular acetylsalicylic acid * Pregnancy and lactation * Women of child-bearing potential either wishing to become pregnant or without effective contraception * Other serious diseases, which are (according to the investigator's assessment) in conflict with the study participation (i.a. also in view of risk factors for a severe course of a potential COVID-19 disease in case of a SARS-CoV-2 infection) * Obvious unreliability or lack of cooperation * Known addiction to alcohol, medicinal products or drugs * Dependency on the sponsor or an investigator * Participation in a clinical trial during the last 30 days * Previous participation in the present clinical trial * Participation of a family member (in the same household) in the present clinical trial

Design outcomes

Primary

MeasureTime frameDescription
Treatment successAt the control visit at the end of treatment (EOT, i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60)Treatment success, defined as complete, dermatoscopically confirmed remission of all initial actinic keratosis (AK) lesions identified at treatment start that have been treated with the investigational product (Complete Clearance)

Secondary

MeasureTime frameDescription
(Healing) status of AK lesionsAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)(Healing) status of AK lesions (number of proliferating lesions, unchanged/stable lesions, lesions being in remission or showing partial remission, lesions with complete remission, and relapses; overall and grouped by localisation and size (0-5 mm, 6-10 mm, 11-15 mm, 16-20 mm)); analysed for a) initial AK lesions identified at treatment start that have been treated with the investigational product, b) new AK lesions appearing in the treated area after treatment start, c) all AK lesions (i.e. a) + b))
Overall number of AK lesionsAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Overall number of initial AK lesions identified at treatment start that have been treated with the investigational product (i.e. without AK lesions with complete remission)
Mean size of AK lesionsAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Mean size of initial AK lesions identified at treatment start that have been treated with the investigational product (lesion size determined by largest diameter)
Partial clearanceAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Number of patients with partial clearance (i.e. all patients with at least 75% of the initial AK lesions identified at treatment start being assessed with complete remission)
Reduction of AK lesion numberAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Reduction of AK lesion number per patient (in % compared to the number of initial AK lesions identified at treatment start) analysed for initial AK lesions identified at treatment start that have been treated with the investigational product
Clinical responseAt all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Clinical response, i.e. the number of patients with at least one AK lesion being assessed with complete remission
Lesion-based treatment success (without consideration of relapses)At all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Number of initial AK lesions identified at treatment start that have been treated with the investigational product, which showed complete remission at least once between treatment start and EOT
Lesion-based treatment success (with consideration of relapses)At all control/follow-up visits with evaluation of lesions (i.e. for Solcera/Placebo 8 weeks (+ potentially 16 weeks) and 24 weeks after treatment start; for Solaraze Day 30, Day 60, Day 90, 24 weeks)Number of initial AK lesions identified at treatment start that have been treated with the investigational product, which showed complete remission at the respectively analysed visit
Patients with relapseAnalysed at the follow-up visit 24 weeks after treatment start for the time period between treatment start and the follow-up visitNumber of patients with at least one initial AK lesion being assessed as relapse after previous Complete Clearance (definition see above), analysed for the time period between treatment start and the follow-up visit after 24 weeks and analysed in reference to a) the number of all patients and b) the number of those patients with previous Complete Clearance
Treatment successFor Solaraze at day 90Treatment success, defined as complete, dermatoscopically confirmed remission of all initial AK lesions identified at treatment start that have been treated with the investigational product (Complete Clearance)
Efficacy assessment by physicianAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startAssessment of the efficacy (scale based on school grades 1-6) by the treating physician
Efficacy assessment by patientAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startAssessment of the efficacy (scale based on school grades 1-6) by the patient
Tolerability assessment by physicianAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startAssessment of the tolerability (scale based on school grades 1-6) by the treating physician
Tolerability assessment by patientAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startAssessment of the tolerability (scale based on school grades 1-6) by the patient
Overall assessment by physicianAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startOverall assessment (scale based on school grades 1-6) by the treating physician
Overall assessment by patientAt EOT (i.e. for Solcera/Placebo at the end of cycle 1, 2 or 3 (each cycle is 56 days, number of cycles depends on course of remission), for Solaraze day 60) and at the follow-up visit 24 weeks after treatment startOverall assessment (scale based on school grades 1-6) by the patient
Adverse Events, Serious Adverse Events, Adverse ReactionsIn the time period between start of treatment and the follow-up visit (24 weeks after treatment start)Number and frequency of Adverse Events, Serious Adverse Events and Adverse Reactions
DropoutsIn the time period between start of treatment and the follow-up visit (24 weeks after treatment start)All dropouts (incl. specification of reason and date)
ComplianceAnalysed for the respective time period of scheduled product application, i.e. Day 0 until Day 60 for Solaraze and 1-3x 28 days (depeding on number of cycles) for Solcera/PlaceboCompliance of the patients with the application schedule of the respective investigational product (based on entries in the patient diary and only overruled by the weight of returned investigational products in case of clear discrepancies)
Lesions with relapseAnalysed at the follow-up visit 24 weeks after treatment start for the time period between treatment start and the follow-up visitNumber of initial AK lesions being assessed as relapse, analysed for the time period between treatment start and the follow-up visit after 24 weeks and analysed in reference to a) the number of all initial lesions and b) the number of those initial lesions with previous complete remission

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026