Intra-oral Treatment of OLP With Rivelin®-CLO Patches

Inclusion Criteria: * OLP patients with at least one visible and measurable symptomatic ulcerative OLP lesion, assessable via OLP Clinician Reported Outcome Measure (OLPClinROM). * Diagnosis of LP histologically confirmed by result of either an existing clinically relevant biopsi or a new clinically representative biopsy at first screening visit (i.e. a biopsy report either indicative of OLP, LP or indicative of lichenoid inflammation will be sufficient). * Patients aged ≥ 18 years. * Patients practicing daily oral hygiene (by tooth brushing and/or mouth rinse) and willing to maintain at least their routine oral hygiene procedure during study participation. * Willingness to keep already used permitted concomitant medication, food supplements (e.g. probiotics) or herbals, which might have in the discretion of the investigator a potential influence on OLP, on a stable basis during the study. Exclusion Criteria: * Patients requiring more than 6 patches (corresponding to an area of approximately 3 cm2 per patch) to cover symptomatic ulcerative and erythematous OLP lesions at baseline visit. * Ongoing active visible fungal, bacterial or viral infection of oral mucosa, including ongoing treatment of those at baseline. * Patient with any un-healed oral surgery (including recent diagnostic biopsies, if applicable) or oral laser therapeutic wound(s) at baseline visit. * Any of the following systemic treatments prior to baseline visit and throughout the study: * Protease inhibitors used for the treatment of HIV (e.g. atazanavir, idinavir, nelfinavir, etc.): 1 week * Corticosteroids (i.v., intra articular, intra-lesional): 4 weeks * Antimycotics: 4 weeks The following systemic treatments are allowed, if on stable dose for a defined period of time to baseline and throughout the study. * Antibiotics: 4 weeks * Corticosteroids (oral, rectal, inhalative) washout/stable with maxinum dose of 10 mg daily prednisolone or equivalent for 4 weeks. * Retinoids: 12 weeks * Immunosuppressive drugs (e.g. azathioprine, cyclosporine, mycophenolate mofetil, or biologics): 12 weeks * Any of the following topical treatments used in the oral cavity prior to baseline visit: * Corticosteroids: 2 weeks * Antibiotics: 2 weeks * Cyclosporine: 2 weeks * Tacrolimus, pimecrolimus: 2 weeks * Antimycotics: 2 weeks * Retinoids: 4 weeks * Phototherapy in oral cavity prior to baseline visit: UVB, PUVA. * Current participation in another clinical study and/or having received treatment with any non-marketed / investigational medicinal product (drug substance or medical device) within 4 weeks prior to screening. * Known or suspected intolerance/hypersensitivity/resistance to clobetasol propionate or any component of the investigational medicinal product. * Any history of squamous cell carcinoma (even if resected), as well as history of other non-squamous cell carcinoma (e.g. sarcoma, salivary gland tumors) that have been managed with radiation or chemotherapy. * History of cancer (except resected cutaneous basal cell carcinoma and except in situ cervical cancer) unless it can be documented that the patient has been in a disease-free state for at least 5 years, or at least 2 years in a disease-free state for low-grade cancers. In case of clinical suspicion of malignancy in the oral cavity, a patient can only be included after an excluding biopsy. * Professional dental cleaning within 2 weeks prior to baseline and unwillingness to refrain from professional dental cleaning during study conduct. * Close affiliation with the investigator (e.g. a close relative) or persons working at the study sites or patient who is an employee of the Sponsor's company. * Pregnant, confirmed by a positive pregnancy test, or nursing (lactating) women, or women of childbearing potential (WOCP) planning to become pregnant or WOCP not using or willing to continue to use a defined highly effective method of contraception throughout the study.