Inclusion Criteria:

• Written informed consent must be obtained before any assessment is performed.
• Female and male patients ≥ 18 years of age.
• Subjects must have biopsy-confirmed forms of cutaneous lichen planus (CLP), mucosal lichen planus (MLP), or active lichen planopilaris (LPP) eligible for systemic therapy based on the following criteria: -rated IGA of ≥ 3 (moderate or severe) AND -inadequate response to topical corticosteroids of high-ultrahigh potency in the opinion of the investigator.
• If using any of the allowed topical treatments on the affected areas, the dose and application frequency should remain stable for 2 weeks prior to randomization and until Week 16.

Exclusion Criteria:

• Clinical history suspicious for lichenoid drug eruption.
• Lichen planus pigmentosus.
• Clinical picture or history suspicious of paraneoplastic mucosal lichen planus.
• Subjects whose lichen planus is a predominantly bullous variant.
• Mucosal LP of the oral cavity or gastrointestinal involvement requiring the patient to use parenteral nutrition or feeding tube.
• Clinical picture of scarring alopecia without active inflammation.
• Clinical picture of burnt-out cicatricial alopecia (alopecia of Brocque).
• Patients diagnosed with frontal fibrosing alopecia (FFA) without active patches of LPP.
• Clinical picture of LPP in patients who have already failed 3 or more systemic immunosuppressive or immunomodulatory agents (e.g., systemic steroids, hydroxychloroquine, cyclosporine, methotrexate and mycophenolate mofetil).
• Currently enrolled in any other clinical trial involving any investigational agent or device.
• Previous exposure to any other biologic drug directly targeting IL-17A or IL-17RA (e.g. secukinumab, ixekizumab or brodalumab) or IL-23/p19 (e.g. tildrakizumab, guselkumab, risankizumab).
• Diagnosis of active infectious diseases of the skin, scalp or mucosa (for example bacterial, viral or fungal infections of the mouth) that may interfere with the assessment of the study disease or require treatment with prohibited medications.
• Diagnosis of active inflammatory diseases of the skin, scalp or mucosa other than lichen planus that may interfere with the assessment of the study disease or require treatment with prohibited medications.
• Presence of any other skin condition that may affect the evaluations of the study disease.
• Underlying conditions (including, but not limited to metabolic, hematologic, renal, hepatic, pulmonary, neurologic, endocrine, cardiac, infectious or gastrointestinal) and/or presence of laboratory abnormalities which in the opinion of the investigator significantly immunocompromises the subject and/or places the subject at unacceptable risk for receiving an immunomodulatory therapy.
• Current, severe, progressive or uncontrolled diseases that render the patient unsuitable for the trial, including any medical or psychiatric condition that, in the Investigator's opinion, would preclude the participant from adhering to the protocol or completing the study per protocol.