Efficacy and Safety of Baricitinib in Oral Lichen Planus: a Proof-of-Concept Study

Inclusion Criteria:

1. Voluntarily signed an Institutional Review Board (IRB) approved informed consent.

2. Be at least ≥ 18 years old.

3. Biopsy proven Oral Lichen Planus (OLP)

4. OLP patients with moderate to severe OLP, and must have failed or not tolerated atleast one non-corticosteroid systemic treatment for OLP (such as metronidazole,hydroxychloroquine, methotrexate, mycophenolate mofetil, azathioprine, acitretin,rituximab, thalidomide, cyclosporine, apremilast, dapsone or systemic calcineurininhibitor).

5. Subjects should practice daily oral hygiene (defined as brushing teeth twice daily)and be willing to maintain their routine oral hygiene procedure during studyparticipation.

6. Willingness to abstain from certain mouth products during the course of the study

7. Must be willing to not receive any live vaccines during and up to 30 days after theend of treatment.

8. Vaccination status of subjects should be reviewed prior to study entry. Subjectsmust be encouraged to receive non-live vaccines following centers of disease control (CDC) guidelines for vaccination of those ≥18 years of age to prevent infectiousdisease 30 days before baseline.

9. Individuals who can potentially become pregnant must have a negative urine pregnancytest at screening and must be confirmed negative at time of enrollment (baselinevisit).

10. Individuals who can potentially become pregnant must agree to use a highly effectiveform of birth control when engaging in sexual intercourse with a male partner duringthe study and for 30 days after the last dose.

11. Male subjects must be willing to use a highly effective method of contraception orpractice true abstinence from sexual intercourse during the study and for 30 daysafter the last dose.

12. Must be able to comply with study instructions and attend all study visits.

Exclusion Criteria:

1. Absolute lymphocyte count <750cells/mm^3 within 30 days of starting study drug

2. Absolute neutrophil count <1200cells/mm^3 within 30 days of starting study drug

3. Hemoglobin <10.0g/dL within 30 days of starting study drug

4. Platelet count <100,000 cells/mm^3 within 30 days of starting study drug

5. Fasting cholesterol levels >400mg/dL or >10.34mmol/L within 30 days of startingstudy drug or levels that may have required hospitalization, caused pancreatitis, orbecame life threatening.

6. Serum triglycerides >500mg/dL or >5.7mmol/L within 30 days of starting study drug.

7. Chronic liver disease with severe hepatic impairment as defined in the protocol.

8. Inadequate renal function tests defined as an estimated glomerular filtration rate (eGFR) based on the most recent available creatinine using the chronic kidneydisease epidemiology collaboration equation (CKD-EPI) creatinine 2009 equation of <60 millimeters/minute/1.73 meters squared (m^2) within 30 days of starting studydrug.

9. Ongoing active or recent clinically serious fungal, bacterial, viral, or parasiticinfection.

10. History of gastrointestinal perforation

11. History of heart attack or significant cardiovascular risk that in theinvestigator's judgement, the risks of the subject participating in the study isgreater than its benefit.

12. Hypercoagulable state such as history of deep vein thromboembolism (VTE) or strokeOR are considered at high risk of VTE.

13. History of cancer (except treated cutaneous basal cell carcinoma (BCC), cutaneoussquamous cell carcinoma in situ (cSCCis) and in situ cervical cancer) unless it canbe documented that the patient has been in a disease-free state for at least 5 yearsfor high grade cancers with the following exception:

• In case of clinical suspicion of malignancy in the oral cavity, a patient canonly be included after an excluding biopsy

• Any history of squamous cell carcinoma or melanoma (even if resected) in themouth, as well as history of other non-squamous cell carcinoma (e.g., sarcoma,salivary gland tumors) in the mouth are excluded.

14. Subjects who may have signs of lymphoproliferative disease, such as lymphadenopathyor splenomegaly unless stable for the last 5 years

15. Professional dental cleaning within 2 weeks prior to baseline

16. Patient with any un-healed oral surgery (including recent diagnostic biopsies, ifapplicable) or oral laser therapeutic wound(s) at baseline visit

17. Subjects must have failed at least one systemic therapy for OLP to be included inthe study. Appropriate washout for past medications received and stable doses forother medications should be followed as outlined in the protocol.

18. Hypersensitivity to Janus kinase (JAK) inhibitors.

19. Subjects with any serious concomitant illness that is anticipated to require the useof systemic corticosteroids or otherwise interfere with study participation orrequire active frequent monitoring (e.g., unstable chronic asthma)

20. Subjects who require major surgery within 8 weeks of baseline and/or during thestudy are excluded.

21. Current participation in another clinical study and/or having received treatmentwith any non-marketed / investigational medicinal product (drug substance or medicaldevice) within 30 days prior to baseline or 5.5 half-lives, whichever is longer.

22. Intention to become pregnant during the study period (30 days after stoppinginvestigational product)

23. Intention to breastfeed until 30 days after stopping investigational product.

24. Any other condition that in the investigator's judgement the subject's risks aregreater than the benefit from participating in the study or may interfere withinterpretation of data.