Can a common arthritis drug help stop vitiligo from spreading?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Subject male or female age over 18 years old * Diagnosis of non-segmental (symmetrical) vitiligo with body surface area ≥10% * Active non-segmental vitiligo defined by Non-segmental vitiligo with new patches or extension of old lesions during the last 6 months AND Presence of hypochromic aspect under Wood's lamp examination and/or perifollicular hypopigmentation under Wood's lamp examination. * Signed informed consent document * Male patients agreeing to use a reliable method of birth control during the study i. e. preservative and for at least 6 months following the last dose of investigational product, the patient's partner treated by methotrexate must be notified of the teratogenic risk of methotrexate and should be under effective contraception throughout the study and for at least 6 months following the last dose of investigational product. * Women of childbearing potential who are negatively tested for pregnancy and agree to use a reliable method of birth control (every month) or remain abstinent during the study and for at least 6 months following the last dose of investigational product. Methods of contraception considered acceptable include oral contraceptives, contraceptive patch, intrauterine device, vaginal ring * Patient registered to the French Social Security Exclusion Criteria: * Segmental or mixed vitiligo * Patients who have known active liver disease (with the exception of a simple liver steatosis, transaminases and/or alkaline phosphatases \> 2 ULM ) or history of liver disease in the past 2 years, whatever the related diagnosis but which could interfere with MTX safety and according to the summary of the SmPC. * Intake of restricted medications (cf section VIII.5.) or other drugs considered likely to interfere with the safe conduct of the study, as assessed by the investigator and according to the Summary of the Product Characteristics (SmPC), including any drug intakes that could interfere with methotrexate metabolism or that could enhance liver and /or hematologic toxicity and according to the SmPC * Patient with evidence or positive test for HIV, Hepatitis C virus, Hepatitis B virus (patients who are negative for hepatitis B surface antigen but positive for anti-hepatitis B anti body (HBsAb+ and HBcAb+) and negative for serum HBV DNA may participate in the study * High alcohol intake defined as more than 60 g of daily intake (approx daily intake of 0.5 l of wine or equivalent), * Patients who have a known allergy or hypersensitivity to MTX * Patients who have a known serious adverse event to MTX prior to the trial leading to MTX discontinuation in the past * Presence of significant hematologic or renal disorder or abnormal laboratory values at screening that, in the opinion of the investigator is associated with an unacceptable risk to the patient to participate in the study * Clinical laboratory test results at screening that are outside a normal reference rating for the population and are considered clinically significant, or/and have any of the following specific abnormalities: * Total white blood cell count \<3G/L * Neutrophil count \< 1.5 G/l * Lymphocytes count \< 0.5G/l * Platelet count \< 100 G/l * Aspartate aminotransferase (AST) or alanine aminotransferase (ALT)\>3 times the upper limit of normal (ULM) * Hemoglobin \<8.5g/dL (85.0 g/L) * Creatinine clearance \<40ml/min (Cockcroft formula) * For women: pregnant or breast feeding * Patients who have an active or serious infection or history of infections (bacterial, viral, fungal or mycobacteria), requiring hospitalization or intra venous anti-infectives infusion within 4 weeks prior to the baseline, * Patients who have primary or secondary active immunodeficiency * Patients who had live vaccine administration within 4 weeks prior to baseline * Patients who had already been treated by at least 250 sessions of phototherapy - Patients who have any current or active cancer (with the exception of patient with successfully treated with in situ cervix carcinoma) * Patients who had history of malignancy within 5 years prior to the trial that could contraindicate the use of an immunosuppressant * Patients who will not be available for protocol which require study visits or procedures * Patients who is not affiliated to the French Social Security system * Patients unable to give informed consent and/or comply with all required study procedures