A Clinical Study of MK-6194 for the Treatment of Vitiligo (MK-6194-007)

Inclusion Criteria:

• Has a clinical diagnosis of non-segmental vitiligo

• Has non-segmental vitiligo with disease duration of at least 6 months

• Has depigmentation contributing to Facial Vitiligo Area Scoring Index (F-VASI) ≥ 0.3at screening and baseline

• Has depigmented facial body surface area (BSA) ≥0.3% at screening and baseline

• Has Total Vitiligo Area Scoring Index (T-VASI) ≥4 at screening and baseline

• Has total body vitiligo area ≥4% at screening and baseline excluding hands and feetinvolvement

Exclusion Criteria:

• Has segmental vitiligo

• Has ≥50% leukotrichia on face or body

• Has any other dermatological diseases that would interfere with vitiligo assessments

• Has history of or current inflammatory condition other than vitiligo that, in theopinion of the investigator, could interfere with the evaluation of vitiligo

• Has a known systemic hypersensitivity to interleukin 2 (IL-2), or modified IL-2including MK-6194, or its inactive ingredients

• Has an active or clinically significant infection requiring hospitalization ortreatment with IV anti-infectives within 4 weeks prior to Randomization, ororal/intramuscular anti-infective therapy within 2 weeks prior to Randomization

• Has symptomatic heart failure (New York Heart Association class III or IV) ormyocardial infarction or unstable angina pectoris within 6 months prior to Screening

• Has a severe chronic pulmonary disease requiring oxygen therapy

• Has a transplanted organ, which requires continued immunosuppression

• Has a history of any malignancy, except for successfully treated non-melanoma skincancer or localized carcinoma in situ of the cervix

• Has evidence of active tuberculosis (TB), latent TB, or inadequately treated TB

• Has confirmed or suspected COVID-19 infection

• Has history of drug or alcohol abuse within 6 months prior to Screening

• Has had major surgery within 3 months prior to Screening OR has a major surgeryplanned during the study

• Has had an inadequate response (as evaluated by a dermatologist or local physicianspecialist equivalent) to previous treatment with a Janus kinase inhibitor (JAKi)after an appropriate treatment duration (eg, ≥12 weeks)

• Has received prohibited medications within protocol-specified timeframes prior toRandomization

• Has participated in another investigational clinical study within 4 weeks prior toRandomization

• Has donated or lost ≥1 unit of blood (approximately 500 mL) within 4 weeks prior tothe Screening Visit

• Has received cosmetic or other procedures that could interfere with evaluation ofvitiligo during the study