Long-Term PF-06651600 for the Treatment of Alopecia Areata

Inclusion Criteria-

For de novo participants and participants from Study B7931005 and B7981015 with >30 days between first visit in B7981032 and last dose in the prior study:

• Clinical diagnosis of alopecia areata (AA) with no other cause of hair loss. Androgenetic alopecia coexistent with AA is allowed.

• De novo participants >=12 to <18 years of age: >=50% terminal hair loss of the scalp due to AA, including alopecia totalis and alopecia universalis

• De novo participants >=18 years of age and participants from Study B7931005 or B7981015 with >30 days between first visit in B7981032 and last dose in the prior study: >=25% terminal hair loss of the scalp due to AA, including alopecia totalis and alopecia universalis

• No evidence of terminal scalp hair regrowth within 6 months (de novo only)

• Current episode of terminal scalp hair loss <=10 years (de novo only)

Exclusion Criteria-

For de novo participants and participants from Study B7931005 and B7981015 with >30 days between first visit in B7981032 and last dose in the prior study:

• Hearing loss with progression over previous 5 years, or sudden hearing loss, or middle or inner ear disease, or other auditory condition that is considered acute, fluctuating or progressive

• History of or current malignancies with the exception of adequately treated or excised non metastatic basal cell or squamous cell cancer of the skin or cervical carcinoma in situ

• History of a single episode of disseminated herpes zoster or disseminated herpes simplex, or a history of more than one episode of localized, dermatomal herpes zoster

• Infection requiring hospitalization, or parenteral antimicrobial therapy within 6 months prior to Day 1

Exclusion criteria for all participants:

• Participants who have previously taken Janus kinase (JAK) inhibitors other than PF-06651600 must have received the last dose >12 weeks prior to the screening visit