This purpose of this trial was to investigate the molecular signature of frontal fibrosing alopecia (FFA) and the effect of delgocitinib cream 2% on reversing the FFA disease signature in active lesions. The trial also investigated the clinical effect of delgocitinib cream on FFA compared to a placebo cream.

Inclusion criteria

For Group 1 only (subjects with FFA):

1. Male or female subject aged 18 years of age or older at the time of consent.
2. Subject has clinically confirmed diagnosis of FFA.
3. Subject has a target area with a perifollicular erythema score ≥ 2 and a perifollicular scale score ≥ 2 at Screening and Day 1.

For Group 2 only (healthy subjects):

1. Female subject aged 45 years of age or older at the time of consent.
2. Female is postmenopausal.
3. Subject is in good general health.

Exclusion criteria

For all subjects:

1. Subject is a female who is breastfeeding, pregnant, or who is planning to become pregnant during the trial.
2. Presence of hepatitis B or C infection or HIV infection at screening.

For Group 1 only (subjects with FFA):

1. History of other scalp/hair disease including discoid lupus erythematosus and central centrifugal cicatricial alopecia.
2. Subject who has undergone scalp reduction surgery or hair transplantation.
3. Subject is known to have immune deficiency or is immunocompromised.
4. Subject has used intralesional scalp corticosteroids or platelet rich plasma injection in the last 4 weeks prior to randomization.
5. Subject has used systemic treatment with immunosuppressive/modulating medication or medication within 4 weeks prior to randomization.
6. Subject has used any topical medicated treatment that could affect FFA within 2 weeks prior to randomization.
7. Subject has received any phototherapy within 4 weeks prior to randomization.

For Group 2 only (healthy subjects):

1. Subject has a history of skin disease or presence of skin condition that, in the opinion of the investigator, would interfere with the trial assessments.
2. Subject has used a topical medicated treatment on the targeted skin sites within 2 weeks prior to trial assessments.