A 16-Week Study to Learn About the Study Medicine Called Ritlecitinib in Adults With Long Lasting Painful Red Skin Lumps, Known by the Medical Term, Hidradenitis Suppurativa, or HS.

What this study involves

The registry does not currently label this study as recruiting. Ask about its status before planning a screening visit.

Study type

Interventional

Phase

Phase 2

Age range

18 years - 75 years

Sex eligible

All sexes

Healthy volunteers

Not accepted

Participants

128 Actual

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

The purpose of this study is to learn about the safety and effects of the study medicine (called Ritlecitinib) for the possible treatment of hidradenitis suppurativa (HS). HS is a disease causing long lasting painful red skin lumps.

This study is seeking participants who:

• have moderate or severe HS
• have previously received antibiotics for HS that did not help, or could not tolerate antibiotics Participants will be randomly (like a flip of coin) assigned to receive either the study medicine or a placebo (a pill that looks like the study medicine but does not contain any medicine). The study medicine or placebo will be taken by mouth once daily at home. For the first part of the study, participants will receive a loading (starting) dose. For the next part of the study, participants will receive a maintenance (ongoing) dose.

Participants will take part in the study for about 24 weeks (about 6 months). There will be about 10 study clinic visits: a screening visit, Day 1, and then every 1, 2, or 4 weeks until week 16. At each visit, participants will report on their health and have tests such as physical exams, blood and urine tests, vital signs, chest X-rays, ECGs, hearing tests, and questionnaires. Participants will record when they take the study medicine and their HS symptoms every day in an eDiary on a mobile phone.

The experiences of participants receiving the study medicine will be compared to those receiving placebo to help see if the study medicine is safe and effective.

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

Key Eligibility Criteria:

Inclusion Criteria:

1. Male or female participants ≥18 to ≤75 years of age.
2. Participants with a diagnosis (based on clinical history and physical examination) of moderate to severe HS for at least 6 months prior to Screening Visit and inadequate response to at least 4-week (28 days) treatment with oral antibiotics for the treatment of HS.

Exclusion Criteria:

1. Presence of ≥20 draining fistulae at Screening or BL visit
2. Evidence of other active skin disease or condition at screening
3. Have a known immunodeficiency disorder
4. Having a history of systemic infection requiring hospitalization or parenteral therapy, including history of infection with Mycobacterium TB
5. Specific Viral Infection History (incl. history of herpes zoster, HBV or HCV Infection
6. Current or recent history of clinically significant severe, progressive, or uncontrolled other medical conditions
7. Any medical or psychiatric condition including any active suicidal ideation in the past year or suicidal behavior in the past 5 years

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Random assignment

Masking

Triple masked

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (57)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

57 locations

Study team and timeline

Lead sponsor

Pfizer

Study start

Nov 13, 2025 Actual

Primary completion

Dec 8, 2026 Estimated

Study completion

Jan 5, 2027 Estimated

First posted

Nov 14, 2025 Actual

Last updated

Nov 10, 2026 Actual

Official study contacts

No central contact is listed. Check the locations and the official record.