Hidradenitis SuppurativaPhase 2NCT07228390
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.
A Phase 2 study testing Ritlecitinib in people with Hidradenitis Suppurativa, run by Pfizer at 60 sites in 6 countries.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Hidradenitis Suppurativa
- What is being tested?
- Ritlecitinib
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 128 participants
- Where
- 60 sitesin 6 countries
- Study dates
- 13 Nov 2025to 5 Jan 2027
- Phase
- Phase 2
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male or female participants ≥18 to ≤75 years of age.
- 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.
Who cannot join
- Presence of ≥20 draining fistulae at Screening or BL visit
- Evidence of other active skin disease or condition at screening
- Have a known immunodeficiency disorder
- Having a history of systemic infection requiring hospitalization or parenteral therapy, including history of infection with Mycobacterium TB
- Specific Viral Infection History (incl. history of herpes zoster, HBV or HCV Infection
- Current or recent history of clinically significant severe, progressive, or uncontrolled other medical conditions
- Any medical or psychiatric condition including any active suicidal ideation in the past year or suicidal behavior in the past 5 years
Trial locations and contacts
60 sites in 6 countries.
60 sites in 6 countries
United States30 sites
Skin Care Research
Boca Raton, Florida, 33486
Columbia Dermatology & Aesthetics
Columbia, South Carolina, 29212
ClinOhio Research Services
Columbus, Ohio, 43213
Eurofins CRL
Forest, Virginia, 24551
First OC Dermatology Research Inc
Fountain Valley, California, 92708
Palmetto Clinical Trial Services - Greenville
Greenville, South Carolina, 29615
Burke Pharmaceutical Research
Hot Springs, Arkansas, 71913
Center for Clinical Studies, LTD. LLP
Houston, Texas, 77004
Olympian Clinical Research
Largo, Florida, 33770
DS Research of Kentucky
Louisville, Kentucky, 40241
Ziaderm Research LLC
North Miami Beach, Florida, 33162
Northridge Clinical Trials
Northridge, California, 91325
Essential Medical Research - Overland Park
Overland Park, Kansas, 66213
Skin and Hair Center
Overland Park, Kansas, 66213
The Indiana Clinical Trials Center, PC
Plainfield, Indiana, 46168
Stracskin
Portsmouth, New Hampshire, 03801
Integrative Skin Science and Research
Sacramento, California, 95815
Advanced Medical Research, PC.
Sandy Springs, Georgia, 30328
Wolverine Clinical Trials
Santa Ana, California, 92706
Endeavor Health
Skokie, Illinois, 60077
Revival Research Institute, LLC
Southfield, Michigan, 48034
D&H Tamarac Research Center
Tamarac, Florida, 33321
NMC Research LLC
Tampa, Florida, 33607
USF - Carol and Frank Morsani Center for Advanced Healthcare-Clinical Research Center
Tampa, Florida, 33612
Alliance Clinical Research of Tampa
Tampa, Florida, 33615
Olympian Clinical Research
Tampa, Florida, 33615
USF Florida Hearing Clinic
Tampa, Florida, 33620
Revival Research Institute, LLC
Troy, Michigan, 48084
TruDerm & TruSpa
Wellington, Florida, 33449
Options Research Group
West Lafayette, Indiana, 47906
Poland10 sites
Penta Hospitals Badania Kliniczne sp. z o.o.
Gdansk, 80-546
Dermedic Jacek Zdybski
Ostrowiec Świętokrzyski, 27-400
Uniwersytecki Szpital kliniczny im. F. Chopina w Rzeszowie
Rzeszów, 35-055
Centrum Zdrowia Dziecka i Rodziny im Jana Pawla II w Sosnowcu
Sosnowiec, 41-200
Twoja Przychodnia Szczecinskie Centrum Medyczne Sp. z o.o.
Szczecin, 71-500
Trialmed CRS - Warszawa
Warsaw, 02-482
Klinika Ambroziak Dermatologia
Warsaw, 02-953
Royalderm Agnieszka Nawrocka
Warsaw, 02-962
Cityclinic Przychodnia Lekarsko-Psychologiczna Matusiak Spółka Partnerska
Wroclaw, Lower Silesian Voivodeship, 50-566
Soft Skin Medical Center Dr Elzbieta Wojtowicz-Prus
Wroclaw, 50-551
Canada9 sites
Dermatology Research Institute
Calgary, Alberta, T2J 7E1
Laser Rejuvenation Clinics Edmonton D.T. Inc
Edmonton, Alberta, T5J 3S9
Skin Physicians Dermatology
Edmonton, Alberta, T6W 4V4
Ryan Clinical Research Inc.
Newmarket, Ontario, L3Y 5G8
DAR Clinical Research
Ottawa, Ontario, K1V 1C1
Centre de Recherche Saint-Louis inc.
Québec, G1W 4R4
CaRe Clinic
Red Deer, Alberta, T4P 1K4
North York Research Inc
Toronto, Ontario, M2N 3A6
FACET Dermatology
Toronto, Ontario, M4E 1R7
Spain5 sites
Hospital Universitario Puerta del Mar
Cadiz, 11009
Hospital Universitario Virgen Nieves
Granada, 18012
Hospital General Universitario Gregorio Maranon
Madrid, 28007
Hospital de Manises
Manises, Valencia, 46940
CHOP-Centro De Especialidades De Mollabao
Pontevedra, 36001
Germany3 sites
Universitaetsklinikum Carl Gustav Carus, Technischen Universitaet Dresden
Dresden, Saxony, 01307
Universitätsklinikum Frankfurt
Frankfurt, 60590
Universitätsklinikum Schleswig Holstein - Campus Lübeck
Lübeck, 23538
Greece3 sites
Athens Medical Center - Psychikon branch
Athens, Attica, 11525
Dermatological and Venereological Hospital Andreas Syggros
Athens, 16121
University General Hospital of Larissa
Larissa, Thessalía, 411 10
About this study
Official title: A PHASE 2, MULTICENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, 16-WEEK STUDY EVALUATING THE SAFETY AND EFFICACY OF RITLECITINIB (PF-06651600) IN ADULTS WITH MODERATE TO SEVERE HIDRADENITIS SUPPURATIVA
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:
Read more
- 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.
- Conditions
- Hidradenitis Suppurativa
- Being tested
- Ritlecitinib, Placebo
- Keywords
- Ritlecitinib
- Medical subject headings
- Hidradenitis Suppurativa
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RitlecitinibDrug
Also called Investigational Product
Participants will receive one oral dose once daily (QD), starting with a loading dose of ritlecitinib for 8 weeks, followed by maintenance for 8 weeks.
PlaceboDrug
Participant will receive matching placebo
| Study group | Role | What they receive |
|---|---|---|
| Study Intervention | Experimental | Participants will receive one oral dose once daily (QD), starting with a loading dose of ritlecitinib for 8 weeks, followed by maintenance for 8 weeks. Receives: Drug: Ritlecitinib |
| Placebo | Placebo comparator | Participants will receive matching placebo. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Difference in proportion of responders based on Hidradenitis Suppurativa Clinical Response achieving at least 50% reduction from baseline (Hidradenitis Suppurativa Clinical Response HiSCR50) in patients with HS treated with ritlecitinib versus placebo.
The difference in proportion of responders based on HiSCR50 response at Week 16 in patients with HS treated with ritlecitinib versus placebo.
Measured: Week 16
Secondary outcomes (20)
Proportion of participants achieving HiSCR50 response
The difference in proportion of responders based on HiSCR50 response at Weeks 1, 2, 4, 6, 8 and 12 in patients with HS treated with ritlecitinib versus placebo
Measured: at Weeks 1, 2, 4, 6, 8 and Week 12.
Proportion of participants achieving HiSCR75 response
The difference in proportion of responders based on HISCR75 response at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib versus placebo
Measured: at Weeks 1, 2, 4, 6, 8, 12 and Week 16.
Proportion of participants achieving HiSCR90 response
The difference in proportion of responders based on HiSCR90 response at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib versus placebo
Measured: at Weeks 1, 2, 4, 6, 8, 12 and Week 16
Response based on a on total abscess and inflammatory nodule count (AN Count) of 0 or 1
The difference in proportion of responders based on a total AN count of 0 or 1 at Week 16 in patients with HS treated with ritlecitinib and placebo
Measured: Week 16
Response based on a total AN count of 0, 1, or 2
The difference in proportion of responders based on a total AN count of 0, 1 or 2 at Week 16 in patients with HS treated with ritlecitinib and placebo.
Measured: At week 16
Percent change from Baseline(CFB) in total AN count
The difference in mean percent CFB in total AN count at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib and placebo
Measured: Weeks 1, 2, 4, 6, 8, 12 and 16.
Absolute score in Hidradenitis Suppurativa Investigator Global Assessment (HS-IGA)
The difference in mean absolute score in HS-IGA at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib and placebo
Measured: at Weeks 1, 2, 4, 6, 8, 12 and 16
CFB in Hidradenitis Suppurativa Investigator Global Assessment (HS-IGA)
Mean CFB in HS-IGA at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib and placebo
Measured: at Weeks 1, 2, 4, 6, 8, 12 and 16
Proportion of participants achieving a HS-IGA=0 or 1
The difference in proportion of responders based on HS-IGA=0 or 1 at Weeks 1, 2, 4, 6, 8, 12 and 16 in patients with HS treated with ritlecitinib and placebo
Measured: Weeks 1, 2, 4, 6, 8, 12 and 16
Participants who experience an HS flare, defined as at least a 25% increase in total AN count with a minimum increase of 2 relative to Baseline
The difference in proportion of HS flare at Weeks 4, 8, 12 and 16 in patients with HS treated with ritlecitinib and placebo
Measured: Weeks 4, 8, 12 and 16.
CFB in Hidradenitis Suppurativa Symptom Daily Diary (HSSDD)
Measured: Weeks 1, 2, 4, 6, 8, 12 and 16
Skin pain NRS30 (numeric rating scale) response, at worst and on average, respectively among participants with baseline skin pain NRS ≥3
Measured: Weeks 1, 2, 4, 6, 8, 12, and 16
Percent CFB in skin pain NRS, at worst and on average, respectively, in participants with baseline skin pain NRS ≥3
Measured: Weeks 1, 2, 4, 6, 8, 12, and 16
CFB in skin pain NRS, at worst and on average, respectively
Measured: at Weeks 1, 2, 4, 6, 8, 12, and 16
Skin pain NRS50 response, at worst and on average, respectively among participants with baseline skin pain NRS ≥3.
Measured: at Weeks 1, 2, 4, 6, 8, 12, and 16
Skin pain NRS70 response, at worst and on average, respectively among participants with baseline skin pain NRS ≥3
Measured: at Weeks 1, 2, 4, 6, 8, 12, and 16,
Incidence of treatment emergent adverse events (TEAE), adverse events (AE) and serious adverse events (SAE) leading to discontinuation
Measured: up to 24 Weeks
Incidence of clinically significant laboratory abnormalities over time
Measured: up to 24 Weeks
Absolute score and CFB in Hidradenitis Suppurativa Quality of Life (HiSQOL)
Measured: at Weeks 1, 2, 4, 6, 8, 12 and 16.
Absolute score and % CFB in International Hidradenitis Suppurativa Severity Score System (IHS4)
Measured: Weeks 1, 2, 4, 6, 8, 12 and 16.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Nov 2025
- Study start13 Nov 2025
- Primary completion8 Dec 2026 (estimated)
- Study completion5 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hidradenitis SuppurativaStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 128 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07228390
- Sponsor's protocol ID
- B7981119
- Other IDs
- 2025-522705-37-00, 2025
- Status last verified
- Oct 2026
- First submitted
- 31 Oct 2025
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.