Phase 3
N=1,052
Long-Term PF-06651600 for the Treatment of Alopecia Areata
Alopecia Areata
Bottom Line
View on ClinicalTrials.gov: NCT04006457 ↗Enrolled (actual)
1,052
Serious AEs
7.0%
Results posted
Aug 2025
Primary outcome: Primary: Main Study: Number of Participants With Treatment Emergent Adverse Events (TEAEs) Until Follow-up Visit — 401; 515 Participants
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- PF-06651600 (Drug); Tetanus and diphtheria toxoids and acellular pertussis (Tdap) vaccine (Biological); Meningococcal (groups A, C, W-135 and Y [ACWY]) oligosaccharide diphtheria CRM197 conjugate vaccine (Biological)
- Age
- Pediatric, Adult, Older Adult · 12+ yrs
- Sex
- All
- Sponsor
- Pfizer
- Primary completion
- Jun 2024
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Main Study: Number of Participants With Treatment Emergent Adverse Events (TEAEs) Until Follow-up Visit |
401; 515 | — |
| PRIMARY Main Study: Number of Participants With Serious Adverse Events (SAEs) and Adverse Events (AEs) Leading to Discontinuation Until Follow-up Visit |
30; 42; 36; 46 | — |
| PRIMARY Main Study: Number of Participants According to Categorization of Vital Signs Data Until Follow-up Visit |
11; 15; 39; 70; 45; 51 | — |
| PRIMARY Main Study: Number of Participants With Clinically Significant Abnormalities in Clinical Laboratory Values Until Follow-up Visit |
390; 490 | — |
| PRIMARY Vaccine Sub-study: Percentage of Participants With Tetanus Booster Response |
62.5 | — |
| SECONDARY Main Study: Number of Participants With Treatment Emergent Adverse Events (TEAEs) Until End of Study |
— | — |
| SECONDARY Main Study: Number of Participants With Serious Adverse Events (SAEs) and Adverse Events (AEs) Leading to Discontinuation Until End of Study |
— | — |
| SECONDARY Main Study: Number of Participants With Clinically Significant Abnormalities in Vital Signs Until End of Study |
— | — |
| SECONDARY Main Study: Number of Participants With Clinically Significant Laboratory Abnormalities Until End of Study |
— | — |
| SECONDARY Main Study: Percentage of Participants Achieving Response Based on Severity of Alopecia Tool (SALT) Overall Score <=10 at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
0.9; 27.9; 16.3; 32.6; 37.7; 39.1 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Response Based on Alopecia Areata (AA) SALT Score <=10 at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
1.0; 28.5; 17.7; 33.5; 39.6; 39.8 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Response Based on SALT Overall Score <= 20 at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
2.5; 35.6; 27.7; 40.2; 50.1; 50.4 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Response Based on AA SALT Score <=20 at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
2.6; 36.6; 27.8; 41.2; 51.2; 51.0 | — |
| SECONDARY Main Study: Change From Baseline in SALT Overall Score at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
-2.8; -41.8; -23.6; -46.0; -36.6; -52.0 | — |
| SECONDARY Main Study: Change From Baseline in AA SALT Score at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
-2.9; -42.8; -23.8; -47.0; -37.3; -52.8 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Atleast 75% Improvement in Overall SALT Score From Baseline at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
0.9; 37.4; 21.5; 42.6; 44.2; 51.3 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Atleast 75% Improvement in AA SALT Score From Baseline at Months 1, 3, 6, 9, 12, 15, 18, 21, 24, 28, 32 and 36 |
1.0; 38.6; 22.8; 43.6; 45.6; 51.8 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Atleast 2-Grade Improvement From Baseline or Absolute Score of 3 in the Eyebrow Assessment (EBA) at Months 1, 3, 6, 12, 18, 24 and 36 in Participants Without Normal EBA Score at Baseline |
4.3; 38.8; 22.3; 43.4; 37.6; 50.0 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Atleast 2-Grade Improvement From Baseline or Absolute Score of 3 in the Eyelash Assessment (ELA) at Months 1, 3, 6, 12, 18, 24 and 36 in Participants Without Normal ELA Score at Baseline |
3.4; 37.7; 17.7; 42.5; 36.7; 47.1 | — |
| SECONDARY Main Study: Percentage of Participants Achieving Patient's Global Impression of Change (PGI-C) Score of Moderately Improved or Greatly Improved at Months 1, 3, 6, 9, 12, 18, 24 and 36 |
16.4; 55.2; 57.0; 59.3; 68.8; 66.4 | — |
| SECONDARY Main Study: Change From Baseline in Alopecia Areata Patient Priority Outcomes (AAPPO) Domain Scores at Months 1, 3, 6, 9, 12, 18, 24 and 36: Emotional Symptoms and Activity Limitations |
-0.33; -0.84; -0.61; -0.86; -0.77; -0.95 | — |
| SECONDARY Main Study: Percentage of Participants With Response Based on Hair Loss Improvement From Baseline in Alopecia Areata Patient Priority Outcomes (AAPPO) Domain Scores at Months 1, 3, 6, 9, 12, 18, 24 and 36, Among Participants With Score >=2 at Baseline |
9.8; 37.2; 27.5; 38.5; 45.7; 46.4 | — |
| SECONDARY Main Study: Change From Baseline in Depression Subscale Score of Hospital Anxiety and Depression Scale (HADS) at Months 1, 3, 6, 9, 12, 18, 24 and 36 |
-0.1; -0.6; -0.4; -0.5; -0.5; -0.7 | — |
| SECONDARY Main Study: Change From Baseline in Anxiety Subscale Score of Hospital Anxiety and Depression Scale (HADS) at Months 1, 3, 6, 9, 12, 18, 24 and 36 |
-0.6; -0.9; -0.7; -0.9; -0.9; -1.2 | — |
| SECONDARY Main Study: Percentage of Participants With Improvement on HADS Depression Score at Months 1, 3, 6, 9, 12, 18, 24 and 36 |
53.1; 56.9; 63.3; 52.6; 70.0; 70.4 | — |
| SECONDARY Main Study: Percentage of Participants With Improvement on HADS Anxiety Score At Months 1, 3, 6, 9, 12, 18, 24 and 36 |
51.1; 54.2; 46.5; 59.6; 53.6; 62.5 | — |
| SECONDARY Vaccine Sub-study: Percentage of Participants With Anti-tetanus Antibody Level >=1.0 International Units Per Milliliter (IU/mL) at Month 1-Tdap Vaccination |
100 | — |
| SECONDARY Vaccine Sub-study: Percentage of Participants With Anti-tetanus Antibody Level >=0.1 IU/mL at Month 1-Tdap Vaccination |
100 | — |
| SECONDARY Vaccine Sub-study: Percentage of Participants With >=4 Times Increase in Anti-tetanus Antibody Level From Baseline at Month 1-Tdap Vaccination |
50 | — |
| SECONDARY Vaccine Sub-study: Geometric Mean Fold Change in Anti-tetanus Levels Above Baseline Values at Month 1-Tdap Vaccination |
5.7 | — |
| SECONDARY Vaccine Sub-study: Geometric Mean Concentrations (GMCs) of Anti-tetanus Antibody Levels at Month 1-Tdap Vaccination |
8.4 | — |
| SECONDARY Vaccine Sub-study: Percentage of Participants With Human Serum Bactericidal Activity (hSBA) Titer >=1:8 at Month 1 Post-vaccination for Serogroup C-Meningococcal ACWY Vaccination |
20 | — |
| SECONDARY Vaccine Sub-study: Percentage of Participants With hSBA Titer >=1:4 at Month 1 Post-vaccination for Serogroup C-Meningococcal ACWY Vaccination |
40 | — |
| SECONDARY Vaccine Sub-study: Geometric Mean Titers (GMT) of Antibodies for Serogroup C at Baseline and Month 1-Meningococcal ACWY Vaccination |
5.7; 14.1 | — |
| SECONDARY Vaccine Sub-study: Number of Participants With SAEs |
0; 0 | — |
| SECONDARY Vaccine Sub-study: Number of Participants With AEs |
3; 1 | — |
| SECONDARY Vaccine Sub-study: Number of Participants With AEs Leading to Discontinuation |
0; 0 | — |
Summary
This is a global Phase 3 study to evaluate the safety and effectiveness of an investigational study drug (called PF-06651600) in adults and adolescents (12 years and older) who have alopecia areata. Eligible patients from the prior studies B7931005 (NCT02974868) and B7981015 (NCT03732807) will have an opportunity to enroll as well as patients who have not previously participated in either of these studies. The study is open-label and all patients entering the study will receive active study drug.
A sub-study of approximately 60 adult patients who are participating in the B7981032 study will be conducted at select sites in the US, Australia and Canada. The sub-study will evaluate the immune response to tetanus and meningococcal vaccines in patients who have received a minimum of 6 months of 50 mg PF-06651600.
Eligibility Criteria
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 =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 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
Data sourced from ClinicalTrials.gov (NCT04006457). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.