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Alopecia AreataPhase 2Allegro2aNCT04517864

PLACEBO-CONTROLLED SAFETY STUDY OF RITLECITINIB (PF-06651600) IN ADULTS WITH ALOPECIA AREATA

A Phase 2 study testing PF-06651600 in people with Alopecia Areata, run by Pfizer at 38 sites in 4 countries.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

This is a global Phase 2a randomized, double-blind, placebo-controlled study to evaluate the safety and tolerability of ritlecitinib in adults aged 18 to ≤50 years of age with ≥25% scalp hair loss due to Alopecia Areata (AA). Read more about this study

Who is it for?
Ages 18 to 50 years
Conditions the study is for
Alopecia Areata
What is being tested?
PF-06651600
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
71 participants
Where
38 sitesin 4 countries
Study dates
15 Sep 2020to 7 May 2024
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 50 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Diagnosis of alopecia areata, including alopecia totalis and alopecia universalis.
  • At least 25% hair loss due to alopecia areata
  • Must have normal hearing and normal brainstem auditory evoked potentials (BAEPs)
  • Must have a normal neurological exam; can have a stable unilateral median neuropathy or ulnar neuropathy
  • Signed informed consent
  • Stable regimen for other medications before and during the study

Who cannot join

  • Other significant medical conditions
  • Occupational or recreational noise exposure
  • History of peripheral neuropathy or first degree relative with a hereditary peripheral neuropathy
  • HbA1c > or = 7.5% at Screening
  • Recurrent or disseminated Herpes Zoster
  • Active or chronic infection; or infection requiring hospitalization or IV antimicrobials within 6 months
Show all 10Show fewer
  • Active or latent (insufficiently treated) Hepatitis
  • Active or latent (insufficiently treated) TB
  • Concomitant medications associated with peripheral neurologic or hearing loss
  • Protocol specific laboratory abnormalities

Trial locations and contacts

38 sites in 4 countries.

38 sites in 4 countries

United States23 sites

  • University of New Mexico Department of Dermatology

    Albuquerque, New Mexico, 87102

  • University of New Mexico Clinical & Translational Sciences Center

    Albuquerque, New Mexico, 87106

  • Tekton Research, Inc.

    Austin, Texas, 78745

  • Skin Care Research, LLC

    Boca Raton, Florida, 33486

  • Summit Clinical Research, LLC

    Franklin, Virginia, 23851

  • Skin Care Research, LLC

    Hollywood, Florida, 33021

  • Center for Clinical Studies, LTD. LLP

    Houston, Texas, 77004

  • Marvel Clinical Research 002, LLC

    Huntington Beach, California, 92647

  • University of California, Irvine

    Irvine, California, 92697

  • Kendall Adkisson, MD - Intracoastal Dermatology

    Jacksonville, Florida, 32224

  • Clinical Neuroscience Solutions, Inc.

    Jacksonville, Florida, 32256

  • The Education & Research Foundation, Inc.

    Lynchburg, Virginia, 24501

  • Y&L Advance Health Care Inc., d/b/a Elite Clinical Research

    Miami, Florida, 33144

  • BRCR Medical Center Inc

    Miramar, Florida, 33027

  • Virginia Dermatology and Skin Cancer Center

    Norfolk, Virginia, 23502

  • Clinical Neuroscience Solutions, Inc. dba CNS Healthcare

    Orlando, Florida, 32801

  • Orlando Dermatology & Skin Cancer Surgery Center

    Oviedo, Florida, 32765

  • M3 Wake Research, Inc.

    Raleigh, North Carolina, 27612

  • NorthShore University HealthSystem Dermatology Clinical Trials Unit

    Skokie, Illinois, 60077

  • NorthShore University HealthSystem Dermatology Clinic

    Skokie, Illinois, 60077

  • Washington University School of Medicine-Dermatology

    St Louis, Missouri, 63108

  • Stony Brook Dermatology

    Stony Brook, New York, 11790

  • USF Health Morsani Center For Advanced Healthcare

    Tampa, Florida, 33612

Other trials in United States

Poland8 sites

  • Niepubliczny Zaklad Opieki Zdrowotnej Specjalistyczny Osrodek Dermatologiczny "DERMAL"

    Bialystok, 15-453

  • Centrum Medyczne Angelius Provita

    Katowice, 40-611

  • AWP Klinika Dermatologii Pod Fortem Anna Wojas-Pelc

    Krakow, 31-302

  • Dermedic Jacek Zdybski

    Ostrowiec Świętokrzyski, 27-400

  • RCMed Oddzial Warszawa

    Warsaw, 00-892

  • MTZ Clinical Research Powered by Pratia

    Warsaw, 02-172

  • Przychodnia przy ul. Lowieckiej

    Wroclaw, 50-220

  • Centrum Medyczne Matusiak

    Wroclaw, 50-566

Other trials in Poland

Canada4 sites

  • Lynderm Research Inc.

    Markham, Ontario, L3P 1X2

  • SKiN Centre for Dermatology

    Peterborough, Ontario, K9J 5K2

  • Centre de Recherche Saint-Louis

    Québec, G1W4R4

  • Sima Recherche

    Verdun, Quebec, H4G 3E7

Other trials in Canada

Australia3 sites

  • Eastern Health - Box Hill Hospital

    Box Hill, Victoria, 3128

  • Sinclair Dermatology

    East Melbourne, Victoria, 3002

  • Premier Specialists Pty Ltd

    Kogarah, New South Wales, 2217

Other trials in Australia

About this study

Official title: A PHASE 2a, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY INVESTIGATING THE SAFETY OF RITLECITINIB (PF-06651600) IN ADULT PARTICIPANTS WITH ALOPECIA AREATA

This is a global Phase 2a randomized, double-blind, placebo-controlled study to evaluate the safety and tolerability of ritlecitinib in adults aged 18 to ≤50 years of age with ≥25% scalp hair loss due to Alopecia Areata (AA).

Conditions
Alopecia Areata
Being tested
PF-06651600, Placebo
Keywords
alopecia totalis, alopecia universalis, hair loss, alopecia, JAK, ritlecitinib, PF-06651600, double-blind, placebo-controlled, phase 2a
Medical subject headings
Alopecia Areata, Alopecia universalis, Alopecia

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PF-06651600Drug

    Also called ritlecitinib

    50 mg tablet, dosed as 200 mg QD or 50 mg QD 50 mg capsule, dosed as 50 mg QD

  • PlaceboDrug

    tablet, dosed as 4 tablets QD or 1 tablet QD

Study groups in NCT04517864
Study groupRoleWhat they receive
Treatment Arm: PF-06651600Experimentalritlecitinib 200 milligram (mg) once per day (QD) (four 50 mg tablets) for 4 weeks then ritlecitinib 50 mg tablet QD through month 24. At Month 9, participants assigned to this treatment arm will also receive 3 tablets of placebo for 4 weeks to maintain the blind with the other arm. After month 24, participants switch to 50 mg capsules, 1 QD, up to month 60.
Receives: Drug: PF-06651600
Control Arm (Placebo) followed by active therapy extensionOthermatching comparator: placebo QD (4 tablets x 4 weeks then 1 tablet x 8 months) then ritlecitinib 200 mg QD (four 50 mg tablets) for 4 weeks then ritlecitinib 50 mg tablet QD through month 24. After month 24, participants switch to 50 mg capsules, 1 QD, up to month 60.
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change From Baseline in I-V Interwave Latency on Brainstem Auditory Evoked Potentials (BAEP) at a Stimulus Intensity of 80 Decibels (dB) From the Right Side at Month 9

    BAEP interwave I-V latency (in milliseconds) was the primary endpoint for this study. High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  2. Change From Baseline in I-V Interwave Latency on BAEP at a Stimulus Intensity of 80 dB From the Left Side at Month 9

    BAEP interwave I-V latency was the primary endpoint for this study. High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

Secondary outcomes (34)

  1. Change From Baseline in I-V Interwave Latency on BAEP at 80 dB From the Right Side at Month 6

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 6 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  2. Change From Baseline in I-V Interwave Latency on BAEP at 80 dB From the Right Side at Month 9E and 15E

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Months 9E and 15E (Month 9/15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-controlled Phase.

  3. Change From Baseline in I-V Interwave Latency on BAEP at 80 dB From the Left Side at Month 6

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 6 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  4. Change From Baseline in I-V Interwave Latency on BAEP at 80 dB From the Left Side at Month 9E and 15E

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that latency were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 9E and 15E (Month 9/15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-controlled Phase.

  5. Change From Baseline in Percentage of Intraepidermal Nerve Fiber (IENF) With Axonal Swelling in Skin Punch Biopsies at Month 9

    The endpoint "axonal dystrophy" referred to the percentage of IENF with axonal swellings. Axonal swellings were evaluated in peripheral skin punch biopsies from the distal part of lower extremities. Axonal swellings were counted by axon. Any IENF with single or multiple swellings was counted as a single event, ie, a single axon with axonal swellings. For each participant, data were reported as the percentage of IENF with any number of swellings. IENF was assessed at Day 1 and Month 9. Participants who had entered the Active Therapy Extension Phase at Month 6 had a skin punch biopsy taken at Month 6 for IENF assessments instead of at Month 9. The skin biopsy was collected before the start of Active Therapy Extension Phase.

    Measured: Baseline, Month 9 (Month 6 for the 2 participants who entered the Active Therapy Extension Phase at Month 6). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  6. Change From Baseline in Percentage of IENFs With Axonal Swelling in Skin Punch Biopsies at Month 15E

    The endpoint "axonal dystrophy" referred to the percentage of IENF with axonal swellings. Axonal swellings were evaluated in peripheral skin punch biopsies from the distal part of lower extremities. Axonal swellings were counted by axon. Any IENF with single or multiple swellings was counted as a single event, ie, a single axon with axonal swellings. For each participant, data were reported as the percentage of IENF with any number of swellings.

    Measured: Baseline, Month 15E (Month 15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  7. Change From Baseline in Intraepidermal Nerve Fiber Density (IENFD) in Skin Punch Biopsies at Month 9

    IENFD was evaluated in peripheral skin punch biopsies from the distal part of lower extremities. IENFD was measured by counting the number of fibers and fiber branches that independently crossed the dermal-epidermal barrier (basement membrane). Secondary branching was excluded from quantification and fragments were not counted. The length of the histology section was measured (mm) and the linear epidermal nerve fiber density was reported as number of intraepidermal nerve fibers/mm.

    Measured: Baseline, Month 9 (Month 6 for the 2 participants who entered the Active Therapy Extension Phase at Month 6). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  8. Change From Baseline in IENFD in Skin Punch Biopsies at Month 15E

    IENFD was evaluated in peripheral skin punch biopsies from the distal part of lower extremities. IENFD was measured by counting the number of fibers and fiber branches that independently crossed the dermal-epidermal barrier (basement membrane). Secondary branching was excluded from quantification and fragments were not counted. The length of the histology section was measured (mm) and the linear epidermal nerve fiber density was reported as number of intraepidermal nerve fibers/mm.

    Measured: Baseline, Month 15E (Month 15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  9. Change From Baseline in Amplitude of Wave V on BAEP at a Stimulus Intensity of 80 dB From the Right Side at Month 6 and Month 9

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that amplitude data were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 6 and Month 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  10. Change From Baseline in Amplitude of Wave V on BAEP at a Stimulus Intensity of 80 dB From the Right Side at Month 9E and 15E

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that amplitude data were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 9E and 15E (Month 9 and 15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  11. Change From Baseline in Amplitude of Wave V on BAEP at a Stimulus Intensity of 80 dB From the Left Side at Month 6 and Month 9

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that amplitude data were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 6 and Month 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  12. Change From Baseline in Amplitude of Wave V on BAEP at a Stimulus Intensity of 80 dB From the Left Side at Month 9E and 15E

    High-intensity stimulation (80dB) was used. Participants had BAEP evaluations performed at the same evaluation center, by the same audiology professional using the same equipment, during the study. Audiology and BAEP evaluations were done on the same day, with audiology assessment first. If they could not be done on the same day, assessments had to be within 7 days of each other. A central reader was used for BAEP to confirm that locally read BAEP waves were labelled appropriately and at their peak so that amplitude data were accurate. Central reading also ensured consistency in BAEP interpretation.

    Measured: Baseline, Month 9E and 15E (Month 9 and 15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase.

  13. Number of Participants With Absence of Wave V on BAEP at Stimulus Intensities Ranging From 80 dB to 40 dB From Right Side up to Month 9

    Absence of wave V on BAEP at stimulus intensities ranging from 80dB to 40dB were summarized descriptively using number of participants by treatment group at each intensity level.

    At Month 9, 1 participant in 200/50 mg had absence of Wave V on BAEP at a stimulus intensity of 40 dB on the right side. The event was unilateral and showed fluctuations in the presence or absence of Wave V at various intensities on repeat assessments starting at Month 6.

    Measured: Baseline, Month 6 and 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase)

  14. Number of Participants With Absence of Wave V on BAEP at Stimulus Intensities Ranging From 80 dB to 40 dB From Right Side at Baseline, Month 3E, 6E, 9E and 15E

    Absence of wave V on BAEP at stimulus intensities ranging from 80dB to 40dB were summarized using number of participants by treatment group at each intensity level.

    All participants had Wave V on BAEP present at stimulus intensities ranging from 80 dB to 40 dB up to Month 15E except for 1 participant. At Month 9 (TP1), 1 participant in 200/50/50 mg had absence of Wave V on BAEP at a stimulus intensity of 40 dB on the right side. Fluctuations were seen in the presence or absence of Wave V at various intensities on repeat assessments starting at Month 6 on the right side.

    Measured: Baseline, Month 3E, 6E, 9E and 15E (Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase)

  15. Number of Participants With Absence of Wave V on BAEP at Stimulus Intensities Ranging From 80 dB to 40 dB From Left Side up to Month 9

    Absence of wave V on BAEP at stimulus intensities ranging from 80dB to 40dB were summarized descriptively using number of participants by treatment group at each intensity level.

    Measured: Baseline, Month 6 and 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase)

  16. Number of Participants With Absence of Wave V on BAEP at Stimulus Intensities Ranging From 80 dB to 40 dB From Left Side at Baseline, Month 3E, 6E, 9E and 15E

    Absence of wave V on BAEP at stimulus intensities ranging from 80dB to 40dB were summarized descriptively using number of participants by treatment group at each intensity level.

    All participants had Wave V on BAEP present at stimulus intensities ranging from 80 dB to 40 dB up to Month 15E except for 1 participant. At Month 9 (TP1), 1 participant in 200/50/50 mg had absence of Wave V on BAEP at a stimulus intensity of 40 dB on the right side. Fluctuations were seen in the presence or absence of Wave V at various intensities on repeat assessments starting at Month 6 on the right side.

    Measured: Baseline, Month 3E, 6E, 9E and 15E (Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase)

  17. Number of Participants With Treatment-Emergent Adverse Events (TEAEs) and Treatment-Emergent Serious Adverse Events (TESAEs)

    An adverse event (AE) was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Seriousness of an AE was assessed under the criteria of serious adverse event (SAE). An SAE was defined as any untoward medical occurrence that, at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/incapacity; was a congenital anomaly/birth defect, etc. Treatment-emergent events were with onset date occurring during the on-treatment period. Relatedness to study treatment was determined by the investigator.

    Measured: Approximately 16 months

  18. Number of Participants Who Discontinued From Study Due to Adverse Event (AEs)

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Participants who had an AE record that indicated that the AE caused the participant to be discontinued from the study. Relatedness to study treatment was determined by the investigator.

    Measured: Approximately 16 months

  19. Number of Participants Who Discontinued Study Drug Due to AE and Continued Study

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. This Outcome Measures presented the number of participants who had an AE record that indicated that action taken with study treatment was drug withdrawn but AE did not cause the participant to be discontinued from study. Relatedness to study treatment was determined by the investigator.

    Measured: Approximately 16 months

  20. Number of Participants With Temporary Drug Discontinuation Due to AEs

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants with temporary drug discontinuation due to both all-causality and treatment-related AEs are presented below. Relatedness to study treatment was determined by the investigator.

    Measured: Approximately 16 months

  21. Number of Participants With Clinically Significant Abnormalities in Vital Signs

    Oral, tympanic, or axillary temperature, pulse rate, respiratory rate, and blood pressure (BP) were assessed. BP and pulse measurements were assessed in a chair, back supported and arms bared (free of restrictions such as rolled-up sleeves, etc) and supported at heart level. Measurements were taken on the same arm at each visit (preferably non-dominant) with a completely automated device. Pulse rate was measured at approximately the same time as BP for a minimum of 30 seconds. BP and pulse measurements should be preceded by at least 5 minutes of rest for the participant in a quiet setting without distractions (eg, television, cell phones). Participants refrained from smoking or ingesting caffeine during the 30 minutes preceding the measurements. The clinical significance was determined by the investigator.

    Measured: Approximately 16 months

  22. Number of Participants With Clinically Significant Abnormalities in Clinical Laboratory Values

    Safety laboratory assessments included the categories of Hematology, Chemistry, Urinalysis and other tests. The clinical significance was determined by the investigator.

    Measured: Approximately 16 months

  23. Change From Baseline in Overall Severity of Alopecia Tool (SALT) Scores up to Month 9

    SALT is a quantitative assessment of AA severity based on scalp terminal hair loss. The overall SALT score included hair loss regardless of etiology (ie, scalp hair loss due to both non-AA and AA) and was collected at study visits. The Overall SALT Score ranged from 0 to 100%, with higher scores representing greater amount of hair loss.

    Measured: Baseline, Months 3, 6 and 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  24. Change From Baseline in Overall SALT Scores at Month 3E, 6E, 9E, 12E and 15E

    SALT is a quantitative assessment of AA severity based on scalp terminal hair loss. The overall SALT score included hair loss regardless of etiology (ie, scalp hair loss due to both non-AA and AA) and was collected at study visits. The Overall SALT Score ranged from 0 to 100%, with higher scores representing greater amount of hair loss.

    Measured: Baseline, Month 3E, 6E, 9E, 12E and 15E (Month 3, 6, 9, 12 and 15 in the Active Therapy Extension Phase). Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase.

  25. Change From Baseline in Alopecia Areata - Severity of Alopecia Tool (AA-SALT) Score up to Month 9

    SALT is a quantitative assessment of AA severity based on scalp terminal hair loss. AA-SALT is the amount of scalp hair loss due to AA. AA SALT score in Placebo-Controlled Phase = overall SALT score - non-AA SALT score (The non-AA SALT score only took into account scalp hair loss other than that due to AA and was required to be assessed only at Month 9 [or Month 6 for those who entered the Active Therapy Extension Phase at Month 6] in Placebo-Controlled Phase). The AA-SALT Score ranged from 0 to 100%, with higher scores representing greater amount of hair loss.

    Measured: Baseline, Months 3, 6 and 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)

  26. Change From Baseline in AA-SALT Score at Month 3E, 6E, 9E, 12E and 15E

    SALT is a quantitative assessment of AA severity based on scalp terminal hair loss. AA-SALT is the amount of scalp hair loss due to AA. AA SALT score = overall SALT score - non-AA SALT score (The non-AA SALT score only took into account scalp hair loss other than that due to AA and was required to be assessed only at Month 9 [or Month 6 for those who entered the Active Therapy Extension Phase at Month 6] in Placebo-Controlled Phase). The AA-SALT Score ranged from 0 to 100%, with higher scores representing greater amount of hair loss.

    Measured: Baseline, Month 3E, 6E, 9E, 12E and 15E (Baseline was defined as the last non-missing measurement obtained before the first dose in the Placebo-Controlled Phase)

  27. Number of Participants With Patient's Global Impression of Change (PGI-C) Response up to Month 9

    The PGI-C asked the participants to evaluate the improvement or worsening of their AA as compared to the start of the study using a single item, "Since the start of the study, my alopecia areata has: …". The participants selected one of seven responses ranging from "greatly improved" to "greatly worsened". This Outcome Measure presented the number of participants with PGI-C response which was defined as "greatly improved" or "moderately improved". Participants with missing PGI-C scores were considered as non-responders.

    Measured: Months 1, 3, 6 and 9

  28. Number of Participants With PGI-C Response at 3E, 6E, 9E, 12E and 15E

    The PGI-C asked the participants to evaluate the improvement or worsening of their AA as compared to the start of the study using a single item, "Since the start of the study, my alopecia areata has: …". The participants selected one of seven responses ranging from "greatly improved" to "greatly worsened". This Outcome Measure presented the number of participants with PGI-C response which was defined as "greatly improved" or "moderately improved". Participants with missing PGI-C scores were considered as non-responders.

    Measured: Month 3E, 6E, 9E, 12E and 15E

  29. Number of Participants With TEAEs and TESAEs: Extension Phase (TP3)

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Seriousness of an AE was assessed under the criteria of SAE. An SAE was defined as any untoward medical occurrence that, at any dose: resulted in death; was life-threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent disability/incapacity; was a congenital anomaly/birth defect, etc. Treatment-emergent events were with onset date occurring during the on-treatment period. Relatedness to study treatment was determined by the investigator.

    Measured: From first dose of treatment up to 28 days follow up after last dose of study treatment (Approximately 19 months)

  30. Number of Participants Who Discontinued From Study Due to AEs: Extension Phase (TP3)

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Participants who had an AE record that indicated that the AE caused the participant to be discontinued from the study. Relatedness to study treatment was determined by the investigator.

    Measured: From first dose of treatment up to 28 days follow up after last dose of study treatment (Approximately 19 months)

  31. Number of Participants Who Discontinued Study Drug Due to AE and Continued Study: Extension Phase (TP3)

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. This outcome measure presented the number of participants who had an AE record that indicated that action taken with study treatment was drug withdrawn but AE did not cause the participant to be discontinued from study. Relatedness to study treatment was determined by the investigator.

    Measured: From first dose of treatment up to 28 days follow up after last dose of study treatment (Approximately 19 months)

  32. Number of Participants With Temporary Drug Discontinuation Due to AEs: Extension Phase (TP3)

    An AE was any untoward medical occurrence in a participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants with temporary drug discontinuation due to both all-causality and treatment-related AEs are presented below. Relatedness to study treatment was determined by the investigator.

    Measured: From first dose of treatment up to 28 days follow up after last dose of study treatment (Approximately 19 months)

  33. Number of Participants With Clinically Significant Abnormalities in Vital Signs: Extension Phase (TP3)

    Oral, tympanic, or axillary temperature, pulse rate, respiratory rate, and blood pressure (BP) were assessed. BP and pulse measurements were assessed in a chair, back supported and arms bared (free of restrictions such as rolled-up sleeves, etc) and supported at heart level. Measurements were taken on the same arm at each visit (preferably non-dominant) with a completely automated device. Pulse rate was measured at approximately the same time as BP for a minimum of 30 seconds. BP and pulse measurements preceded by at least 5 minutes of rest for the participant in a quiet setting without distractions (eg, television, cell phones). Participants were refrained from smoking or ingesting caffeine during the 30 minutes preceding the measurements. The clinical significance was determined by the investigator.

    Measured: From screening up to 28 days follow up after last dose of study treatment (maximum up to 19 months)

  34. Number of Participants With Clinically Significant Abnormalities in Clinical Laboratory Values: Extension Phase (TP3)

    Safety laboratory assessments included the categories of hematology, chemistry, urinalysis and other tests. The clinical significance was determined by the investigator.

    Measured: From screening up to 28 days after last dose of study treatment (maximum up to 19 months)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted18 Aug 2020
  2. Study start15 Sep 2020
  3. Primary completion4 Jan 2022
  4. Study completion7 May 2024

Why it stopped: For business reasons

Resources

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
Other
Allocation
Randomised
Intervention model
Sequential
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
71 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04517864
Sponsor's protocol ID
B7981037
Other IDs
2020-001509-21
Acronym
Allegro2a
Status last verified
Jun 2025
First submitted
14 Aug 2020
Last updated
11 Jul 2025
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.

Publications

  • Senna M, Hanna S, Ueki R, Zhang X, Aguh C, Piraccini BM, Wajsbrot D, Nagy E, Sadrarhami M, Chen S, Wolk R, Tran H, Lejeune A. Updated Integrated Safety Analysis of Ritlecitinib up to ~ 5 Years in Patients with Alopecia Areata from the ALLEGRO Clinical Trial Program. Am J Clin Dermatol. 2026 Jul 22. doi: 10.1007/s40257-026-01062-x. Online ahead of print.

    PubMed 42481842

  • Senna M, Soung J, Figueras I, King B, Kinoshita-Ise M, Hanna S, Wu W, Wajsbrot D, Woodworth D, Wolk R, Chaudhry A, Lejeune A, Tran H. Long-Term Efficacy and Safety of Ritlecitinib in Adults and Adolescents with Alopecia Areata: 3-Year Results from the ALLEGRO Phase 2b/3 and ALLEGRO-LT Phase 3 Clinical Studies. Am J Clin Dermatol. 2026 Mar 31. doi: 10.1007/s40257-026-01029-y. Online ahead of print.

    PubMed 41917311

  • King B, Soung J, Tziotzios C, Rudnicka L, Joly P, Gooderham M, Sinclair R, Mesinkovska NA, Paul C, Gong Y, Anway SD, Tran H, Wolk R, Zwillich SH, Lejeune A. Integrated Safety Analysis of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, for the Treatment of Alopecia Areata from the ALLEGRO Clinical Trial Program. Am J Clin Dermatol. 2024 Mar;25(2):299-314. doi: 10.1007/s40257-024-00846-3. Epub 2024 Jan 23.

    PubMed 38263353

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing PF-06651600 in people with Alopecia Areata, run by Pfizer at 38 sites in 4 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: stopped early, as of the sponsor's last update on 11 Jul 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 38 sites in United States, Poland, Canada, Australia. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 28 Dec 2022). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change From Baseline in I-V Interwave Latency on Brainstem Auditory Evoked Potentials (BAEP) at a Stimulus Intensity of 80 Decibels (dB) From the Right Side at Month 9 (time frame: Baseline, Month 9 (Baseline was defined as the last non-missing measurement obtained before the first dose in the placebo-controlled phase)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04517864, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jul 2025.

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