← Back to Search

Janus Kinase (JAK) Inhibitor

Ritlecitinib for Alopecia Areata (Allegro2a Trial)

Phase 2
Waitlist Available
Research Sponsored by Pfizer
Eligibility Criteria Checklist
Specific guidelines that determine who can or cannot participate in a clinical trial
Must have
Diagnosis of alopecia areata, including alopecia totalis and alopecia universalis
Diagnosis of alopecia areata, including alopecia totalis and alopecia universalis.
Must not have
Active or chronic infection; or infection requiring hospitalization or IV antimicrobials within 6 months
Concomitant medications associated with peripheral neurologic or hearing loss
Timeline
Screening 3 weeks
Treatment Varies
Follow Up 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.

Summary

This trial is testing a medication called ritlecitinib to see if it is safe for adults aged 18 to 50 who have lost a lot of hair due to Alopecia Areata. The medication works by stopping the immune system from attacking hair follicles, which may help hair grow back. Ritlecitinib is being investigated as a treatment for alopecia areata, offering a rapid onset and potentially superior safety profile over other treatments.

Who is the study for?
Adults aged 18 to ≤50 with Alopecia Areata, including alopecia totalis and universalis, who have lost at least 25% of scalp hair. Participants must have stable health conditions, normal neurological exams (except for certain neuropathies), normal hearing, and no significant medical issues or recent serious infections.
What is being tested?
The trial is testing the safety of a drug called ritlecitinib (PF-06651600) compared to a placebo in treating hair loss from Alopecia Areata. It's a global Phase 2a study where participants are randomly assigned to receive either the drug or placebo without knowing which one they're getting.
What are the potential side effects?
Potential side effects may include reactions specific to ritlecitinib but are not detailed here. Common side effects could range from mild skin irritation at the application site to more systemic responses depending on how the body reacts to new medication.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below
Select...
I have been diagnosed with a form of severe hair loss.
Select...
I have been diagnosed with a form of severe hair loss.
Select...
My hearing and brainstem auditory tests are normal.
Select...
I have lost at least 25% of my hair due to alopecia areata.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:
Select...
I haven't had a serious infection or needed IV antibiotics in the last 6 months.
Select...
I am not taking any medications that could cause nerve damage or hearing loss.
Select...
I have active or untreated hepatitis.
Select...
I or a close family member have had issues with nerve damage.
Select...
I have had shingles more than once or it has spread in my body.
Select...
I have active or untreated latent TB.

Timeline

Screening ~ 3 weeks
Treatment ~ Varies
Follow Up ~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.
This trial's timeline: 3 weeks for screening, Varies for treatment, and 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. for reporting.

Treatment Details

Study Objectives

Study objectives can provide a clearer picture of what you can expect from a treatment.
Primary study objectives
Change From Baseline in I-V Interwave Latency on BAEP at a Stimulus Intensity of 80 dB From the Left Side at Month 9
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
Secondary study objectives
Change From Baseline in AA-SALT Score at Month 3E, 6E, 9E, 12E and 15E
Change From Baseline in Alopecia Areata - Severity of Alopecia Tool (AA-SALT) Score up to Month 9
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
+25 more

Side effects data

From 2023 Phase 2 trial • 244 Patients • NCT03395184
7%
Headache
6%
Lymphopenia
6%
Acne
6%
Abdominal pain
3%
Crohn's disease
3%
Arthralgia
1%
Musculoskeletal chest pain
1%
Hypertension
1%
Cytomegalovirus colitis
1%
Cytomegalovirus infection
1%
SARS-CoV-2 test positive
100%
80%
60%
40%
20%
0%
Study treatment Arm
Induction Period: Placebo QD
OLE Period: Placebo QD -> Brepocitinib 30 mg QD
Induction Period: Brepocitinib 60 mg QD
OLE Period: Ritlecitinib 200 mg/50 mg QD -> Ritlecitinib 50 mg QD
Induction Period: Ritlecitinib 200 mg/50 mg QD
OLE Period: Placebo QD -> Ritlecitinib 50 mg QD
OLE Period: Brepocitinib 60 mg QD -> Brepocitinib 30 mg QD

Trial Design

2Treatment groups
Experimental Treatment
Group I: Treatment Arm: PF-06651600Experimental Treatment1 Intervention
ritlecitinib 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.
Group II: Control Arm (Placebo) followed by active therapy extensionExperimental Treatment1 Intervention
matching 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.
Treatment
First Studied
Drug Approval Stage
How many patients have taken this drug
Placebo
1995
Completed Phase 3
~2670
PF-06651600
2019
Completed Phase 2
~1900

Research Highlights

Information in this section is not a recommendation. We encourage patients to speak with their healthcare team when evaluating any treatment decision.
Mechanism Of Action
Side Effect Profile
Prior Approvals
Other Research
Janus Kinase (JAK) inhibitors, such as Ritlecitinib, work by interfering with the JAK-STAT signaling pathways, which are involved in the immune response that leads to hair follicle destruction in Alopecia Areata. By inhibiting these pathways, JAK inhibitors can reduce inflammation and autoimmunity, promoting hair regrowth. Other common treatments include topical immunotherapy (e.g., DPCP, SADBE), which induces a mild allergic reaction to distract the immune system from attacking hair follicles, and corticosteroids, which reduce inflammation and suppress the immune response. Understanding these mechanisms is crucial for patients, as it helps them grasp how these treatments can potentially restore hair growth and manage their condition.
Case Report: Successful Treatment of Alopecia Universalis With Tofacitinib and Increased Cytokine Levels: Normal Therapeutic Reaction or Danger Signal?

Find a Location

Who is running the clinical trial?

PfizerLead Sponsor
4,658 Previous Clinical Trials
17,877,216 Total Patients Enrolled
14 Trials studying Alopecia Areata
86,001 Patients Enrolled for Alopecia Areata
Pfizer CT.gov Call CenterStudy DirectorPfizer
3,544 Previous Clinical Trials
14,918,392 Total Patients Enrolled
7 Trials studying Alopecia Areata
2,895 Patients Enrolled for Alopecia Areata

Media Library

Ritlecitinib (PF-06651600) (Janus Kinase (JAK) Inhibitor) Clinical Trial Eligibility Overview. Trial Name: NCT04517864 — Phase 2
Alopecia Areata Research Study Groups: Treatment Arm: PF-06651600, Control Arm (Placebo) followed by active therapy extension
Alopecia Areata Clinical Trial 2023: Ritlecitinib (PF-06651600) Highlights & Side Effects. Trial Name: NCT04517864 — Phase 2
Ritlecitinib (PF-06651600) (Janus Kinase (JAK) Inhibitor) 2023 Treatment Timeline for Medical Study. Trial Name: NCT04517864 — Phase 2
Alopecia Areata Patient Testimony for trial: Trial Name: NCT04517864 — Phase 2
~14 spots leftby Nov 2025