---
title: A Study to Learn About the Study Medicine (Called Ritlecitinib) For the Potential Treatment of Severe Alopecia Areata (AA) In Children 6 To Less Than 12 Years of Age
nct_id: NCT05650333
overall_status: COMPLETED
phase: PHASE1
sponsor: Pfizer
study_type: INTERVENTIONAL
primary_condition: Alopecia Areata
countries: United States
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT05650333.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05650333"
ct_last_update_post_date: 2024-10-08
last_seen_at: "2026-05-12T06:42:05.885Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# A Study to Learn About the Study Medicine (Called Ritlecitinib) For the Potential Treatment of Severe Alopecia Areata (AA) In Children 6 To Less Than 12 Years of Age

**Official Title:** AN INTERVENTIONAL PK, PD, PHASE 1, OPEN-LABEL STUDY TO INVESTIGATE PK AND PD OF MULTIPLE-DOSE RITLECITINIB IN CHILDREN 6 TO LESS THAN 12 YEARS OF AGE WITH SEVERE ALOPECIA AREATA

**NCT ID:** [NCT05650333](https://clinicaltrials.gov/study/NCT05650333)

## Key Facts

- **Status:** COMPLETED
- **Phase:** PHASE1
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 15
- **Lead Sponsor:** Pfizer
- **Conditions:** Alopecia Areata
- **Start Date:** 2023-03-02
- **Completion Date:** 2023-08-11
- **CT.gov Last Update:** 2024-10-08

## Brief Summary

The purpose of the study is to evaluate the pharmacokinetics (how the medicine is changed and eliminated from your body after you take it) and pharmacodynamics (effects of the medicine in the body) of the study medicine (called Ritlecitinib) in children of 6 to \<12 years of age with Alopecia Areata, a condition of scalp hair loss. 12 children with alopecia areata will be participating in this study. All participants will receive study medicine with a dose of 20 milligram (mg) orally once daily for 7 days. 5 blood samples will be collected on day 7 for pharmacokinetic evaluation and 2 blood samples each at screening and on Day 7 will be collected for pharmacodynamic evaluation. Participants will take part in the study for about 10 weeks.

## Detailed Description

This is an interventional, Pharmacokinetic (PK), Pharmacodynamic (PD), phase 1, open label study in children 6 to less than 12 years of age with ≥50% scalp hair loss due to severe alopecia areata. The purpose of the study is to collect data to support dose selection for subsequent studies in the same population.

Participants will be screened and, if all eligibility criteria are met, will receive the first dose of Investigational product within 28 days after the screening visit.

Participants will receive 20 mg ritlecitinib in one dose, daily, for 7 consecutive days. Blood samples for pharmacodynamic evaluation will be collected on screening and Day 7. Blood samples for pharmacokinetic evaluation will be collected on Day 7 at: 0 hr (pre-dose), 0.5 hr, 1 hr, 3 hrs, and 8 hrs after dosing.

At least 12 evaluable participants with respect to the primary endpoint will be enrolled in the study.

Participants and their parents/legal guardians will be required to visit the study site 3 times during the study (Screening, Day 1 and Day 7) A safety follow-up visit will be conducted by phone, 28 to 35 days after the last dose of ritlecitinib.

## Eligibility

- **Minimum age:** 6 Years
- **Maximum age:** 11 Years
- **Sex:** ALL
- **Healthy Volunteers:** No

```
Key Inclusion criteria:

1. Participants who are 6 to less than12 years old at the baseline visit.
2. A diagnosis of severe AA, including AT and AU, with ≥50% scalp hair loss due to AA (ie, a SALT score of ≥50) at both the Screening and Baseline visits, without evidence of terminal hair regrowth within the previous 12 months.

Key Exclusion Criteria:

1. A known congenital cause of AA, other systemic diseases that may cause hair loss (eg, lupus erythematosus, thyroiditis, systemic sclerosis, lichen planus, etc) or other etiology of hair loss (eg, telogen effluvium, androgenetic alopecia, etc).
2. Any present malignancies or history of malignancies, history of any lymphoproliferative disorder
3. History (one or more episodes) of CMV, varicella, herpes zoster (shingles) or disseminated herpes simplex.
4. Other medical or psychiatric condition (including recent \[within the past year\] or active suicidal ideation/behavior) that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
5. Not up to date with all age appropriate vaccines (including 2-dose vaccination for varicella) or vaccination with attenuated live vaccine within 6 weeks of first dose of study medicine.
```

## Arms

- **Ritlecitinib 20 mg** (EXPERIMENTAL) — Participants will receive Ritlecitinib 20 mg by mouth once daily (QD).

## Interventions

- **Ritlecitinib 20 mg** (DRUG) — orally administered, Ritlecitinib 20 mg once daily (QD)

## Primary Outcomes

- **Area Under the Plasma Concentration-Time Profile Over the Dosing Interval of 24 Hours, at Steady State (AUC24ss/AUCtau) of Ritlecitinib on Day 7** _(time frame: Day 7: 0 (pre-dose), 0.5, 1, 3, 8 and 24 hours [pre-dose concentration was used as an estimate for the concentration of 24 hours post dose])_ — Linear-log trapezoidal method was used for evaluation. For the calculation of AUCtau, pre-dose concentration of Day 7 was used as an estimate for the concentration of 24 hours post-dose on Day 7.

## Secondary Outcomes

- **Maximum Observed Plasma Concentration (Cmax) of Ritlecitinib** _(time frame: 0 (pre-dose), 0.5, 1, 3 and 8 hours post-dose on Day 7)_
- **Time to Reach Maximum Observed Plasma Concentration (Tmax) of Ritlecitinib** _(time frame: 0 (pre-dose), 0.5, 1, 3 and 8 hours post-dose on Day 7)_
- **Apparent Oral Clearance (CL/F) of Ritlecitinib** _(time frame: 0 (pre-dose), 0.5, 1, 3 and 8 hours post-dose on Day 7)_
- **Apparent Volume of Distribution (Vz/F) of Ritlecitinib** _(time frame: 0 (pre-dose), 0.5, 1, 3 and 8 hours post-dose on Day 7)_
- **Elimination Half-Life (t1/2) of Ritlecitinib** _(time frame: 0 (pre-dose), 0.5, 1, 3 and 8 hours post-dose on Day 7)_
- **Change From Baseline in Interferon Gamma Induced Protein 10 (IP-10) on Day 7** _(time frame: Baseline and Day 7)_
- **Change From Baseline in T Lymphocytes on Day 7** _(time frame: Baseline and Day 7)_
- **Change From Baseline in B Lymphocytes on Day 7** _(time frame: Baseline and Day 7)_
- **Change From Baseline in Natural Killer (NK) Cells on Day 7** _(time frame: Baseline and Day 7)_
- **Number of Participants With Treatment Emergent Adverse Events (TEAEs)** _(time frame: Day 1 of dosing up to 35 days after the last dose (maximum up to Day 42))_
- **Number of Participants With Treatment Related AEs** _(time frame: Day 1 of dosing up to 35 days after the last dose (maximum up to Day 42))_
- **Number of Participants With Serious AEs (SAEs)** _(time frame: Day 1 of dosing up to 35 days after the last dose (maximum up to Day 42))_
- **Number of Participants With AEs Leading to Treatment Discontinuation** _(time frame: Day 1 up to Day 7)_
- **Number of Participants With Clinically Significant Abnormalities in Vital Signs** _(time frame: Day 1 up to Day 7)_
- **Number of Participants With Clinically Significant Abnormalities in Clinical Laboratory Values** _(time frame: Day 1 up to Day 7)_
- **Number of Participants as Per Score for Pediatric Taste Assessment Questionnaire** _(time frame: Day 1 and 7)_

## Locations (9)

- California Dermatology & Clinical Research Institute, Encinitas, California, United States
- Pediatric Skin Research,LLC, Coral Gables, Florida, United States
- Nicklaus Children's Hospital, Miami, Florida, United States
- Dawes Fretzin Clinical Research Group, LLC, Indianapolis, Indiana, United States
- University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States
- UNMH, Albuquerque, New Mexico, United States
- Vital Prospects Clinical Research Institute, PC, Tulsa, Oklahoma, United States
- Northwest Dermatology Institute, Portland, Oregon, United States
- Texas Dermatology and Laser Specialists, San Antonio, Texas, United States

## Recent Field Changes (last 30 days)

- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.overallStatus` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.california dermatology & clinical research institute|encinitas|california|united states` — added _(2026-05-12)_
- `locations.pediatric skin research,llc|coral gables|florida|united states` — added _(2026-05-12)_
- `locations.nicklaus children's hospital|miami|florida|united states` — added _(2026-05-12)_
- `locations.dawes fretzin clinical research group, llc|indianapolis|indiana|united states` — added _(2026-05-12)_
- `locations.university of new mexico health sciences center|albuquerque|new mexico|united states` — added _(2026-05-12)_
- `locations.unmh|albuquerque|new mexico|united states` — added _(2026-05-12)_
- `locations.vital prospects clinical research institute, pc|tulsa|oklahoma|united states` — added _(2026-05-12)_
- `locations.northwest dermatology institute|portland|oregon|united states` — added _(2026-05-12)_
- `locations.texas dermatology and laser specialists|san antonio|texas|united states` — added _(2026-05-12)_

---

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*Source data (authoritative): https://clinicaltrials.gov/study/NCT05650333*  
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