Ritlecitinib (Litfulo)
Ritlecitinib (Litfulo) is approved in at least one market for alopecia areata, developed by Pfizer.
A JAK inhibitor approved in the US and EU for severe alopecia areata from age 12, not for pattern baldness.
- Developed by
- Pfizer
- Current phase
- Approved
- Mechanism
- JAK inhibitor
- Indications
- Alopecia areata
- Also known as
- PF-06651600, Litfulo
- Last public activity
- September 2026
- Copy last reviewed
- September 2026
- Record confidence
- High
Cleared for sale for a hair-loss indication in at least one market.
Calms the immune attack on the follicle by blocking JAK signalling - the class that transformed alopecia areata.
A research record, not medical advice: being listed here says nothing about whether a treatment works or whether it is right for you. Talk to a dermatologist about your own case.
Why it matters
Worth keeping in the register precisely because it is so often misread. Ritlecitinib, like baricitinib and deuruxolitinib, is approved for alopecia areata, which is autoimmune. None of them is indicated for androgenetic alopecia, the kind most people mean by 'going bald'.
Where it is approved
Marketing authorisation is granted country by country, for a specific indication. A drug approved for hair loss in one market may be approved only for something else — or not at all — in another.
- European UnionEMAApprovedLitfulo· prescription only
Severe alopecia areata, adults and adolescents 12 and older
Centrally authorised, so the authorisation covers France directly. Holder: Pfizer Europe MA EEIG.
Regulator filing ↗ - FranceEMAApprovedLitfulo· prescription only
Pelade sévère, adulte et adolescent à partir de 12 ans
Centrally authorised, so the EU decision covers France directly. Listed and marketed in France as LITFULO 50 mg. Confirmed against BDPM after checking that the authorisation date and the hair-loss indication are the same event — which they are here, because ritlecitinib was first authorised for this condition.
Regulator filing ↗ - United StatesFDAApprovedLitfulo· prescription only
Severe alopecia areata, adults and adolescents 12 and older
Regulator filing ↗
Development history
- Phase 2/3Phase 3
First Phase 3 trial on record: NCT04006457 — Long-Term PF-06651600 for the Treatment of Alopecia Areata
ClinicalTrials.gov ↗ - Phase 2Phase 2/3
First Phase 2/3 trial on record: NCT03732807 — PF-06651600 for the Treatment of Alopecia Areata
ClinicalTrials.gov ↗ - Phase 2
First Phase 2 trial on record: NCT02974868 — Study To Evaluate The Efficacy And Safety Profile Of PF-06651600 And PF-06700841 In Subjects With Alopecia Areata
ClinicalTrials.gov ↗
Registered trials
Pulled automatically from ClinicalTrials.gov. Matching is by name and development code, so occasional gaps are possible — tell us if you spot one.
Pre-approval Single-patient Expanded Access for Ritlecitinib (PF-06651600)
Pfizer
Real-World Effectiveness of Ritlecitinib in Alopecia Areata Patients in the US: A Retrospective Analysis Using EHR and Claims Data
Pfizer · n=7500 · August 2026
A Study in Young People and Adults to Learn About the Medicine Ritlecitinib for Treatment of Patchy Hair Loss, Known by the Medical Term as Moderate Alopecia Areata
Pfizer · n=336 · July 2026
Utilization and Effectiveness of Ritlecitinib in a Real-World Population With Severe AA in the US
Pfizer · n=300 · December 2025
A Long-Term Study to Learn About The Study Medicine Called Ritlecitinib in Children With Severe Alopecia Areata.
Pfizer · n=140 · September 2025
A Study to Learn About Litfulo Capsule in People With Severe Alopecia Areata in Routine Clinical Practice.
Pfizer · n=3000 · August 2025
A Study to Learn About Medicine Called Ritlecitinib in Children Aged Between 6 to 12 Years With Severe Alopecia Areata
Pfizer · n=208 · July 2025
A Study of 2 Doses of Ritlecitinib in People 12 Years of Age and Older With Alopecia Areata
Pfizer · n=674 · April 2025
A Study to Learn About the Medicine Called Ritlecitinib in Adults With Severe Alopecia Areata in Real-world Settings
Pfizer · n=123 · February 2025
Characterization And Clinical Outcomes of AA Patients Treated With Ritlecitinib
Pfizer · n=450 · August 2024
Litfulo Capsules Special Investigation
Pfizer · n=664 · March 2024
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
Pfizer · n=15 · March 2023
Ritlecitinib for Cicatricial Alopecia
Emma Guttman · n=50 · December 2022
PLACEBO-CONTROLLED SAFETY STUDY OF RITLECITINIB (PF-06651600) IN ADULTS WITH ALOPECIA AREATA
Pfizer · n=71 · September 2020
Long-Term PF-06651600 for the Treatment of Alopecia Areata
Pfizer · n=1057 · July 2019
PF-06651600 for the Treatment of Alopecia Areata
Pfizer · n=718 · December 2018
Listing a trial is not a recommendation to join one. Eligibility, risks and costs vary enormously — discuss any trial with your own doctor first.
Sources
- Litfulo — European public assessment report — Regulator filing, September 2023
- LITFULO (ritlecitinib) — FDA approval letter, NDA 215830 — Regulator filing, June 2023
- LITFULO (ritlecitinib) capsules — prescribing information — Regulator filing, June 2023
Related programmes
Other programmes in the register with the same mechanism: JAK inhibitor.
Cite this page
Hair Pipeline, "Ritlecitinib (Litfulo) — development record", hairpipeline.com/pipeline/ritlecitinib