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Long-Term Study of Ritlecitinib Tosilate for Adults and Adolescents with Alopecia Areata

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the long-term safety and effectiveness of a medication called Ritlecitinib Tosilate for treating a condition known as Alopecia Areata. Alopecia Areata is a disease that causes hair loss, often in patches, and can affect both adults and adolescents. The medication being tested, Ritlecitinib Tosilate, is taken orally in the form of capsules or tablets and works as a Janus Kinase 3 inhibitor, which is a type of treatment that targets specific pathways in the body to help manage the condition.

The purpose of this study is to evaluate how safe and tolerable Ritlecitinib Tosilate is for people with Alopecia Areata over a long period. Participants in the study will take the medication and attend regular visits to monitor their health and any changes in their condition. The study will track any side effects or adverse events that may occur, as well as any improvements in hair growth or other symptoms related to Alopecia Areata.

Throughout the study, participants will be asked to follow a treatment plan and attend scheduled visits for check-ups and tests. The study aims to provide valuable information about the long-term use of Ritlecitinib Tosilate in managing Alopecia Areata, helping to determine its potential as a treatment option for this condition.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Joining the study

    Upon joining the study, the participant will be informed about the trial's purpose, which is to evaluate the long-term safety and tolerability of PF-06651600 in individuals with alopecia areata.

    Participants must meet specific criteria related to their condition, such as having a clinical diagnosis of alopecia areata with a certain percentage of hair loss.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to confirm eligibility. This includes verifying the percentage of hair loss and ensuring no recent hair regrowth in affected areas.

    Participants will also undergo a review of their medical history and current medications.

  3. Step 3

    Medication administration

    Participants will receive ritlecitinib tosilate, administered orally in the form of capsules or tablets.

    The dosage and frequency will be determined by the study protocol and adjusted as necessary based on individual response and tolerability.

  4. Step 4

    Regular follow-up visits

    Participants will attend regular follow-up visits to monitor their response to the medication and any side effects.

    These visits will include physical examinations, laboratory tests, and assessments of hair regrowth.

  5. Step 5

    Monitoring for side effects

    Throughout the study, participants will be monitored for any adverse events or side effects related to the medication.

    Any significant changes in health or laboratory values will be documented and addressed.

  6. Step 6

    Completion of the study

    The study is expected to continue until 2026, with participants completing a final follow-up visit or 28 days after the last dose.

    The primary focus will be on the incidence of treatment-related adverse events and the overall safety of the medication.

Who can join the trial?

12 criteria

  • Participants must have a clinical diagnosis of Alopecia Areata (AA), which is a condition causing hair loss, and no other reasons for hair loss.
  • For new participants aged 12 to under 18, they must have at least 50% hair loss on the scalp due to AA.
  • For new participants aged 18 and older, they must have at least 25% hair loss on the scalp due to AA.
  • Participants should not have any hair regrowth in the affected areas within 6 months before starting the study.
  • The current episode of hair loss due to AA should not be longer than 10 years.
  • Participants from previous related studies must meet specific conditions, such as having completed a certain period of study intervention.
  • All participants must be at least 12 years old. In some regions, only those 18 years or older can join.
  • Both males and females can participate. Female participants must not be pregnant or breastfeeding and should use effective birth control if they can have children.
  • Participants must be able to give informed consent, meaning they understand and agree to the study's requirements.
  • Participants must be willing to attend scheduled visits, follow the treatment plan, and undergo tests and procedures.
  • If taking other medications, participants should be on a stable dose and willing to continue this during the study.
  • Participants must agree to avoid prolonged sun exposure and not use tanning booths or sun lamps during the study.

Who cannot join the trial?

8 criteria

  • Participants who have any other medical condition that might interfere with the study.
  • Individuals who are currently taking medications that could affect the study results.
  • People who have had a recent surgery or are planning to have surgery during the study period.
  • Participants who are pregnant or breastfeeding.
  • Individuals with a history of severe allergic reactions.
  • People who have participated in another clinical trial recently.
  • Participants who have a history of drug or alcohol abuse.
  • Individuals with any condition that the study doctors believe would make it unsafe for them to participate.
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Investigated drugs

PF-06651600 is a medication being studied for its safety and effectiveness in treating alopecia areata, a condition that causes hair loss. This trial is focused on understanding how well the medication works over a long period and how well it is tolerated by both adults and adolescents who have this condition.

What is already known about the treatment

PF-06651600 – This medication is administered orally and is currently being studied in clinical trials for its safety and effectiveness in treating alopecia areata, a condition that causes hair loss. It is in the investigational stage, meaning it is not yet approved for general medical use but is being evaluated in medical research. The main therapeutic indication for PF-06651600 is alopecia areata. At the molecular level, it works by inhibiting certain enzymes that are involved in the immune response, which may help reduce inflammation and prevent hair loss. It is classified pharmacologically as a Janus kinase (JAK) inhibitor.

Investigated diseases

Alopecia Areata – Alopecia areata is an autoimmune condition characterized by sudden hair loss in round patches on the scalp and other areas of the body. The immune system mistakenly attacks hair follicles, leading to hair loss. The progression of the disease can vary greatly among individuals, with some experiencing only a few small patches of hair loss, while others may lose more extensive areas of hair. In some cases, the hair may regrow on its own, while in others, the condition may persist or recur. The exact cause of alopecia areata is not fully understood, but it is believed to involve a combination of genetic and environmental factors. The condition can affect people of all ages and genders.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-509801-59-00Protocol codeB7981032Estimated enrolment930 patientsSponsorPfizer Inc.

sourced from the EU Clinical Trials Register and site verification

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