Use Of Oral Janus Kinase Inhibitors For The Treatment Of Severe Alopecia Areata: Narrative Review And Real-World Experience

March 2026 in “ Immunological Medicine ”

Manabu Ohyama, M. Fukuyama, Reina Hayakawa, Misaki Kinoshita-Ise

alopecia areata autoimmune hair loss Janus kinase inhibitors baricitinib ritlecitinib IFN-γ-IL-15 cytokine loop JAK inhibitors AA

From the encyclopedia

Alopecia Areata →

autoimmune disorder causing patchy hair loss

Baricitinib →

JAK inhibitor that reduces inflammation and immune attacks on hair follicles, leading to potential hair regrowth, especially in alopecia areata cases

Studysummary This review discusses the use of Janus kinase inhibitors for severe alopecia areata in Japan, noting their effectiveness in some patients but highlighting the need for new therapies due to non-responsiveness and relapse in others; it reports no new clinical results. Our plain-language summary of this paper — not a Tressless recommendation.

Oral Janus kinase inhibitors (JAKis), such as baricitinib and ritlecitinib, have shown promise in treating severe alopecia areata (AA), with clinical trials like BRAVE-AA and ALLEGRO demonstrating significant hair regrowth in 30-40% of patients. However, about 30% of patients do not respond, and relapses can occur during treatment. The BRAVE-AA1 and -AA2 studies reported that 37.5% of patients achieved a SALT score ≤20 by Week 104 with baricitinib, while the ALLEGRO study found 45.5% of patients showed early response to ritlecitinib. Both drugs have acceptable safety profiles, with minor adverse events. Real-world data from Japan and the UK support these findings. Continuous treatment is recommended to maintain benefits, but discontinuation may lead to relapse. Further research is needed to optimize treatment strategies and address the unmet needs of non-responders.

View this study on tandfonline.com →

Discuss this study in the Community →

Research cited in this study

31 / 31 results

research Defining a Therapeutic Window of Opportunity in Alopecia Areata: Predictors of Early Response to Baricitinib

October 2025 in “Journal of Clinical Medicine”

This study found that in patients with severe alopecia areata, those who responded early to baricitinib treatment typically had a lower baseline Severity of Alopecia Tool score, shorter disease duration, and higher erythrocyte sedimentation rate, suggesting these factors may predict therapeutic success.

Rationale and Design of a Novel, Phase 3, External and Synthetic Placebo-Controlled Clinical Trial of Ritlecitinib 50 mg and 100 mg for Alopecia Areata

research Rationale and Design of a Novel, Phase 3, External and Synthetic Placebo-Controlled Clinical Trial of Ritlecitinib 50 mg and 100 mg for Alopecia Areata

October 2025 in “Dermatology and Therapy”

This study evaluates the efficacy and safety of a higher dose (100-mg) of ritlecitinib for treating severe alopecia areata, comparing it to external and synthetic placebo control groups.

research Safety of Oral JAK Inhibitors in Treating Alopecia Areata: A Systematic Review and Network Meta-Analysis

3 citations , August 2025 in “Frontiers in Pharmacology”

Oral JAK inhibitors are safe for alopecia areata, but baricitinib may cause more acne and infections.

research Long-Term Real-World Outcomes of Baricitinib in Severe Alopecia Areata: A 104-Week Retrospective Analysis From a Single Institute

June 2025 in “The Journal of Dermatology”

This study found that baricitinib was effective and well tolerated for long-term scalp hair regrowth in severe alopecia areata patients, with certain predictors identified for treatment response.

research Safety of Baricitinib in Adults with Severe Alopecia Areata from Two Phase III Trials Over a Median of 2.3 Years and Up to 4 Years of Treatment

3 citations , April 2025 in “American Journal of Clinical Dermatology”

Baricitinib is generally safe for long-term use in treating severe alopecia areata.

research Understanding Eyebrow and Eyelash Involvement in Patients with Alopecia Areata and Responsiveness to Treatment with Baricitinib

April 2025 in “PubMed”

In these randomized, placebo-controlled trials, patients with alopecia areata who received baricitinib showed significantly higher eyebrow and eyelash hair regrowth rates compared to placebo, with greater responses observed at the 4 mg dose and in those achieving overall scalp hair improvement by Week 52.

research Patterns of Clinical Response in Patients With Alopecia Areata Treated With Ritlecitinib in the Allegro Clinical Development Programme

13 citations , February 2025 in “Journal of the European Academy of Dermatology and Venereology”

Ritlecitinib shows promise for treating alopecia areata, especially with early and extended treatment.

Predictive Factors for Treatment Responses to Baricitinib in Severe Alopecia Areata: A Retrospective, Multivariate Analysis of 70 Cases from a Single Center

research Predictive Factors for Treatment Responses to Baricitinib in Severe Alopecia Areata: A Retrospective, Multivariate Analysis of 70 Cases from a Single Center

January 2025 in “The Journal of Dermatology”

In this study at Tohoku University Hospital, 41% of severe alopecia areata patients achieved significant hair regrowth with baricitinib treatment over 9 months, with predictors of better outcomes including shorter disease duration, female sex, initial mild disease, certain alopecia types, and prior IVMP therapy.

research Long-Term Safety and Efficacy of Ritlecitinib in Adults and Adolescents with Alopecia Areata and at Least 25% Scalp Hair Loss: Results from the ALLEGRO-LT Phase 3, Open-Label Study

15 citations , January 2025 in “Journal of the European Academy of Dermatology and Venereology”

Ritlecitinib is effective and safe for treating alopecia areata, promoting significant hair regrowth.

research Real-Life Effectiveness and Safety of Baricitinib in 17 Japanese Patients With Alopecia Areata: A 60-Week Single Center Study

January 2025 in “Journal of Cutaneous Immunology and Allergy”

In this study, the researchers reported that baricitinib improved hair loss in a real-world setting for Japanese adults with alopecia areata, with a 64.7% success rate at 60 weeks, though prolonged episodes reduced efficacy. Common side effects were acne and mildly decreased renal function.

Continued Treatment With Baricitinib Results in Meaningful Scalp Responses Among Scalp Non-Responder Patients With Eyebrow/Eyelash Regrowth in the First Year

research Continued Treatment With Baricitinib Results in Meaningful Scalp Responses Among Scalp Non-Responder Patients With Eyebrow/Eyelash Regrowth in the First Year

November 2024 in “Journal of the European Academy of Dermatology and Venereology”

This study found that nearly 40% of patients with severe alopecia areata who showed eyebrow or eyelash regrowth on baricitinib 4 mg achieved significant scalp hair regrowth by the second year of treatment.

research Systematic Review and Indirect Treatment Comparisons of Ritlecitinib Against Baricitinib in Alopecia Areata

October 2024 in “Journal of the European Academy of Dermatology and Venereology”

This study reported that ritlecitinib 50 mg and baricitinib 4 mg showed similar efficacy in treating severe alopecia areata, with no significant difference in hair regrowth outcomes at Week 24, but there remains considerable uncertainty and a need for further research.

research Baricitinib Withdrawal and Retreatment in Patients With Severe Alopecia Areata

August 2024 in “JAMA Dermatology”

In this study, withdrawal of baricitinib therapy in patients with severe alopecia areata who had achieved hair regrowth led to a loss of benefit in almost all patients, suggesting that continued treatment is necessary to maintain hair regrowth.

research Efficacy and Safety of Deuruxolitinib, an Oral Selective Janus Kinase Inhibitor, in Adults with Alopecia Areata: Results from the Phase 3 Randomized, Controlled Trial (THRIVE-AA1)

63 citations , July 2024 in “Journal of the American Academy of Dermatology”

This study found that the oral JAK1/JAK2 inhibitor deuruxolitinib effectively promoted hair regrowth and patient satisfaction in adults with alopecia areata over 24 weeks.

research Baricitinib Therapy for Moderate to Severe Alopecia Areata: A Retrospective Review of 95 Japanese Patients

January 2024 in “Acta dermato-venereologica”

research European Expert Consensus Statement on the Systemic Treatment of Alopecia Areata

4 citations , January 2024 in “JEADV. Journal of the European Academy of Dermatology and Venereology/Journal of the European Academy of Dermatology and Venereology”

This consensus statement outlines a treatment algorithm for alopecia areata, detailing systemic treatment indications and options, including EMA-approved medications baricitinib and ritlecitinib for severe cases, as well as other off-label treatments and adjuvant therapies like oral minoxidil.

Expecting Scalp Hair Regrowth During Severe Alopecia Areata Treatment with Baricitinib: Insights from Patient Trajectories in Phase III Trials

research Expecting Scalp Hair Regrowth During Severe Alopecia Areata Treatment with Baricitinib: Insights from Patient Trajectories in Phase III Trials

September 2023 in “British Journal of Dermatology”

In this study, researchers identified subgroups of patients with severe alopecia areata treated with baricitinib who experienced early, gradual, or late hair regrowth, finding that response was influenced by baseline disease severity and duration of hair loss.

research Economic Burden of Alopecia Areata: A Study of Direct and Indirect Cost in Japan Using Real-World Data

2 citations , July 2023 in “Journal of dermatology”

This study reported that alopecia areata imposes a significant personal and national economic burden in Japan, with estimated total costs of 112.7 billion yen due largely to productivity loss.

research Efficacy and Safety of Ritlecitinib in Adults and Adolescents With Alopecia Areata: A Randomised, Double-Blind, Multicentre, Phase 2b–3 Trial

227 citations , April 2023 in “The Lancet”

Ritlecitinib effectively treats alopecia areata and is well-tolerated.

research Prevalence of Alopecia Areata in Japan: Estimates from a Nationally Representative Sample

18 citations , November 2022 in “The Journal of Dermatology”

This study in Japan identified an estimated prevalence of alopecia areata between 1.45% and 2.18%, highlighting a significant psychological burden and potential unmet need for treatment among affected individuals.

research Maintenance, Withdrawal, and Re-Treatment with Ritlecitinib and Brepocitinib in Patients with Alopecia Areata in a Single-Blind Extension of a Phase 2a Randomized Clinical Trial

20 citations , December 2021 in “Journal of the American Academy of Dermatology”

This study found that the oral JAK inhibitors ritlecitinib and brepocitinib were effective in maintaining hair regrowth in alopecia areata with continuous use, though efficacy decreased after withdrawal.

research Two Cases in Which Tofacitinib Effectively Treated Both Ulcerative Colitis and Alopecia Areata

2 citations , June 2020 in “Clinical Journal of Gastroenterology”

This case report describes two patients with ulcerative colitis and alopecia areata who did not respond to various treatments but achieved remission and improved hair growth after starting tofacitinib.

research What Is Behind the 'Swarm of Bees' in Alopecia Areata

7 citations , November 2018 in “British Journal of Dermatology”

Alopecia areata is caused by immune system issues, and JAK inhibitors might help treat it.

research Comorbidities in Alopecia Areata: A Systematic Review and Meta-Analysis

100 citations , July 2018 in “Journal of The American Academy of Dermatology”

This study found that alopecia areata is linked with a higher prevalence of systemic and psychiatric diseases, suggesting that physicians should monitor for these potential comorbidities.

research Alopecia Areata: A Review of Disease Pathogenesis

191 citations , May 2018 in “British journal of dermatology/British journal of dermatology, Supplement”

This study reviewed recent theories on alopecia areata's pathogenesis, highlighting its autoimmune nature due to immune privilege disruption in hair follicles, and noted current treatments have limited efficacy with high relapse rates, underscoring the need for further research into its mechanisms for better therapies.

research Alopecia Areata Is Driven by Cytotoxic T Lymphocytes and Is Reversed by JAK Inhibition

701 citations , August 2014 in “Nature medicine”

This study found that JAK inhibitors promote hair regrowth in both mice and human alopecia areata cases by blocking key immune pathways involved in disease development.

research British Association of Dermatologists’ Guidelines for the Management of Alopecia Areata 2012

218 citations , April 2012 in “British Journal of Dermatology”

This updated guideline from the British Association of Dermatologists discusses current recommendations for managing alopecia areata but reports no new clinical research findings.

research Alopecia Areata: An Autoimmune Disease Causing Hair Loss

421 citations , April 2012 in “The New England Journal of Medicine”

Alopecia Areata is an autoimmune condition causing hair loss with no cure and treatments that often don't work well.

research Prevalence of Dermatological Disorders in Japan: A Nationwide, Cross-Sectional, Seasonal, Multicenter, Hospital-Based Study

141 citations , March 2011 in “Journal of Dermatology”

This study in Japan found varying prevalence of skin disorders, with atopic dermatitis common in children and tinea pedis in the elderly, and observed gender differences in disease susceptibility.

research Maintenance of Hair Follicle Immune Privilege Is Linked to Prevention of NK Cell Attack

253 citations , December 2007 in “Journal of Investigative Dermatology”

This study suggests that human hair follicles may actively suppress natural killer cells, which contrasts with the observed defects in NK cell regulation in alopecia areata.

Androgen-Inducible TGF-β1 from Balding Dermal Papilla Cells Inhibits Epithelial Cell Growth: A Clue to Understanding Paradoxical Effects of Androgen on Human Hair Growth

research Androgen-Inducible TGF-β1 from Balding Dermal Papilla Cells Inhibits Epithelial Cell Growth: A Clue to Understanding Paradoxical Effects of Androgen on Human Hair Growth

190 citations , October 2002 in “The FASEB journal”

In this study, androgen did not affect keratinocyte growth in coculture with androgenetic alopecia-derived dermal papilla cells, but did significantly suppress keratinocyte growth when androgen receptor was overexpressed in the papilla cells.