Janus Kinase Inhibitors for the Treatment of Alopecia Areata

June 2025 in “ Revista Foco ”

C.R. Camargo, Kathellin Bianca Boletta Oliveira, Theresa Pacheco

alopecia areata Janus kinase inhibitors JAK inhibitors ritlecitinib baricitinib autoimmune disease hair loss topical treatment systemic treatment 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 assessed randomised clinical trials on the efficacy and safety of topical and systemic JAK inhibitors for alopecia areata, finding significant hair coverage improvement with ritlecitinibe and baricitinibe, though prolonged treatment is often needed to maintain results. Our plain-language summary of this paper — not a Tressless recommendation.

Alopecia areata (AA) is an autoimmune disease causing non-scarring hair loss, potentially progressing to more severe forms. This review analyzed randomized clinical trials from 2016 to 2025 on the efficacy and safety of topical or systemic Janus kinase (JAK) inhibitors for AA treatment, involving 5,116 patients. Significant hair coverage improvement was noted, particularly with ritlecitinibe and baricitinibe, even in extensive cases. Adverse effects were mostly mild to moderate, such as headache, acne, and respiratory infections. Treatment discontinuation often led to loss of results, suggesting the need for prolonged maintenance. JAK inhibitors are effective for severe AA with an acceptable safety profile, though long-term studies are needed for definitive therapeutic guidelines.

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Research cited in this study

23 / 23 results

research Efficacy and Safety of the Oral Janus Kinase 3/Tyrosine Kinase Inhibitor Ritlecitinib Over 24 Months: Integrated Analysis of the ALLEGRO Phase IIb/III and Long-Term Phase III Clinical Studies in Alopecia Areata

23 citations , October 2024 in “British Journal of Dermatology”

In this study, ritlecitinib showed sustained effectiveness and a favorable safety profile in treating alopecia areata in patients aged 12 and older over 24 months, with improvements observed in hair and eyebrow regrowth and patient satisfaction.

research Sustained Hair Regrowth With Continued Ritlecitinib Treatment Through Week 48 in Patients With Alopecia Areata: Post Hoc Analysis of the ALLEGRO Phase 2b/3 Trial

7 citations , October 2024 in “Journal of the American Academy of Dermatology”

This source reported that patients who initially responded to ritlecitinib treatment showed sustained hair regrowth through week 48, with up to one-third of those not meeting target efficacy at week 24 also achieving a response with continued treatment.

research Efficacy and Safety of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, in Adolescent and Adult Patients with Alopecia Totalis and Alopecia Universalis

7 citations , September 2024 in “The Journal of Dermatology”

This study evaluated the effectiveness and safety of ritlecitinib in patients aged 12 or older with alopecia totalis or universalis, finding higher hair regrowth response rates compared to placebo at 24 weeks, with continued improvement and acceptable safety through 48 weeks.

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 The Biology and Genomics of Human Hair Follicles: A Focus on Androgenetic Alopecia

February 2024 in “International Journal of Molecular Sciences”

This review outlines the functional anatomy, pathology, and molecular mechanisms of androgenetic alopecia, emphasizing the need for multi-omics approaches to better understand this condition's biology.

Integrated Safety Analysis of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, for the Treatment of Alopecia Areata from the ALLEGRO Clinical Trial Program

research Integrated Safety Analysis of Ritlecitinib, an Oral JAK3/TEC Family Kinase Inhibitor, for the Treatment of Alopecia Areata from the ALLEGRO Clinical Trial Program

January 2024 in “American journal of clinical dermatology”

This study reports that ritlecitinib, when used for up to 24 months in patients aged 12 and older with alopecia areata, has an acceptable safety profile, with a similar proportion of adverse events in both ritlecitinib and placebo groups in the placebo-controlled cohort.

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 Efficacy and Safety of Baricitinib in Patients with Severe Alopecia Areata Over 52 Weeks in Phase III Trials

20 citations , February 2023 in “American Journal of Clinical Dermatology”

In this study, 40.9% of patients taking 4 mg baricitinib and 21.2% taking 2 mg achieved significant hair regrowth over 52 weeks, indicating potential long-term benefits for adults with severe alopecia areata without introducing new safety concerns.

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 Ritlecitinib And Brepocitinib Demonstrate Significant Improvement In Scalp Alopecia Areata Biomarkers

36 citations , December 2021 in “The journal of allergy and clinical immunology/Journal of allergy and clinical immunology/The journal of allergy and clinical immunology”

This study observed that both ritlecitinib and brepocitinib improved scalp biomarkers in patients with alopecia areata, with associations to hair regrowth seen in this phase 2a trial.

Efficacy and Safety of the Oral Janus Kinase Inhibitor Baricitinib in the Treatment of Adults with Alopecia Areata: Phase 2 Results from a Randomized Controlled Study

research Efficacy and Safety of the Oral Janus Kinase Inhibitor Baricitinib in the Treatment of Adults with Alopecia Areata: Phase 2 Results from a Randomized Controlled Study

66 citations , June 2021 in “Journal of The American Academy of Dermatology”

In this phase 2 study, baricitinib at 2 mg and 4 mg doses significantly improved hair regrowth in adults with alopecia areata and ≥50% scalp hair loss compared to placebo, without new safety concerns, although the small sample size limits the results' generalizability.

research Selective Inhibition of JAK3 Signaling Is Sufficient to Reverse Alopecia Areata

42 citations , April 2021 in “JCI insight”

In this study, selective inhibition of JAK3 signaling effectively prevented and reversed alopecia areata in a mouse model, while JAK2 inhibitors did not restore hair growth.

research A Phase 2a Randomized, Placebo-Controlled Study to Evaluate the Efficacy and Safety of the Oral Janus Kinase Inhibitors Ritlecitinib and Brepocitinib in Alopecia Areata: 24-Week Results

138 citations , March 2021 in “Journal of the American Academy of Dermatology”

This study found that treatment with ritlecitinib or brepocitinib was effective in improving scalp hair loss for patients with alopecia areata over 24 weeks compared to placebo.

research The Effect of JAK Inhibitor on Survival, Anagen Re-Entry, and Hair Follicle Immune Privilege Restoration in Human Dermal Papilla Cells

16 citations , July 2020 in “International Journal of Molecular Sciences”

This study found that ruxolitinib modulated inflammatory changes and stimulated growth factor signals by blocking the JAK-STAT pathway in an in vitro model of alopecia areata.

research Targeting Wnt/β-Catenin Pathway for Developing Therapies for Hair Loss

86 citations , July 2020 in “International Journal of Molecular Sciences”

This review discusses the role of Wnt/β-catenin signaling in hair follicle regeneration and highlights recent progress in developing hair loss treatments targeting this pathway, but reports no new clinical results.

research Pathomechanisms of Immune-Mediated Alopecia

45 citations , April 2019 in “International Immunology”

This review discusses the mechanisms behind alopecia areata and primary cicatricial alopecia and reports no new clinical results, aiming to guide the development of targeted treatments.

research JAK Inhibitors for Treatment of Alopecia Areata

63 citations , July 2018 in “The journal of investigative dermatology/Journal of investigative dermatology”

In this review, the researchers reported that JAK inhibitors, originally approved by the FDA for other uses, have shown effectiveness in reversing hair loss in patients with moderate to severe alopecia areata, based on current preclinical and clinical studies.

research Role of Janus Kinase Inhibitors in the Treatment of Alopecia Areata

53 citations , July 2018 in “Drug design, development and therapy”

This review summarizes existing evidence on the efficacy and safety of JAK inhibitors for treating alopecia areata and emphasizes the need for improved topical formulations.

An Open-Label Pilot Study to Evaluate the Efficacy of Tofacitinib in Moderate to Severe Patch-Type Alopecia Areata, Totalis, and Universalis

research An Open-Label Pilot Study to Evaluate the Efficacy of Tofacitinib in Moderate to Severe Patch-Type Alopecia Areata, Totalis, and Universalis

130 citations , February 2018 in “Journal of Investigative Dermatology”

This study found that tofacitinib led to ≥50% hair regrowth in eight out of twelve patients with moderate to severe alopecia areata, suggesting a potential benefit for using JAK inhibitors in treating this condition.

Alopecia Areata: Overview and Insights from January 2018