Evolving research landscapes warrant updates in drug development strategy. Collaborations between pharmaceutical industry and academic institutions are crucial for accelerating drug development, leveraging individual expertise in clinical trial conduct and pathophysiological investigations. This review highlights key collaborations between Pfizer and academic institutions in inflammation and immunology research, including dermatology, gastroenterology, rheumatology, and autoimmunity. These collaborations harness and enhance the development of innovative disease models, large clinical databases, registries, and novel clinical trial designs, and open new avenues in disease management to improve patient outcomes.

Alopecia areata (AA) is a chronic autoimmune disorder characterized by non-scarring hair loss, with subtypes ranging from patchy alopecia (AAP) to alopecia totalis and universalis (AT/AU). The aim of this research is to investigate molecular features across AA severity by performing an integrated analysis of scalp transcriptomic datasets (GSE148346, GSE68801, GSE45512, GSE111061) and matched serum proteomic data from GSE148346. Differential expression analysis indicated that, relative to normal scalp, non-lesional AA tissue shows early immune activation—including Type 1 (C-X-C motif chemokine ligand 9 (CXCL9), CXCL10, CD8a molecule (CD8A), C-C motif chemokine ligand 5 (CCL5)) and Type 2 (CCL13, CCL18) signatures—together with reduced expression of hair-follicle structural genes (keratin 32(KRT32)–35, homeobox C13 (HOXC13)) (FDR < 0.05, |fold change| > 1.5). Lesional AAP and AT/AU scalp showed stronger pro-inflammatory upregulation and greater loss of keratins and keratin-associated proteins (KRT81, KRT83, desmoglein 4 (DSG4), KRTAP12/15) compared with non-lesional scalp (FDR < 0.05, |fold change| > 1.5). Ferroptosis-associated genes (cAMP responsive element binding protein 5 (CREB5), solute carrier family 40 member 1 (SLC40A1), (lipocalin 2) LCN2, SLC7A11) and IRS (inner root sheath) differentiation genes (KRT25, KRT27, KRT28, KRT71–KRT75, KRT81, KRT83, KRT85–86, trichohyalin (TCHH)) were consistently repressed across subtypes, with the strongest reductions in AT/AU lesions versus AAP lesions, suggesting that oxidative-stress pathways and follicular structural integrity may contribute to subtype-specific pathology. Pathway analysis of lesional versus non-lesional scalp highlighted enrichment of IFN-α/γ, cytotoxic, and IL-15 signaling. Serum proteomic profiling, contrasting AA vs. healthy controls, corroborated scalp findings, revealing parallel alterations in immune-related proteins (CXCL9–CXCL10, CD163, interleukin-16 (IL16)) and structural markers (angiopoietin 1 (ANGPT1), decorin (DCN), chitinase-3-like protein 1 (CHI3L1)) across AA subtypes. Together, these data offer an integrated view of immune, oxidative, and structural changes in AA and found ferroptosis-related and IRS genes, along with immune signatures, as potential molecular indicators to support future studies on disease subtypes and therapeutic strategies.

BACKGROUND:Alopecia areata (AA) is an autoimmune disease characterized by hair loss. This study examined changes in molecular signatures in lesional scalp of patients with AA subtypes (patchy-type AA [AAP] or alopecia totalis/alopecia universalis [AT/AU]) in response to treatment with JAK3/TEC family kinase inhibitor ritlecitinib and evaluated correlations between potential biomarker levels/changes and scalp hair regrowth. METHODS:This was a post hoc analysis of a biopsy substudy from a phase 2a trial of ritlecitinib in patients with AA and ≥ 50% scalp hair loss. Transcriptomic expression profiles from scalp samples of patients with AAP or AT/AU were analyzed using microarray. Changes from baseline in transcriptional and serum protein expression were evaluated, as were correlations between both these changes and the baseline profile with clinical response (scalp hair regrowth). RESULTS:Following 12 and 24 weeks of treatment, ritlecitinib downregulated key Type I (CCL5, CD8A, and GZMB) and Type II immunity-related genes (CCL13, CCL18, and IL13RA1), downregulated genes related to ritlecitinib's mechanism of action (ITK, JAK3, and BTK), and upregulated hair keratin genes in AAP and AT/AU lesions, with a lesser extent in AT/AU than AAP lesions. Baseline expression levels and changes from baseline to Weeks 12 and/or 24 in levels of genes and serum proteins related to Type I and II immunity, hair structure/function, and ritlecitinib's mechanism of action significantly correlated with clinical response at Weeks 12 and/or 24. CONCLUSION:These results provide support that treatment with ritlecitinib improves the gene expression profile in AA lesional scalp and is correlated with subsequent hair regrowth response. TRIAL REGISTRATION:NCT02974868.

Background: Vitiligo is an autoimmune depigmenting disorder with no effective and safe treatments. Its pathogenesis is not fully elucidated. Objective: This substudy of a randomized, double-blind, placebo-controlled phase 2b trial (NCT03715829) evaluated effects of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, on skin and blood biomarkers in participants with nonsegmental vitiligo (NSV). Methods: Sixty-five adults with NSV participated in the substudy and received daily treatment for 24 weeks with placebo (n = 14) or ritlecitinib with or without a 4-week loading dose: 200 (loading dose)/50 mg (n = 13), 100/50 mg (n = 12), 50 mg (n = 11), 30 mg (n = 8), or 10 mg (n = 6). Skin (lesional and nonlesional) biopsy samples were obtained at baseline and at 4 and 24 weeks. Changes from baseline to weeks 4 and 24 in skin and blood molecular and cellular biomarkers were evaluated by RNA sequencing, quantitative real-time PCR, proteomic analysis, and flow cytometry. Results: Ritlecitinib-treated groups showed downregulation of immune biomarkers and upregulation of melanocyte-related markers at weeks 4 and 24 compared to baseline and/or placebo. Significant reductions were seen in CD3(+)/CD8(+) T-cell infiltrates, with significant increases in melanocyte markers (tyrosinase; Melan-A) in NSV lesions in the 50 mg ritlecitinib groups (both P < .05). There was significant, dose-dependent downregulation in T-cell activation, NK, cytotoxic, and regulatory markers in lesional skin (IL-2, IL2-RA, IL-15, CCR7, CD5, CRTAM, NCR1, XCL1, KIR3DL1, FASLG, KLRD; P < .05). T(H)1 and T(H)2 markers were also downregulated in lesional skin and blood in a dose-dependent manner (P < .05). Changes in immune biomarkers correlated with clinical response. Conclusions: Ritlecitinib significantly downregulated proinflammatory biomarkers and increased melanocyte products in skin and blood of participants with NSV, suggesting its potential in treatment. Ritlecitinib-mediated changes positively correlated with clinical response. (J Allergy Clin Immunol 2024;153:161-72.)

Both alopecia areata (AA) and vitiligo are distinct, heterogenous, and complex disease entities, characterized by nonscarring scalp terminal hair loss and skin pigment loss, respectively. In AA, inflammatory cell infiltrates are in the deep reticular dermis close to the hair bulb (swarm of bees), whereas in vitiligo the inflammatory infiltrates are in the epidermis and papillary dermis. Immune privilege collapse has been extensively investigated in AA pathogenesis, including the suppression of immunomodulatory factors (e.g., transforming growth factor-β (TGF-β), programmed death-ligand 1 (PDL1), interleukin-10 (IL-10), α-melanocyte-stimulating hormone (α-MSH), and macrophage migration inhibitory factor (MIF)) and enhanced expression of the major histocompatibility complex (MHC) throughout hair follicles. However, immune privilege collapse in vitiligo remains less explored. Both AA and vitiligo are autoimmune diseases that share commonalities in pathogenesis, including the involvement of plasmacytoid dendritic cells (and interferon-α (IFN- α) signaling pathways) and cytotoxic CD8+ T lymphocytes (and activated IFN-γ signaling pathways). Blood chemokine C-X-C motif ligand 9 (CXCL9) and CXCL10 are elevated in both diseases. Common factors that contribute to AA and vitiligo include oxidative stress, autophagy, type 2 cytokines, and the Wnt/β-catenin pathway (e.g., dickkopf 1 (DKK1)). Here, we summarize the commonalities and differences between AA and vitiligo, focusing on their pathogenesis.

The efficacy of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, on active and stable lesions was evaluated in patients with active non-segmental vitiligo in a phase 2b trial (NCT03715829). Patients were randomized to placebo or daily ritlecitinib 50 mg (with or without 4-week 100-mg or 200-mg loading dose), 30 mg, or 10 mg for 24 weeks. Active lesions showed greater baseline expression of inflammatory/immune markers IFNG and CCL5, levels of CD103, and T-cell infiltrates than stable lesions. Patients with more active than stable vitiligo lesions showed higher baseline serum levels of CXCL9 and PD-L1, while patients with more stable than active lesions showed higher baseline serum levels of HO-1. At Week 24, ritlecitinib 50 mg significantly stabilized mean percent change from baseline in depigmentation extent in both active lesions and stable lesions vs. placebo-response, with stable lesions showing greater repigmentation. After 24 weeks of treatment, ritlecitinib 50 mg increased expression of melanocyte markers in stable lesions, while Th1/Th2-related and co-stimulatory molecules decreased significantly in both stable and active lesions. Serum from patients with more active than stable lesions showed decreased levels of ICOS and NK cell activation markers. These data, confirmed at transcription/protein levels, indicate that stable lesion repigmentation occurs early with ritlecitinib, while active lesions require stabilization of inflammation first. ClinicalTrials.gov: NCT03715829.

Both alopecia areata (AA) and vitiligo share common pathogenesis involving, interferon-γ (IFN-γ) and interleukin-15 (IL-15) signalling pathways that activate cytotoxic CD8+ T lymphocytes. These shared mechanisms may explain why both diseases respond to currently available treatments (e.g. topical/systemic corticosteroid) and emerging treatment modalities. As compared with the speed of re-pigmentation in vitiligo lesions, the regeneration of pigmented terminal hair follicles in AA lesions appears fast in response to treatments targeting the inhibition of the Janus kinases (JAKs) and other kinases. We summarize the commonalities and differences between AA and vitiligo focusing on the treatment modalities, followed by recent findings associated with hair follicle stem cells (HFSC) in hair bulge (HBg) and melanocyte stem cells (McSC) in HBg and hair germ (HGm). We then discuss how HFSC and HGm-McSC are involved in the initiation of anagen phase, followed by pigmented terminal hair regrowth in the recovering AA lesions in association with immunology. We also discuss how HBg-McSC contribute to the migration of fully dendritic mature melanocytes into interfollicular epidermis and the equal distribution of melanin in recovering vitiligo lesions. Finally, we present four hypotheses to elucidate the delayed distribution of melanin by mature melanocytes in depigmented vitiligo lesions from the aspects of stem cell biology, as compared with quick hair recovery in AA: (1) McSC are less abundant than HFSC. (2) McSC require a long travel, whereas HFSC reside close to hair regeneration trigger point. (3) Keratinocyte scaffold to accept melanin is not well preserved, whereas scaffold for hair regrowth is well preserved. (4) Inhibitors targeting JAKs and other kinases have less direct effects on melanocyte proliferation and differentiation in vitiligo than hair regrowth in AA. Our review provides an overview of treatment modalities and bridges the gap between scientific advancement and clinical practice in AA and vitiligo management.

With several vitiligo therapies currently under development, a reliable clinician-reported outcome is needed to assess disease severity and treatment response. The objective of the current study is to evaluate inter- and intra-rater reliabilities of the F-VASI for assessing extent and severity of vitiligo in a central reader paradigm as part of a clinical trial of the oral, dual JAK3/TEC family kinase inhibitor ritlecitinib in patients with vitiligo. We found strong and consistent inter-rater agreement between two central readers across all F-VASI measurements and observed similar reliability for intra-rater assessments across 2 separate readings of the same patient images.

Ritlecitinib, a JAK3/TEC family kinase inhibitor, demonstrated efficacy in a Phase 2b trial of patients with NSV. To evaluate the efficacy and tolerability of ritlecitinib with or without nbUVB add-on therapy in patients with NSV. In a Phase 2b trial, following a 24-week placebo-controlled dose-ranging period, patients with NSV received ritlecitinib 200 mg for 4 weeks then 50 mg for 20 weeks, with or without nbUVB phototherapy 2x/week. Missing data were handled using observed case (OC) and last observation carried forward (LOCF). 43 and 187 patients received ritlecitinib+nbUVB and ritlecitinib-monotherapy, respectively. Nine patients receiving ritlecitinib+nbUVB discontinued due to nbUVB group-specific efficacy criteria requiring >10% improvement in %change from baseline (CFB) in Total-Vitiligo Area Scoring Index (T-VASI) at Week 12. At Week 24, mean (90% CI) %CFB in Facial-VASI (F-VASI) was -69.6 (-79.1, -60.1) vs -55.1 (-59.4, -50.7) (OC; P=0.009) and -57.0 (-65.3, -48.7) vs -51.5 (-55.9, -47.1) (LOCF; P=0.158), for ritlecitinib+nbUVB vs ritlecitinib-monotherapy, respectively. 60.9% (43.1%, 77.2%) vs 29.2% (22.8%, 35.9%) (OC; P=0.007) and 44.4% (30.2%, 59.1%) vs 27.4% (21.7%, 33.4%) (LOCF; P=0.081) of patients, respectively, achieved ≥75% improvement in F-VASI. Mean (90% CI) %CFB in T-VASI at Week 24 was -46.8 (-54.5, -39.2) vs -24.5 (-28.1, -21.0) (OC; P<0.001) and -29.4 (-36.5, -22.2) vs -21.2 (-25.0, -17.4) (LOCF; P=0.043) for ritlecitinib+nbUVB vs ritlecitinib-monotherapy, respectively. 50.0% (33.3%, 66.7%) vs 15.2% (11.1%, 20.3%) (OC; P<0.001) and 32.6% (22.1%, 44.7%) vs 14.4% (10.6%, 19.0%) (LOCF, P=0.014) of patients, respectively, achieved ≥50% improvement in T-VASI. nbUVB addition to ritlecitinib was well-tolerated with no new safety signals. Ritlecitinib alone and with nbUVB therapy improved facial and total body repigmentation and was well-tolerated. nbUVB may improve ritlecitinib efficacy.

INTRODUCTION:There is limited epidemiologic evidence on keloids using real-world data, especially in the United States (US) across race and ethnicity. METHODS:We conducted a retrospective cohort study using Cerner Real-World Data, between 2015 and 2021, to describe the demographic and clinical characteristics of US adults with keloids. Keloids were identified using a combination of ICD-10 and (Systemized Nomenclature of Medicine-Clinical Terms [SNOMED] codes). Demographics (including race and ethnicity), clinical characteristics, treatment patterns, and healthcare utilization were compared across keloid and non-keloid populations. RESULTS:Among 5,457 keloid patients identified in the study, the majority were female (61.8%) with a mean age of 34.2 years and of non-Hispanic Black, Hispanic, and Asian descent (P < 0.001). Relative to non-keloid cohorts, patients with keloids had significantly higher rates of integumentary, cardiorespiratory, general, auditory, and ocular surgeries and burns (all P < 0.05). Patients with keloids were also more likely to have comorbidities like obesity, hypertension, hyperlipidemia, and diabetes (P < 0.05) when compared to those with no keloids. A large proportion of keloids were untreated; among those treated, the most common keloid treatments were medication therapy (51.5%) and surgical excision (10.6%). Non-Hispanic Black and Hispanic keloid patients were significantly more likely to receive medication therapy and surgical excision (P < 0.001) compared to keloid patients of other races or ethnicities. CONCLUSIONS:This study provided real-world insights into the keloid population in the US. Our findings emphasize the high burden of keloids and its substantial impact on ethnic minorities. Given high keloid recurrence rates and limited standardized treatments for keloids, further research into keloids is crucial to the development of keloid-specific therapeutic options.

Efficacy and safety of ritlecitinib (an oral JAK3/TEC family kinase inhibitor) were evaluated in patients with nonsegmental vitiligo (NSV) across Fitzpatrick skin types (FSTs). Patients with FST I-III ('light skin'; n = 247) and FST IV-VI ('dark skin'; n = 117) received once-daily ritlecitinib 50 mg (with/without 4-week loading dose), low-dose ritlecitinib or placebo for 24 weeks. At baseline, patients with light skin displayed higher CLM-1 and NCR1 serum levels than patients with dark skin (p < 0.05). At 24 weeks, ritlecitinib 50 mg improved the extent of depigmentation measured by percent change from baseline in facial-vitiligo area scoring index (placebo-adjusted mean difference [90% CI]) in patients with light (-15.2 [-24.7, -5.8]; p = 0.004) and dark (-37.4 [-50.3, -24.4]; p < 0.0001) skin, with continuous re-pigmentation through week 48. Treatment-emergent adverse events were similar across FSTs. At weeks 4 and 24, ritlecitinib 50 mg reduced CXCL11 serum levels (p < 0.001) in patients with light skin, whereas patients with dark skin had increased levels at week 4 (p = 0.05) and no significant change at week 24. Ritlecitinib 50 mg decreased IL-9 and IL-22 expression levels in dark skin compared with light skin (qPCR; p < 0.05). These differences in immune dysregulations may explain why NSV patients with dark skin respond to therapy earlier than patients with light skin.

BACKGROUND:Ritlecitinib demonstrated efficacy in a phase 2b trial of nonsegmental vitiligo. OBJECTIVE:To evaluate the efficacy and tolerability of ritlecitinib with add-on narrow-band ultraviolet B (nbUVB) phototherapy in patients with nonsegmental vitiligo. METHODS:Following a 24-week, placebo-controlled, dose-ranging period, patients received ritlecitinib 200 mg for 4 weeks then 50 mg for 20 weeks, with or without nbUVB phototherapy 2x/week. Missing data were handled using last observation carried forward and observed case (OC). RESULTS:Forty-three patients received ritlecitinib + nbUVB and 187 received ritlecitinib-monotherapy. Nine patients receiving ritlecitinib + nbUVB discontinued due to nbUVB group-specific efficacy criteria requiring >10% improvement in % change from baseline (% change from baseline) in Total-Vitiligo Area Scoring Index at week 12. At week 24, mean % change from baseline in Facial-VASI score was -57.0 vs -51.5 (last observation carried forward; P = .158) and -69.6 vs -55.1 (OC; P = .009), for ritlecitinib + nbUVB vs ritlecitinib-monotherapy, respectively. Mean % change from baseline in Total-Vitiligo Area Scoring Index at week 24 was -29.4 vs -21.2 (last observation carried forward; P = .043) and -46.8 vs -24.5 (OC; P < .001), respectively. nbUVB addition to ritlecitinib was well tolerated with no new safety signals. LIMITATIONS:Exploratory analysis; discontinuation criterion applied only to the ritlecitinib + nbUVB group; small sample size. CONCLUSION:Ritlecitinib alone and with nbUVB therapy improved facial and total body repigmentation and was well tolerated. Adding nbUVB may improve ritlecitinib efficacy.

Background: Vitiligo is an autoimmune disorder that causes patchy loss of skin pigmentation. Up to 2.16% of pediatric patients may have vitiligo. This study estimated vitiligo point prevalence in children and adolescents (ages: 4-11 and 12-17 years) in the United States (US). Methods: An online, population-based survey of a nationally representative sample of individuals based on 2017 US Census Bureau estimates for age, race, Hispanic origin, income, and geographic region was conducted from December 2019 to March 2020. Parent/legal guardian proxies responded on behalf of their children or adolescents to vitiligo screening questions. Proxy-reported vitiligo status was adjudicated by expert dermatologists who reviewed photographs of vitiligo lesions uploaded by proxies using a teledermatology application. Estimated point prevalence (including diagnosed and undiagnosed vitiligo and its subtypes) was calculated for proxy-reported and clinician-adjudicated vitiligo. Results: There were 9,118 eligible proxy responses (5,209 children, mean age 7.7 years; 3,909 adolescents, mean age 14.4 years). The proxy-reported vitiligo prevalence (95% confidence interval) for children and adolescents was 1.52% (1.11-1.93) and 2.16% (1.66-2.65), respectively. The clinician-adjudicated prevalence (sensitivity analysis bounds) was 0.84% (0.83-1.23) and 1.19% (1.18-1.74), respectively. Approximately 69% of children and 65% of adolescents had nonsegmental vitiligo (clinician adjudicated) and up to 50% may be undiagnosed. Conclusion: Based on the clinician-adjudicated prevalence estimates, there were more than 591,000 cases of vitiligo in children and adolescents in the US in 2020. More than two-thirds had nonsegmental vitiligo and nearly half may be undiagnosed. Future studies should confirm these findings.

Background: Vitiligo is a chronic autoimmune disorder characterized by depigmented patches of the skin.Objective: To evaluate the efficacy and safety of ritlecitinib, an oral JAK3 (Janus kinase)/TEC (tyrosine kinase expressed in hepatocelluar carcinoma) inhibitor, in patients with active nonsegmental vitiligo in a phase 2b trial (NCT03715829).Methods: Patients were randomized to once-daily oral ritlecitinib 6 4-week loading dose (200/50 mg, 100/ 50 mg, 30 mg, or 10 mg) or placebo for 24 weeks (dose-ranging period). Patients subsequently received ritlecitinib 200/50 mg daily in a 24-week extension period. The primary efficacy endpoint was percent change from baseline in Facial-Vitiligo Area Scoring Index at week 24.Results: A total of 364 patients were treated in the dose-ranging period. Significant differences from placebo in percent change from baseline in Facial-Vitiligo Area Scoring Index were observed for the ritlecitinib 50 mg groups with (-21.2 vs 2.1; P < .001) or without (-18.5 vs 2.1; P < .001) a loading dose and ritlecitinib 30 mg group (-14.6 vs 2.1; P = .01). Accelerated improvement was observed after treatment with ritlecitinib 200/50 mg in the extension period (n = 187). No dose-dependent trends in treatment -emergent or serious adverse events were observed across the 48-week treatment.Limitations: Patients with stable vitiligo only were excluded.Conclusions: Oral ritlecitinib was effective and well tolerated over 48 weeks in patients with active nonsegmental vitiligo. ( J Am Acad Dermatol 2023;88:395-403.)

Our understanding of allergic contact dermatitis mechanisms has progressed over the past decade. Innate immune cells that are involved in the pathogenesis of allergic contact dermatitis include Langerhans cells, dermal dendritic cells, macrophages, mast cells, innate lymphoid cells (ILCs), neutrophils, eosinophils, and basophils. ILCs can be subcategorized as group 1 (natural killer cells; ILC1) in association with Th1, group 2 (ILC2) in association with Th2, and group 3 (lymphoid tissue-inducer cells; ILC3) in association with Th17. Pattern recognition receptors (PRRs) including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) in innate immune cells recognize damage-associated molecular patterns (DAMPs) and cascade the signal to produce several cytokines and chemokines including tumor necrosis factor (TNF)-α, interferon (IFN)-α, IFN-γ, interleukin (IL)-1β, IL-4, IL-6, IL-12, IL-13, IL-17, IL-18, and IL-23. Here we discuss the recent findings showing the roles of the innate immune system in allergic contact dermatitis during the sensitization and elicitation phases.

Background: Vitiligo is an autoimmune disorder in which the immune system targets melanocytes, manifesting in patches of lost skin pigmentation. Objectives: To characterize the occurrence of autoimmune/autoinflammatory and/or nonautoimmune comorbid conditions in patients with vitiligo. Methods: Adults representative of the 2017 US Census population were recruited for an online, cross-sectional survey. Based on responses to vitiligo screening questions, participants were categorized into one of three groups: diagnosed vitiligo, undiagnosed vitiligo and no vitiligo. Participants reported clinical-diagnosed conditions from prespecified lists of 13 autoimmune/autoinflammatory conditions and 21 nonautoimmune conditions. Results: A total of 40,888 adults participated in the online survey; 315 (0.8%) were categorized as diagnosed vitiligo, 249 (0.6%) as undiagnosed vitiligo and 40,325 (98.6%) as no vitiligo. The percentage of participants with at least one autoimmune/autoinflammatory comorbidity was 2.65 times greater in the diagnosed vitiligo group than in the no vitiligo group. Psoriasis, rheumatoid arthritis and multiple sclerosis had the greatest difference in the percentage of participants between the diagnosed vitiligo and no vitiligo groups. The percentage of participants with nonautoimmune comorbidities was higher in the diagnosed vitiligo group than in the no vitiligo group. Vision changes, arthritis, back pain, anxiety, depression and sudden hearing loss had the greatest difference in the percentage of participants between the diagnosed vitiligo group and the no vitiligo group. Conclusions: This large survey found that both autoimmune/autoinflammatory and nonautoimmune conditions were more common among adults with vitiligo. The greater percentage of autoimmune/autoinflammatory conditions in participants with vitiligo suggests that screening for such comorbidities may be beneficial and may indicate important opportunities for early intervention.

In a randomized, placebo-controlled phase 2b trial in NSV, the efficacy of the oral JAK3/TEC family kinase inhibitor ritlecitinib with or without a 4-week loading dose (200/50mg, 100/50mg, 50mg, 30mg, 10mg) or placebo for 24 weeks was evaluated in patients with lighter skin (FST I-III) vs darker skin (FST IV-VI); 50mg dose groups (50mg) and 30/10mg (low dose) groups were combined for analysis. Treatment with 50mg ritlecitinib significantly reduced depigmentation extent at Week 24 [W24] vs placebo both in patients with FST I-III (% change from baseline [%CFB] in Facial-Vitiligo Area Scoring Index -15.2,P=0.004) and FST IV-VI (-37.4, P<0.0001). At Week 48, there was no difference in %CFB between FST I-III and FST IV-VI groups (-63.1 vs -66.8). Immune biomarkers were evaluated. Blood collected at baseline, Week 4 [W4], and W24 was analyzed by Olink proteomics cardiovascular, neurology, immuno-oncology, and inflammation target panels. At baseline, patients with FST I-III had elevated levels of serum proteins such as CLM-1 and CSF-1, and patients with FST IV-VI had elevated levels of NOS3. Following ritlecitinib treatment, patients with FST I-III in the 50mg groups had decreased CXCL11 levels from baseline (W24: P=9e-5), while patients with FST IV-VI had increased levels of CXCL11 (W24: P=0.05), IL-10 (W24: P=0.003), and IL-27 (W4: P=0.0007). These results suggest that NSV immune system dysregulation can vary, leading to differential molecular changes in response to JAK3/TEC family kinase inhibition.

INTRODUCTION:Keloids are lesions characterized by the growth of dense fibrous tissue extending beyond original wound boundaries. Research into the natural history of keloids and potential differences by sociodemographic factors in the USA is limited. This real-world, retrospective cohort study aimed to characterize a population of patients with keloids compared with matched dermatology and general cohorts. METHODS:Patients with ≥ 2 International Classification of Diseases codes for keloid ≥ 30 days apart and a confirmed keloid diagnosis from clinical notes enrolled in the OM1 Real-World Data Cloud between 1 January 2013 and 18 March 2022 were age- and sex-matched 1:1:1 to patients without keloids who visited dermatologists ("dermatology cohort") and those who did not ("general cohort"). Results are presented using descriptive statistics and analysis stratified by cohort, race, ethnicity, household income, and education. RESULTS:Overall, 24,453 patients with keloids were matched to 23,936 dermatology and 24,088 general patients. A numerically higher proportion of patients with keloids were Asian or Black. Among available data for patients with keloids, 67.7% had 1 keloid lesion, and 68.3% had keloids sized 0.5 to < 3 cm. Black patients tended to have larger keloids. Asian and Black patients more frequently had > 1 keloid than did white patients (30.6% vs. 32.5% vs. 20.5%). Among all patients with keloids who had available data, 56.4% had major keloid severity, with major severity more frequent in Black patients. Progression was not significantly associated with race, ethnicity, income, or education level; 29%, 25%, and 20% of the dermatology, keloid, and general cohorts were in the highest income bracket (≥ US$75,000). The proportion of patients with income below the federal poverty line (< US$22,000) and patterns of education level were similar across cohorts. CONCLUSION:A large population of patients in the USA with keloids was identified and characterized using structured/unstructured sources. A numerically higher proportion of patients with keloids were non-white; Black patients had larger, more severe keloids at diagnosis.

IMPORTANCE Vitiligo can have profound effects on patients and is often associated with other autoimmune comorbid conditions. It is important to understand the current prevalence of vitiligo, including diagnosed, undiagnosed, and subtypes (nonsegmental and segmental). OBJECTIVE To estimate the point prevalence of vitiligo in the US. Design, Setting, and Participants For this population-based study of adults in the US, a cross-sectional online survey was administered between December 2019 and March 2020 to obtain participant self-reported vitiligo status. A representative sample of the US adult general population, aged 18 to 85 years, was recruited using a stratified proportional, sampling design from general population research panels. Additionally, 3 expert dermatologists adjudicated participants' self-reported vitiligo diagnosis by reviewing photographs uploaded by the participants using a teledermatology app designed and tested specifically for this study. MAIN OUTCOMES AND MEASURES The main outcomes were the point prevalence estimates of overall vitiligo, as well as diagnosed, undiagnosed, nonsegmental, and segmental vitiligo. RESULTS Among the 40 888 eligible adult participants, the mean (SD) age was 44.9 (17.4) years, 23 170 (56.7%) were female, 30 428 (74.4%) were White, and 4225 (10.3%) were of Hispanic, Latino, or Spanish origin. Self-reported vitiligo prevalence was 1.38% (95% CI, 1.26%-1.49%), with 0.77% (95% CI, 0.68%-0.85%) for diagnosed and 0.61% (95% CI, 0.54%-0.69%) for undiagnosed. Based on expert dermatologist review of 113 photographs of participants with self-reported vitiligo, clinician-adjudicated vitiligo prevalence (sensitivity bounds) was 0.76% (0.76%-1.11%), with 0.46% (0.46%-0.61%) for diagnosed and 0.29% (0.29%-0.50%) for undiagnosed. Self-reported nonsegmental vitiligo prevalence was 0.77% (95% CI, 0.68%-0.85%), with 0.48% (95% CI, 0.41%-0.55%) for diagnosed and 0.29% (95% CI, 0.23%-0.34%) for undiagnosed. Clinician-adjudicated nonsegmental vitiligo prevalence (sensitivity bounds) was 0.58% (0.57%-0.84%), with 0.37% (0.37%-0.49%) for diagnosed and 0.21% (0.20%-0.36%) for undiagnosed. Self-reported segmental vitiligo prevalence was 0.61% (95% CI, 0.53%-0.69%), with 0.28% (95% CI, 0.23%-0.33%) for diagnosed and 0.33% (95% CI, 0.27%-0.38%) for undiagnosed. Clinician-adjudicated segmental vitiligo prevalence (sensitivity bounds) was 0.18% (0.18%-0.27%), with 0.09% (0.09%-0.12%) for diagnosed and 0.08% (0.08%-0.15%) for undiagnosed. CONCLUSIONS AND RELEVANCE Results of this survey study demonstrated that the current US population-based prevalence estimate of overall (diagnosed and undiagnosed combined) vitiligo in adults is between 0.76% (1.9 million cases in 2020) and 1.11% (2.8 million cases in 2020). Additionally, this study suggests that approximately 40% of adult vitiligo in the US may be undiagnosed. Future studies should be performed to confirm these findings.