Baricitinib treatment resolves lower-airway macrophage inflammation and neutrophil recruitment in SARS-CoV-2-infected rhesus macaques.

SARS-CoV-2-induced hypercytokinemia and inflammation are critically associated with COVID-19 severity. Baricitinib, a clinically approved JAK1/JAK2 inhibitor, is currently being investigated in COVID-19 clinical trials. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages, and tissues was not reduced with baricitinib. Type I interferon (IFN) antiviral responses and SARS-CoV-2-specific T cell responses remained similar between the two groups. Animals treated with baricitinib showed reduced inflammation, decreased lung infiltration of inflammatory cells, reduced NETosis activity, and more limited lung pathology. Importantly, baricitinib-treated animals had a rapid and remarkably potent suppression of lung macrophage production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for inflammation induced by SARS-CoV-2 infection.

JAK inhibitor treatment for inborn errors of JAK/STAT signaling: An ESID/EBMT-IEWP retrospective study.

BACKGROUND: Inborn errors of immunity (IEI) with dysregulated JAK/STAT signaling present with variable manifestations of immune dysregulation and infections. Hematopoietic stem cell transplantation (HSCT) is potentially curative, but initially reported outcomes were poor. JAK inhibitors (JAKi) offer a targeted treatment option that may be an alternative or bridge to HSCT. However, data on their current use, treatment efficacy and adverse events are limited. OBJECTIVE: We evaluated the current off-label JAKi treatment experience for JAK/STAT inborn errors of immunity (IEI) among European Society for Immunodeficiencies (ESID)/European Society for Blood and Marrow Transplantation (EBMT) Inborn Errors Working Party (IEWP) centers. METHODS: We conducted a multicenter retrospective study on patients with a genetic disorder of hyperactive JAK/STAT signaling who received JAKi treatment for at least 3 months. RESULTS: Sixty-nine patients (72% children) were evaluated (45 STAT1 gain of function [GOF], 21 STAT3-GOF, 1 STAT5B-GOF, 1 suppressor of cytokine signaling 1 [aka SOCS1] loss of function, 1 JAK1-GOF). Ruxolitinib was the predominantly prescribed JAKi (80%). Overall, treatment resulted in improvement (partial or complete remission) of clinical symptoms in 87% of STAT1-GOF and in 90% of STAT3-GOF patients. We documented highly heterogeneous dosing and monitoring regimens. The response rate and time to response varied across different diseases and manifestations. Adverse events including infection and weight gain were frequent (38% of patients) but were mild (grade I-II) and transient in most patients. At last follow-up, 52 (74%) of 69 patients were still receiving JAKi treatment, and 11 patients eventually underwent HSCT after receipt of previous JAKi bridging therapy, with 91% overall survival. CONCLUSIONS: Our study suggests that JAKi may be highly effective to treat symptomatic JAK/STAT IEI patients. Prospective studies to define optimal JAKi dosing for the variable clinical presentations and age ranges should be pursued.

JAK inhibition during the early phase of SARS-CoV-2 infection worsens kidney injury by suppressing endogenous antiviral activity in mice.

Coronavirus disease 2019 (COVID-19) induces respiratory dysfunction as well as kidney injury. Although the kidney is considered a target organ of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and affected by the COVID-19-induced cytokine storm, the mechanisms of renal reaction in SARS-CoV-2 infection are unknown. In this study, a murine COVID-19 model was induced by nasal infection with mouse-adapted SARS-CoV-2 (MA10). MA10 infection induced body weight loss along with lung inflammation in mice 4 days after infection. Serum creatinine levels and the urinary albumin/creatinine ratio increased on day 4 after MA10 infection. Measurement of the urinary neutrophil gelatinase-associated lipocalin/creatinine ratio and hematoxylin and eosin staining revealed tubular damage in MA10-infected murine kidneys, indicating kidney injury in the murine COVID-19 model. Interferon (IFN)-γ and interleukin-6 upregulation in the sera of MA10-infected mice, along with the absence of MA10 in the kidneys, implied that the kidneys were affected by the MA10 infection-induced cytokine storm rather than by direct MA10 infection of the kidneys. RNA-sequencing analysis revealed that antiviral genes, such as the IFN/Janus kinase (JAK) pathway, were upregulated in MA10-infected kidneys. Upon administration of the JAK inhibitor baricitinib on days 1-3 after MA10 infection, an antiviral pathway was suppressed, and MA10 was detected more frequently in the kidneys. Notably, JAK inhibition upregulated the hypoxia response and exaggerated kidney injury. These results suggest that endogenous antiviral activity protects against SARS-CoV-2-induced kidney injury in the early phase of infection, providing valuable insights into the pathogenesis of COVID-19-associated nephropathy.NEW & NOTEWORTHY Patients frequently present with acute kidney injury or abnormal urinary findings after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we investigated how the kidneys respond during SARS-CoV-2 infection using a murine coronavirus disease 2019 (COVID-19) model and showed that Janus kinase-mediated endogenous antiviral activity protects against kidney injury in the early phase of SARS-CoV-2 infection. These findings provide valuable insights into the renal pathophysiology of COVID-19.

Discovery of a novel and highly selective JAK3 inhibitor as a potent hair growth promoter.

JAK-STAT signalling pathway inhibitors have emerged as promising therapeutic agents for the treatment of hair loss. Among different JAK isoforms, JAK3 has become an ideal target for drug discovery because it only regulates a narrow spectrum of γc cytokines. Here, we report the discovery of MJ04, a novel and highly selective 3-pyrimidinylazaindole based JAK3 inhibitor, as a potential hair growth promoter with an IC50 of 2.03 nM. During in vivo efficacy assays, topical application of MJ04 on DHT-challenged AGA and athymic nude mice resulted in early onset of hair regrowth. Furthermore, MJ04 significantly promoted the growth of human hair follicles under ex-vivo conditions. MJ04 exhibited a reasonably good pharmacokinetic profile and demonstrated a favourable safety profile under in vivo and in vitro conditions. Taken together, we report MJ04 as a highly potent and selective JAK3 inhibitor that exhibits overall properties suitable for topical drug development and advancement to human clinical trials.

Differential properties of Janus kinase inhibitors in the treatment of immune-mediated inflammatory diseases.

Janus kinases (JAKs) are a family of cytosolic tyrosine kinases that regulate cytokine signal transduction, including cytokines involved in a range of inflammatory diseases, such as RA, psoriasis, atopic dermatitis and IBD. Several small-molecule JAK inhibitors (JAKis) are now approved for the treatment of various immune-mediated inflammatory diseases. There are, however, key differences between these agents that could potentially translate into unique clinical profiles. Each JAKi has a unique chemical structure, resulting in a distinctive mode of binding within the catalytic cleft of the target JAK, and giving rise to distinct pharmacological characteristics. In addition, the available agents have differing selectivity for JAK isoforms, as well as off-target effects against non-JAKs. Other differences include effects on haematological parameters, DNA damage repair, reproductive toxicity and metabolism/elimination. Here we review the pharmacological profiles of the JAKis abrocitinib, baricitinib, filgotinib, peficitinib, tofacitinib and upadacitinib.

Glucocorticoid sparing effect of Janus Kinase inhibitors compared to biological Disease Modifying Anti-Rheumatic Drugs in rheumatoid arthritis, a single-center retrospective analysis.

BACKGROUND: Glucocorticoid sparing in rheumatoid arthritis (RA) treatment is crucial to minimizing adverse effects associated with long-term use. Janus kinase inhibitors (JAKi) could potentially offer a more potent glucocorticoid-sparing effect than biological Disease-Modifying Antirheumatic Drugs (bDMARDs). MATERIAL AND METHODS: This is a single-center retrospective analysis of RA patients treated with JAKi or bDMARDs. Glucocorticoid tapering, rescue therapy and discontinuation were analyzed through mixed-effects models, Poisson regression, and multivariable logistic regression, respectively, adjusting for baseline disease activity, demographic factors, and treatment line. RESULTS: A total of 716 RA patients treated with JAKi (n = 156) or bDMARDs (n = 560) were evaluated. JAKi treatment was associated with a more rapid reduction in glucocorticoid dose within the first 6 months and 60% higher odds of discontinuation compared with bDMARDs (adjusted odds ratio 1.63, 95% CI 1.02-2.60, p 0.039). Despite a higher baseline glucocorticoid dose, over 50% of JAKi-treated patients discontinued glucocorticoids after 12 months, vs ∼40% for bDMARDs. The need for glucocorticoid rescue therapy was significantly higher in the bDMARD group (rate ratio 2.66 (95% CI, 1.88-3.74)). CONCLUSION: Our findings indicate that JAK inhibitors facilitate more rapid glucocorticoid tapering compared with bDMARDs in RA patients. These results underscore the potential of JAK inhibitors to reduce long-term glucocorticoid exposure, highlighting their value in RA management strategies, including minimizing glucocorticoid-related adverse effects.

Efficacy of baricitinib in patients with moderate-to-severe rheumatoid arthritis up to 6.5 years of treatment: results of a long-term study.

OBJECTIVES: To evaluate the long-term efficacy of once-daily baricitinib 4 mg or 2 mg in patients with active rheumatoid arthritis who had inadequate response (IR) to MTX, csDMARDs or bDMARDs. METHODS: Data from three completed phase III studies-RA-BEAM (MTX-IR), RA-BUILD (csDMARD-IR) and RA-BEACON (bDMARD-IR)-and one completed long-term extension study (RA-BEYOND) were analysed up to 6.5 years [340 weeks (RA-BEAM) and 336 weeks (RA-BUILD and RA-BEACON)]. Low disease activity (LDA) [Simplified Disease Activity Index (SDAI) ≤11], clinical remission (SDAI ≤3.3) and physical function [Health Assessment Questionnaire Disability Index (HAQ-DI) ≤0.5] were the main outcomes assessed. Completer and non-responder imputation (NRI) analyses were conducted on each population. RESULTS: At week 340 or 336, LDA was achieved in 37%/83% of MTX-IR, 35%/83% of csDMARD-IR and 23%/73% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. Remission was achieved in 20%/40% of MTX-IR, 13%/32% of csDMARD-IR and 9%/30% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. HAQ-DI ≤0.5 was reached in 31%/51% of MTX-IR, 25%/46% of csDMARD-IR and 24%/38% of bDMARD-IR patients treated with baricitinib 4 mg, assessed by NRI/completer analyses, respectively. CONCLUSION: Treatment with baricitinib 4 mg or 2 mg demonstrated efficacy up to 6.5 years with maintained LDA/remission results across SDAI, CDAI and DAS28-hsCRP consistent with previously reported data, and was well tolerated. TRIAL REGISTRATION: United States National Library of Medicine clinical trials database www.clinicaltrials.gov; RA-BEYOND; NCT01885078.

Elicitation of expert prior opinion to design the BARJDM trial in juvenile dermatomyositis.

OBJECTIVES: To elicit and quantify expert opinion concerning the relative merits of two treatments for a rare inflammatory disease: Juvenile dermatomyositis (JDM). The formal expression of expert opinion reported in this paper will be used in a Bayesian analysis of a forthcoming randomised controlled trial known as BARJDM (baricitinib for juvenile dermatomyositis). METHODS: A Bayesian prior elicitation meeting was convened, following a previously described methodological template. Opinion was sought on the probability that a patient in the BARJDM trial would achieve clinically inactive disease, off glucocorticoids (GC) within a 12-month period with either methotrexate (standard of care); or baricitinib (a Janus kinase inhibitor, JAKi), with GC schedules identical in both arms of the trial. Experts' views were discussed and refined following presentation and further discussion of summated published data regarding efficacy of methotrexate or JAKi for JDM. RESULTS: Ten UK paediatric rheumatology consultants (including one adolescent paediatric rheumatologist) participated in the elicitation meeting. All had expertise in JDM, leading active National Health Service clinics for this disease. Consensus expert prior opinion was that the most likely probability of clinically inactive disease off GC within 12 months was 0.55 on baricitinib and 0.23 on methotrexate, with a greater degree of uncertainty for baricitinib. CONCLUSION: Experts currently think that baricitinib is superior to MTX for the treatment of JDM, although there is uncertainty around this. BARJDM will therefore integrate randomised trial data with this expert prior opinion to derive a posterior distribution for the relative efficacy of baricitinib compared with MTX.

Baricitinib protects ICIs-related myocarditis by targeting JAK1/STAT3 to regulate Macrophage polarization.

PURPOSE: The emergence of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, but these drugs can also cause severe immune-related adverse effects (irAEs), including myocarditis. Researchers have become interested in exploring ways to mitigate this side effect, and one promising avenue is the use of baricitinib, a Janus kinase inhibitor known to have anti-inflammatory properties. This study aimed to examine the potential mechanism by which baricitinib in ICIs-related myocarditis. METHODS: To establish an ICIs-related myocarditis model, BALB/c mice were administered murine cardiac troponin I (cTnI) peptide and anti-mouse programmed death 1 (PD-1) antibodies. Subsequently, baricitinib was administered to the mice via intragastric administration. Echocardiography, HE staining, and Masson staining were performed to evaluate myocardial functions, inflammation, and fibrosis. Immunofluorescence was used to detect macrophages in the cardiac tissue of the mice.In vitro experiments utilized raw264.7 cells to induce macrophage polarization using anti-PD-1 antibodies. Different concentrations of baricitinib were applied to assess cell viability, and the release of pro-inflammatory cytokines was measured. The activation of the JAK1/STAT3 signaling pathway was evaluated through western blot analysis. RESULTS: Baricitinib demonstrated its ability to improve cardiac function and reduce cardiac inflammation, as well as fibrosis induced by ICIs. Mechanistically, baricitinib treatment promoted the polarization of macrophages towards the M2 phenotype. In vitro and in vivo experiments showed that anti-PD-1 promoted the release of inflammatory factors. However, treatment with baricitinib significantly inhibited the phosphorylation of JAK1 and STAT3. Additionally, the use of RO8191 reversed the effects of baricitinib, further confirming our findings. CONCLUSION: Baricitinib demonstrated its potential as a protective agent against ICIs-related myocarditis by modulating macrophage polarization. These findings provide a solid theoretical foundation for the development of future treatments for ICIs-related myocarditis.

From pre-clinical efficacy to promising clinical trials that delay Type 1 diabetes.

Recent advancements in immunology and islet biology have unveiled remarkable prospects for the postponement of Type 1 diabetes (T1D) through the strategic modulation of the immune system. In this Perspective, we discuss the pharmaceutical strides achieved, traversing from pre-clinical validation to the execution of impactful clinical trials. We begin with the initial investigations involving cyclosporine and glucocorticoids in rodent models, such as the non-obese diabetic (NOD) mouse, which guided early clinical trials. We then discuss the pre-clinical studies using suitable mouse models that eventually led to contemporary clinical trials targeting immune cell functionality and cytokine signaling pathways. Collectively, these discoveries promote the exciting paradigm of immune system modulation to mitigate autoimmunity, which continues to broaden. Notably, the use of baricitinib, a potent JAK1/2 inhibitor, and teplizumab, an anti-CD3 monoclonal antibody, represent discrete methodologies converging upon a singular outcome: the preservation of islet beta-cell functionality. The latter interventional strategies build on the original idea that tempering specific facets of the immune system will generate therapeutic benefit. Enthusiasm from these discoveries stems from efficacy with reduced side effects when compared with past approaches. The success of therapeutic intervention(s) in pre-clinical studies, combined with knowledge about stages of progression to clinical T1D, have ultimately encouraged the design of more successful clinical trials targeting highly specific populations at risk. Collectively, these findings instill a profound sense of optimism, suggesting that the prevention and even reversal of T1D may soon be within reach.

Oral Janus Kinase Inhibitors in Pediatric Atopic Dermatitis.

PURPOSE OF REVIEW: To analyze the efficacy and safety of Janus kinase inhibitors (JAKi) in the treatment of pediatric AD. RECENT FINDINGS: Adolescents with moderate and severe atopic dermatitis (AD) need systemic therapies, as stated several recent practice guidelines. (JAKi) have shown their efficacy in the treatment of adult AD, however, there is a lack of information concerning efficacy and safety of their use in pediatric AD. We found that the JAKi's abrocitinib (ABRO), baricitinib (BARI), and upadacitinib (UPA), are all an effective treatment option with a very fast onset of action for adolescents with moderate-to-severe AD. BARI was not effective in children between 2 and 10 years with moderate-to-severe AD. Fortunately, major safety issues with JAKi in adolescents with AD have not been documented in the trials, so far, contrasting with the reports in adults with AD, where these events have very rarely occurred. There are some reports of herpes zoster (HZ) infection in adolescents on JAKi, but it is not a major safety concern. Acne is a relatively common AE with UPA in adolescents; however, it is responsive to standard treatment. This review will help the clinician to choose among the JAKi according to the needs and clinical features of patients with moderate and severe AD. In the following years, with the advent of new biologicals and JAKi, these therapies will fall into place in each phase of the evolution of patients with AD.

The effect of baricitinib and corticosteroid compared to that of corticosteroid monotherapy in severely and critically ill patients with COVID-19: A Japanese multicenter inpatient database study.

BACKGROUND: Systemic baricitinib and corticosteroids play important roles in treating severely and critically ill patients with coronavirus disease 2019 (COVID-19). However, the efficacy of the combination of baricitinib and corticosteroids compared to that of corticosteroid monotherapy in severely and critically ill hospitalized patients with COVID-19 remains unclear. METHODS: We analyzed severely and critically ill hospitalized patients with COVID-19 aged >18 years between January 1, 2020 and May 31, 2023, using a Japanese multicenter inpatient database. We performed propensity score matching to analyze the effect of the combination of baricitinib and corticosteroids within 2 days of hospital admission (combination group) on the 28-day and in-hospital mortality rates compared with those of corticosteroid monotherapy within 2 days of hospital admission (control group). Sensitivity analysis was performed using inverse probability weighting analysis and the generalized estimating equation method. RESULTS: The eligible patients (n = 7433) were divided into a combination (n = 679) and a control group (n = 6754). One-to-four propensity score matching analyses included 566 combination and 2264 control group patients. There was no significant difference in 28-day (8.5 % vs. 8.8 %; risk difference, -0.3 % [95 % confidence interval, -2.9 to 2.3]) or in-hospital (11 % vs. 10 %; risk difference, 1.0 [-1.9 to 3.9]) mortality rates between 2 groups. The sensitivity analysis showed similar outcomes. CONCLUSION: This observational study, using a Japanese multicenter inpatient database, found that the combination of baricitinib and corticosteroid therapy did not improve the 28-day or in-hospital mortality rates in severely and critically ill patients with COVID-19 compared to corticosteroid monotherapy.

A systematic review of case series and clinical trials investigating systemic oral or injectable therapies for the treatment of vitiligo.

AIMS AND OBJECTIVES: The purpose of this study is to investigate the effectiveness and safety of oral and injectable systemic treatments, such as methotrexate, azathioprine, cyclosporine, tofacitinib, baricitinib, corticosteroids, statins, zinc, apremilast, etc., for treating vitiligo lesions. METHOD: Databases including PubMed, Scopus, and Web of Science were meticulously searched for studies spanning from 2010 to August 2023, focusing on systemic oral and injectable therapies for vitiligo, using comprehensive keywords and search syntaxes tailored to each database. Key data extracted included study design, treatment efficacy, patient outcomes, patient satisfaction, and safety profiles. RESULTS: In a total of 42 included studies, oral mini-pulse corticosteroid therapy (OMP) was the subject of six studies (14.2%). Minocycline was the focus of five studies (11.9%), while methotrexate, apremilast, and tofacitinib each were examined in four studies (9.5%). Antioxidants and Afamelanotide were the subjects of three studies each (7.1%). Cyclosporine, simvastatin, oral zinc, oral corticosteroids (excluding OMP) and injections, and baricitinib were each explored in two studies (4.8%). Azathioprine, mycophenolate mofetil, and Alefacept were the subjects of one study each (2.4%). CONCLUSION: Systemic treatments for vitiligo have been successful in controlling lesions without notable side effects. OMP, Methotrexate, Azathioprine, Cyclosporine, Mycophenolate mofetil, Simvastatin, Apremilast, Minocycline, Afamelanotide, Tofacitinib, Baricitinib, Antioxidants, and oral/injectable corticosteroids are effective treatment methods. However, oral zinc and alefacept did not show effectiveness.

Baricitinib for anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis-associated interstitial lung disease: a case series and literature review on Janus kinase inhibitors for the disease.

Anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis (anti-MDA5-DM) is frequently complicated by progressive interstitial lung disease (ILD), the prognosis of which is poor, and management is a major challenge. We treated three patients with anti-MDA5-DM-associated ILD (anti-MDA5-DM-ILD) using the Janus kinase (JAK) inhibitor, baricitinib, which improved lung opacities and saved two patients. We reviewed 6 patients with anti-MDA5-DM-ILD who had been treated with tofacitinib at our institution. Five of the patients survived, although discontinuation of tofacitinib due to complications was frequently observed. In addition, a literature search of patients with anti-MDA5-DM-ILD who were treated with JAK inhibitors yielded 21 articles involving 79 cases. All patients except one were treated with tofacitinib, and the survival rate was 75.9%. Although not statistically confirmed, the deceased patients tended to be older and had higher ferritin levels. A total of 92 complications were observed, 11 of which resulted in JAK inhibitor discontinuation. Cytomegalovirus reactivation comprised a substantial percentage of all complications and of those patients who required JAK inhibitor discontinuation. Five cases with fatal infective complications were also observed. While tofacitinib has been proposed to be a therapeutic option for anti-MDA5-DM-ILD, other JAK inhibitors, including baricitinib, are a treatment option. Further investigation is warranted to optimize treatment of anti-MDA5-DM-ILD.

How international guidelines recommend treating children who have severe COVID-19 or risk disease progression.

AIM: This study reviewed the current knowledge and guidelines on managing COVID-19 in children and proposed a practical approach to drug treatment. METHODS: We analysed international guidelines from four prominent scientific bodies on treating COVID-19 in children. These were the UK National Institute for Health and Care Excellence, the American National Institutes of Health, the Infectious Diseases Society of America and the Australian National Clinical Evidence Taskforce COVID-19. RESULTS: Most paediatric patients with COVID-19 only require symptomatic treatment. There was limited evidence on treatment recommendations for children with severe COVID-19 or at risk of disease progression. However, several drugs are available for children and we have summarised the guidelines, in order to provide a concise, practical format for clinicians. All the guidelines agree that nirmatrelvir plus ritonavir or remdesivir can be used as prophylaxis for severe COVID-19 in high-risk patients. Remdesivir can also be used for severe COVID-19 cases. Glucocorticosteroids are recommended, particularly in patients requiring oxygen therapy. Tocilizumab or baricitinib should be reserved for patients with progressive disease and/or signs of systemic inflammation. CONCLUSION: The guidelines provide useful advice and a degree of consensus on specific drug treatment for children with severe COVID-19 or at risk of progression.

A case of mother and child with CANDLE syndrome: Diagnosis and subsequent treatment with baricitinib.

Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) or proteasome-associated autoinflammatory syndrome is a rare autoinflammatory disorder that typically presents in infancy with characteristic symptoms, including recurrent fever, panniculitis, and progressive lipodystrophy, among other findings. We present a case of mother and child with CANDLE syndrome. The child was eventually started on baricitinib with normalization of rash and systemic findings.

Use of tofacitinib in baricitinib-refractory atopic dermatitis: An example of JAK inhibitor switching.

Atopic dermatitis (AD) is predominantly mediated by a T-helper 2 immune system response. While JAK inhibitors have gained treatment approval for AD, data regarding interclass efficacy and therapeutic rationale is lacking. We report a patient with recalcitrant AD who failed baricitinib but demonstrated an excellent response to the pan-JAK inhibitor tofacitinib.

Successful treatment of actinic prurigo with baricitinib in an 8-year-old child: A case report.

Actinic prurigo is a rare photodermatosis characterized by pruritic papulonodular lesions. Treatment is challenging, especially in children, as sun protection strategies need to be rigorously implemented and symptoms often persist throughout the year. Herein, we present a case of actinic prurigo in an 8-year-old patient with rapid and successful relief with baricitinib.

Successful treatment of infantile refractory bullous pemphigoid with baricitinib.

Infantile bullous pemphigoid (BP) is a rare autoantibody-mediated skin disorder. We report the effective treatment of a 6-month-old infant with BP using baricitinib, a Janus kinase (JAK) inhibitor, after failure with steroids and intravenous immunoglobulin. The patient achieved full remission and discontinued all medications without any relapses. To our knowledge, this is the first case of baricitinib used in an infant with BP.

JAK inhibitors in refractory dermatomyositis: A case series.

This retrospective cohort study assessed the efficacy and safety of Janus kinase (JAK) inhibitors, tofacitinib and baricitinib, in 14 patients with refractory dermatomyositis (DM), a multisystemic autoimmune disorder with limited therapeutic options. Results demonstrated a significant median decrease of 21 points and a 76% reduction in the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) scores, along with a complete resolution of muscular symptoms in 64% of the patients. JAK inhibitors were effective in managing refractory DM across various subtypes with mild and manageable adverse events.