Higher infection risk for JAK inhibitors tofacitinib and baricitinib compared to subcutaneous biological DMARDs.

INTRODUCTION: Rheumatoid arthritis (RA) is usually treated with disease modifying antirheumatic drugs (DMARDs), including biological DMARDs (bDMARDs) and more recently, Janus kinase inhibitors (JAKi). Randomized trials suggest similar infection risks for JAKi and bDMARDs, but real-world data are scarce. METHODS: From a nationally representative prescription database, adult RA patients starting a new JAKi or bDMARD between August 1st, 2018, and January 31st, 2021, were included. Prescriptions of antibiotic, antiviral or antifungal medication were used as proxy for infections. Infection incidence rates (IR) were compared between JAKi and bDMARDs and infection risks were estimated using multilevel Poisson regression adjusted for follow-up time and potential confounders and stratified for age < 65 and ≥ 65 years. RESULTS: In 14,989 patients, we identified 20,050 treatment episodes with either JAKi or bDMARDs. The infection IR was significantly higher in JAKi (48/100 patient years) compared bDMARDs (35/100 patient years, adjusted incidence rate ratio (IRR) 1.22, 95% CI 1.12-1.33). More herpes zoster infections were seen in JAKi compared to bDMARDs (adjusted IRR 2.65, 95% CI 1.94-3.60). No significant differences in infection IRs were found comparing JAKi baricitinib and tofacitinib. In older patients, infection IRs were higher, but IRRs were similar between age groups. CONCLUSION: In comparison to bDMARDs, JAKi are associated with a slightly higher infection risk and a higher risk of herpes zoster specifically. In older patients, infection IRs are higher but similar infection risks for JAKi and bDMARDs are observed. No differences in infection risk between tofacitinib and baricitinib were found. Key Points • Compared to bDMARDs, JAKi are associated with a slightly higher infection risk for all ages • An increased risk of herpes zoster in patients who use JAK inhibitors was confirmed • No significant differences in infection incidence were found between tofacitinib and baricitinib.

Efficacy and safety study of targeted small-molecule drugs in the treatment of systemic lupus erythematosus.

BACKGROUND: Targeted small-molecule drugs in the treatment of systemic lupus erythematosus (SLE) have attracted increasing attention from clinical investigators. However, there is still a lack of evidence on the difference in the efficacy and safety of different targeted small-molecule drugs. Therefore, this study was conducted to assess the efficacy and safety of different targeted small-molecule drugs for SLE. METHODS: Randomized controlled trials (RCTs) on targeted small-molecule drugs in the treatment of SLE in PubMed, Web of Science, Embase, and Cochrane Library were systematically searched as of April 25, 2023. Risk of bias assessment was performed for included studies using the Cochrane's tool for evaluating the risk of bias. The primary outcome indicators were SRI-4 response, BICLA response, and adverse reaction. Because different doses and courses of treatment were used in the included studies, Bayesian network meta-regression was used to investigate the effect of different doses and courses of treatment on efficacy and safety. RESULTS: A total of 13 studies were included, involving 3,622 patients and 9 targeted small-molecule drugs. The results of network meta-analysis showed that, in terms of improving SRI-4, Deucravacitinib was significantly superior to that of Baricitinib (RR = 1.32, 95% CI (1.04, 1.68), P < 0.05). Deucravacitinib significantly outperformed the placebo in improving BICLA response (RR = 1.55, 95% CI (1.20, 2.02), P < 0.05). In terms of adverse reactions, targeted small-molecule drugs did not significantly increase the risk of adverse events as compared to placebo (P > 0.05). CONCLUSION: Based on the evidence obtained in this study, the differences in the efficacy of targeted small-molecule drugs were statistically significant as compared to placebo, but the difference in the safety was not statistically significant. The dose and the course of treatment had little impact on the effect of targeted small-molecule drugs. Deucravacitinib could significantly improve BICLA response and SRI-4 response without significantly increasing the risk of AEs. Therefore, Deucravacitinib is very likely to be the best intervention measure. Due to the small number of included studies, more high-quality clinical evidence is needed to further verify the efficacy and safety of targeted small-molecule drugs for SLE.

Peripheral oedema as an adverse effect of treatment of secondary progressive multiple sclerosis with siponimod: A case series.

Siponimod is a sphingosine 1-phosphate receptor (S1P) modulator used to treat secondary progressive multiple sclerosis (SPMS). We report 3 SPMS patients treated with siponimod who developed new or worsening peripheral oedema soon after commencing treatment. In one case, peripheral oedema resulted in immobility. Siponimod-related peripheral oedema deserves wider recognition due to the potential for morbidity and over-investigation. Clinicians should assess for pre-existing oedema and coexisting conditions that may predispose to developing peripheral oedema prior to commencing siponimod.

Baricitinib for refractory Takayasu arteritis: a prospective cohort study in a tertiary referral centre.

OBJECTIVE: To investigate the treatment efficacy and safety of baricitinib in patients with refractory Takayasu arteritis (TAK). METHODS: We performed a prospective cohort study in which baricitinib 4 mg daily was prescribed to patients with refractory TAK, combined with oral glucocorticoids (GCs). RESULTS: 10 patients with refractory TAK were enrolled with a median age of 28 (IQR=22-37) years, median disease duration of 50 (IQR=24-65) months. The median dose of GCs was 10 (IQR=8.1-22.5) mg prednisone or equivalence dosage at baseline. At 6 months of baricitinib treatment, 6/10 (60%) patients had an overall treatment response. During an average follow-up of 15.3 (range 4-31) months, 4/10 (40%) patients maintained overall treatment response. 8/10 (80%) patients tapered or maintained the same dose of GCs with no change of the combined classical synthetic disease-modifying antirheumatic drugs. Two patients discontinued GCs at 18 and 24 months and were in continuous remission till the end of the study. One patient withdrew baricitinib due to liver dysfunction. CONCLUSION: Baricitinib 4 mg daily is effective for refractory TAK and is well tolerated.

JAK inhibitors in the treatment of adult patients with juvenile idiopathic arthritis: a retrospective monocentric experience.

OBJECTIVES: This study aims to evaluate the efficacy and safety of JAK inhibitors (JAKi) in a monocentric cohort of adult patients with juvenile idiopathic arthritis (JIA). METHODS: Patients attending a rheumatology transition clinic were retrospectively included in case of: i) JIA diagnosis according to current classification criteria (1); ii) age ≥18 years and iii) treatment with JAKi for at least 3 months. RESULTS: Seventeen adult patients with JIA were treated with JAKi (as first JAKi, 9 patients (52.9%) received tofacitinib and 8 (47.1%) baricitinib). At 3 months after JAKi initiation, 8 patients (47%) achieved a response and 4 patients (23.5%) achieved disease remission (3 patients with baricitinib and 1 with tofacitinib, 37.5% vs. 16.7%, p=0.294). None of those with systemic JIA and enthesitis-related arthritis obtained remission; the remission rate at 3 months was higher, although not significantly, in the oligoarticular subset compared to the polyarticular subset (37.5% vs. 20%). Patients with ≤1 active joint involvement at JAKi start had a higher remission rate (50% vs. 22.2%). Subjects who achieved remission on JAKi had a significantly lower pre-treatment DAS28-CRP compared to those with still active disease (p=0.010, Mann-Whitney U=4). A pre-treatment DAS28-CRP <3.76 predicted response to JAKi with 100% sensitivity and 84.6% specificity (p=0.023). The remission rate was lower among patients who had been treated with ≥2 biological drugs before JAKi start (9% vs. 66.7%; p=0.05). One patient in concomitant treatment with leflunomide developed severe arterial hypertension. CONCLUSIONS: JAKi may represent an effective and safe treatment option for adult JIA patients with low/moderate disease activity, particularly in case of oligoarticular involvement.

Long-term efficacy and safety of baricitinib in patients with severe alopecia areata: 104-week results from BRAVE-AA1 and BRAVE-AA2.

BACKGROUND: Efficacy of the Janus kinase (JAK) inhibitor baricitinib for severe alopecia areata (AA) continuously increased over 52 weeks in two Phase 3 trials. There are limited long-term data on JAK inhibitors in AA. OBJECTIVES: To evaluate efficacy and safety of baricitinib for severe AA through 104 weeks of continuous therapy. METHODS: Integrated data from the BRAVE-AA1 and BRAVE-AA2 Phase 3 trials included adults with Severity of Alopecia Tool (SALT) scores ≥50 (≥50% scalp hair loss) randomized to and continuously treated with 2-mg or 4-mg baricitinib through Week 104. Patients who qualified to remain on continuous treatment included subjects who achieved SALT score ≤20 at Week 52 (Week-52 responders; 2-mg: N = 65; 4-mg: N = 129) and baricitinib 4-mg-treated patients who had SALT score >20 at Week 52 but achieved SALT score ≤20 at prior visit(s) and/or had significant improvement in eyebrow or eyelash hair growth relative to baseline by Week 52 (Week-52 mixed responders; N = 110). Week-104 outcomes included the proportion of patients achieving SALT score ≤20 (≤20% scalp hair loss). Data were censored after treatment discontinuation. RESULTS: Among baricitinib 4-mg-treated and baricitinib 2-mg-treated Week-52 responders, 90.7% and 89.2%, respectively, maintained SALT score ≤20 at Week 104. Among Week-52 mixed responders, 39.1% reached SALT score ≤20 by Week 104. Continued improvement in eyebrow and eyelash regrowth was observed across groups. The most frequent treatment-emergent adverse events were COVID-19, upper respiratory tract infection, headache, nasopharyngitis, acne, urinary tract infection and creatine phosphokinase increase. CONCLUSIONS: Baricitinib demonstrated a high level of maintenance of efficacy over 104 weeks in patients with severe AA. Efficacy increased in Week-52 mixed responders, illustrating that long-term treatment is necessary to observe maximum benefit in some patients. No new safety signals were observed.

Does baricitinib reduce disease activity in patients with systemic lupus erythematosus? A systematic review and meta-analysis of randomized controlled trials.

Baricitinib is a selective Janus kinase inhibitor that has recently been approved for treating certain autoimmune disorders. This meta-analysis pooled the conflicting results from all published randomized controlled trials (RCTs) about the efficacy and safety of baricitinib in patients with systemic lupus erythematosus (SLE). We systemically searched four electronic databases. RCTs comparing baricitinib versus placebo were included. Our outcomes were pooled as the risk ratio (RR) in the random effects model. Our primary outcome was the proportion of patients who achieved a SLE Responder Index-4 (SRI-4) response. A total of three RCTs, comprising 1849 patients, were included. Baricitinib 4 mg was associated with a significantly higher proportion of patients who attained SRI-4 response at week 24 (RR = 1.19, 95% CI [1.05, 1.35], P < 0.01). However, this did not reach statistical significance with baricitinib 4 mg at week 52 and baricitinib 2 mg at both week 24 and week 52 (RR = 1.13, 95% CI [0.96, 1.34], P = 0.15; RR = 1.09, 95% CI [0.96, 1.24], P = 0.20; RR = 1.05, 95% CI [0.92, 1.19], P = 0.50, respectively). The risk for serious infections was higher in the baricitinib 4 mg group (RR = 2.23, 95% CI [1.13, 4.37], P = 0.02). Baricitinib 2 mg did not show any clinical benefit. In contrast, baricitinib 4 mg might have the potential to reduce SLE disease activity; however, further research is required to evaluate its long-term efficacy. Until higher-quality evidence is developed, the benefits and risks of baricitinib should be considered before initiating its therapy. Key Points • Baricitinib is a selective Janus kinase inhibitor that has recently been approved for treating certain autoimmune disorders; however, its efficacy in patients with systemic lupus erythematosus (SLE) is still inconclusive. • In our meta-analysis, baricitinib 2 mg did not show any clinical benefit. In contrast, baricitinib 4 mg significantly reduced SLE activity in terms of SRI-4 response at week 24. However, this did not reach statistical significance at week 52. • Further studies are required to investigate the long-term efficacy of baricitinib 4 mg in patients with SLE.

Evaluating the safety and efficacy of baricitinib for the treatment of moderate-to-severe atopic dermatitis.

INTRODUCTION: New biologic and small molecule therapeutics have emerged for the treatment of moderate-to-severe atopic dermatitis (AD), including oral Janus kinase (JAK) inhibitors such as baricitinib. While JAK inhibitors are commonly used to treat rheumatoid arthritis and inflammatory bowel disease, these agents are relatively new in the field of dermatology. AREAS COVERED: In this review, we outline the efficacy and safety data of phase III randomized controlled trials investigating the use of baricitinib for moderate-to-severe AD. A literature search was performed using PubMed.gov to identify articles relevant to the topic published before August 2023. EXPERT OPINION: Oral JAK inhibitors in AD management are highly efficacious, whether used alone, in conjunction with topical corticosteroids, or in patients who have failed other conventional systemic medications for AD. JAK inhibitors appear to be well tolerated in the AD patient population with fewer major safety risks than what has been seen in other patient populations. Assessing patient risk factors for cardiovascular, thromboembolic, and oncologic diseases is now an important part of the office visit for patients in whom you may consider using a JAK inhibitor.

Efficacy and safety of baricitinib for the treatment of hospitalized adults with COVID-19: a systematic review and meta-analysis.

OBJECTIVES: Several clinical trials have evaluated the efficacy and safety of baricitinib in COVID-19 patients. Recently, there have been reports on critical patients, which are different from previous research results. The meta-analysis was performed to investigate the effects of baricitinib in COVID-19, by pooling data from all clinically randomized controlled trials (RCTs) available to increase power to testify. METHODS: Studies were searched in PubMed, Embase, and Cochrane Library databases on January 31, 2023. We performed a meta-analysis to estimate the efficacy and safety of baricitinib for the treatment of hospitalized adults with COVID-19. This study is registered with INPLASY, number 202310086. RESULTS: A total of 3010 patients were included in our analyses. All included studies were randomized controlled trials or prospective study. There was no difference in 14-day mortality between the two groups [OR 0.23 (95% CI 0.03-1.84), I2 = 72%, P = 0.17]. In subgroup analyses we found that baricitinib did not seem to improve significantly in 24-day mortality critically ill patients [OR 0.60 (95% CI 0.35-1.02), I2 = 0%, P = 0.06]. Fortunately, baricitinib have led to faster recovery and shorter hospital stays for COVID-19 patients. There were no difference in infections and infestations, major adverse cardiovascular events, deep vein thrombosis and pulmonary embolism. CONCLUSIONS: Baricitinib did not increase the incidence of adverse reactions. At the same time, we can find that it reduces the mortality of COVID-19 patients, not including the critically ill.

Infectious adverse events in patients with atopic dermatitis treated with baricitinib.

Baricitinib is a JAK1-2 inhibitor recently approved in Europe and Japan for the treatment of moderate-to-severe atopic dermatitis in adult patients at doses of 2 and 4 mg daily. The aim of this article is to discuss the safety profile of baricitinib in atopic dermatitis using data from clinical trials and the supporting literature, with a focus on infectious adverse events. An integrated analysis of safety data from eight clinical trials described infections as the most frequent treatment-emergent adverse events, mainly of mild-to-moderate severity, notably upper respiratory tract infections and herpes simplex exacerbations. Real-world data are still limited and will contribute to precisely profile the patients that might benefit from this treatment.

Baricitinib is a drug taken by mouth, currently approved for the treatment of moderate-to-severe atopic dermatitis in adults who are candidates for systemic therapy, a medication that is designed to be absorbed into the bloodstream and work throughout the body. Baricitinib is available as 2- and 4-mg tablets and has been shown to improve the cutaneous manifestations, such as dry and cracked skin, redness and symptoms of atopic dermatitis, especially itchiness. Baricitinib is generally well tolerated. The most common adverse events that have emerged from clinical trials include headache, nausea and high cholesterol. Another reported side effect is an increased risk of infections, mainly of mild-to-moderate severity, especially upper respiratory tract infections such as nasopharyngitis (inflammation of the nose and throat) and reactivation of herpes zoster, a virus that causes a painful rash on one side of the body, and herpes simplex, which causes clustered blisters usually on the lips or genitals. There is still a lack of data from real-world experience, which will be important for the development of a more precise profile of patients who may benefit from this treatment.

Impact of Baricitinib on Patients' Quality of Life after One Year of Treatment for Atopic Dermatitis in Real-World Practice: Results of the Observatory of Chronic Inflammatory Skin Diseases Registry.

The efficacy and safety of baricitinib for treatment of atopic dermatitis have been demonstrated in clinical trials; however, very few real-life studies have been published to date. The Observatory of Chronic Inflammatory Skin Diseases (OMCCI) registry was initiated to prospectively determine the long-term impairment caused by chronic inflammatory dermatoses on patients' lives. The study included 88 patients starting baricitinib for treatment of atopic dermatitis. Clinical evaluation and patient-reported outcomes were recorded at baseline and after 6 and 12 months. After 6 months and 1 year of follow-up, 65 and 47 patients, respectively, were still being treated with baricitinib. Treatment failure was the main reason for discontinuation. Only 1 patient stopped baricitinib because of a side-effect. After 1 year of follow-up, the mean Eczema Area and Severity Index score decreased significantly from 20.7 to 6.4; the percentage of patients with severe atopic dermatitis decreased from 42.9% to 6.5% and a significant improvement in most patient-reported outcomes was noted. There was no difference in terms of efficacy whether or not patients were previously treated with dupilumab. The results remained stable after 6 and 12 months of treatment, which suggests a sustained efficacy of the treatment in patients who initially responded well.

Crucial safety issues on Janus kinase inhibitors in rheumatoid arthritis might be associated with the lack of LDL-cholesterol management: a reasoned literature analysis.

This point of view explores the safety concerns of Janus kinase inhibitors (JAK-Is), used in treating rheumatoid arthritis (RA) and other rheumatologic conditions. Increasing evidence shows that JAK-Is may elevate the risk of venous thromboembolism (VTE), especially pulmonary embolism. This fact has prompted the European Medicines Agency to advise cautious use of these drugs in patients over 65, smokers, and those at risk of cardiovascular issues or cancer. The paper analyses the evidence on the association between VTE risk and RA and whether different JAK-Is pose different risks. It also probes the link between VTE, lipids, and JAK inhibition, noting that JAK-Is can alter HDL and LDL levels. On the other hand, some evidence indicates that tighter LDL-cholesterol control could mitigate VTE risk, particularly pulmonary embolism. Moreover, data from trials show little attention to treating this main cardiovascular and VTE risk factor in rheumatological patients. Although the lipid paradox theory emphasizes the U-shaped relationship between LDL cholesterol and cardiovascular risk in patients with RA, uncontrolled levels of clinically relevant LDL cholesterol remain closely linked to cardiovascular and VTE risk. In conclusion, high-potency statins could help to manage the increased cardiovascular and VTE risk concomitant to JAK-Is treatment in rheumatologic patients without depriving them of the best therapeutic choice and, in addition, reducing the inherent risk associated with the disease.

Review of Baricitinib in the Treatment of Alopecia Areata.

BACKGROUND: Alopecia areata (AA) is a debilitating autoimmune disease that results in non-scarring hair loss. Baricitinib is the Food and Drug Administration (FDA) approved treatment for AA.  Objective: Review the mechanism of action, pharmacokinetics, pharmacodynamics, efficacy, and safety of baricitinib in the treatment of AA.  Methods: A literature review was conducted using the MEDLINE (PubMed) and EMBASE databases for articles published between January 2010 to November 2022. Articles in English discussing baricitinib's efficacy and safety in AA, pharmacodynamic, and pharmacokinetic profiles were included. RESULTS: Two identical phase III trials (BRAVE-AA1 and BRAVE-AA2) were evaluated. A greater percentage of subjects receiving baricitinib 4 mg or 2 mg dose achieved a Severity of Alopecia Tool score equal to or less than 20 vs placebo. In BRAVE-AA1, for 4 mg, 2 mg, and placebo, respectively, these values were 38.8%, 22.8%, and 6.2%; in BRAVE-AA2, these values were 35.9%, 19.4%, and 3.3% (P<0.001). DISCUSSION: Baricitinib is the first FDA-approved treatment for AA. Other treatments for AA are used off-label with variable efficacy. Baricitinib is associated with black-box warnings due to adverse effects (AEs) associated with other Janus Kinase (JAK) inhibitors or use in other diseases. In the two large AA trials, AEs were considered mild or moderate; those reported more often with baricitinib than placebo included acne, elevations of low- and high-density lipoprotein cholesterol, and elevation of creatinine kinase. Baricitinib is a relatively tolerable and safe therapeutic alternative for severe AA, although additional study is needed to assess its long-term efficacy and safety.  Citation: Singh R, Driscoll MS. Review of baricitinib in the treatment of alopecia areata. J Drugs Dermatol. 2023;22(9):935-939. doi:10.36849/JDD.7357.

Effects of baseline age and disease duration on the efficacy and safety of siponimod in patients with active SPMS: Post hoc analyses from the EXPAND study.

BACKGROUND: Older age and longer disease duration (DD) may impact the effectiveness of disease-modifying therapies in patients with multiple sclerosis (MS). Siponimod is a sphingosine 1-phosphate receptor modulator approved for the treatment of active secondary progressive MS (SPMS) in many countries. The pivotal phase 3 EXPAND study examined siponimod versus placebo in a broad SPMS population with both active and non-active disease. In this population, siponimod demonstrated significant efficacy, including a reduction in the risk of 3-month confirmed disability progression (3mCDP) and 6-month confirmed disability progression (6mCDP). Benefits of siponimod were also observed across age and DD subgroups in the overall EXPAND population. Herein we sought to assess the clinical impact of siponimod across age and disease duration subgroups, specifically in participants with active SPMS. METHODS: This study is a post hoc analysis of a subgroup of EXPAND participants with active SPMS (≥ 1 relapse in the 2 years before the study and/or ≥ 1 T1 gadolinium-enhancing magnetic resonance imaging lesion at baseline) receiving oral siponimod (2 mg/day) or placebo during EXPAND. Data were analyzed for participant subgroups stratified by age at baseline (primary cut-off: < 45 year ≥ 45 years; and secondary cut-off: < 50 years or ≥ 50 years) and by DD at baseline (< 16 years or ≥ 16 years). Efficacy endpoints were 3mCDP and 6mCDP. Safety assessments included adverse events (AEs), serious AEs, and AEs leading to treatment discontinuation. RESULTS: Data from 779 participants with active SPMS were analyzed. All age and DD subgroups had 31-38% (3mCDP) and 27-43% (6mCDP) risk reductions with siponimod versus placebo. Compared with placebo, siponimod significantly reduced the risk of 3mCDP in participants aged ≥ 45 years (hazard ratio [HR]: 0.68; 95% confidence interval [CI]: 0.48-0.97), < 50 years (HR: 0.69; 95% CI: 0.49-0.98), ≥ 50 years (HR: 0.62; 95% CI: 0.40-0.96), and in participants with < 16 years DD (HR: 0.68; 95% CI: 0.47-0.98). The risk of 6mCDP was significantly reduced with siponimod versus placebo for participants aged < 45 years (HR: 0.60; 95% CI: 0.38-0.96), ≥ 45 years (HR: 0.67; 95% CI: 0.45-0.99), < 50 years (HR: 0.62; 95% CI: 0.43-0.90), and in participants with < 16 years DD (HR: 0.57; 95% CI: 0.38-0.87). Increasing age or longer MS duration did not appear to increase the risk of AEs, with an observed safety profile that remained consistent with the overall active SPMS and overall SPMS populations in EXPAND. CONCLUSIONS: In participants with active SPMS, treatment with siponimod demonstrated a statistically significant reduction in the risk of 3mCDP and 6mCDP compared with placebo. Although not every outcome reached statistical significance in the subgroup analyses (possibly a consequence of small sample sizes), benefits of siponimod were seen across a spectrum of ages and DD. Siponimod was generally well tolerated by participants with active SPMS, regardless of baseline age and DD, and AE profiles were broadly similar to those observed in the overall EXPAND population.

Efficacy of Baricitinib in Patients with Refractory Adult-Onset Still's Disease.

BACKGROUND AND OBJECTIVE: Adult-onset Still's disease (AOSD) is an idiopathic systemic inflammatory disease of unknown aetiology. Some patients exhibit resistance to conventional treatment during long-term therapy. Janus kinase inhibitors (JAKinibs) may contribute to the improvement in AOSD symptoms via the JAK-signal transducer and activator of transcription (STAT) pathway. We aimed to explore the efficacy and safety of baricitinib in patients with refractory AOSD. METHODS: Patients were enrolled if they fulfilled the Yamaguchi AOSD classification criteria in China between 2020 and 2022. All patients were recognized as having refractory AOSD and were treated with oral baricitinib at a dosage of 4 mg once daily. A systemic score and prednisone dosage were used to evaluate the efficacy of baricitinib at months 1, 3, and 6 and at the last follow-up visit. The safety profiles were recorded and analysed at every assessment. RESULTS: Seven female patients with refractory AOSD received baricitinib. The median age was 31 (IQR 10) years. Treatment was terminated in one patient due to progressive macrophage activation syndrome (MAS). Others continued baricitinib treatment until the last assessment. The systemic score decreased significantly at 3 months (p = 0.0216), 6 months (p = 0.0007), and the last follow-up visit (p = 0.0007) compared with baseline. One month after the initiation of baricitinib, the rates of improvement in fever, rash, sore throat, and myalgia symptoms were 71.4% (5/7), 40% (2/5), 80% (4/5), and 66.7% (2/3), respectively. Five patients remained symptom-free at the last follow-up visit. In most patients, their laboratory values had returned to normal by the last follow-up visit. A significant reduction in the levels of C-reactive protein (CRP) (p = 0.0165) and ferritin (p = 0.0047) was observed at the last visit compared with baseline. The daily prednisolone dosage significantly decreased from 35.7 ± 15.1 mg/day at baseline to 8.8 ± 4.4 mg/day by month 6 (p = 0.0256), and it was 5.8 ± 4.7 mg/day at the last assessment (p = 0.0030). Leukopenia due to MAS was noted in one patient. Except for mild abnormalities in lipid parameters, no other severe adverse events occurred during follow-up. CONCLUSIONS: Our findings suggest that baricitinib therapy could provide rapid and durable clinical and laboratory improvement in patients with refractory AOSD. Treatment seemed to be well tolerated by these patients. The long-term efficacy and safety of baricitinib therapy for AOSD should be assessed further in prospective controlled clinical trials in the future. TRIAL REGISTRATION: Trial registration number (TRN): ChiCTR2200061599. Date of registration: 29 June 2022 (retrospectively registered).