Bicyclic azetidines target acute and chronic stages of Toxoplasma gondii by inhibiting parasite phenylalanyl t-RNA synthetase.

Toxoplasma gondii commonly infects humans and while most infections are controlled by the immune response, currently approved drugs are not capable of clearing chronic infection in humans. Hence, approximately one third of the world's human population is at risk of reactivation, potentially leading to severe sequelae. To identify new candidates for treating chronic infection, we investigated a series of compounds derived from diversity-oriented synthesis. Bicyclic azetidines are potent low nanomolar inhibitors of phenylalanine tRNA synthetase (PheRS) in T. gondii, with excellent selectivity. Biochemical and genetic studies validate PheRS as the primary target of bicyclic azetidines in T. gondii, providing a structural basis for rational design of improved analogs. Favorable pharmacokinetic properties of a lead compound provide excellent protection from acute infection and partial protection from chronic infection in an immunocompromised mouse model of toxoplasmosis. Collectively, PheRS inhibitors of the bicyclic azetidine series offer promise for treatment of chronic toxoplasmosis.

Association and pharmacological synergism of the triple drug therapy baricitinib/remdesivir/rhACE2 for the management of COVID-19 infection.

A massive vaccination campaign against the global COVID-19 pandemic caused by SARS-CoV-2 virus began worldwide in January 2021. However, studies continue to investigate the most effective and safe drug therapies to manage the various stages of viral infection. It is critical in the therapeutic management of the patient, with ongoing COVID-19 infection, to reduce viral load and replication, and to regulate the generalized hyperinflammatory state caused by the cytokine storm that occurs in the most severe phases. Probably the right drug therapy is represented by the use of different drugs acting in different modalities and on different targets, to avoid also viral drug resistance. In this article, we describe an interesting scientific pharmacological hypothesis arising from the evidence in the literature; we believe that the association of baricitinib/remdesivir/rhACE2, administered at the right time and dose, represents an important pharmacological synergism that can be therapeutically more effective for the treatment of COVID-19 infection than the single administration of drugs and avoid the phenomenon of drug resistance caused by the virus.

Clinical efficacy and adverse events of baricitinib treatment for coronavirus disease-2019 (COVID-19): A systematic review and meta-analysis.

The benefits of baricitinib in coronavirus disease-2019 are inadequately defined. We performed a systematic review and meta-analysis of studies of baricitinib to determine its clinical efficacy and adverse events in patients with COVID-19. Databases were searched from their inception to September 5, 2021. The primary outcome was the coefficient of mortality. We also compared secondary indicators and adverse events between baricitinib treatment and placebo or other treatments. Twelve studies of 3564 patients were included and assessed qualitatively (modified Jadad and Newcastle-Ottawa Scale scores). Baricitinib effectively improved the mortality rate (relative risk of mortality = 0.56; 95% confidence interval: 0.46-0.69; p < 0.001; I2 = 2%), and this result was unchanged by subgroup analysis. Baricitinib improved intensive care unit admission, the requirement for invasive mechanical ventilation, and improved the oxygenation index. Data from these studies also showed that baricitinib slightly reduced the risk of adverse events. Regarding the choice of the drug dosage of baricitinib, the high-dose group appeared to have additional benefits for clinical efficacy. Our study shows that baricitinib may be a promising, safe, and effective anti-severe acute respiratory syndrome-coronavirus-2 drug candidate, with the advantages of low cost, easy production, and convenient storage.

Multicenter randomized phase II trial of atezolizumab with or without cobimetinib in biliary tract cancers.

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

COVID-19 Infection in Fingolimod- or Siponimod-Treated Patients: Case Series.

BACKGROUND AND OBJECTIVES: A descriptive analysis of COVID-19 infection in patients with multiple sclerosis (MS) receiving fingolimod or siponimod. METHODS: We reviewed the cases of COVID-19 from postmarketing or ongoing clinical trials reported to Novartis through December 27, 2020. RESULTS: As of December 27, 2020, 283 cases had been reported in fingolimod-treated patients. The mean age was 44 years (from n = 224; range 11-69 years), and 190 were women. Of 161 cases with available information, 138 were asymptomatic (6), mild (100), or moderate (32); 50 cases required hospitalization. At the last follow-up, 140 patients were reported as recovered/recovering, condition was unchanged in 22, and deteriorated in 3 patients; 4 patients had a fatal outcome. Information was not available for 114 patients. Of the 54 cases of COVID-19 reported in siponimod-treated patients, 45 were from the postmarketing setting and 9 from an ongoing open-label clinical trial. The mean age was 54 years (from n = 45; range 31-70), and 30 were women. Of 28 cases with available information, 24 were asymptomatic (2), mild (17), or moderate (5); 9 cases required hospitalization. At the last follow-up, 27 patients were reported as recovered/recovering, condition remained unchanged for 1, and 3 patients had a fatal outcome. Information was not available for 23 patients. DISCUSSION: Based on a review of available information, the risk of more severe COVID-19 in patients receiving fingolimod or siponimod seems to be similar to that reported in the general population and the MS population with COVID-19. However, limitations of spontaneous reporting, especially missing data, should be considered in the interpretation of these observations.

Phase I study in healthy participants to evaluate safety, tolerability, and pharmacokinetics of inhaled nezulcitinib, a potential treatment for COVID-19.

Nezulcitinib (TD-0903), a lung-selective pan-Janus-associated kinase (JAK) inhibitor designed for inhaled delivery, is under development for treatment of acute lung injury associated with coronavirus disease 2019 (COVID-19). This two-part, double-blind, randomized, placebo-controlled, single ascending dose (part A) and multiple ascending dose (part B) phase I study evaluated the safety, tolerability, and pharmacokinetics (PK) of nezulcitinib in healthy participants. Part A included three cohorts randomized 6:2 to receive a single inhaled dose of nezulcitinib (1, 3, or 10 mg) or matching placebo. Part B included three cohorts randomized 8:2 to receive inhaled nezulcitinib (1, 3, or 10 mg) or matching placebo for 7 days. The primary outcome was nezulcitinib safety and tolerability assessed from treatment-emergent adverse events (TEAEs). The secondary outcome was nezulcitinib PK. All participants completed the study. All TEAEs were mild or moderate in severity, and none led to treatment discontinuation. Overall (area under the plasma concentration-time curve) and peak (maximal plasma concentration) plasma exposures of nezulcitinib were low and increased in a dose-proportional manner from 1 to 10 mg in both parts, with no suggestion of clinically meaningful drug accumulation. Maximal plasma exposures were below levels expected to result in systemic target engagement, consistent with a lung-selective profile. No reductions in natural killer cell counts were observed, consistent with the lack of a systemic pharmacological effect and the observed PK. In summary, single and multiple doses of inhaled nezulcitinib at 1, 3, and 10 mg were well-tolerated in healthy participants, with dose-proportional PK supporting once-daily administration.

Baricitinib reduces 30-day mortality in older adults with moderate-to-severe COVID-19 pneumonia.

BACKGROUND: Older adults are at the highest risk of severe disease and death due to COVID-19. Randomized data have shown that baricitinib improves outcomes in these patients, but focused stratified analyses of geriatric cohorts are lacking. Our objective was to analyze the efficacy of baricitinib in older adults with COVID-19 moderate-to-severe pneumonia. METHODS: This is a propensity score [PS]-matched retrospective cohort study. Patients from the COVID-AGE and Alba-Score cohorts, hospitalized for moderate-to-severe COVID-19 pneumonia, were categorized in two age brackets of age <70 years old (86 with baricitinib and 86 PS-matched controls) or ≥70 years old (78 on baricitinib and 78 PS-matched controls). Thirty-day mortality rates were analyzed with Kaplan-Meier and Cox proportional hazard models. RESULTS: Mean age was 79.1 for those ≥70 years and 58.9 for those <70. Exactly 29.6% were female. Treatment with baricitinib resulted in a significant reduction in death from any cause by 48% in patients aged 70 or older, an 18.5% reduction in 30-day absolute mortality risk (n/N: 16/78 [20.5%] baricitinib, 30/78 [38.5%] in PS-matched controls, p < 0.001) and a lower 30-day adjusted fatality rate (HR 0.21; 95% CI 0.09-0.47; p < 0.001). Beneficial effects on mortality were also observed in the age group <70 (8.1% reduction in 30-day absolute mortality risk; HR 0.14; 95% CI 0.03-0.64; p = 0.011). CONCLUSIONS: Baricitinib is associated with an absolute mortality risk reduction of 18.5% in adults older than 70 years hospitalized with COVID-19 pneumonia.

Impact of high dose of baricitinib in severe COVID-19 pneumonia: a prospective cohort study in Bangladesh.

PURPOSE: Hyperinflammation in severe COVID-19 infection increases the risk of respiratory failure and one of the cogent reasons of mortality associated with COVID-19. Baricitinib, a janus kinases inhibitor, can potentially suppress inflammatory cascades in severe COVID-19 pneumonia. METHODS: The objective of this study was to compare the clinical outcomes of high dose of baricitinib with its usual dose in patients with severe COVID-19 pneumonia. This prospective cohort study was conducted on 238 adult patients with severe COVID-19 pneumonia. Eight milligram and 4 mg of baricitinib was given orally to 122 patients in the high dose (HD) group and 116 patients the usual dose (UD) group, respectively daily for 14 days, and clinical outcomes were compared among the groups. RESULTS: Blood oxygen saturation level was stabilized (≥94% on room air) earlier in the HD group compared to the UD group [5 (IQR: 4-5)/8 (IQR: 6-9), P < 0.05]. Patients in the HD group required intensive care unit (ICU) and intubation supports more in the UD group than that in patients of the HD group [17.2%/9%, P < 0.05; 11.2%/4.1%, P > 0.05; N = 116/122, respectively]. The 30-day mortality and 60-day rehospitalization rate were higher in the UD group than the HD group [6%/3.3%, P < 0.01; 11.9%/7.6%, P > 0.05; N = 116/122, respectively]. CONCLUSION: The daily high dose of baricitinib in severe COVID-19 results in early stabilization of the respiratory functions, declined requirements of critical care supports, reduced rehospitalization with mortality rate compared to its daily usual dose.

Current jakinibs for the treatment of rheumatoid arthritis: a systematic review.

OBJECTIVE: One-third of patients with severe rheumatoid arthritis (RA) do not achieve remission or low disease activity, or they have side effects from cDMARD and bDMARD. They will need a new treatment option such as the small molecule JAK inhibitors. In this systematic review, we evaluate the efficacy and safety data of the current jakinibs: tofacitinib, peficitinib, decernotinib, upadacitinib, baricitinib and filgotinib in patients in whom treatment with conventional or biological disease-modifying antirheumatic drugs (cDMARD and/or bDMARD) failed. METHODS: We searched for randomized controlled trials comparing efficacy and safety of jakinibs for RA treatment using the Web of Science, Scopus, PubMed, and clinicaltrials.gov databases with the terms: "rheumatoid arthritis" OR "arthritis rheumatoid" OR "RA" AND "inhibitor" OR "jak inhibitor" AND "clinical trial" OR "treatment" OR "therapy". RESULTS: All jakinibs achieved good results in ACR 20, 50, 70 and with CRP-DAS28 for LDA and remission, upadacitinib showed better results compared to the others. In ESR-DAS28 for remission, tofacitinib achieved the best result. Regarding the safety of all jakinibs, peficitinib, baricitinib and filgotinib did not register deaths in their studies unlike tofacitinib that presented 11 deaths. Despite all benefits of jakinibs, the use in patients with severe liver and kidney disease should be avoided. CONCLUSIONS: Jakinibs in monotherapy or in combination with methotrexate can be considered a viable alternative in the treatment of moderate-to-severe RA. Even after failures with combination of cDMARDS and bDMARDS, jakinibs demonstrated efficacy.

Effect of Baricitinib on TPA-induced psoriasis like skin inflammation.

Psoriasis is a chronic inflammatory disorder of the skin and is characterized by hyper-dividing keratinocytes. This hyper-proliferation of keratinocytes is due to the high level of inflammatory cytokines. In this study, we evaluated the effect of topically applied Baricitinib, JAK1/2 inhibitor on chronic 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced psoriasis model in mice. To our knowledge, this is the first report evaluating the topical route of administration of Baricitinib in the context of psoriasis in vivo. TPA-induced inflammation was induced by the topical application of TPA in both ears. Thirty minutes before the application of TPA, the inner and outer surface of each ear was treated with Baricitinib for 6 days. Topical application of Baricitinib inhibited the expression of inflammation markers up-regulated by TPA. Besides, Baricitinib substantially reduced ear swelling, infiltration of leukocytes, the proliferation of epidermal cells, and angiogenesis of the dermal layer. The results suggest that Baricitinib significantly reduced phosphorylation of STAT3 and STAT1 levels in turn attenuating the downstream expression of inflammatory cytokines. Collectively, these results suggest that Baricitinib can be a potential therapeutic through topical route for psoriasis progresses.

Safety of Baricitinib 4 mg for the Treatment of Moderate to Severe Rheumatoid Arthritis.

OBJECTIVE: We evaluated the safety of baricitinib 4 mg at 24 weeks for the treatment of moderate to severe rheumatoid arthritis (RA). METHODS: Multiple databases were searched from inception up to November 26, 2019 for randomized controlled trials comparing baricitinib 4 mg with placebo for the treatment of moderate to severe RA. The safety outcomes of interest were the incidence of serious adverse events, adverse events leading to study discontinuation, all infections, and serious infections. Adjusted risk ratios (RRs) with 95% confidence intervals (CIs) were pooled for safety outcomes. The Cochrane tool was used to assess the risk of bias. RESULTS: This analysis included four randomized controlled trials with 3106 patients. For serious adverse events, the pooled RR (95% CI) was 1.09 (0.76-1.57). For adverse events leading to study discontinuation, the pooled RR (95% CI) was 1.41 (0.94-2.11). For all reported infections, the pooled RR (95% CI) was 1.24 (1.10-1.40), For serious infections, pooled RR (95% CI) was 0.97 (0.51-2.57). CONCLUSIONS: Patients with RA taking 4 mg baricitinib daily did have an increased risk of infections; however, the incidence of serious adverse events, adverse events leading to study discontinuation, or serious infections were not significantly different in patients treated with baricitinib 4 mg compared with placebo.

Vascular priming with RRx-001 to increase the uptake and accumulation of temozolomide and irinotecan in orthotopically implanted gliomas.

Vascular normalisation refers to a 'remodeling' of the dysfunctional tumour capillary network, which regresses under the influence of anti-VEGF treatment, resulting in improved blood flow and oxygenation. RRx-001 is an anti-CD47-SIRPα small molecule with vascular normalising properties under investigation in clinical trials for the treatment of glioblastoma, brain metastases, lung cancer and colorectal cancer, with FDA Orphan Drug Designation in glioblastoma and other tumour types. This study investigated whether the improved oxygenation and perfusion that has been previously observed with RRx-001 both preclinically and clinically in the context of a brain metastasis trial was correlated with increased penetration and accumulation of the cytotoxic chemotherapies, irinotecan and temozolomide, in orthotopically implanted gliomas, priming tumours for improved response. The experiments demonstrate that administration of RRx-001 prior to temozolomide or irinotecan results in significantly increased uptake of irinotecan and temozolomide in orthotopic glioma tumours. Since the success of chemotherapy in the brain (and outside of it) is limited by subtherapeutic tumoral drug concentrations, vascular normalisation-enhanced delivery of standard cytotoxics as demonstrated with RRx-001 may mitigate or reverse clinical drug resistance and thereby improve the outcome of cancer therapy, particularly in the brain.

Extended Safety Analysis of Baricitinib 2 mg in Adult Patients with Atopic Dermatitis: An Integrated Analysis from Eight Randomized Clinical Trials.

BACKGROUND: Baricitinib, a selective Janus kinase 1/Janus kinase 2 inhibitor, is indicated in the European Union and Japan for the treatment of moderate-to-severe atopic dermatitis (AD) in adults who are candidates for systemic therapy. OBJECTIVE: The objective of this study was to evaluate the safety of baricitinib 2 mg in the AD clinical program. METHODS: Six double-blind, randomized, placebo-controlled studies, and two long-term extension studies were summarized in two datasets. Placebo comparison was based on six 16-week studies with baricitinib 2 mg. All-bari-2-mg-AD included patients who received baricitinib 2 mg at any time during the eight studies. RESULTS: In total, 1598 patients received once-daily baricitinib 2 mg for 1434.2 patient-years of exposure (median 330 days/maximum 2.4 years). Treatment-emergent adverse events were higher for baricitinib 2 mg (57.9%) vs placebo (51.6%). Serious adverse events, serious infections, and opportunistic infections were low in frequency and similar between baricitinib 2 mg and placebo. There were no malignancies, gastrointestinal perforations, or major adverse cardiovascular events with baricitinib 2 mg in the placebo-controlled period. Herpes simplex (cluster) was higher for baricitinib 2 mg (3.8%) vs placebo (2.8%); rates decreased with extended 2 mg exposure. In All-bari-2-mg-AD, there were five malignancies other than non-melanoma skin cancer, two major adverse cardiovascular events, one peripheral venous thrombosis, one arterial thrombosis, and no pulmonary embolisms, deep vein thromboses, or deaths. CONCLUSIONS: This integrated analysis in patients with moderate-to-severe AD confirms the established safety profile of baricitinib 2 mg. Longer exposure to treatment is required to evaluate risks of malignancies and major adverse cardiovascular events. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifiers: NCT02576938 (first posted 15 October, 2015); NCT03334396 (7 November, 2017); NCT03334422 (7 November, 2017); NCT03428100 (9 February, 2018); NCT03435081 (15 February, 2018); NCT03733301 (7 November, 2018); NCT03334435 (7 November, 2017); NCT03559270 (18 June, 2018).

Baricitinib is a medication that helps an overactive immune system adjust itself, leading to improvements in the inflammatory condition atopic dermatitis. Baricitinib is approved for patients with moderate-to-severe atopic dermatitis in 40 countries. Because it works with the immune system, it is important to understand the safety of baricitinib. Safety information was collected from eight studies and analyzed in two datasets. The first dataset compared the safety of baricitinib 2 mg with placebo in six 16-week studies in which neither patient nor physician knew whether they were taking baricitinib or placebo. The second dataset included an additional two extension studies and examined the safety of baricitinib in all patients receiving at least one dose of baricitinib 2 mg. Patients took baricitinib 2 mg for a maximum of 2.4 years, with a median time of 330 days. In the first dataset, adverse events were higher for baricitinib 2 mg (57.9%) than placebo (51.6%). Serious adverse events, serious infections, and opportunistic infections were low in number and similar for patients taking baricitinib 2 mg or placebo. Herpes simplex infections were more frequent in patients taking baricitinib 2 mg (3.8%) than in those taking placebo (2.8%), but rates in those taking baricitinib 2 mg decreased with a longer treatment duration. There were no occurrences of cancer, gastrointestinal perforations, or major adverse cardiovascular events. In the second dataset, there were five reports of cancer other than non-melanoma skin cancer, two major adverse cardiovascular events, one peripheral venous thrombosis, one arterial thrombosis, and no pulmonary embolisms, deep vein thromboses, or deaths. Longer treatment with baricitinib is required to better understand the risks of developing cancer or major adverse cardiovascular events. This analysis of safety in patients with moderate-to-severe atopic dermatitis is consistent with the safety reported previously for baricitinib 2 mg. Extended Safety Analysis of Baricitinib 2 mg in Adult Patients with Atopic Dermatitis: An Integrated Analysis from Eight Randomized Clinical Trials (MP4 87244 kb).

FOXD1 promotes dedifferentiation and targeted therapy resistance in melanoma by regulating the expression of connective tissue growth factor.

Metastatic melanoma is an aggressive skin cancer and associated with a poor prognosis. In clinical terms, targeted therapy is one of the most important treatments for patients with BRAFV600E -mutated advanced melanoma. However, the development of resistance to this treatment compromises its therapeutic success. We previously demonstrated that forkhead box D1 (FOXD1) regulates melanoma migration and invasion. Here, we found that FOXD1 was highly expressed in melanoma cells and was associated with a poor survival of patients with metastatic melanoma. Upregulation of FOXD1 expression enhanced melanoma cells' resistance to vemurafenib (BRAF inhibitor [BRAFi]) or vemurafenib and cobimetinib (MEK inhibitor) combination treatment whereas loss of FOXD1 increased the sensitivity to treatment. By comparing gene expression levels between FOXD1 knockdown (KD) and overexpressing (OE) cells, we identified the connective tissue growth factor (CTGF) as a downstream factor of FOXD1. Chromatin immunoprecipitation and luciferase assay demonstrated the direct binding of FOXD1 to the CTGF promoter. Similar to FOXD1, knockdown of CTGF increased the sensitivity of BRAFi-resistant cells to vemurafenib. FOXD1 KD cells treated with recombinant CTGF protein were less sensitive towards vemurafenib compared to untreated FOXD1 KD cells. Based on these findings, we conclude that FOXD1 might be a promising new diagnostic marker and a therapeutic target for the treatment of targeted therapy resistant melanoma.

Baricitinib Ameliorates Experimental Autoimmune Encephalomyelitis by Modulating the Janus Kinase/Signal Transducer and Activator of Transcription Signaling Pathway.

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis (MS) and a CD4+ T cell-mediated autoimmune disease. The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is recognized as the major mechanism that regulates the differentiation and function of T helper (Th) 1 and Th17 cells, which are recognized as pivotal effector cells responsible for the development of EAE. We used baricitinib, a JAK 1/2 inhibitor, to investigate the therapeutic efficacy of inhibiting the JAK/STAT pathway in EAE mice. Our results showed that baricitinib significantly delayed the onset time, decreased the severity of clinical symptoms, shortened the duration of EAE, and alleviated demyelination and immune cell infiltration in the spinal cord. In addition, baricitinib treatment downregulated the proportion of interferon-γ+CD4+ Th1 and interleukin-17+CD4+ Th17 cells, decreased the levels of retinoic acid-related orphan receptor γ t and T-bet mRNA, inhibited lymphocyte proliferation, and decreased the expression of proinflammatory cytokines and chemokines in the spleen of mice with EAE. Furthermore, our results showed the role of baricitinib in suppressing the phosphorylation of STATs 1, 3, and 4 in the spleen of EAE mice. Therefore, our study demonstrates that baricitinib could potentially alleviate inflammation in mice with EAE and may be a promising candidate for treating MS.

Selective inhibition of JAK3 signaling is sufficient to reverse alopecia areata.

The Janus kinase/signal transducers and activators of transcription (JAK/STAT) are key intracellular mediators in the signal transduction of many cytokines and growth factors. Common γ chain cytokines and interferon-γ that use the JAK/STAT pathway to induce biological responses have been implicated in the pathogenesis of alopecia areata (AA), a T cell-mediated autoimmune disease of the hair follicle. We previously showed that therapeutic targeting of JAK/STAT pathways using the first-generation JAK1/2 inhibitor, ruxolitinib, and the pan-JAK inhibitor, tofacitinib, was highly effective in the treatment of human AA, as well as prevention and reversal of AA in the C3H/HeJ mouse model. To better define the role of individual JAKs in the pathogenesis of AA, in this study, we tested and compared the efficacy of several next-generation JAK-selective inhibitors in the C3H/HeJ mouse model of AA, using both systemic and topical delivery. We found that JAK1-selective inhibitors as well as JAK3-selective inhibitors robustly induced hair regrowth and decreased AA-associated inflammation, whereas several JAK2-selective inhibitors failed to restore hair growth in treated C3H/HeJ mice with AA. Unlike JAK1, which is broadly expressed in many tissues, JAK3 expression is largely restricted to hematopoietic cells. Our study demonstrates inhibiting JAK3 signaling is sufficient to prevent and reverse disease in the preclinical model of AA.

Baricitinib in patients with moderate-to-severe atopic dermatitis: Results from a randomized monotherapy phase 3 trial in the United States and Canada (BREEZE-AD5).

BACKGROUND: Baricitinib, an oral selective Janus kinase 1/Janus kinase 2 inhibitor, is being studied for moderate-to-severe atopic dermatitis (AD) in adults. OBJECTIVE: To evaluate the efficacy and safety of baricitinib monotherapy in a North American phase 3 trial (BREEZE-AD5/NCT03435081) of adults with moderate-to-severe AD who responded inadequately or were intolerant to topical therapy. METHODS: Patients (N = 440) were randomized 1:1:1 to once-daily placebo or baricitinib (1 mg or 2 mg). The primary endpoint was the proportion of patients achieving ≥75% reduction in the Eczema Area and Severity Index at week 16. A key secondary endpoint was the proportion of patients achieving a validated Investigator Global Assessment for AD score of 0 (clear)/1(almost clear) with ≥2-point improvement. RESULTS: At week 16, the proportion of patients achieving Eczema Area and Severity Index was 8%, 13%, and 30% (P < .001, 2 mg vs placebo) and those with a validated Investigator Global Assessment for AD score of 0/1 were 5%, 13%, and 24% (P < .001, 2 mg vs placebo) for placebo, baricitinib 1 mg, and baricitinib 2 mg, respectively. Safety findings were similar to those of other baricitinib AD studies. LIMITATIONS: Short-term clinical trial results may not be generalizable to real-world settings. CONCLUSION: Baricitinib was efficacious for patients with moderate-to-severe AD with no new safety findings over 16 weeks.