Selective JAK1 Inhibitor Research Articles

Pluronic F127/lecithin PLGA nanoparticles as carriers of monocyte-targeted jakinibs: a potential therapeutic platform.

Aim: In this study, PLGA nanoparticles (PNPs) emulsified in Pluronic F127 (F127)/Lecithin (LEC) were designed to load Itacitinib (ITA), a selective JAK1 inhibitor, for targeting human monocytes.Materials & methods: The physicochemical characteristics of empty and ITA-loaded F127/LEC PNPs were analyzed. The binding and internalization of NPs in leukocytes were evaluated. The effect of NPs on monocyte activation and JAK1 inhibition was assessed.Results: F127/LEC PNPs were selectively bound and internalized by monocytes, sparing other leukocytes. ITA-F127/LEC PNPs significantly dampened monocyte activation. They also inhibited the monocyte's ability to promote T-cell proliferation and inhibited proinflammatory cytokine production.Conclusion: ITA-loaded F127/LEC PNPs showed potential for monocyte-targeted therapy, offering new avenues for disease treatment.

JAK Inhibitors for Myelofibrosis: Strengths and Limitations.

The landscape of myelofibrosis (MF) has changed since the discovery of the JAK2 V617F mutation and subsequent development of JAK inhibitors (JAKis). However, treatment with JAKis remain a challenge. In this review we critically analyze the strengths and limitations of currently available JAK inhibitors. In MF patients, JAK inhibitors have been associated with reduced symptom burden and spleen size, as well as improved survival. However, durability of response and development of treatment resistance remain an issue. Recently, there has been increased efforts to optimize treatment with the development of highly selective JAK inhibitors, as well as use of combination agents to counter disease resistance through targeting aberrant signaling pathways. Treatment of MF patients with JAKi therapy can be challenging but the development of more potent and selective JAK inhibitors, as well as combination therapies, represent exciting treatment advances in this field.

Therapeutic JAK1 Inhibition Reverses Lupus Nephritis in a Mouse Model and Demonstrates Transcriptional Changes Consistent With Human Disease.

Janus kinase family members are essential for signaling by multiple cytokines, including many implicated in systemic lupus erythematosus (SLE) pathogenesis. To test whether inhibition of JAK1 signaling can be efficacious in SLE, we used a JAK1-selective inhibitor (ABT-317) and evaluated its ability to ameliorate disease in murine SLE. Efficacy of ABT-317 was evaluated using NZB/W-F1 mice treated prophylactically and therapeutically. Primary endpoints were proteinuria, survival, and saliva production. Other endpoints included histological analysis of kidneys and salivary glands, flow cytometric analysis of splenic cell populations, and gene expression analysis by RNA sequencing in the kidneys, salivary glands, and blood. Publicly available human kidney gene transcription data were used to assess the translatability of the mouse findings. ABT-317 was efficacious when dosed prophylactically and prevented disease for up to two months after treatment cessation. When dosed therapeutically, ABT-317 quickly reversed severe proteinuria and restored saliva production, as well as diminished kidney and salivary gland inflammation. ABT-317-induced changes in glomerular morphology coincided with normalization of a human nephrotic gene signature, suggesting translatability to human lupus nephritis (LN). JAK1 inhibition prevented and reversed kidney and salivary gland manifestations of murine lupus with long-lasting effects after treatment cessation. These data, along with the presence of JAK1 and nephrotic gene signatures in human LN glomeruli, suggest that a JAK1-selective inhibitor may be an effective therapeutic in the treatment of human SLE and LN.

Type 2 cytokine-JAK1 signaling is involved in the development of dry-skin induced mechanical alloknesis

BackgroundMechanical alloknesis (m-alloknesis) is itch hypersensitivity induced by normally innocuous stimuli. It is sometimes observed in dry skin based itch-related diseases such as atopic dermatitis (AD), and often triggers the vicious itch-scratch cycle. The acetone-ether and water (AEW) mouse model mimics dry skin induced m-alloknesis, yet its underlying mechanism remains unclear. Janus kinase (JAK) inhibitors are used to treat AD, but their effects on m-alloknesis are not fully known. ObjectiveTo reveal the effects of various oral JAK inhibitors on m-alloknesis and their action points, using AEW model. MethodsAEW model was prepared by treatment with a mixture of acetone-ether, and they were orally administrated a JAK1/2 inhibitor baricitinib, a selective JAK1 inhibitor abrocitinib, or a JAK2 selective inhibitor AZ960, and evaluated m-alloknesis score as the total number of scratching responses in 30 mechanical stimulations. To further elucidate the mechanism of action, IL-4, IL-13 or thymic stromal lymphopoietin (TSLP) or their neutralizing antibodies were also applied to mice. In addition, the levels of these cytokines in mouse skin were measured using multiple immunoassays. ResultsAll of JAK inhibitors effectively reduced m-alloknesis, with abrocitinib demonstrating the most significant inhibition. The neutralizing antibodies against IL-4, IL-13, and TSLP inhibited m-alloknesis in AEW mice. Intradermal administration of IL-4, IL-13, or TSLP induced m-alloknesis, and abrocitinib effectively mitigated each cytokine-induced response. Highly sensitive assays detected IL-4, IL-13, IL-31 and TSLP in AEW-treated skin, with TSLP levels significantly increased. ConclusionType 2 cytokine-JAK1 signaling is involved in the development of m-alloknesis in dry skin.

Effectiveness and safety of upadacitinib in acute severe ulcerative colitis patients from single Chinese IBD Center: a monocentric study

Upadacitinib is an oral new selective JAK1 inhibitor that has been approved for treating adult patients with moderately to severely active ulcerative colitis. However, a growing number of studies are needed on the effectiveness of upadacitinib in the treatment of acute severe ulcerative colitis. This study was mainly aimed to describe the clinical and endoscopic effectiveness of upadacitinib 45 mg in Chinese acute severe ulcerative colitis patients following eight weeks of treatment. In this study, we examined all patients with acute severe ulcerative colitis from Xijing IBD Center, Xi’an, China, with acute severe ulcerative colitis. All patients were initially given oral upadacitinib 45 mg. Clinical indicators, C-reactive protein, and erythrocyte sedimentation rates were collected. Clinical response and clinical remission were assessed using modified Mayo. Endoscopic evaluation was performed carried out using the Mayo Endoscopic Score and Ulcerative colitis endoscopic index of severity score. A total of 14 patients who received upadacitinib were included in the study period. All patients exhibited a clinical response to 45 mg upadacitinib initially. All patients completed the 8-week induction. The clinical remission rate was 28.6% after eight weeks. Two patients revealed endoscopic remission at 14.3%. The pathology improved in 50.0% of patients. The 8-week surgical resection rate was 7.1%, with the 16-week surgical resection rate being 14.3%. Adverse events included herpes simplex virus infection and increased thrombin time. The results of our study support the short-term effectiveness and safety of upadacitinib in acute severe ulcerative colitis, providing new choices for patients’ treatment. However, more extended investigation needs to be performed on the long-term effectiveness and safety.

Safety and efficacy of itacitinib, a selective JAK1 inhibitor, in advanced hepatocellular cancer: Phase 1b trial (JAKAL).

Overactivation of the JAK/STAT pathway is one of the drivers for the pathophysiology of hepatocellular carcinoma (HCC). We propose a Phase Ib study to evaluate the safety and efficacy of itacitinib, a selective JAK1 inhibitor, as a second-line treatment for patients with advanced or metastatic HCC.Twenty-five patients will receive 400mg itacitinib orally daily, 28-day cycle. Safety will be reviewed prior to each cycle. Tumor response assessed every 2months until disease progression, death or withdrawal. Tumor biopsies and blood samples will be taken for presence of JAK1 mutations.Activation of JAK/STAT pathway drives HCC development and is associated with immunotherapy resistance. Itacitinib is hypothesized to be safe and effective in HCC patients that have progressed after first-line therapies.Clinical Trial Registration: EudraCT: 2017-004437-81 NCT04358185 (ClinicalTrials.gov).

Upadacitinib - New Janus Kinase Inhibitor - Literature Review

Atopic dermatitis (AD) is a chronic, recurrent dermatosis that affects an increasing percentage of the population. It usually affects children and resolves spontaneously, however, symptoms can persist into adulthood and even appear de novo later in life. The skin lesions that appear in this disease significantly reduce patients quality of life. Visual skin symptoms are exacerbated during stress, and pruritus leads to sleep problems. The effect of an inadequately controlled disease can even be a reduction in social activities and a reluctance to leave the house. The basis of treatment is skin care using emollients and avoiding triggers and aggravating factors. In the next stage, the doctor may prescribe topical or systemic treatment for the patient, depending on the severity of the disease. Such measures may not be enough, so more and more new drugs are being registered for the treatment of atopic dermatitis. One of them is upadacitinib, which appears to be extremely effective compared to other medications used to treat moderate to severe ad. It is a selective JAK inhibitor that reduces the inflammatory response by inhibiting migration, proliferation and cytokine secretion by granulocytes. It brings rapid and sustained effects in reducing skin lesions and reducing one of the most bothersome symptoms, pruritus.It may serve as a good alternative to the existing methods for treating moderate to severe atopic dermatitis The purpose of our study is to describe this new drug, its mechanism of action and discuss its possible benefits versus side effects.

Efficacy and Safety of Upadacitinib for Axial Spondyloarthritis: A Systematic Review and Meta-Analysis.

Upadacitinib, a selective JAK1 inhibitor, has demonstrated promising results in the treatment of axial Spondyloarthritis (AxSpA). AxSpA management remains challenging since there is a gap in knowledge regarding the potential effect of upadacitinib in axSpA patients. Exploring novel therapeutic options is crucial. Therefore, we performed this systematic review and meta-analysis to summarize and synthesize results collected from available randomized-- controlled trials (RCTs) about the efficacy and safety of upadacitinib for patients with axSpA. A systematic literature search of Medline via PubMed, Web of Science, Scopus, EBSCO, and Cochrane Central was conducted in October 2023. Relevant RCTs were selected, and their data were extracted and analyzed using the RevMan 5.4 software. The main outcomes were assessment in Spondylarthritis International Society (ASAS) 20, ASAS40, SPARCC MRI sacroiliac joint, and Bath Ankylosing Spondylitis disease activity index (BASDAI) 50. Three RCTs with a total of 920 participants were included in this study. Upadacitinib showed significant improvement in the ASAS40 response, ASAS20 response, BASDAI50 response, and SPARCC MRI Sacroiliac Joint change from baseline compared to placebo at 14-week duration (RR 2.19, 95% CI (1.79 to 2.68), P < 0.00001), (RR 1.62, 95% CI [1.42 to 1.84), P < 0.00001), (RR 2.16, 95% CI (1.75 to 2.67), P < 0.00001), and (MD -3.32 points, 95% CI (-3.96 to -2.68), P < 0.00001) respectively. However, this efficacy decreased after the 52-week duration in terms of ASAS40 RR 2.19 vs. 1.02, ASAS20 RR 1.62 vs. 0.98, BASDAI 50 RR 2.16 vs. 1.05, and ASAS Partial Remission RR 3.82 vs. 1.07. Upadacitinib 15 mg showed satisfactory and promising efficacy in the treatment of AxSpA, with no difference in safety profile compared to the placebo.

Oclacitinib (APOQUEL®) is a selective Janus kinase 1 inhibitor with efficacy in a canine model of flea allergic dermatitis.

Oclacitinib is a novel Janus kinase (JAK) inhibitor that potently inhibits JAK1-dependent cytokines involved in allergy, inflammation, and pruritus (IL-2, IL-4, IL-6, IL-13, and IL-31). Oclacitinib (Apoquel®, Zoetis Inc, Parsippany, NJ) is approved for the treatment/control of pruritus associated with allergic dermatitis and treatment/control of clinical manifestations of atopic dermatitis in dogs at least 12 months of age. To evaluate the effectiveness of oclacitinib in dogs with flea allergy dermatitis, the JAK1 selective inhibitor was tested in a placebo-controlled, masked, single-dose (0.4 mg/kg) or repeat-dose (0.4 mg/kg, twice daily for 2 weeks) study. Pruritic behaviors were quantitated by video recording, and erythema and skin lesions were assessed using a 10-cm visual analog scale (VAS). Results showed that oclacitinib reduced pruritus by 61% as early as 1.5 h after a single oral dose compared to placebo, with an average reduction (compared to placebo) of 85% 1-5 h after dosing (0.4 mg/kg; p < .0001). Oclacitinib also significantly reduced erythema (p < .0001) and skin lesion (p < .0005) VAS scores on Day 14 compared to placebo in a repeat dose study. No adverse events were noted during the conduct of these studies. IL-31 concentrations were elevated in the majority of dogs after flea infestation, suggesting JAK1-dependent cytokines may drive clinical signs of flea allergy dermatitis. These findings show that oclacitinib, an inhibitor of JAK1-dependent cytokines involved in allergy and inflammation can rapidly reduce clinical signs associated with flea allergic dermatitis in dogs.

Adolescent with severe atopic dermatitis and comorbid joit disease: remission achievement by selective JAK1-inhibitor treatment

Atopic dermatitis is a heterogenous in terms of inflammatory pathways and severity prognosis skin disease. The typical clinical manifestations of the disease are intense itching and eczematisation of the skin. The prevalence of atopic dermatitis is markedly higher in children than in adult patients. Persistence of clinical manifestations and recurrent exacerbations of the disease in adolescents can determine the prognosis for decades of working age, leading to a decrease in the quality of life, socialisation and educational success. Some patients demonstrate severe recurrent course of the disease which do not respond on standard topical anti-inflammatory preparations. Comorbid diseases (not only atopic ones) could serve additional factors complicating atopic dermatitis control achievement. The adolescent patient (well-known for low adherence to topical treatment) could become a special difficulty in clinical management. A clinical case of successful systemic therapy (upadacitinib 15 mg once daily) of severe atopic dermatitis patient comorbid with immunologically-driven joint disease presented. Previous topical treatment of atopic dermatitis was inefficient. Effectiveness (indexes SCORAD and DLQI, digital itch scale) and safety (laboratory data and complains) were evaluated for more than 1 year (15 months) of therapy. Rapid and sustain positive changes in course control of atopic dermatitis with possible T2-associated and other inflammatory mediators were demonstrated.

CS12192: A novel selective and potent JAK3 inhibitor mitigates acute graft-versus-host disease in bone marrow transplantation

BackgroundDespite the significant role of JAK3 in various autoimmune diseases, including graft-versus-host disease (GVHD), there has been a lack of potent and selective JAK3 inhibitors specifically studied for GVHD. In our preclinical investigations, we evaluated a novel JAK3 inhibitor called CS12192, which is already undergoing clinical investigation in autoimmune diseases. MethodsWe evaluated the efficacy of CS12192 in GVHD through mixed lymphocyte reaction (MLR) in both mouse and human cells, as well as allogeneic bone marrow transplantation (BMT) in a murine model. ResultsCS12192, starting at a concentration of 0.5 μM, dose-dependently reduced the intracellular positivity for cytokines TNF-α and IFN-γ in CD4+ T cells (p < 0.05 to p < 0.0001) and CD8+ T cells (p < 0.01 to p < 0.0001) during mouse allogeneic MLR assays. This effect was observed for both single and double positivity of the cytokines. Moreover, In MLR assays with three different human donors, CS12192 also demonstrated a dose-dependent reduction in the proportion of IFN-γ positive CD4+ T cells (p < 0.0001) and CD8+ T cells (p < 0.01 to p < 0.0001). Additionally, it suppressed T cell proliferation in the mouse MLR (p < 0.05 to p < 0.0001), but this effect was observed in only one human donor (p < 0.001 to p < 0.0001). Furthermore, the administration of CS12192 at 40 and 80 mg/kg BID significantly improved the survival rate in the BMT model, resulting in cumulative 62-day survival rates of 88.89% (p < 0.01) and 100% (p < 0.001), respectively, compared with prednisolone (p < 0.05). ConclusionsCS12192 is a novel, potent and selective JAK3 inhibitor demonstrating great potential to mitigate acute GVHD.

Plasma ctDNA biomarker study in patients with non-small cell lung cancer with EGFR exon 20 insertion mutation treated with sunvozertinib.

8563 Background: There are limited reports on biomarker studies of non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertion mutation (exon20ins). Sunvozertinib (DZD9008), an oral, potent, irreversible and selective EGFR tyrosine kinase inhibitor (TKI), has been granted conditional approval in China for the treatment of NSCLC with EGFR exon20ins in the ≥ second-line setting. Here we report biomarker analysis of EGFR exon20ins in large sample size, by pooling data from WU-KONG series of studies. Methods: Serial plasma ctDNA samples were collected from baseline until progressive disease (PD). Next generation sequencing was used to assess EGFR exon20ins in baseline plasma ctDNA, and to analyze genetic alterations in baseline and PD plasma ctDNA to identify potential resistance mechanisms to sunvozertinib. Droplet digital PCR was used to dynamically monitor the quantity of EGFR exon20ins during treatment. In addition, association between baseline EGFR exon20ins and disease characteristics as well as antitumor activity of sunvozertinib was analyzed. Furthermore, in vitro and in vivo experiments were performed to explore potential approach which may overcome the resistance to sunvozertinib. Results: A total of 121 patients were included in this biomarker analysis, among them 81 out of 121 (66.9%) had detectable EGFR exon20ins in baseline plasma ctDNA. There was a positive correlation between detectable EGFR exon20ins and higher number of metastasis sites. In addition, higher EGFR exon20ins abundance was positively correlated with more metastasis sites and brain metastasis. Patients with EGFR exon20ins negative in plasma ctDNA achieved a higher objective response rate (ORR) (68.0% vs. 45.8%) and longer median progression free survival (PFS) (7.4 months vs. 5.5 months) with sunvozertinib treatment. In patients with baseline detectable EGFR exon20ins, the mutant allele decreased over time with treatment in majority of patients (12/14, 85.7%), and the earliest clearance of EGFR exon20ins occurred after one week of treatment. In patients who developed disease progression, 12 of 18 (66.7%) maintained EGFR exon20ins at PD, and among them, 3 concurrently acquired EGFR C797S, all in cis with exon20ins. In addition, EGFR G724S and other genetic aberrations in EGFR downstream signaling pathway, were also detected. Exploratory work on overcoming resistance to sunvozertinib suggests that combination of golidocitinib, a selective JAK1 inhibitor, with chemotherapy could be a potential approach. Conclusions: This study showed that positive EGFR exon20ins in plasma ctDNA is associated with advanced disease characteristics. Sunvozertinib can effectively clear EGFR exon20ins in plasma ctDNA, confirming its direct effect on EGFR pathway. The resistance to sunvozertinib can be through EGFR-dependent and EGFR-independent mechanisms.

Real-World Data on the Effectiveness and Safety of Filgotinib for Ulcerative Colitis in Japanese Patients: A Single-Center Experience.

Introduction Filgotinib is a JAK-1 selective inhibitor approved for ulcerative colitis (UC) treatment in Japan. Its effectiveness has been confirmed but remains unknown in actual clinical practice. Therefore, we aimed to evaluate the effectiveness and safety of filgotinib and identify suitable patients in the Japanese population. Methods We retrospectively reviewed the background, clinical course, and laboratory data of patients treated with filgotinib 200 mg for UC between May 2022 and December 2023. Results The median observation period for the 25 patients was 232 days (interquartile ranges (IQR) 102-405). The median age of the patients was 43 years (IQR 29-55), disease duration was nine years (IQR 2-12), and 36% (9/25) of patients were biologic or small molecule naïve. The median patient-reported outcome (PRO2) and partial Mayo (pMayo) scores at agent initiation were 3 (IQR 1-4) and 4.5 (IQR 3-6), respectively. The PRO2 and pMayo scores improved significantly two weeks after treatment initiation (p < 0.05). Clinical remission rates at 24 weeks after treatment initiation were 60% (15/25) for PRO2 ≤ 1 and 52% (13/25) for pMayo ≤ 1. The Mayo endoscopic subscoresignificantly improved after filgotinib initiation (p=0.04), and the endoscopic remission rate was 47% (8/17). At 24 weeks, patients in clinical remission, compared to those not in remission, had significantly lower baseline PRO2 and pMayo scores and longer disease duration (p=0.03, p=0.03, and p=0.04, respectively). The filgotinib persistence rate was 68% (17/25), with no discontinuation because of adverse events. Patients who continued treatment had significantly lower PRO2, pMayo scores, and blood neutrophil counts at initiation than those who discontinued (p=0.02, p=0.03, and p=0.02, respectively). Conclusion Filgotinib appears to be effective and safe in Japanese patients with UC. Effectiveness and persistence were high in patients whose PRO2 and pMayo scores were low at the time of treatment initiation.

Abrocitinib-associated adverse events: a real-world pharmacovigilance study using the FAERS database

ABSTRACT Background Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Janus kinase (JAK) modulates cytokines involved in AD pathophysiology, and JAK inhibitors have emerged as effective pharmacotherapeutic remedies for AD. Abrocitinib, an oral selective inhibitor of JAK1, is indicated for the management of moderate-to-severe AD. The current study evaluated the adverse events (AEs) associated with abrocitinib in a real-world setting. Methods To quantify the signals of abrocitinib-associated AEs, we used the US Food and Drug Administration Adverse Event Reporting System (FAERS) for this pharmacovigilance study with two established pharmacovigilance methods. Results A total of 1071 AEs of abrocitinib were investigated as the primary suspected from the FAERS to detect and characterize relevant safety signals. The analysis revealed 85 signals for abrocitinib. The most common AE for abrocitinib was drug ineffective. The signal strength of eczema herpeticum was 515.87 (277.80–957.98) and 510.59 (5148.65) and exhibited the highest strength for abrocitinib. Rare AEs such as aggravated condition, pruritus, and hypersensitivity were not listed on the label, and attention to these AEs is required. Conclusion The analysis of the AE signals may provide support for clinical monitoring and risk identification of abrocitinib.

Efficacy of upadacitinib in the achievement of clinical and endoscopic remission in hospitalized patients with ulcerative colitis.

Janus kinase (JAK) inhibitors have been developed and are clinically available for management of active UC patients although most studies have been conducted for the outpatients and few studies have demonstrated its efficacy in endoscopic and histological remission of hospitalized patients with UC. The aim of the present study was to investigate the efficacy of upadacitinib, which is a novel selective JAK1 inhibitor, in the treatment of ulcerative colitis. We present the cases of three hospitalized patients with ulcerative colitis who achieved clinical remission after significant and rapid improvement with upadacitinib. While upadacitinib was used as the second-line treatment for patients with insufficient treatment effects for corticosteroids or ustekinumab, a patient received it just after admission because they were steroid dependent and previously used advanced therapy before hospitalization. All patients demonstrated rapid clinical responses within 7days and the partial Mayo scores were 0 at week 8. All patients achieved confirmed endoscopic and histological remissions. We conclude that upadacitinib is a potential treatment option for hospitalized patients with an inadequate response to other biologics and JAK inhibitors.

OA39 The influence of safety warnings on the prescribing of JAK inhibitors in England: an interrupted time-series analysis

Abstract Background/Aims JAK inhibitors (JAKi) were launched in the UK for rheumatoid arthritis in 2017. Licenced indications have subsequently expanded to include other inflammatory arthritides, inflammatory bowel disease, psoriasis and atopic dermatitis. Since then, there have been numerous safety warnings from regulatory bodies, with signals for cancer, venous thromboembolism and cardiovascular events. We set out to compare how these safety warnings have influenced prescribing behaviour for individual JAKi medications in England. Methods We analysed aggregate prescribing data from all NHS hospitals in England between January 2019 and July 2023. We compared monthly prescriptions issued for individual JAKi (tofacitinib, baricitinib, upadacitinib, filgotinib) across all licenced indications. Standardisation was performed using WHO Daily Defined Doses. We conducted interrupted time-series analyses to evaluate whether changes in prescribing behaviour occurred after: i) the initial press release for the ORAL Surveillance trial data (January 2021); and ii) the European Medicines Agency (EMA) safety committee warning for the JAKi class as a whole (October 2022). Results Overall, JAKi prescribing has increased year-on-year since 2019; however, striking differences exist for individual JAKi medications. Pre-2021, an estimated additional 93 patients per month were newly initiated on tofacitinib. After the ORAL Surveillance press release (January 2021), tofacitinib initiations decreased to 26 new patients/month (p &amp;lt; 0.001). Following the EMA safety warning (October 2022), tofacitinib prescribing fell sharply (71 fewer patients/month; p &amp;lt; 0.001). A similar pattern was observed for baricitinib - pre-2021: 145 new patients/month; post-Jan 2021: 15 new patients/month; post-Oct 2022: 60 fewer patients/month (all, p &amp;lt; 0.001). In contrast, prescriptions for the JAK1-selective inhibitors (upadacitinib and filgotinib) have increased markedly since 2021, with no apparent impact of the pan-JAKi safety warnings. In July 2023, baricitinib remained the most prescribed JAKi in England across all indications (175,245 defined daily doses [DDD]) followed by upadacitinib (154,510 DDD), tofacitinib (105,215 DDD), and filgotinib (72,445 DDD). Conclusion Prescribing of JAKi has changed markedly in association with emerging safety warnings, with significant reductions in prescriptions for tofacitinib and baricitinib. It is notable that warnings have emerged for the JAKi class as a whole, yet prescriptions for the JAK1-selective inhibitors, upadacitinib and filgotinib, have continued to increase. Explanations could include clinicians' interpretation of risk differences within the JAKi class, as well as external pressures such as price and licenced indications. Disclosure M.D. Russell: Honoraria; AbbVie, Biogen, Eli Lilly, Galapagos, Menarini. Grants/research support; Eli Lilly, Janssen, Pfizer, UCB. Z. Yang: None. B. Walter: None. E. Alveyn: None. K. Bechman: Grants/research support; Versus Arthritis/Pfizer. A. Miracle: None. D. Nagra: None. M.A. Adas: None. J.B. Galloway: Honoraria; Abbvie, Biovitrum, BMS, Celgene, Chugai, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, Sobi, UCB.

176 JAK1-selective inhibitor upadacitinib induced dynamic immunologic alterations and clinical response in treatment-resistant CVID gastrointestinal disease

176 JAK1-selective inhibitor upadacitinib induced dynamic immunologic alterations and clinical response in treatment-resistant CVID gastrointestinal disease

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.

Disseminated Histoplasmosis in a Patient with Myelofibrosis on Ruxolitinib: A Case Report and Review of the Literature on Ruxolitinib-Associated Invasive Fungal Infections.

Ruxolitinib, a selective inhibitor of Janus kinases, is a standard treatment for intermediate/high-risk myelofibrosis (MF) but is associated with a predisposition to opportunistic infections, especially herpes zoster. However, the incidence and characteristics of invasive fungal infections (IFIs) in these patients remain uncertain. In this report, we present the case of a 59-year-old woman with MF who developed disseminated histoplasmosis after seven months of ruxolitinib use. The patient clinically improved after ten weeks of combined amphotericin B and azole therapy, and ruxolitinib was discontinued. Later, the patient received fedratinib, a relatively JAK2-selective inhibitor, without relapse of histoplasmosis. We also reviewed the literature on published cases of proven IFIs in patients with MF who received ruxolitinib. Including ours, we identified 28 such cases, most commonly due to Cryptococcus species (46%). IFIs were most commonly disseminated (39%), followed by localized lung (21%) infections. Although uncommon, a high index of suspicion for opportunistic IFIs is needed in patients receiving JAK inhibitors. Furthermore, the paucity of data regarding the optimal management of IFIs in patients treated with JAK inhibitors underscore the need for well-designed studies to evaluate the epidemiology, pathobiology, early diagnosis, and multimodal therapy of IFIs in patients with hematological malignancies receiving targeted therapies.

Baricitinib Demonstrates Rapid Action Within Just 2 Months of Treatment in Severe and Unresponsive Alopecia Areata: A Case Report

Alopecia areata (AA) is a form of nonscarring alopecia, and is the most common immune-mediated cause of hair loss worldwide. Numerous therapeutic schedules available as off-label options have demonstrated only limited results. However, in 2022, baricitinib, a selective JAK1 and JAK2 inhibitor, was approved as an oral administered systemic therapy for severe AA. Based on this, the authors used it in a 21-year-old White female, who presented with a 15-year history of severe AA (Severity of Alopecia Tool score [SALT]: score 88) and immense psychological burden. After laboratory examinations within normal limits, baricitinib was administered as monotherapy with a 4 mg daily dosage. The severe AA improved rapidly after the first month, and resulted in total hair restoration just after the second month under baricitinib treatment. Besides clinical improvement, SALT score impressively reduced to 30 and 10, respectively, in 2 and 6 months. Six months later, the patient is keeping up the same treatment with no sign of relapse, and is on a 2-month follow-up schedule. In the authors’ patient, almost total hair restoration was achieved in less than 3 months of treatment, which strongly advocates for the addition of baricitinib in the dermatologic armament as a safe, adequate, and fast AA remedy.