JAK Inhibitors Research Articles

Abstract 260: Depletion of Ezh2 in the intestinal adenoma induced by JAK2V617F mutation leads to the malignant neoplasm

Abstract Background The increased JAK2 and EZH2 plays a critical role in the colorectal or colon cancer (CRC) progression. Targeting aberrant JAK2 expression caused by JAK2 gain-of-function (GOF) mutation, JAK2V617F and deregulated EZH2 kinase activity, JAK2 and/or EZH2 inhibitors have been used to treat the advanced CRCs. However, it is unclear whether the aberrant JAK2 can directly induce CRC or intestinal epithelial (IEC) malignancy. We hypothesize that the overexpressed JAK2 driven by JAK2V617F GOF mutation increases IEC neoplasia in which depletion of EZH2 can lead to IEC malignant neoplasm. Materials and Methods Colorectal samples were collected from 20 cases of CRC patients. Immunohistochemistry staining (IH), confocal immunofluorescence staining (IF) and bulk RNAseq were used to determine LGR5, Ki67, JAK2, EZH2, mutant β-catenin and JAK2V617F GOF mutation. Crypt-derived organoids or tumoroids were used to determine the JAK2 and EZH2 in the proliferative LGR5 cells (Ki67hiLGR5+) and were treated with JAK2 and/or EZH2 inhibitors. The mice with JAK2 and/or EZH2 deficiency in IECs were generated by crossing VilCreER mice, floxed-Jak2 and/or floxed-Ezh2 mice to determine the intestinal and colonic neoplasia. Lgr5, Ki67, Cdx2 Jak2, Ezh2, and mutant β-catenin IH or IF, organoids culture and peritoneal xenograft were used to determine the malignant neoplasm. The JAK2V617F-transfected HT29 or Caco-2 cells were used to determine the migration induced by JAK2V617F GOF mutation, then treated with EZH2 inhibitors to determine the effects of EZH2 inhibition on JAK2V617F GOF mutation-induced migration. The spheres were formed with Caco-cells with JAK2V617F GOF mutation and were used to observe the effects of JAK2V617F GOF mutation on IEC neoplasia formation. Results JAK2 and/or EZH2 overexpression are positively correlated with the probability of CRC initiation. JAK2 and EZH2 are highly expressed in the CRC tumoroids. Inhibition of EZH2 increases the CRC tumoroids growth and spheroid formation, and reduces budding numbers while reducing the proliferation of organoids from healthy crypts. Jak2 over-expression in IECs increases intestinal microadenoma, and depletion of EZH2 in the adenoma increases mutant β-catenin and severity of intestinal adenoma, suggesting that depletion of EZH2 enhances the malignancy of overexpressed Jak2-derived IEC neoplasia. Consistently, JAK2V617F GOF mutation increases HT29 or Caco-2 cell migration. Conclusion JAK2V617F GOF mutation can drive IEC neoplastic proliferation and adenoma, depletion of EZH2 in the adenoma leads to IEC malignant neoplasm. Our research suggests that loss of Ezh2 may synergistically cooperate with the Jak2V617F mutation in the pathogenesis of IEC malignant neoplasm. Citation Format: Nardana Esmaeili, Ahmed Bakheet, Wen Gao, Haifeng Li, Dan Cai, Xiaonan Han. Depletion of Ezh2 in the intestinal adenoma induced by JAK2V617F mutation leads to the malignant neoplasm [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 260.

Abstract 2837: Conservation of JAK-STAT signaling in canine lymphocytes responding to human IL-6, IL-7, and IL-1 alpha

Abstract Dogs share physiological similarities with humans, positioning them as valuable models for studying the efficacy and safety of drugs and their underlying mechanisms of action. The JAK-STAT pathway, a highly conserved signaling pathway across species, including humans and dogs, presents an opportunity to investigate the therapeutic potential of cytokines that utilize this pathway. In this study, we aimed to evaluate the functional activity of three canine cytokines on canine cells. To assess stimulation of the JAK/STAT pathway, we used a flow cytometry assay that measures phospho-STAT in activated canine or human lymphocytes in whole blood specimens. Testing of commercially available human and canine IL-6 proteins revealed that canine lymphocytes respond poorly to most canine IL-6 products, whereas all recombinant human IL-6 products stimulated STAT phosphorylation in canine lymphocytes, despite sharing low sequence similarity with canine IL-6. In human T cells, both canine IL-6 and human IL-6 stimulated STAT phosphorylation, demonstrating biological activity from the canine IL-6 products. Several JAK inhibitors inhibited cytokine-induced STAT phosphorylation in both canine and human CD4 T-cells, consistent with JAK inhibition, but targeting the IL-6 receptor with tocilizumab only blocked IL-6-induced STAT phosphorylation in human but not canine CD4 T-cells in whole blood. These findings demonstrate the potential of our assay system to assess cross-species cytokine reactivity, determine if JAK/STAT inhibitors used clinically might be useful in treating inflammatory conditions in dogs, and identify novel canine-specific inhibitors. Additionally, we explored the induction of IL-8 by human and canine IL-1 alpha in IL-1 alpha sensitive human cells. Human IL-1 alpha failed to stimulate a canine IL-1 alpha sensitive cell line, suggesting species-specific differences in IL-1 alpha activity. Furthermore, we discovered that canine IL-7 and human IL-7 are species-specific. In summary, this proof-of-concept study highlights the capability to assess the activation of STATs and pathway inhibition by JAK inhibitors in canine whole blood using flow cytometry. We confirmed that human IL-6 stimulates JAK/STAT signaling in canine CD4 T-cells. Our results also revealed significant differences in species cross-reactivity of human IL-6, IL-7, and IL-1 alpha, underscoring the importance of species-specific investigations. Leveraging the similarities and differences between canine and human cytokines targeting the JAK-STAT pathway can enhance drug development efforts and contribute to the advancement of safer and more effective therapies for both humans and pet dogs with similar diseases. This study was funded by NCI Contract No. 75N91019D00024. Citation Format: King Leung Fung, Melissa L. Breiner, James B. Mitchell, Ralph E. Parchment. Conservation of JAK-STAT signaling in canine lymphocytes responding to human IL-6, IL-7, and IL-1 alpha [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2837.

Abstract 146: Development of a novel pediatric patient-derived xenograft model with THPO and NDUFB3 mutations

Abstract Familial myeloproliferative neoplasms (MPN) of childhood are extremely rare and have propensity towards malignant transformation such as leukemia and lymphoma. Due to the rarity of these cases, few cellular and mouse models are available for understanding the tumor biology. Therefore, the molecular mechanisms of malignant transformation remain poorly understood limiting the therapeutic progress to treat these conditions. Here, we report the development of a novel pediatric patient-derived xenograft (PDX) mouse model harboring mutations in the THPO and mitochondrial subunit NDUFB3 genes and characterization of their functions. THPO is a regulator of hematopoiesis and induces trilineage hematopoiesis through HSPC proliferation while NDUFB3 is a subunit of the mitochondrial complex 1. We isolated malignant cells from an enlarged spleen sample and blood sample from a pediatric patient with TPO mediated MPN and established a PDX model (PDX-2333) that recapitulates the patient’s disease. Short tandem repeat analyses confirmed an exact match between the PDX-2333 tumors and patient samples. Exome and Sanger sequencing analyses were performed to identify mutations. Immunohistochemistry staining was used for tumor characterization. Wildtype (WT) and mutant forms of NDUFB3 genes were cloned into expression plasmids with a puromycin selection marker and stably transfected in HEK-293 cells. Stable clones of HEK-293 overexpressing WT and NDUFB3 mutants were tested for growth and sensitivity to anti-cancer therapies. We established a novel PDX model of lymphomagenesis harboring unique mutations in THPO and NDUFB3 genes. The THPO (c.-52C>T) mutation in upstream open reading frame causes loss of inhibition of THPO mRNA expression. The NDUFB3 (c.23 A>G) mutation results in a change of amino acid from glutamine 8 (E8) to glycine 8 (G8) (Ndufb3_E8) and is highly conserved in many vertebrate species. HEK-293 cell lines stably overexpressing WT or NDUFB3 mutants were tested for growth and their sensitivity to ruxolitinib, a Jak2 inhibitor and doxorubicin, an FDA-approved treatment for leukemia and lymphoma. Our data showed that cells overexpressing Ndufb3_E8 have increased proliferation and are highly resistant to ruxolitinib and doxorubicin in comparison to the WT NDUFB3. Developing a novel pediatric PDX model and exome sequencing allow us to identify novel genes involved in malignant transformation leading to lymphoma development. Our data demonstrated that mutations in the THPO (c.-52C>T) and NDUFB3 (c.23 A>G) genes play a key role in the pathogenesis of a lymphoma and in regulating drug sensitivity. Citation Format: Jonathan Shilyansky, Casandro J. Chan, Kristen L. Coleman, Mariah Leidinger, Sharathkumar Bhagavathi, Anjali Sharathkumar, Po Hien Ear. Development of a novel pediatric patient-derived xenograft model with THPO and NDUFB3 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 146.

Abstract 5214: HYAL4 splice variant induces treatment-resistance in advanced bladder cancer

Abstract Introduction and Objective: Precision-based treatment approaches could improve the prognosis of patients with bladder cancer (BC). We recently discovered a first-in-class human Chondroitinase (Chase) that degrades chondroitin sulfate. This Chase is a splice variant of HYAL4 (V1) and promotes a malignant phenotype and chemoresistance in BC cells. We evaluated V1/Chase expression and functions in BC and inhibitors to overcome V1/Chase-mediated Gemcitabine (Gem) resistance. Methods: Cohort 1: 653 voided urine specimens (BC, 160; non-BC, 493); cohort 2: 40 cystectomy specimens from MIBC patients who received adjuvant Gemcitabine plus cisplatin (G+C) treatment. Gene expression was measured by q-PCR and urine was assayed by the Chase test. V1 was expressed in BC cell lines or silenced and the transfectants were analyzed for sensitivity to Gem and Cisplatin. The mechanism of Gem resistance was evaluated in preclinical in vitro and in vivo models. Results: In cohort 1, Chase levels were 7-10-fold elevated in patients with BC compared to patients with benign genitourinary conditions, history of BC, or other cancers. Chase test detected BC with 94.4% and 87.4% specificity. Chase test had 84% accuracy in correctly diagnosing the cases with atypical cytology inference. Stem cell marker CD44 was the major substrate of Chase in BC cells. V1’s Chase activity induced CD44 cleavage and shedding. Intracellularly, CD44 cleavage induced JAK2/Stat3 pathway and subsequently upregulation of cytidine deaminase. CDA induces Gem metabolism and efflux of dFdU, an inactive Gem metabolite. HPLC analysis showed, V1 transfectants have increased levels of dFdU and higher efflux. STAT3 and CDA inhibitors synergistically re-sensitized V1-expressing cells to Gem. In cohort 2, V1, p-JAK2 and CDA expression predicted failure to G+C treatment (P<0.0001). JAK2, STAT3 and CDA inhibitors synergistically re-sensitized V1-expressing cells to Gem. V1-induced muscle invasive tumors that were metastatic. While V1-expressing tumors were resistant, combination of Gem with a CDA or JAK-2 inhibitor abrogated V1 tumor growth with minimal toxicity. Conclusion: V1/Chase is a potential diagnostic and prognostic biomarker for bladder cancer and drives muscle-invasion, metastasis, and Gem resistance in BC. Inhibitors of the Chase signaling pathway overcome V1-induced Gem resistance, suggesting a precision-based treatment approach to improve treatment response. Support: 1R01CA227277-05A1; 1R01CA283699-01 Citation Format: Karina Aguilar, Sunita Panda, Joshua Van Der Eerden, Luis Lopez, Martha Terris, Pablo Santamaria, Bal Lokeshwar, Vinata B. Lokeshwar. HYAL4 splice variant induces treatment-resistance in advanced bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5214.

Abstract 585: Regorafenib antitumor immune response is enhanced by a novel drug combination in CRC syngeneic model

Abstract Purpose: In the United States, colorectal cancer (CRC) is the second leading cause of cancer mortality. Metastatic CRC (mCRC) refractory to traditional chemotherapy is managed with regorafenib, a multiple-kinase inhibitor. However, patients show only a modest improvement in overall survival but experience high drug toxicity, adverse side effects, and poor tolerability. Thus, to reduce regorafenib-induced toxicity and to enhance antitumor activity, we combined it with a hybrid/dual JAK/HDAC small-molecule inhibitor (JAK/HDACi) to leverage the advantages of both JAK and HDAC inhibition in a single agent. With syngeneic mice, the efficacy and impact on immunomodulation of this drug combination was assessed. Methods: To assess effects of the agents, C57BL/6 immunocompetent mice were injected with MC38 murine CRC cells and treated with regorafenib (6mg/kg body wt) or JAK/HDACi (30mg/kg body wt), and their combination every third day for 21 days. Upon completion of the experiment, the tumors were harvested and processed for RNA and protein expression profiles. The effect of drug treatment on immune response was analyzed by nCounter Gene Expression assays (NanoString Technologies). Cytokines were measured in serum using the MesoScale Discovery mouse V-Plex Proinflammatory Panel kit. For pharmacokinetic studies, plasma samples were assayed from C57BL/6 treated with drugs after 1, 7, 21, and 48 hrs of treatment. Results: The combination treatment significantly reduced tumor growth (volume and weight),relative to the vehicle control or single treatments. Gene expression showed higher CD45 abundance score in the combination treatment. This is an exciting observation, as CD45 has phosphatase activity and dephosphorylates key targets of the drugs used in the study. Additionally, after treatment with the combination, there was higher expression of Gzmb and Gzme and lower expression of Cx3cr1, indicating enhanced immuno modulation relative to regorafenib alone. We confirmed these findings by immunoprofiling of tumors. Higher CD45 staining, noted in tumors of mice treated with the combination, corroborated the gene expression results. Pronounced CD8 T lymphocytes infiltration was observed in combination, compared to regorafenib alone. Reduction of proinflammatory cytokine, TNF-α was noted in the combination group. This is an interesting observation as CD45 negatively regulates TNF, and combination treated mice had highest number of CD45 positive cells. Pharmacokinetic studies showed that the bioavailability of regorafenib was elevated after combination treatment relative to single-agent treatment. Conclusions: Relative to the single agents, the combination of regorafenib with JAK/HDACi was more effective, with an elevated antitumor immune response and with sustained inhibition of tumor growth. A clinical trial to evaluate this combination for the treatment of mCRCs is warranted. Citation Format: Prachi Bajpai, Farrukh Afaq, Sameer Al Diffalha, Sumit Agarwal, Hyung Gyoon Kim, Dennis Otali, Sooryanarayana Varambally, Ashish Manne, Ravi Paluri, Moh’d Khushman, Upender Manne. Regorafenib antitumor immune response is enhanced by a novel drug combination in CRC syngeneic model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 585.

Interleukin 3 Inhibits Glutamate-Cytotoxicity in Neuroblastoma Cell Line.

Interleukin 3 (IL-3) is a well-known pleiotropic cytokine that regulates the proliferation and differentiation of hematopoietic progenitor cells, triggering classical signaling pathways such as JAK/STAT, Ras/MAPK, and PI3K/Akt to carry out its functions. Interestingly, the IL-3 receptor is also expressed in non-hematopoietic cells, playing a crucial role in cell survival. Our previous research demonstrated the expression of the IL-3 receptor in neuron cells and its protective role in neurodegeneration. Glutamate, a principal neurotransmitter in the central nervous system, can induce cellular stress and lead to neurotoxicity when its extracellular concentrations surpass normal levels. This excessive glutamate presence is frequently observed in various neurological diseases. In this study, we uncover the protective role of IL-3 as an inhibitor of glutamate-induced cell death, analyzing the cytokine's signaling pathways during its protective effect. Specifically, we examined the relevance of JAK/STAT, Ras/MAPK, and PI3 K signaling pathways in the molecular mechanism triggered by IL-3. Our results show that the inhibition of JAK, ERK, and PI3 K signaling pathways, using pharmacological inhibitors, effectively blocked IL-3's protective role against glutamate-induced cell death. Additionally, our findings suggest that Bcl-2 and Bax proteins may be involved in the molecular mechanism triggered by IL-3. Our investigation into IL-3's ability to protect neuronal cells from glutamate-induced damage offers a promising therapeutic avenue with potential clinical implications for several neurological diseases characterized by glutamate neurotoxicity.

Management of Patients Affected by Moderate-to-Severe Atopic Dermatitis with JAK Inhibitors in Real-World Clinical Practice: An Italian Delphi Consensus.

Several systemic therapies have been approved for the treatment of severe AD. In particular, Janus kinase inhibitors (JAKi), including abrocitinib, baricitinib, and upadacitinib, recently received approval for the treatment of patients with severe AD after being evaluated in several clinical trials. However, a few concerns have been raised regarding their long-term safety and the management of these drugs in real-world clinical practice. In this article we described the results of a Delphi consensus aimed at describing the knowledge on JAKi and focusing, in particular, on providing clinical recommendations for dermatologists in daily practice regarding the use of these drugs. Twelve Italian dermatologists reviewed the most recent literature regarding the efficacy and safety profiles of JAKi and proposed 24 statements. Agreement was reached for statements focusing on three main topics: (1) place in therapy of JAKi in patients with moderate-to-severe AD; (2) effectiveness and safety of JAK inhibitors in different phenotypes; (3) different approaches to the management of patients treated with JAKi in clinical practice. The panel proposed several recommendations regarding all the statements. Given the wide use of JAKi in clinical practice, it is crucial to establish a specific follow-up for each patient's phenotype in order to achieve the best possible clinical outcome and minimize potential adverse events.

Therapeutic efficacy and safety of JAK inhibitors in treating polymyositis/dermatomyositis: a single-arm systemic meta-analysis.

We performed a single-arm meta-analysis to evaluate the efficacy and safety of JAK inhibitors in the treatment of dermatomyositis (DM)/ polymyositis (PM). Relevant studies from four databases were systematically searched until April 25, 2023. The primary endpoint was Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) and other outcomes were Manual Muscle Testing (MMT) and Creatine Kinase (CK). According to the type of JAK and medication regimen, we conducted subgroup analyses. The registration number in PROSPERO was CRD42023416493. According to the selection criteria, we identified 7 publications with a total of 91 patients. Regarding skin lesions, the CDASI decreased by 17.67 (95% CI: -20.94 ~ -14.41). The CK increased by 8.64 U (95% CI: -28.25 ~ 45.53). About muscle lesions, MMT increased by 10.31 (95% CI: -2.83 ~ 23.46). Subgroup analysis revealed that different types of JAK inhibitors had various degrees of reduction. CDASI in patients treated with RUX had the lowest one [-20.00 (95% CI: -34.9 ~ -5.1)], followed by TOF [-18.29 (95% CI: -21.8 ~ -14.78)] and BAR [-11.2 (95% CI: -21.51 ~ -0.89)]. Additionally, the mean reduction in CDASI in patients treated with TOF alone was 16.16 (95% CI: -21.21 ~ -11.11), in combination with other immunosuppressants was 18.59 (95% CI: -22.74 ~ -14.45). For safety evaluation, one patient developed Orolabial HSV, and two patients developed thromboembolism events. In summary, this meta-analysis demonstrated that JAK inhibitors can potentially treat DM/PM without severe adverse reactions. https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42023416493, identifier CRD42023416493.

Real-Life Comparison of Four JAK Inhibitors in Rheumatoid Arthritis (ELECTRA-i Study).

Background: Real-world evidence of the efficacy and adverse events of JAK inhibitor treatment (Tofacitinib, Baricitinib, Upadacitinib, and Filgotinib) in rheumatoid arthritis is still limited. Methods: We studied 115 patients from the Rheumatology Unit of S. Giovanni di Dio Hospital affected by D2T-RA, according to the 2010 EULAR criteria. Out of the 115 patients, 17 had been treated with Baricitinib 8 mg/daily, 32 with Filgotinib 200 mg/daily, 21 with Tofacitinib 10 mg/daily, and 45 with Upadacitinib 15 mg/daily. We evaluated the clinical response after 3, 6, and 12 months of treatment and the follow-up from September 2022 to September 2023. All patients were evaluated according to the number of tender joints (NTJs), number of swollen joints (NSJs), visual analog scale (VAS), global assessment (GA), health assessment questionnaire (HAQ), Disease Activity Score (DAS28), and CDAI. Furthermore, laboratory parameters of efficacy and tolerability were evaluated. Results: All treatments demonstrated a statistically significant decrease in the DAS28 and CDAI scores, tender and swollen joint counts, VAS, HAQ, and patient global assessment (PGA) after 3, 6, and 12 months of treatment. All treatments showed similar behavior, and statistically significant decreases in circulating calprotectin, TNFα, and IL-6 were observed for all drugs after 12 months of treatment. In addition, soluble urokinase plasminogen activator receptor (suPAR) values showed significant differences at baseline and after 12 months of treatment for Filgotinib: 4.87 ± 4.53 vs. 3.61 ± 0.9 (0.009) and Upadacitinib: 6.64 ± 7.12 vs. 4.06 ± 3.61 (0.0003), while no statistically significant differences were found for Baricitinib: 3.4 ± 0.1 vs. 3.78 ± 0.1 and Tofacitinib: 3.95 ± 1.77 vs. 2.58 ± 0.1. The TC/HDL-C ratio (atherogenic index) showed significant differences when comparing Baricitinib vs. Filgotinib (0.0012), Filgotinib vs. Tofacitinib (0.0095), and Filgotinib vs. Upadacitinib (0.0001); furthermore, the LDL-C/HDL-C ratio in the Filgotinib group did not change (2.37 ± 0.45 vs. 2.35 ± 2.13 (NS)) after 12 months of treatment. Venous Thrombotic Events (VTEs) and major adverse cardiovascular events (MACEs) accounted for 1% of adverse events after treatment with Baricitinib. Herpes zoster reactivation accounted for 1% of adverse events after treatment with Filgotinib and Tofacitinib, while non-melanoma skin cancer (NMSC) accounted for 1% of adverse events after Upadacitinib treatment. Conclusions: Our real-world data from patients with RA show differences in some laboratory parameters and in the impact of lipid metabolism in JAK inhibitor treatment.

Drug Repositioning via Graph Neural Networks: Identifying Novel JAK2 Inhibitors from FDA-Approved Drugs through Molecular Docking and Biological Validation.

The increasing utilization of artificial intelligence algorithms in drug development has proven to be highly efficient and effective. One area where deep learning-based approaches have made significant contributions is in drug repositioning, enabling the identification of new therapeutic applications for existing drugs. In the present study, a trained deep-learning model was employed to screen a library of FDA-approved drugs to discover novel inhibitors targeting JAK2. To accomplish this, reference datasets containing active and decoy compounds specific to JAK2 were obtained from the DUD-E database. RDKit, a cheminformatic toolkit, was utilized to extract molecular features from the compounds. The DeepChem framework's GraphConvMol, based on graph convolutional network models, was applied to build a predictive model using the DUD-E datasets. Subsequently, the trained deep-learning model was used to predict the JAK2 inhibitory potential of FDA-approved drugs. Based on these predictions, ribociclib, topiroxostat, amodiaquine, and gefitinib were identified as potential JAK2 inhibitors. Notably, several known JAK2 inhibitors demonstrated high potential according to the prediction results, validating the reliability of our prediction model. To further validate these findings and confirm their JAK2 inhibitory activity, molecular docking experiments were conducted using tofacitinib-an FDA-approved drug for JAK2 inhibition. Experimental validation successfully confirmed our computational analysis results by demonstrating that these novel drugs exhibited comparable inhibitory activity against JAK2 compared to tofacitinib. In conclusion, our study highlights how deep learning models can significantly enhance virtual screening efforts in drug discovery by efficiently identifying potential candidates for specific targets such as JAK2. These newly discovered drugs hold promises as novel JAK2 inhibitors deserving further exploration and investigation.

Safety and Effectiveness of Janus Kinase Inhibitors in the Management of Inflammatory Bowel Disease Following Liver Transplantation.

The management of inflammatory bowel disease [IBD] patients with concurrent liver transplantation is challenging, and data regarding the safety and efficacy of Janus kinase [JAK] inhibitors with anti-rejection medications are required. We report the experience of all liver transplant recipients receiving tofacitinib and/or upadacitinib for IBD across three states in Australia. All liver transplant recipients from the Australian states of Victoria, New South Wales, and Tasmania, who required tofacitinib or upadacitinib for the treatment of IBD, were identified using prospectively maintained liver transplant databases. Patients were followed up until medication cessation or last follow-up. Clinical safety and efficacy data were collected. Eight patients [median age 30 years] were included, seven of whom received first-line JAK inhibition with tofacitinib. All patients had failed one or more biologic therapies prior to commencing JAK inhibition, including six patients who had failed two or more agents. JAK inhibition was continued for a median of 17 months, with 143 patient-months of combined follow-up. The anti-rejection medication tacrolimus was prescribed in all patients. Overall, seven [88%] patients achieved clinical remission, including all three patients who were switched from tofacitinib to upadacitinib. One patient required colectomy after 1 month of treatment. There were no other cases of serious infection, venous thromboembolism, or major adverse cardiovascular events during follow-up. As the largest case series to date, these data indicate that combining JAK inhibition with transplant anti-rejection medication may be a safe and clinically effective method of treating IBD in patients with prior biologic failure.

Latent Tuberculosis Screening Among New Users of a Biologic or Targeted Synthetic Disease-Modifying Antirheumatic Drug: Gaps in Screening Overall and Among Janus Kinase Inhibitors.

We combined claims and electronic health record (EHR) data to provide contemporary and accurate estimates of latent tuberculosis (TB) screening among new users of a biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD) and assess potential gaps in testing by drug type, patient characteristics, and practice. Our denominator population was patients in the Rheumatology Informatics System for Effectiveness (RISE) registry and Medicare using a b/tsDMARD in 2018 without a claim or prescription in the year prior. TB screening was assessed in both Medicare and RISE 1 and 3 years before the medication start date. We calculated the proportion screened overall, by medication class, and by practice. We tested for demographic differences in screening using logistic regression. In the year before drug starts, 65.6% of patients had any TB screening; in a 3-year window, 72.9% had any TB screening. Rates of screening within 1 year by drug type were greater or equal to the overall screening rate for most drugs except for JAK inhibitors (JAKis) (46%) and interleukin-17 inhibitors (IL-17is) (11.5%). A lower proportion of Hispanic and Asian patients were screened compared with White patients. Practice screening rates ranged from 20.0% to 92.9% of patients within 1 year. We report higher screening rates than have previously been published because of combining claims and EHR data. However, important safety gaps remain, namely, reduced screening among new users of a JAKi or IL-17i and among Asian and Hispanic patients, as well as low-performing practices. Educational initiatives, team-based care delivery, task shifting, and technological interventions to address observed gaps in patient safety procedures are needed.

Treatment of Steroid-Resistant Beard-Restricted Alopecia Areata with Baricitinib

Alopecia areata is an autoimmune disorder causing localized hair loss due to T-cell attack on hair follicles. Beard involvement holds psychological and cultural significance, and treatment guidance for steroid-resistant cases is limited. We present a case of the successful treatment of steroid-resistant beard alopecia areata (BAA) with baricitinib, a JAK-1/2 inhibitor, in a 37-year-old male. Prior therapies, including topical ruxolitinib and intralesional steroids, had failed. Over 9 months, baricitinib (4 mg daily) and oral minoxidil led to reduced alopecic patches, increased hair density, and resolved inflammation. This case underscores the potential of JAK inhibitors for BAA, emphasizing the importance of establishing clear guidelines to direct treatment of in order to optimize patient outcomes.

Modulation of the expression of connexins 37, 40, and 43 in endothelial cells in a culture.

Connexin (Cx) 37, 40, and 43 are implicated in vascular function, specifically in the electrical coupling of endothelial cells and vascular smooth-muscle cells. In the present study, we investigated whether factors implicated in vascular dysfunction can modulate the gene expression of Cx37, Cx40, and Cx43 and whether this is associated with changes in endothelial layer barrier function in human microvascular endothelial cells (HMEC-1). First, HMEC-1 were subjected to stimuli for 4 and 8h. We tested their responses to DETA-NONOate, H2O2, high glucose, and angiotensin II, none of which relevantly affected the transcription of the connexin genes. Next, we tested inflammatory factors IL-6, interferon gamma (IFNγ), and TNFα. IFNγ (10ng/mL) consistently induced Cx40 expression at 4 and 8 h to 10-20-fold when corrected for the control. TNFα and IL-6 resulted in small but significant depressions of Cx37 expression at 4h. Two JAK inhibitors, epigallocatechin-3-gallate (EGCG) (100-250μM) and AG490 (100-250μM), dose-dependently inhibited the induction of Cx40 expression by IFNγ. Subsequently, HMEC-1 were subjected to 10ng/mL IFNγ for 60h, and intercellular and transcellular impedance was monitored by electric cell-substrate impedance sensing (ECIS). In response to IFNγ, junctional-barrier impedance increased more than cellular-barrier impedance; this was prevented by AG490 (5μM). In conclusion, IFNγ can strongly induce Cx40 expression and modify the barrier properties of the endothelial cell membrane through the JAK/STAT pathway. Moreover, the Cx37, Cx40, and Cx43 expression in endothelial cells is stable and, apart from IFNγ, not affected by a number of factors implicated in endothelial dysfunction and vascular diseases.

A panel of janus kinase inhibitors identified with anti-inflammatory effects protect mice from lethal influenza virus infection.

Influenza remains a significant threat to public health. In severe cases, excessive inflammation can lead to severe pneumonia or acute respiratory distress syndrome, contributing to patient morbidity and mortality. While antivirals can be effective if administered early, current anti-inflammatory drugs have limited success in treating severe cases. Therefore, discovering new anti-inflammatory agents to inhibit influenza-related inflammatory diseases is crucial. Herein, we screened a drug library with known targets using a human monocyte U937 infected with the influenza virus to identify novel anti-inflammatory agents. We also evaluated the anti-inflammatory effects of the hit compounds in an influenza mouse model. Our research revealed that JAK inhibitors exhibited a higher hit rate and more potent inhibition effect than inhibitors targeting other drug targets in vitro. Of the 22 JAK inhibitors tested, 15 exhibited robust anti-inflammatory activity against influenza virus infection in vitro. Subsequently, we evaluated the efficacy of 10 JAK inhibitors using an influenza mouse model and observed that seven provided protection ranging from 40% to 70% against lethal influenza virus infection. We selected oclacitinib as a representative compound for an extensive study to further investigate the in vivo therapeutic potential of JAK inhibitors for severe influenza-associated inflammation. Our results revealed that oclacitinib effectively suppressed neutrophil and macrophage infiltration, reduced pro-inflammatory cytokine production, and ultimately mitigated lung injury in mice infected with lethal influenza virus without impacting viral titer. These findings suggest that JAK inhibitors can modulate immune responses to influenza virus infection and may serve as potential treatments for influenza.IMPORTANCEAntivirals exhibit limited efficacy in treating severe influenza when not administered promptly during the infection. Current steroidal and nonsteroidal anti-inflammatory drugs demonstrate restricted effectiveness against severe influenza or are associated with significant side effects. Therefore, there is an urgent need for novel anti-inflammatory agents that possess high potency and minimal adverse reactions. In this study, 15 JAK inhibitors were identified through a screening process based on their anti-inflammatory activity against influenza virus infection in vitro. Remarkably, 7 of the 10 selected inhibitors exhibited protective effects against lethal influenza virus infection in mice, thereby highlighting the potential therapeutic value of JAK inhibitors for treating influenza.

TYK2: an emerging therapeutic target in rheumatic disease.

Tyrosine kinase 2 (TYK2) is a member of the JAK kinase family of intracellular signalling molecules. By participating in signalling pathways downstream of type I interferons, IL-12, IL-23 and IL-10, TYK2 elicits a distinct set of immune events to JAK1, JAK2 and JAK3. TYK2 polymorphisms have been associated with susceptibility to various rheumatic diseases including systemic lupus erythematosus and dermatomyositis. In vitro and animal studies substantiate these findings, highlighting a role for TYK2 in diseases currently managed by antagonists of cytokines that signal through TYK2. Various inhibitors of TYK2 have now been studied in human disease, and one of these inhibitors, deucravacitinib, has now been approved for the treatment of psoriasis. Phase II trials of deucravacitinib have also reported positive results in the treatment of psoriatic arthritis and systemic lupus erythematosus, with a preliminary safety profile that seems to differ from that of the JAK1, JAK2 and JAK3 inhibitors. Two other inhibitors of TYK2, brepocitinib and ropsacitinib, are also in earlier stages of clinical trials. Overall, TYK2 inhibitors hold promise for the treatment of a distinct spectrum of autoimmune diseases and could potentially have a safety profile that differs from other JAK inhibitors.

Triple-Negative Myelofibrosis: Disease Features, Response to Treatment and Outcomes

BackgroundMyelofibrosis is the most aggressive subtype among classical BCR::ABL1 negative myeloproliferative neoplasms. About 90% of cases are driven by constitutive activation of 1 of 3 genes impacting the JAK/STAT pathway: JAK2, CALR, and MPL. Triple-negative myelofibrosis (TN-MF) accounts for only 5%-10% of cases and carries the worst outcomes. Little has been described about this subset of disease. Given the marked heterogeneity surrounding disease biology, clonal architecture, clinical presentation, and poor outcomes in TN-MF, identification of features of interest and assessment of treatment response are areas in need of further investigation. Patients and methodsWe collected and evaluated baseline clinical and molecular parameters from 626 patients with a diagnosis of myelofibrosis who presented to the H. Lee Moffitt Cancer Center in Tampa (Florida, US) between 2003 and 2021 and compared them based on presence or absence of the three classical phenotypic driver mutations. ResultsA small proportion of patients (6%) harbored TN-MF which correlated with inferior outcomes, marked by a 4-year reduction in overall survival time compared to the non-TN cohort (mOS 37.4 months vs. 85.7 months; P = .009) and higher rates of leukemic transformation. More pronounced thrombocytopenia and anemia, lower LDH, EPO levels, as well as lower percentage of marrow blasts at baseline were more commonly seen in TN-MF (P < .05). Similarly, patients with TN-MF had higher risk disease per DIPSS+ and GIPSS. Mutations impacting RNA splicing, epigenetic modification and signaling, specifically SRSF2, SETBP1, IDH2, CBL, and GNAS, were more commonly seen among those lacking a classical phenotypic driver. The prevalence of co-mutant ASXL1/SRSF2 clones was significantly higher in TN-MF as was trisomy 8. TN patients had fewer responses (46.2% vs. 63.4%) and shorter duration of response to ruxolitinib. ConclusionTN-MF is invariably associated with significantly decreased survival and more aggressive clinical behavior with higher rates of leukemic transformation and shorter duration of response to ruxolitinib. Mutations impacting RNA splicing, epigenetic modification and signaling (SRSF2, SETBP1, IDH2, CBL, and GNAS) are more common in TN-MF, which likely drive its aggressive course and may account for suboptimal responses to JAK inhibition.

PIM Kinases as Potential Biomarkers and Therapeutic Targets in Inflammatory Arthritides.

The Proviral Integration site for the Moloney murine leukemia virus (PIM)-1 kinase and its family members (PIM-2 and PIM-3) regulate several cellular functions including survival, proliferation, and apoptosis. Recent studies showed their involvement in the pathogenesis of rheumatoid arthritis RA, while no studies are available on psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA). The main objective of this study is to assess the expression of PIM kinases in inflammatory arthritides, their correlation with proinflammatory cytokines, and their variation after treatment with biologic disease-modifying anti-rheumatic drugs or JAK inhibitors. We evaluated PIM-1, -2, and -3 expression at the gene and protein level, respectively, in the peripheral blood mononuclear cells and serum of patients with RA, PsA, axSpA, and healthy individuals (CTR). All the samples showed expression of PIM-1, -2, and -3 kinases both at the gene and protein level. PIM-1 was the most expressed protein, PIM-3 the least. PIM kinase levels differed between controls and disease groups, with reduced PIM-1 protein and increased PIM-3 protein in all disease samples compared to controls. No difference was found in the expression of these molecules between the three different pathologies. PIM levels were not modified after 6 months of therapy. In conclusion, our preliminary data suggest a deregulation of the PIM pathway in inflammatory arthritides. In-depth studies on the role of PIM kinases in this field are warranted.

Differential effects of itacitinib, fedratinib, and ruxolitinib in mouse models of hemophagocytic lymphohistiocytosis

AbstractHemophagocytic lymphohistiocytosis (HLH) comprises a severe hyperinflammatory phenotype driven by the overproduction of cytokines, many of which signal via the JAK/STAT pathway. Indeed, the JAK1/2 inhibitor ruxolitinib has demonstrated efficacy in preclinical studies and early-phase clinical trials in HLH. Nevertheless, concerns remain for ruxolitinib-induced cytopenias, which are postulated to result from the blockade of JAK2-dependent hematopoietic growth factors. To explore the therapeutic effects of selective JAK inhibition in mouse models of HLH, we carried out studies incorporating the JAK1 inhibitor itacitinib, JAK2 inhibitor fedratinib, and JAK1/2 inhibitor ruxolitinib. All 3 drugs were well-tolerated and at the doses tested, they suppressed interferon-gamma (IFN-γ)–induced STAT1 phosphorylation in vitro and in vivo. Itacitinib, but not fedratinib, significantly improved survival and clinical scores in CpG–induced secondary HLH. Conversely, in primary HLH, in which perforin-deficient (Prf1−/−) mice are infected with lymphocytic choriomeningitis virus (LCMV), itacitinib, and fedratinib performed suboptimally. Ruxolitinib demonstrated excellent clinical efficacy in both HLH models. RNA-sequencing of splenocytes from LCMV-infected Prf1−/− mice revealed that itacitinib targeted inflammatory and metabolic pathway genes in CD8 T cells, whereas fedratinib targeted genes regulating cell proliferation and metabolism. In monocytes, neither drug conferred major transcriptional impacts. Consistent with its superior clinical effects, ruxolitinib exerted the greatest transcriptional changes in CD8 T cells and monocytes, targeting more genes across several biologic pathways, most notably JAK-dependent proinflammatory signaling. We conclude that JAK1 inhibition is sufficient to curtail CpG-induced disease, but combined inhibition of JAK1 and JAK2 is needed to best control LCMV-induced immunopathology.

Disease-modifying antirheumatic drug selection in Japanese patients with rheumatoid arthritis treated with biologics or JAK inhibitors without methotrexate: A retrospective hospital-based administrative claims database study.

We evaluated the medication selection and clinical characteristics of rheumatoid arthritis patients who started treatment with/without methotrexate (MTX) (using biologic disease-modifying antirheumatic drugs or Janus kinase inhibitors instead) in Japan. Using a Japanese hospital-based administrative claims database, rheumatoid arthritis patients who received treatment [abatacept (ABA), interleukin-6 receptor inhibitor, tumor necrosis factor inhibitor, or Janus kinase inhibitor] between 1 January 2015 and 31 December 2019 were enrolled. Overall, 19,301 patients were included (10,530 receiving MTX; 8771 not receiving MTX within 60 days of the first treatment). Mean ages at diagnosis were 60.7 and 65.9 years in the MTX and non-MTX groups, respectively (P < .0001). The non-MTX group had higher proportions of patients with Charlson Comorbidity Index ≥1 (P < .0001) and higher comorbidity rates. ABA was the most frequently used drug among patients with infectious/parasitic, circulatory, and respiratory diseases at baseline. Interleukin-6 receptor inhibitor had the highest use rate among patients with neoplasms; blood, gastrointestinal, and genitourinary diseases; and abnormal clinical/laboratory findings. ABA had the highest persistence probability from 6 months onward. MTX is used less frequently among older Japanese rheumatoid arthritis patients or those with comorbidities. In such patients, ABA is the most frequently used drug, followed by interleukin-6 receptor inhibitor, when MTX is not used at treatment start.