Effects Of Ruxolitinib Research Articles

Effect of ruxolitinib and magrolimab on calreticulin in myelofibrosis CD34+ cells in vitro: Proof of concept for combination therapy.

118 Background: In solid tumours, calreticulin (CALR) overexpression produces a pro-phagocytic signal and is counteracted by concomitant expression of anti- phagocytic CD47, reflecting an apoptosis vs survival mechanism. We have previously found that CD47, not CALR, is overexpressed on the membrane of patients with MPN. Anti-CD47 Magrolimab, is currently being evaluated in clinical trials in AML, MDS but have yet to be tested, either in monotherapy or in combination in MF. Methods: Mononuclear cells were collected by Ficoll separation from bone marrow of 6 MF patients and from 2 controls. CD34+ cells and monocytes were purified using Dynabeads kits from Thermofisher. Cells expression of CALR and CD47 was measured by flow cytometry, before and after incubation with ruxolitinib (Jak inhibitor) alone and in combination with magrolimab. Cells survival was calculated after combining CD34 with monocytes. Informed Consent was obtained for all samples collected. Results: CD47 membrane expression was 57% in untreated MF cells compared to 12% in the control samples and CALR membrane expression was 51.8% in untreated MF cell compared to 12.5% in the control samples. After incubation with ruxolitinib, MF CD34+ cell survival decreased to 98.2%. Following Incubation with magrolimab alone, MF CD34+ cells show no changes in survival (100% alive). The combination of ruxolitinib and magrolimab reduced slightly the MF CD34+ cell survival to 92%. A substantial membrane overexpression of CALR was observed in MF CD34+ cells when incubated with Ruxo and Magrolimab, 74.1%, vs Ruxo alone 52.6%, Magrolimab alone 53.4% and in untreated (51.8%). Interestingly, in the healthy controls, the exposure to combination therapy did not cause the same degree of CALR overexpression (20.7% vs 12.5%), indicating a much stronger pro-phagocytic effect following magrolimab/ruxolitinib combo in MF cancer cells. Conclusions: In vitro, treatment with ruxolitinib or ruxolitinib plus magrolimab, slightly reduce the overall cell survival rate in CD34+ MF samples, comparing with no significant changes in single agent magrolimab. However, the combination of Ruxolitinib and Magrolimab significantly increases CALR membrane expression comparing with Ruxo or Magrolimab alone, signalling a much stronger pro-phagocytic message in MF cells comparing with controls. The induced CALR over-expression, could stimulate a stronger immune response in vivo, where the presence of macrophages would allow removal of CALR rich cells and potentiate the cytoreductive activity towards MF clone. These data support the rational of combining Ruxolitinib with Magrolimab in the next clinical trial stage in myelofibrosis.

Еarly splenic response to ruxolitinib correlates with survival: a russian retrospective multicenter study in patients with myelofibrosis

We retrospectively analyzed the effectiveness of ruxolitinib in patients with myelofibrosis (MF) in real clinical practice in Russia. The study included 42 patients with MF with an average age of 56 years from 10 inpatient and outpatient clinics. The majority of patients (55 %) belonged to the intermediate risk group 1 on the DIPSS scale, 86 % had massive splenomegaly and 88 % had constitutional symptoms. The average initial dose of ruxolitinib was 15 mg twice a day. At the time of analysis, 74 % of patients continued taking ruxolitinib with an average duration of therapy of 20 months. A decrease in the palpable size of the spleen by at least 50 % was recorded in 36 % and 46 % of patients assessed after 3 and 6 months of treatment, respectively. A correlation was found between OV, initial splenomegaly and splenic response after 3 months of therapy. It should be noted that no deaths were recorded in patients with a decrease in the size of the spleen by ≥ 50 %. There were no cases of discontinuation of treatment due to side effects. In general, in our retrospective study, ruxolitinib effectively controlled constitutional symptoms and reduced the size of the spleen in patients with MF. An early splenic response after 3 months of therapy is apparently a prognostic factor for OS, and a decrease in the size of the spleen by less than 25 % should be considered as treatment ineffectiveness in patients with MF taking ruxolitinib.

Sex-Specific Protection of Endothelial Function after Vascular Ischemia/Reperfusion Injury by the Senomorphic Agent Ruxolitinib.

Ischemia/reperfusion (I/R)-induced endothelial dysfunction occurs in various cardiovascular disorders. I/R injury is partially driven by the release of cytokines. Known for its use in senotherapy, the JAK inhibitor ruxolitinib is able to block the release of cytokines. We investigated the effect of ruxolitinib on the cytokine release and endothelial-dependent vasorelaxation in an in vitro model of I/R. Aortic segments of C57BL/6J mice (N = 12/group) were divided into three groups: control, in vitro I/R (I/R group), and in vitro I/R with ruxolitinib during ischemic incubation (I/R+Ruxo group). We determined cytokine expression. In organ bath chambers, we investigated the maximal endothelial-dependent relaxation to acetylcholine (RmaxACh) and maximal endothelial-independent relaxation to sodium-nitroprusside (RmaxSNP). RmaxACh was decreased in I/R compared to the control (83.6 ± 2.4 vs. 48.6 ± 3.4%; p < 0.05) and I/R+Ruxo (74.4 ± 2.6 vs. 48.6 ± 3.4%; p < 0.05). RmaxSNP was comparable between all groups. IL-10 was detectable only in I/R+Ruxo. CXCL5, CCL2, CCL3, CCL8, CCL11, ICAM-1, IL-1α, IL-7, TNF-α, and G-CSF were decreased or not detectable in I/R+Ruxo. In I/R+Ruxo, ICAM-1 was reduced in rings only from male mice. Treatment of the aorta from mice during in vitro ischemia with the senomorphic agent ruxolitinib reduces cytokine release and protects the endothelium from I/R-mediated dysfunction.

Ruxolitinib versus basiliximab for steroid-refractory acute graft-versus-host disease: a retrospective study.

Acute graft-versus-host disease (aGVHD) remains a major limitation of allogeneic hematopoietic stem cell transplantation; not all patients respond to standard glucocorticoids treatment. This study retrospectively evaluated the effects of ruxolitinib compared with basiliximab for steroid-refractory aGVHD (SR-aGVHD). One hundred and twenty-nine patients were enrolled, 81 in ruxolitinib and 48 in basiliximab group. The overall response (OR) at day 28 was higher in ruxolitinib group (72.8% vs. 54.2%, P = 0.031), as with complete response (CR) (58.0% vs. 35.4%, P = 0.013). Ruxolitinib led to significantly lower 1-year cumulative incidence of chronic GVHD (cGVHD) (29.6% vs. 43.8%, P = 0.021). Besides, ruxolitinib showed higher 1-year overall survival (OS) and 1-year cumulative incidence of failure-free survival (FFS) (OS: 72.8% vs. 50.0%, P = 0.008; FFS: 58.9% vs. 39.6%, P = 0.014). The 1-year cumulative incidence of non-relapse mortality (NRM) was lower in ruxolitinib group (16.1% vs. 37.5%, P = 0.005), and the 1-year relapse was not different. The 1-year cumulative incidence of cytomegalovirus (CMV) viremia, CMV-associated diseases and Epstein-Barr virus (EBV)-associated diseases was similar between the two groups, but EBV viremia was significantly lower in ruxolitinib group (6.2% vs. 29.2%, P < 0.001). Subgroup analyses revealed that OR and survival were similar in ruxolitinib 5mg twice daily (bid) and 10mg bid groups. However, ruxolitinib 10mg bid treatment markedly reduced 1-year cumulative incidence of cGVHD compared with 5mg bid (21.1% vs. 50.0%, P = 0.016). Our study demonstrated that ruxolitinib was superior to basiliximab in SR-aGVHD treatment and cGVHD prophylaxis, therefore should be recommended.

Effects of ruxolitinib on murine regulatory T cells are immune-context dependent

Aplastic anemia is a bone marrow failure (BMF) disorder characterized by pancytopenia and hypocellular marrow from an immune-mediated etiology. Regulatory T cells (Tregs) prevent autoimmunity by suppressing autoreactive T cells. We recently demonstrated the efficacy of ruxolitinib (RUX), a JAK 1/2 inhibitor, in attenuating murine BMF. Herein, we investigated the changes of Tregs in the context of RUX treatment for murine BMF. Tregs are conventionally identified by surface expression of CD4 and CD25, in addition to intracellular transcription factor FoxP3. RUX promoted the expansion of Tregs in BMF mice defined by increased expression of FoxP3 in CD4 T cells but suppressed expression of activation marker CD25 in CD4 and CD8 T cells. In this context, CD25 is no longer a reliable surface marker for Tregs. We observed strong co-expression of FoxP3 with surface marker GITR instead of CD25 in RUX-treated BMF mice. Fluorescence-activated cell sorting (FACS)-sorted CD4+GITRhi cells showed high FoxP3 expression and intact suppressive function in vitro, suggesting GITR to be a surrogate marker for Tregs. In contrast to its expansive effect on Tregs in BMF, RUX suppressed Tregs in normal and sublethal irradiation conditions, indicating that the effects of RUX on Tregs are immune-context dependent.

Energy expenditure in myelofibrosis patients treated with a JAK1/2 inhibitor.

Weight gain is a known adverse effect of ruxolitinib, a JAK1/2 inhibitor that is the mainstay of treatment for many patients with myelofibrosis. The mechanisms behind weight increase with ruxolitinib is incompletely understood, although decreased adipose tissue lipolysis and increased appetite due to blocking the effects of leptin in the hypothalamus have been proposed. In order to explore the metabolic changes in ruxolitinib-treated patients with myelofibrosis, we performed a pilot study to assess the feasibility of using a portable indirect calorimeter to quantify energy expenditure before and during ruxolitinib treatment and report the results of two patients. Waist circumference increased during ruxolitinib treatment in both patients. Energy expenditure initially increased followed by a decrease and then increase again, but to levels below baseline. These results suggest that weight gain secondary to ruxolitinib may be related to changes in whole body energy expenditure.

Effects of ruxolitinib and magrolimab on calreticulin in myelofibrosis CD34+ cells in vitro: Proof of concept for combination therapy.

7064 Background: In solid tumours, calreticulin (CALR) overexpression produces a pro-phagocytic signal and is counteracted by concomitant expression of anti- phagocytic CD47, reflecting an apoptosis vs survival mechanism. We have previously found that CD47, not CALR, is overexpressed on the membrane of patients with MPN. Anti-CD47 Magrolimab, is currently being evaluated in clinical trials in AML, MDS but have yet to be tested, either in monotherapy or in combination in MF. Methods: Mononuclear cells were collected by Ficoll separation from bone marrow of 6 MF patients and from 2 controls. CD34+ cells and monocytes were purified using Dynabeads kits from Thermofisher. Cells expression of CALR and CD47 was measured by flow cytometry, before and after incubation with ruxolitinib (Jak inhibitor) alone and in combination with magrolimab. Cells survival was calculated after combining CD34 with monocytes. Informed Consent was obtained for all samples collected. Results: CD47 membrane expression was 57% in untreated MF cells compared to 12% in the control samples and CALR membrane expression was 51.8% in untreated MF cell compared to 12.5% in the control samples. After incubation with ruxolitinib, MF CD34+ cell survival decreased to 98.2%. Following Incubation with magrolimab alone, MF CD34+ cells show no changes in survival (100% alive). The combination of ruxolitinib and magrolimab reduced slightly the MF CD34+ cell survival to 92%. A substantial membrane overexpression of CALR was observed in MF CD34+ cells when incubated with Ruxo and Magrolimab, 74.1%, vs Ruxo alone 52.6%, Magrolimab alone 53.4% and in untreated (51.8%). Interestingly, in the healthy controls, the exposure to combination therapy did not cause the same degree of CALR overexpression (20.7% vs 12.5%), indicating a much stronger pro-phagocytic effect following magrolimab/ruxolitinib combo in MF cancer cells. Conclusions: In vitro, treatment with ruxolitinib or ruxolitinib plus magrolimab, slightly reduce the overall cell survival rate in CD34+ MF samples, comparing with no significant changes in single agent magrolimab. However, the combination of Ruxolitinib and Magrolimab significantly increases CALR membrane expression comparing with Ruxo or Magrolimab alone, signalling a much stronger pro-phagocytic message in MF cells comparing with controls. The induced CALR over-expression, could stimulate a stronger immune response in vivo, where the presence of macrophages would allow removal of CALR rich cells and potentiate the cytoreductive activity towards MF clone. These data support the rational of combining Ruxolitinib with Magrolimab in the next clinical trial stage in myelofibrosis.

Ruxolitinib inhibits the proliferation and induces the apoptosis of MLL-r ALL cells through inactivating JAK/STAT signaling pathway.

The childhood patients with mixed-lineage leukemia rearrangement (MLL-r) gene have worse outcome than non-MLL, and thus often treated with high-risk chemotherapy regimens, so targeted therapy is important for this type of leukemia. This purpose of study was to explore the effects of ruxolitinib on the proliferation, apoptosis, and cell cycle of Nalm-6 cells. In this study, human acute lymphoblastic leukemia (ALL) cell line Nalm-6 was used as the research object. By constructing an MLL overexpression vector to transfect Nalm-6 cells, exogenous JAK2/STAT3 signal pathway inhibitor ruxolitinib was applied to observe the proliferation, apoptosis, and cell cycle changes of the transfected Nalm-6 cells. Western blot was performed to determine the proteins (MLL-BP, JAK, STAT) involved in the mechanism of action of MLL-r leukemia. CCK8 assay and flow cytometry (FCM) were used for testing the proliferation and apoptosis among MLL-BP transfected Nalm-6 cells. Firstly, we determine the IC50 of ruxolitinib on Nalm-6 cells. Secondly, FCM and CCK8 showed that ruxolitinib dosedependentlyinhibits proliferation of Nalm-6 cells by blocking the cell cycle at G0/G1 phase. In addition, FCM showed that ruxolitinib promoted the apoptosis of MLL-BP transfected Nalm-6 cells. Mechanistically, ruxolitinib inactivated JAK/STAT signaling pathway in MLL-BP transfected Nalm-6 cells, mediating ruxolitinib's inhibition of cell proliferation, and inducing apoptosis. Finally, ruxolitinib significantly inhibited the proliferation of MLL-r ALL cells and promoted their apoptosis. These data provide compelling evidence that ruxolitinib is a promising agent against MLL-r leukemia cell line. However, it needs going through multiple more steps to confirm before it can be an option in clinical practice.

A cost-effectiveness analysis of ruxolitinib versus best alternative therapy for patients with steroid-refractory chronic graft-versus-host disease aged > 12 years in Singapore

BackgroundApproximately 30–70% of patients who have undergone allogeneic (allo) hematopoietic stem cell transplantation (HSCT) eventually experience chronic graft-versus-host disease (cGVHD). Patients who develop steroid-refractory (SR)-cGVHD are the most severely impacted due to significant disease and financial burden. There remains an unmet need for safe, efficacious, and accessible treatments for these patients. The objective of this study was to determine the cost effectiveness of ruxolitinib for treatment of SR-cGvHD from the Singapore healthcare system perspective.MethodsBased on data from the REACH3 randomized open-label trial, a semi-Markov model was developed to evaluate cost-effectiveness of ruxolitinib compared with investigators' choice of best alternative therapy (BAT) for treatment of patients > 12 years of age with SR-cGVHD in Singapore over a 40-year time horizon. The model only considered direct medical-care costs related to the treatment of SR-cGVHD and reported them in Singapore Dollars (SGD). Half-cycle correction was applied to all costs and outcomes, which were discounted at 3%. Probabilistic sensitivity analysis (PSA), one-way sensitivity analysis (OWSA), and scenario analysis were conducted to explore the drivers of uncertainty in the model.ResultsIn the deterministic base case, more life years (LY; 10.28 vs. 9.42) and quality-adjusted life years (QALYs; 7.31 vs. 6.51) were gained with ruxolitinib than BAT at higher costs (SGD 303,214 vs. SGD 302,673) leading to an incremental cost-effectiveness ratio (ICER) of SGD 677/QALY. At a willingness-to-pay threshold of SGD 75,000/QALY gained, PSA found that ruxolitinib had a 78.52% probability of being cost-effective. Findings were sensitive to variations in non-responder utilities in the BAT arm and duration of BAT treatment in the OWSA, or comparison to either methotrexate (MTX) or mycophenolic acid as a single comparator in the scenario analysis. ICERs remained lower than SGD 75,000/QALY in all other tested variations and scenarios.ConclusionRuxolitinib is likely to be cost-effective from Singapore healthcare system’s perspective for patients with SR-cGVHD, which is promising in the management of patients with unmet clinical needs.

Paradoxical activation of chronic lymphocytic leukemia cells by ruxolitinib in vitro and in vivo.

Chronic lymphocytic leukemia (CLL) is characterized by an aberrant cytokine network that can support tumor growth by triggering janus kinase (JAK)/STAT pathways. Targeting cytokine-signaling should then be a rational therapeutic strategy but the JAK inhibitor ruxolitinib failed to control and seemingly accelerated the disease in clinical trials. The effect of ruxolitinib on primary human CLL cells was studied in vitro and in vivo. Ruxolitinib increased phosphorylation of IRAK4, an important toll-like receptor (TLR)- signaling intermediate, in circulating CLL cells in vitro. It also enhanced p38 and NFKB1 phosphorylation while lowering STAT3 phosphorylation in CLL cells activated with TLR-7/8 agonists and IL-2. Among the cytokines made by activated CLL cells, high levels of IL-10 contributed strongly to STAT3 phosphorylation and inhibited TLR7 activity. Ruxolitinib limited TLR-mediated IL10 transcription and markedly reduced IL-10 production in vitro. It also decreased blood levels of IL-10 while increasing TNFα along with phospho-p38 expression and gene sets associated with TLR-activation in CLL cells in vivo. The bruton's tyrosine kinase inhibitor ibrutinib decreased IL-10 production in vitro but, in contrast to ruxolitinib, blocked initial IL10 transcription induced by TLR-signaling in vitro, decreased TNFα production, and deactivates CLL cells in vivo. These findings suggest the possible benefits of inhibiting growth factors with JAK inhibitors in CLL are outweighed by negative effects on potential tumor suppressors such as IL-10 that allow unrestrained activation of NFκB by drivers such as TLRs. Specific inhibition of growth-promoting cytokines with blocking antibodies or infusing suppressive cytokines like IL-10 might be better strategies to manipulate cytokines in CLL.

The Inhibition of Glycolysis in T Cells by a Jak Inhibitor Ameliorates the Pathogenesis of Allergic Contact Dermatitis in Mice

Allergic contact dermatitis (ACD) and atopic dermatitis (AD) develop through delayed-type hypersensitivity reactions mediated by T cells. The development of immunomodulatory drugs, such as Jak inhibitors (jakinibs), would be useful for the long-term management of these diseases due to their profile of favorable adverse effects. However, the efficacy of jakinibs for ACD treatment has not been fully determined under a variety of settings. Therefore, we evaluated the effects of ruxolitinib (Rux), a jakinib for Jak1 and Jak2, using a mouse ACD model. As a result, the lower numbers of immune cells including CD4+ T cells, CD8+ T cells, neutrophils and possibly macrophages as well as milder pathophysiological aspects have been observed in the inflamed skin of ACD with the administration of Rux. In addition, the treatment of differentiating T cells with Rux downregulated the level of IL-2-mediated glycolysis in vitro. Furthermore, symptoms of ACD did not develop in T cell-specific Pgam1-deficient mice whose T cells had no glycolytic capacity. Taken together, our data suggest that the downregulation of glycolysis in T cells by Rux could be an important factor for the suppression of ACD development in mice.

Abstract 4497: Efficacy of Jak1/2 inhibition in murine myeloproliferative neoplasms is mediated by targeting nonmalignant cells

Abstract Ruxolitinib (Jakavi) is a potent JAK1/JAK2 specific inhibitor, approved for the treatment of myeloproliferative neoplasia (MPN) such as primary myelofibrosis (PMF) and polycythemia Vera (PV). The primary clinical benefit of ruxolitinib in MPN patients is reduction in spleen size and alleviation of constitutional symptoms and significant improvement in the quality of life. However, the effect of ruxolitinib on bone marrow fibrosis and JAK2V617F allelic burden is modest. In addition, JAK2V617F negative MPNs also demonstrated clinical benefits, thus, is not clear whether the ruxolitinib primarily blocks the proliferation of the malignant clone or exerts its effects by targeting non-malignant cells. To gain the mechanism of ruxolitinib action in MPNs, we developed two JAK2V617F-driven MPN mouse models harboring ruxolitinib resistant mutations JAK2V617F+L902Q and JAK2V617F+L983F in the malignant clone. Similar to JAK2V617F recipients, JAK2V617F+L902Q and JAK2V617F+L983F transplanted mice showed an increase in WBC, HCT, RBC, HB and reticulocyte values. Histopathological analysis revealed that the myeloproliferative phenotype resembles PV with a proliferation of all three lineages albeit with only a moderate increase in megakaryopoeisis. Grade II bone marrow fibrosis was observed in JAK2V617F+L902Q and JAK2V617F+L983F after 2-3 months similar to JAK2V617F mice. Surprisingly, these mice respond to ruxolitinib treatment similar to ruxolitinib sensitive JAK2V617F mice, indicated by reduction of spleen size, leukocyte count and proinflammatory cytokines in the serum. Mechanistically, we could identify a direct role of ruxolitinib in the impairment of inflammatory processes in the bone marrow microenvironment, particularly on the cytokine production of mesenchymal stem cells and endothelial cells. These results suggest that the ruxolitinib mediated effects in MPN patients are mainly due to abrogation of inflammatory signaling processes in non-malignant cells. Therefore, combination treatment of JAK1/2 inhibitors with novel inhibitors, which specifically act on malignant cells might improve the clinical benefit for MPN patients to JAK family inhibitors. Citation Format: Sivahari Prasad Gorantla, Michael Rassner Rassner, Tony Andreas Müller, Teresa Poggio, Kirstyn Anne Crossley, Anna-Lena Denecke, Kornelia R Fritsch, Geoffroy Andrieux, Helen Kleinfelder, Shifa Khaja Saleem, Sudheer Madan Mohan Gambheer, Irene Gonzalez Menendez, Detlef Bentrop, Rainer Trittler, Svetlana Rylova, Dietmar Pfeifer, Leticia Quintanilla Martinez, Christine Dierks, Robert Zeiser, Anna Lena Illert, Nikolas von Bubnoff, Justus Duyster. Efficacy of Jak1/2 inhibition in murine myeloproliferative neoplasms is mediated by targeting nonmalignant cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4497.

Ruxolitinib, a promising therapeutic candidate for traumatic brain injury through maintaining the homeostasis of cathepsin B

Traumatic brain injury (TBI) is one of the main causes of death and disability in the world. Owing to the heterogeneity and complexity of TBI pathogenesis, there is still no specific drug. Our previous studies have proved the neuroprotective effect of Ruxolitinib (Ruxo) on TBI, but further are needed to explore the potent mechanisms and potential translational application. Compelling evidence indicates that Cathepsin B (CTSB) plays an important role in TBI. However, the relationships between Ruxo and CTSB upon TBI remain non-elucidated. In this study, we established a mouse model of moderate TBI to clarify it. The neurological deficit in the behavioral test was alleviated when Ruxo administrated at 6 h post-TBI. Additionally, Ruxo significantly reduced the lesion volume. As for the pathological process of acute phase, Ruxo remarkably reduced the expression of proteins associated with cell demise, neuroinflammation, and neurodegeneration. Then the expression and location of CTSB were detected respectively. We found that the expression of CTSB exhibits a transient decrease and then persistent increase following TBI. The distribution of CTSB, mainly located at NeuN-positive neurons was unchanged. Importantly, the dysregulation of CTSB expression was reversed with the treatment of Ruxo. The timepoint was chosen when CTSB decreased, to further analyze its change in the extracted organelles; and Ruxo maintained the homeostasis of it in sub-cellular. In summary, our results demonstrate that Ruxo plays neuroprotection through maintaining the homeostasis of CTSB, and will be a promising therapeutic candidate for TBI in clinic.

Ruxolitinib Alleviates Inflammation, Apoptosis, and Intestinal Barrier Leakage in Ulcerative Colitis via STAT3.

Ulcerative colitis (UC) is an idiopathic, chronic inflammatory disorder of the colonic mucosa with increasing prevalence and limited management. Ruxolitinib is a new anti- JAK/STAT3 biologic agent that has shown potential in protecting against colitis. We first constructed an in vivo UC model and an in vitro colonic epithelial cell inflammation model. Ruxolitinib was administered via gavage in mice. After treatment, colon tissues, cells, and cell lysates were collected and prepared for histological evaluation, immunohistochemistry, immunofluorescence staining, quantitative reverse-transcriptase polymerase chain reaction, Western blotting, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling staining, and cytokine analysis. STAT3 expression was silenced and overexpressed via small interfering RNA and overexpression plasmid transfection, respectively, and quantitative reverse-transcriptase polymerase chain reaction was used to examine the downstream effects. Ruxolitinib administration significantly alleviated colitis both in vivo and in vitro, as manifested by reduced body weight loss, shortened colon lengths, relieved disease activity (measured by the disease activity index), and prolonged survival. A mechanistic study showed that ruxolitinib attenuated nuclear factor kappa B-induced inflammation, reduced apoptosis, and ameliorated epithelial barrier leakage, and thereby reduced colitis activity in vivo. STAT3 knockdown partially reversed the protective effect of ruxolitinib against colitis, while STAT3 overexpression exaggerated the reductions in proinflammatory cytokine levels upon ruxolitinib treatment. We demonstrate that ruxolitinib alleviates colitis by inhibiting nuclear factor kappa B-related inflammation and apoptosis in addition to restoring epithelial barrier function via STAT3, providing a new strategy for UC treatment.

Effects of Ruxolitinib on fibrosis in preclinical models of systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune fibrotic disorder notably characterized by the production of antinuclear autoantibodies, which have been linked to an excess of apoptotic cells, normally eliminated by a macrophagic efferocytosis. As interferon (IFN) signature and phosphorylation of JAK-STAT proteins are hallmarks of SSc tissues, we tested the hypothesis that a JAK inhibitor, ruxolitinib, targeting the IFN signaling, could improve efferocytosis of IFN-exposed human macrophages in vitro as well as skin and lung fibrosis.In vivo, BLM- and HOCl-induced skin thickness and fibrosis is associated with an increase of caspase-3 positive dermal cells and a significant increase of IFN-stimulated genes expression. In BLM-SSc model, ruxolitinib prevented dermal thickness, fibrosis and significantly decreased the number of cleaved caspase-3 cells in the dermis. Ruxolitinib also improved lung architecture and fibrosis although IFN signature was not entirely decreased by ruxolitinib. In vitro, ruxolitinib improves efferocytosis capacity of human monocyte-differentiated macrophages exposed to IFN-γ or IFN-β. In human fibroblasts derived from lung (HLF) biopsies isolated from patients with idiopathic pulmonary fibrosis, the reduced mRNA expression of typical TGF-β-activated markers by ruxolitinib was associated with a decrease of the phosphorylation of SMAD2 /3 and STAT3.Our finding supports the anti-fibrotic properties of ruxolitinib in a systemic SSc mouse model and in vitro in human lung fibroblasts.

Ruxolitinib does not completely abrogate the functional capabilities of TLR4/9 ligand-activated NK cells.

Natural killer (NK) cells are lymphocytes from the innate immune system part of the first defense barrier against infected and transformed cells, representing 5%-15% of peripheral blood lymphocytes. The cytotoxic capacity of NK cells is controlled by a balance between inhibitory and activating NK receptors expressed on their surface, which recognize and interact with the ligands on stressed cells. The cytokines involved in NK cell activation, proliferation, survival, and cytotoxicity are signaled mainly through the Janus kinase and signal transducer and activator of transcription proteins (JAK/STAT) pathway. NK cells are also activated in response to pathogens through Toll-like receptors (TLRs) expressed on their surface. Ruxolitinib is a specific JAK1/2 inhibitor approved for treating myelofibrosis and for steroid-refractory acute and chronic graft-versus-host disease (SR-GvHD). Purified NK cells from healthy donors were stimulated with two TOLL-like receptor ligands, LPS and CpG, in the presence of different concentrations of Ruxolitinib. This study showed the effects of ruxolitinib on TLR4 and TLR9 ligand-activated NK cells from healthy donors. Ruxolitinib did not completely inhibit STAT3 phosphorylation and had a moderate effect on NK cell cytokine activation via the TLR pathway. Only the highest doses of ruxolitinib led to a decrease in the pro-inflammatory cytokines tumor necrosis factor α, interferon-γ, interleukin-6, and interleukin-1β. The cytotoxic capacity of stimulated NK cells versus K562, SEM, and MV-4-11 cell lines was reduced by increasing doses of ruxolitinib, but it was not completely abolished and we observed no major changes in degranulation capacity. Phenotypic changes were observed in activated NK cells in the presence of ruxolitinib. In a small cohort of pediatric patients treated with ruxolitinib for SR-GvHD, we observed no decrease in NK cell counts; however, further prospective studies with larger cohorts are necessary to confirm this finding. In summary, our results showed that the functional capabilities and phenotype of NK cells activated through TLR4/9 agonists were not completely abolished by the inhibition of the JAK-STAT pathway by ruxolitinib.

Effects of Ruxolitinib on Myeloproliferative Neoplasms via the Negative Regulators.

We evaluated the JAK2V617F mutation and p-JAK2, SOCS-1, SHP-1 expression in JAK2V617F positive myeloproliferative neoplasms (MPNs) patients and the role of JAK/STAT pathway in human erythroleukemia (HEL) cells, which had JAK2V617F mutation. Protein expression of p-JAK2, SOCS-1, SHP-1 in bone marrow biopsies (BMBs) were detected by immunohistochemical staining methods. Cell apoptosis and cell cycle were detected by flow cytometry and Caspase 3/7 assay kits. 1. The p-JAK2, SOCS-1, and SHP-1 expressions were significantly different between JAK2V617F positive MPN and control patients (p < 0.01); 2. After being treated for 3 months, the p-JAK2, SOCS-1, and SHP-1 expressions were significantly different compared with newly diagnosed patients (p < 0.01). 3. HEL cell viabilities were significantly different after being treated with different concentrations of ruxolitinib. Ruxolitinib had a significant effect on the cell apoptosis, viability, and the protein activity of caspase-3 and -7 of HEL cells. 3. The mRNA and protein expressions of JAK2 and the protein expression of p-JAK2 were gradually decreased (p ＜ 0.01, p ＜ 0.05), while the mRNA and protein expressions of SOCS1 and SHP1 were gradually increased (all p ＜ 0.01).

Ruxolitinib enhances cytotoxic and apoptotic effects of temozolomide on glioblastoma cells by regulating WNT signaling pathway-related genes.

Although temozolomide is the primary chemotherapeutic agent in glioblastoma, current studies have focused on its combinational applications to overcome resistance by targeting multiple pathways. JAK/STAT and WNT are among the essential cancer-related signaling pathways. Ruxolitinib, the first approved JAK1/2 inhibitor, has promise in glioblastoma with its blood-brain barrier (BBB) crossing ability. The mentioned study aims to evaluate the anti-cancer potential of ruxolitinib individually and in combination with temozolomide on glioblastoma cells, brain cancer stem cells (BCSCs), and BBB-forming healthy cells. It also intends to determine the effects of JAK inhibitor treatment in combination with temozolomide on WNT signaling, which is known to cross-talk with the JAK/STAT pathway. The U87MG, BCSC, and HBMEC cell lines were the in vitro models. The cytotoxic and apoptotic effects of ruxolitinib and the combination were determined by the WST-1 test and Annexin V assay, respectively. The expression level changes of WNT signaling pathway genes caused by ruxolitinib and the combination treatments were defined by the qRT-PCR method. Network analysis of significantly upregulated and downregulated genes was performed via the GO KEGG pathway enrichment module of the String V11.5 database. The IC50 value of the ruxolitinib on U87MG glioblastoma cells was determined as 94.07µM at 24th h. The combination of temozolomide and ruxolitinib had a synergistic effect on U87MG cells at 24th h. The combination index (CI) was determined as 0.796, and ED60 values of ruxolitinib and temozolomide were determined as 89.75 and 391.48µM, respectively. Ruxolitinib improves the apoptotic effect of temozolomide on glioblastoma cells and brain cancer stem cells. Ruxolitinib regulates the WNT signaling pathway both individually and in combination with temozolomide. Our study indicates the potential of ruxolitinib to increase the cytotoxic and apoptotic activity of temozolomide in glioblastoma cells, also considering CSCs and healthy BBB-forming cells. As supported by gene expression and network analyses, the BBB-crossing agent ruxolitinib promises the potential to increase the efficacy of temozolomide in glioblastoma by affecting multiple signaling pathways in both cancer cells and CSCs.

Immunomodulators in Mechanically Ventilated Patients With COVID-19: Lessons Learned From Underpowered Trials.

Immunomodulators in Mechanically Ventilated Patients With COVID-19: Lessons Learned From Underpowered Trials.

Safety and Effectiveness of Ruxolitinib in Real-World Patients with Myelofibrosis: A 2-Year Observational Study from Taiwan

Introduction Ruxolitinib (RUX) is an approved JAK1/JAK2 inhibitor for the treatment of intermediate or high-risk myelofibrosis, including primary myelofibrosis (PMF), post-polycythemia vera myelofibrosis (PPV-MF), and post-essential thrombocythemia myelofibrosis (PET-MF), but real-world safety and efficacy of RUX in Taiwan are not well understood. This study was conducted to evaluate the safety and efficacy of treatment with RUX with intermediate-2 or high risk PMF, PPV-MF or PET-MF in routine clinical practice. Method This 2-year, single-arm, multicenter, post-marketing surveillance registry collected data on the safety, tolerability, efficacy, and other clinical information of adult patients (pts) aged ≥20 years with a confirmed diagnosis of intermediate-2 or high-risk PMF, PPV-MF, or PET-MF who either received RUX or starting RUX in accordance with the general clinical practice in Taiwan. Primary endpoint included collection of adverse events (AEs), AE of special interest (AESIs; anemia, thrombocytopenia, leukocytosis, hepatitis B virus (HBV) infection or reactivation, tuberculosis (TB) infection, and other infections), and serious adverse events (SAEs) throughout the study. Key secondary endpoints included treatment duration, discontinuation rates, dosage of prescribed RUX, Myeloproliferative Neoplasm symptom assessment form (MPN-10) score after study entry and change in spleen size, specifically in naïve patients who were eligible for spleen response evaluation. Results A total of 99 (51% PMF, 22.4% PPV-MF, and 26.5% PET-MF) pts were recruited, of which 38 (38.4%) pts discontinued due to consent withdrawal (n=11), death (n=10), discontinued prescription of RUX for 3 months (n=4), AEs (n = 2), unsatisfactory therapeutic effect (n=2), administrative problems (n=1), disease progression (n=1), required immediate stem cell transplantation (n=1), and others (n=6). Median age was 68.1 (range: 38.3-87.2) years and gender ratio was balanced, with 97 Taiwanese pts (98.0%). Median disease duration was 13.9 months (range: 0-967.6 months) and 70.7% and 28.3% of pts were identified with the risk of intermediate-2 or high using IPSS/DIPSS risk assessment, respectively. Majority of the recruited pts were RUX pre-treated (n=75; 75.8%) and 24.2% (n=24) pts were RUX-naïve at baseline. During the study, 88 pts (89.8%) had 673 AEs, and 44 (44.9%) experienced 159 SAEs. Half of the pts (55.1%) had moderate or severe SAEs and 39 pts recovered. Over 80% of SAEs (n=131) were not related to RUX. Major AESIs were anemia (29.6%) and thrombocytopenia (20.4%). There were no HBV infection or reactivation reported; 2% of pts had TB while 3% of pts had herpes zoster infections. The major reported infection was pneumonia (20.4%). Key safety data are summarized in Table 1. Most pts had their AEs resolved (77.6%), while 10 deaths occurred due to AEs (10.2%). Majority of the pts (41.8%) received a daily dose of RUX 20 mg at the enrolment, with an average mean daily dose of 22.7±9.2 mg (Figure 1). For naïve pts, mean initial dose was 18.8 ± 8.50 mg and gradually titrated up to 22.3 ± 8.69 mg at 3 months and to 24.0 ± 9.17 mg at 6 months. Among 98 pts, 13.3% pts whose platelet counts between 100-200×103/μL and 21.4% pts whose platelet counts were >200×103/μL were treated with RUX 5-10 mg twice daily. Among 27 RUX pre-treated patients (mean RUX duration before study entry: 17.0 ± 20.98 months), spleen size by palpation was relatively stable throughout the study period. For the 7 RUX naïve pts, the mean spleen size change from baseline was -15.9 %± 28.72 at 12 weeks, -30.8% ± 31.28 at 24 weeks, -54.2% ± 41.93 at 48 weeks and -52.0% ± 36.41 at 96 weeks. However, it should be interpreted with caution due to the small pt pool. A total of 65 pts (65.7%) had >50% improvement in the symptom response by MPN-10 during 2-year study period. . Conclusion This is the first real-world study in Taiwan to evaluate safety and efficacy with RUX in patients with MF. It was observed that physicians employed a conservative strategy for a lower starting dose with gradual titration resulting in comparable safety profile, but lower incidences of thrombocytopenia compared to published clinical trials. The majority of pts reported continuous symptomatic improvement and a small number of RUX naïve pts had pronounced spleen size reduction. Further investigations are required to evaluate whether optimal dose of RUX or titration speed would improve spleen response. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal