Janus kinases restrain chronic lymphocytic leukemia cells in patients on ibrutinib: Results of a phase II trial

Preclinical observations that killing of chronic lymphocytic leukemia (CLL) cells was dexamethasone (DEX) were enhanced by concomitant inhibition of Bruton's tyrosine kinase and janus kinases (JAKs) motivated a phase II trial to determine if clinical responses to ibrutinib could be deepened by DEX and the JAK inhibitor ruxolitinib. Patients on ibrutinib at 420 mg daily for 2 months or with abnormal serum β2M levels after 6 months or with persistent lymphadenopathy or splenomegaly after 12 months were randomized to receive DEX 40 mg on days 1-4 of a 4-week cycle for six cycles alone (three patients) or with ruxolitinib 15 mg BID on days 1-21 of each cycle (five patients). Ruxolitinib dosing was based on a previous phase I trial. Steroid withdrawal symptoms and significantly decreased serum IgG levels occurred in all patients regardless of their exposure to ruxolitinib. A fatal invasive fungal infection was seen in a patient taking DEX without ruxolitinib. Complete responses anticipated with addition of ruxolitinib were not seen. Gene expression studies suggested ruxolitinib had turned off interferon signaling in CLL cells and turned on genes associated with the activation of NFκB by TNF-α. Ruxolitinib increased blood levels of TNF-α by cycle 3 and decreased the inhibitory cytokine IL-10. These results suggest ruxolitinib releases activating signals for CLL cells that persist in patients on ibrutinib. This inhibitory JAK signaling may contribute to the therapeutic activity of ibrutinib. Thus JAK inhibitors provide no added value with ibrutinib for disease control and should be used with caution in CLL patients. Combining glucocorticoids with ibrutinib may increase the risk of serious infects.

Ruxolitinib Ameliorates Airway Hyperresponsiveness and Lung Inflammation in a Corticosteroid-Resistant Murine Model of Severe Asthma

Asthma prevalence has increased considerably over the decades and it is now considered as one of the most common chronic disorders in the world. While the current anti-asthmatic therapies are effective for most asthma patients, there are 5-10% subjects whose disease is not controlled by such agents and they account for about 50% of the asthma-associated healthcare costs. Such patients develop severe asthma (SA), a condition characterized by a dominant Th1/Th17 cytokine response that is accompanied by Type 2 (T2)-low endotype. As JAK (Janus Kinase) signaling is very important for the activation of several cytokine pathways, we examined whether inhibition of JAKs might lessen the clinical and laboratory manifestations of SA. To that end, we employed a recently described murine model that recapitulates the complex immune response identified in the airways of human SA patients. To induce SA, mice were sensitized with house dust mite extract (HDME) and cyclic (c)-di-GMP and then subsequently challenged with HDME and a lower dose of c-di-GMP. In this model, treatment with the JAK inhibitor, Ruxolitinib, significantly ameliorated all the features of SA, including airway hyperresponsiveness and lung inflammation as well as total IgE antibody titers. Thus, these studies highlight JAKs as critical targets for mitigating the hyper-inflammation that occurs in SA and provide the framework for their incorporation into future clinical trials for patients that have severe or difficult-to manage asthma.

Novel strategies for challenging scenarios encountered in managing myelofibrosis

Given its rarity, multi-faceted clinical presentation and the relative paucity of approved therapies, the management of myeloproliferative neoplasm (MPN)-associated myelofibrosis (MF) can be challenging. Janus kinase (JAK) inhibitors, the only approved agents at present, have brought many clinical benefits to patients, with prolongation of survival also demonstrated for ruxolitinib. However, these agents have clear limitations. Optimal management of anemia in MF remains a major unmet need. Neither ruxolitinib nor fedratinib is recommended for use in patients with severe thrombocytopenia, i.e. platelets <50 × 10⁹/L, who have a particularly poor prognosis. The search for the optimal partner for JAK inhibitors to address some of the shortcomings of these agents (e.g. limited ability to improve bone marrow fibrosis, cytopenias and induce molecular responses) and achieve meaningful 'disease modification' continues. This has led to the development of a number of rational, preclinically synergistic combinations for use either upfront or in the setting of sub-optimal response to JAK inhibition. Finally, the outlook for patients whose disease progresses on JAK inhibitor therapy continues to be grim, and agents with alternative mechanisms of action may be needed in this setting. In this article, we use a case-based approach to illustrate challenges commonly encountered in clinical practice and our management of the same. Fortunately, there has been enormous growth in drug development efforts in the MF space in the last few years, some of which appear poised to bear fruit in the very near future.

Ruxolitinib-Associated Phaeohyphomycosis: A Case Report

We present the findings of a rare fungal infection phaeohyphomycosis caused by Pleurostoma richardsiae (P. richardsiae) in an immunocompromised 82-year-old male with myelodysplastic syndrome on treatment with the Janus kinase inhibitor ruxolitinib. Hematologists, infectious disease physicians, and surgeons should consider a fungal etiology in cases of cellulitis refractory to standard treatments in those patients with underlying immune dysfunction and/or in those receiving therapy with ruxolitinib or similar agents.

Improving Ineffective Erythropoiesis in Thalassemia: A Hope on the Horizon

Beta-thalassemia is an inherited hemoglobinopathy characterized by the impaired synthesis of beta-globin chains of hemoglobin leading to chronic hemolytic anemia. The mainstay of treatment for most patients remains regular blood transfusions and iron chelation. This conventional therapy has many limitations and challenges. Allogeneic hematopoietic stem cell transplant (HSCT) is the only available curative treatment but the availability of a suitable donor, financial constraints, and a need for specialist physicians can be limiting factors. Gene therapy is an upcoming curative therapeutic modality. An increased understanding of the underlying pathophysiology and molecular mechanisms of thalassemia has paved the way for novel pharmacological agents targeting ineffective erythropoiesis. These drugs act by decreasing transfusion requirements and hence decrease transfusion-related complications. The present review intends to provide an insight into the recent advances in pharmacological agents targeting ineffective erythropoiesis. Literature was searched and relevant articles evaluating newer drugs in thalassemia were collected from databases, including Pubmed, Scopus, Prospero, Clinicaltrials.gov, Google Scholar, and the Google search engine. We used the following keywords: thalassemia, novel, treatment, drugs, and ineffective erythropoiesis during the initial search. Relevant titles and abstracts were screened to choose relevant articles. Further, the full-text articles were retrieved and relevant cross-references were scanned to collect information for the present review.

Ruxolitinib (a JAK2 inhibitor) as an emerging therapy for refractory pruritis in a patient with low-risk polycythemia vera: A case report

INTRODUCTION

Polycythemia vera (PV) is a Philadelphia-negative myeloproliferative neoplasm (MPN) characterized by the overproduction of red blood cells. The presence of JAK2 mutation is detected in up to 99% of patients with PV. Pruritis is commonly encountered in patients with PV and is considered the most troublesome symptom. Multiple treatment modalities are used for treatment; however, their efficacy is variable. Sometimes, pruritis will not improve even by the use of combined therapies. Recently, Ruxolitinib (a JAK2 inhibitor) has been shown to be very effective, especially in patients with refractory pruritis in the setting of other treatment modalities failure.

PATIENT CONCERN

We describe a 55-year-old male with history of low risk PV presented with severe itching despite using different therapies, including phlebotomy and hydroxyurea. His laboratory results on presentation were significant for red blood cells (RBC) of 8.2 × 106/uL (normal = 4.5-5.5), hematocrit (Hct) of 52.8% (normal = 40-50%), platelet count of 519 × 103/uL (normal = 150-400), white blood cells count of 12.3 × 103/uL (normal = 4-10), and basophils count of 0.22 × 103/uL (normal < 0.1).

DIAGNOSIS

PV related refractory pruritis.

INTERVENTION

Pruritis improved dramatically after starting Ruxolitinib therapy with an improvement of hematological parameters (both hematocrit and platelet count).

CONCLUSION

Different treatment modalities have shown to be beneficial in treating PV-related pruritis, but the clinical outcomes are highly variable. This case report aims to shed light on Ruxolitinib as an emerging therapy for the treatment of refractory cases of PV-related pruritis.

Efficacy and safety of ruxolitinib in ineffective erythropoiesis suppression as a pretransplantation treatment for pediatric patients with beta-thalassemia major

BACKGROUND

Ineffective erythropoiesis (IE) is the most prominent feature of transfusion-dependent beta-thalassemia (TDT), which leads to extramedullary hemopoiesis. The rejection rate in allogeneic hematopoietic stem cell transplantation (HSCT) is high in heavily transfused patients with TDT accompanied by prominent IE. Therefore, a pretransplantation treatment bridging to HSCT is often used to reduce allosensitization and IE. Ruxolitinib is a JAK-1/JAK-2 inhibitor and has showed its efficacy in suppressing IE and the immune system. A previously published study on RUX in adult patients with TDT has revealed that this treatment significantly reduces spleen size and is well tolerated.

PROCEDURE

Ten patients (5-14 years old) with TDT and an enlarged spleen were enrolled. The dose of ruxolitinib was adjusted for age: for patients <11 years: 40-100 mg/m² total daily dose and for patients >11 years: 20-30 mg/m² total daily dose. HSCT was performed in 8 of 10 patients.

RESULTS

After the first 3 months of ruxolitinib therapy, spleen volume decreased in 9 of 10 cases by 9.1%-67.5% (M = 35.4%) compared with the initial size (P = 0.003). The adverse events of ruxolitinib (infectious complications, moderate thrombocytopenia, and headache) were successfully managed by reducing the dose. The outcomes of HSCT were favorable in seven of eight cases.

CONCLUSION

Ruxolitinib is promising as a short-term pre-HSCT treatment for pediatric patients with TDT and pronounced IE.

Diagnosis and Treatment of Myeloproliferative Neoplasms With PCM1-JAK2 Rearrangement: Case Report and Literature Review

Myeloproliferative neoplasm (MPN) with PCM1-JAK2 rearrangement is a rare disease with poor prognosis and lacks uniform treatment guidelines. Several studies confirmed the efficacy of ruxolitinib in hematological malignancies with PCM1-JAK2 fusion, but the efficacy is variable. Here, we report two patients diagnosed with MPN with PCM1-JAK2 fusion who were treated with ruxolitinib-based regimen, including the first case of ruxolitinib combined with pegylated interferon (Peg-IFN), and we conduct a literature review. We found that ruxolitinib combined with Peg-IFN is an effective treatment option in the case of poor efficacy of ruxolitinib monotherapy.

Evaluating topical JAK inhibitors as a treatment option for atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a chronic, inflammatory skin condition mediated by cytokines that utilize the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) signaling cascade. Topical JAK inhibitors are an emerging alternative in the treatment of AD.

AREAS COVERED

This expert review presents an overview of the underlying molecular pathophysiology of AD, current standards of care, and evaluation of the efficacy and safety of topical JAK inhibitors. A PubMed database search was utilized with a focus on the evidence from double-blind, randomized Phase I, II, and III clinical trials published between January 2015 and July 2021.

EXPERT OPINION

Current topical therapies for AD are efficacious but limited by their adverse side effects. Long-term topical corticosteroid use leads to loss of pigmentation, striae, and skin atrophy. Patients may be concerned about topical calcineurin inhibitors' black box warning of increased risk of malignancy. Topical crisaborole, a phosphodiesterase four inhibitor, is limited by application site burning. Topical ruxolitinib is a JAK inhibitor comparable to triamcinolone in efficacy without the adverse effects seen with long-term topical corticosteroid use. Although topical JAK inhibitors have promising efficacy and safety profiles, poor medication adherence common to topical treatments may limit their utility in a clinical setting.

Posterior Reversible Encephalopathy Syndrome (PRES) in a Patient With Primary Myelofibrosis on Ruxolitinib

Posterior reversible encephalopathy syndrome (PRES) is a reversible neurological syndrome characterized by headache, seizures, altered mental status, and visual abnormalities, in association with the characteristic bilateral white matter abnormalities in the posterior cerebral hemispheres. As the name suggests, it is typically reversible with clinical recovery within a few days, while the magnetic resonance imaging (MRI) abnormalities resolve much more slowly. We present a 78-year-old female with a known diagnosis of primary myelofibrosis (PMF), on ruxolitinib, a Janus kinase (JAK) 1 and 2 inhibitor, presenting with altered mental status. On presentation, she was hypertensive and with possible sepsis, secondary to urinary tract infection (UTI). She was intubated because of her low Glasgow Coma Scale (GCS), to secure her airways. Computed tomography (CT) of the brain did not reveal any acute ischemic changes. MRI of the brain exhibited findings suggestive of PRES. Ruxolitinib was held and the patient was treated with antihypertensives, anticonvulsants, and antibiotics. Within 24 hours of hospitalization, the patient had a complete neurological recovery, which is diagnostic of PRES. She was extubated successfully and was discharged with a resolution of her symptoms. Although several chemotherapeutic and immunosuppressant drugs are reported to be associated with PRES, the association between ruxolitinib and PRES has not been well established. Thus, case reporting is important to highlight the possible association between ruxolitinib and PRES.

Platelet transcriptome identifies progressive markers and potential therapeutic targets in chronic myeloproliferative neoplasms

Predicting disease progression remains a particularly challenging endeavor in chronic degenerative disorders and cancer, thus limiting early detection, risk stratification, and preventive interventions. Here, profiling the three chronic subtypes of myeloproliferative neoplasms (MPNs), we identify the blood platelet transcriptome as a proxy strategy for highly sensitive progression biomarkers that also enables prediction of advanced disease via machine-learning algorithms. The MPN platelet transcriptome reveals an incremental molecular reprogramming that is independent of patient driver mutation status or therapy. Subtype-specific markers offer mechanistic and therapeutic insights, and highlight impaired proteostasis and a persistent integrated stress response. Using a LASSO model with validation in two independent cohorts, we identify the advanced subtype MF at high accuracy and offer a robust progression signature toward clinical translation. Our platelet transcriptome snapshot of chronic MPNs demonstrates a proof-of-principle for disease risk stratification and progression beyond genetic data alone, with potential utility in other progressive disorders.

Clinical Efficacy of Ruxolitinib in Patients with Myelofibrosis: A Nationwide Population-Based Study in Korea

Previous studies have reported the survival benefit after ruxolitinib treatment in patients with myelofibrosis (MF). However, population-based data of its efficacy are limited. We analyzed the effects of ruxolitinib in MF patients with data from the Korean National Health Insurance Database. In total, 1199 patients diagnosed with MF from January 2011 to December 2017 were identified, of which 731 were included in this study. Patients who received ruxolitinib (n = 224) were matched with those who did not receive the drug (n = 507) using the 1:1 greedy algorithm. Propensity scores were formulated using five variables: age, sex, previous history of arterial/venous thrombosis, and red blood cell (RBC) or platelet (PLT) transfusion dependence at the time of diagnosis. Cox regression analysis for overall survival (OS) revealed that ruxolitinib treatment (hazard ratio (HR), 0.67; p = 0.017) was significantly related to superior survival. In the multivariable analysis for OS, older age (HR, 1.07; p < 0.001), male sex (HR, 1.94; p = 0.021), and RBC (HR, 3.72; p < 0.001) or PLT (HR, 9.58; p = 0.001) transfusion dependence were significantly associated with poor survival, although type of MF did not significantly affect survival. Considering evidence supporting these results remains weak, further studies on the efficacy of ruxolitinib in other populations are needed.

The Slower Antibody Response in Myelofibrosis Patients after Two Doses of mRNA SARS-CoV-2 Vaccine Calls for a Third Dose

Immunization with mRNA SARS-CoV-2 vaccines has been highly recommended and prioritized in fragile subjects, including patients with myelofibrosis (MF). Available data on the vaccine immune response developed by MF patients and the impact of ruxolitinib treatment are still too fragmented to support an informed decision on a third dose for this category of subjects. Here, we show that 76% of MF patients develop spike-specific IgG after the second mRNA SARS-CoV-2 vaccine dose, but the response has a slower kinetics compared to healthy subjects, suggesting a reduced capability of their immune system to promptly react to vaccination. A reduced ACE2/RBD binding inhibition activity of spike-specific antibodies was also observed, especially in ruxolitinib-treated patients. Our results, showing slow kinetics of antibody responses in MF patients following vaccination with mRNA SARS-CoV-2 vaccines, support the need for a third vaccine dose.

Janus Kinase inhibitors for the treatment of hospitalized patients with COVID-19

PURPOSE OF REVIEW

Janus Kinase (JAK) inhibitors have been successfully utilized in the clinical treatment of several rheumatologic (e.g. rheumatoid arthritis) and inflammatory diseases (e.g. hemophagocytic lymphohistiocytosis). Based on the growing evidence that moderate and severe COVID-19 infections are associated with a dysregulated inflammatory state, this class of medications has been repurposed as a potential therapy for COVID-19, an infection caused by Severe Acute Respiratory Syndrome Coronavirus 2.

RECENT FINDINGS

Three JAK inhibitors have been evaluated in human studies of COVID-19: Baricitinib, Tofacitinib, and Ruxolitinib. Most published studies are observational, but three randomized placebo-controlled double-blind trials have been completed: two large trials (N = 2,558 patients) with baricitinb demonstrated significant faster improvement in clinical status and reduction in the recovery time, as well as, significant reduction in the progression to invasive mechanical ventilation and mortality. One smaller randomized trial (N = 289) involving tofacitinib showed significant reduction in the progression to invasive ventilation or death. Notably, these three randomized placebo-controlled trials with close to 3,000 patients did not reveal any safety concerns associated with JAK inhibitors in terms of secondary infections or venous thromboembolism. Based on this high-quality evidence, both the Infectious Diseases Society of America and the National Institutes of Health guidelines recommend using baricitinib as part of the treatment approach for hospitalized patients with COVID-19.

SUMMARY

JAK inhibitors are novel treatment agents in the field of infectious diseases. One JAK inhibitor, baricitinib has demonstrated significant clinical and survival benefits in hospitalized patients with COVID-19 in phase III randomized placebo-controlled trials. Baricitinib is already recommended for clinical practice by multiple guidelines.

Idiopathic multicentric Castleman disease with TAFRO clinical subtype responsive to IL-6/JAK inhibition: A pediatric case series

TAFRO (thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin myelofibrosis, renal dysfunction, and organomegaly) clinical subtype of idiopathic multicentric Castleman disease (iMCD-TAFRO) is a rare lymphoproliferative disease characterized by systemic inflammation. First-line treatment for iMCD-TAFRO includes steroids and interleukin (IL)-6 blockade. Many patients have refractory disease, which is associated with significant morbidity and mortality, and treatment remains challenging. We present two pediatric cases of iMCD-TAFRO. One patient responded to IL-6 blockade; the other was refractory to siltuximab and chemotherapy, ultimately responding to JAK inhibition with ruxolitinib. This is the first reported pediatric case of refractory iMCD-TAFRO responding to JAK inhibition.

Efficacy and safety of the oral Janus kinase inhibitor baricitinib in the treatment of adults with alopecia areata: Phase 2 results from a randomized controlled study

BACKGROUND

There are no treatments approved by the Food and Drug Administration for alopecia areata.

OBJECTIVE

To evaluate the efficacy and safety of baricitinib in patients with ≥50% scalp hair loss in a phase 2 study of adults with alopecia areata (BRAVE-AA1).

METHODS

Patients were randomized 1:1:1:1 to receive placebo or baricitinib 1 mg, 2 mg, or 4 mg once daily. Two consecutive interim analyses were performed after all patients completed weeks 12 and 36 or had discontinued treatment prior to these time points. The primary endpoint was the proportion of patients achieving a Severity of Alopecia Tool (SALT) score ≤20 at week 36. Logistic regression was used with nonresponder imputation for missing data.

RESULTS

A total of 110 patients were randomized (placebo, 28; baricitinib 1-mg, 28; 2-mg, 27; 4-mg, 27). The baricitinib 1-mg dose was dropped after the first interim analysis based on lower SALT₃₀ response rate. At week 36, the proportion of patients achieving a SALT score of ≤20 was significantly greater in baricitinib 2-mg (33.3%, P = .016) and 4-mg (51.9%, P = .001) groups versus placebo (3.6%). Baricitinib was well tolerated with no new safety findings.

LIMITATIONS

Small sample size limits generalizability of results.

CONCLUSION

These results support the efficacy and safety of baricitinib in patients with ≥50% scalp hair loss.

Combined Pulmonary Tuberculosis with Pulmonary and Pleural Cryptococcosis in a Patient Receiving Ruxolitinib Therapy

With an advance in therapy, there are increasing emerging and re-emerging opportunistic infections among patients with hematologic conditions and malignancy. Herein, we present a 56-year-old woman with primary myelofibrosis who developed combined tuberculosis (TB) and cryptococcosis with extensive pulmonary, pleural, and nodal involvement during ruxolitinib therapy. Marked clinical and radiologic improvements were undoubtedly evident after receiving anti-TB and antifungal therapies and pleural drainage. Hence, the presence of atypical clinical and radiologic manifestations and incomplete responses, despite receiving adequate antimicrobial treatment, should raise concerns regarding the combined emerging and re-emerging opportunistic infections and the possibility of unusual radiologic manifestations of cryptococcosis in a ruxolitinib-treated patient.

Carfilzomib Enhances the Suppressive Effect of Ruxolitinib in Myelofibrosis

As the first FDA-approved tyrosine kinase inhibitor for treatment of patients with myelofibrosis (MF), ruxolitinib improves clinical symptoms but does not lead to eradication of the disease or significant reduction of the mutated allele burden. The resistance of MF clones against the suppressive action of ruxolitinib may be due to intrinsic or extrinsic mechanisms leading to activity of additional pro-survival genes or signalling pathways that function independently of JAK2/STAT5. To identify alternative therapeutic targets, we applied a pooled-shRNA library targeting ~5000 genes to a JAK2^V617F-positive cell line under a variety of conditions, including absence or presence of ruxolitinib and in the presence of a bone marrow microenvironment-like culture medium. We identified several proteasomal gene family members as essential to HEL cell survival. The importance of these genes was validated in MF cells using the proteasomal inhibitor carfilzomib, which also enhanced lethality in combination with ruxolitinib. We also showed that proteasome gene expression is reduced by ruxolitinib in MF CD34⁺ cells and that additional targeting of proteasomal activity by carfilzomib enhances the inhibitory action of ruxolitinib in vitro. Hence, this study suggests a potential role for proteasome inhibitors in combination with ruxolitinib for management of MF patients.

Ruxolitinib in Patients With Chronic Active Epstein-Barr Virus Infection: A Retrospective, Single-Center Study

Background: Chronic active Epstein-Barr virus (CAEBV) infection is one of the EBV-positive T- or NK-cell lymphoproliferative diseases. There is no safe and effective treatment currently and the only proven curable therapy is allogeneic hematopoietic stem cell transplantation (allo-HSCT). The JAK1/2 inhibitor, ruxolitinib, is now considered a novel therapy in inflammatory disease, and hypercytokinemia is an important feature of CAEBV.

Method: All patients who suffered active CAEBV and were treated with ruxolitinib as compassionate use in our center from Sep 1, 2017, and Apr 30, 2019, were retrospectively analyzed.

Results: In general, seven out of nine patients responded to ruxolitinib. Six out of seven patients became afebrile within 48 h. The AST/ALT level of three out of four patients decreased after ruxolitinib treatment. Two patients with cytopenia recovered. No significant decrease in the EBV-DNA copy number was observed (p = 0.161). For those seven patients who responded to ruxolitinib, the median continuing period in remission was 7.1 weeks (range, 3.4–101.0 weeks). Two patients achieved long-term stable remission with ruxolitinib monotherapy. None of these patients discontinued ruxolitinib due to the possible toxicity.

Conclusion: Ruxolitinib is an effective and rather safe option for controlling the inflammatory symptoms of active CAEBV, especially in patients with CAEBV who have failed previous treatments or have relapsed. It can also play a promising role in improving the quality of daily life of patients and successfully bridging to allo-HSCT.

Venetoclax or Ruxolitinib in Pre-Transplant Conditioning Lowers the Engraftment Barrier by Different Mechanisms in Allogeneic Stem Cell Transplant Recipients

Allogeneic stem cell transplantation (alloSCT) is utilised to cure haematological malignancies through a combination of conditioning regimen intensity and immunological disease control via the graft versus tumour (GVT) effect. Currently, conventional myeloablative chemotherapeutic or chemoradiation conditioning regimens are associated with significant side effects including graft versus host disease (GVHD), infection, and organ toxicity. Conversely, more tolerable reduced intensity conditioning (RIC) regimens are associated with unacceptably higher rates of disease relapse, partly through an excess incidence of mixed chimerism. Improvement in post-alloSCT outcomes therefore depends on promotion of the GVT effect whilst simultaneously reducing conditioning-related toxicity. We have previously shown that this could be achieved through BCL-2 inhibition, and in this study, we explored the modulation of JAK1/2 as a strategy to lower the barrier to donor engraftment in the setting of RIC. We investigated the impact of short-term treatment of BCL2 (venetoclax) or JAK1/2 (ruxolitinib) inhibition on recipient natural killer and T cell immunity and the subsequent effect on donor engraftment. We identified striking differences in mechanism of action of these two drugs on immune cell subsets in the bone marrow of recipients, and in the regulation of MHC class-II and interferon-inducible gene expression, leading to different rates of GVHD. This study demonstrates that the repurposed use of ruxolitinib or venetoclax can be utilised as pre-transplant immune-modulators to promote the efficacy of alloSCT, whilst reducing its toxicity.

Janus kinase inhibitors for the therapy of atopic dermatitis

The JAK-STAT pathway is involved in the signaling of multiple cytokines driving cutaneous inflammation in atopic dermatitis (AD). Janus kinase (JAK) inhibitors target individual receptor-associated kinases, thereby preventing the mediation of inflammatory signals. Several JAK inhibitors with varying mechanism of action, potency, and safety represent potential therapeutic options for AD in both topical and systemic application. The JAK1/2 selective JAK inhibitor baricitinib was the first substance from this class of drugs approved by the EMA for the systemic oral treatment of AD. The clinical development program of the JAK1 selective inhibitors upadacitinib and abrocitinib is finalized with positive results for AD. The PAN-JAK inhibitor delgocitinib was the first substance being approved for the treatment of AD (in Japan). This review article covers the rising data on investigational and approved JAK inhibitors in the context of the treatment of AD.

Early-onset pulmonary and cutaneous vasculitis driven by constitutively active SRC-family kinase HCK

BACKGROUND

Inborn errors of immunity (IEI) are genetic disorders characterized by various degrees of immune dysregulation that can manifest as immune deficiency, autoimmunity or autoinflammation. The routine use of next-generation sequencing in the clinic has facilitated the identification of an ever-increasing number of IEI, revealing the roles of immunologically important genes in human pathologies. However, despite this progress, treatment is still extremely challenging.

OBJECTIVE

We report a new monogenic autoinflammatory disorder caused by a de novo activating mutation, p.Tyr515*, in hematopoietic cell kinase (HCK). The disease is characterized by cutaneous vasculitis and chronic pulmonary inflammation that progresses to fibrosis.

METHODS

Whole-exome sequencing, Sanger sequencing, mass spectrometry and western blotting were performed to identify and characterize the pathogenic HCK mutation. Dysregulation of mutant HCK was confirmed ex vivo in primary cells and in vitro in transduced cell lines.

RESULTS

Mutant HCK lacking the C-terminal inhibitory tyrosine Tyr522 exhibited increased kinase activity and enhanced myeloid cell priming, migration and effector functions, such as production of the inflammatory cytokines IL-1β, IL-6, IL-8 and TNFα and production of reactive oxygen species. These aberrant functions were reflected by inflammatory leukocyte infiltration of the lungs and skin. Moreover, an overview of the clinical course of the disease, including therapies, provides evidence for the therapeutic efficacy of the Janus kinase (JAK) 1/2 inhibitor ruxolitinib in inflammatory lung disease.

CONCLUSION

We propose HCK-driven pulmonary and cutaneous vasculitis as a novel autoinflammatory disorder of IEI.

Adherence to ruxolitinib, an oral JAK1/2 inhibitor, in patients with myelofibrosis: interim analysis from an Italian, prospective cohort study (ROMEI)

ROMEI, a prospective, observational study in patients with myelofibrosis receiving the oral JAK1/2 inhibitor ruxolitinib in real-world practice, assesses treatment adherence based on the 8-item Morisky Medication Adherence Scale (MMAS-8). Here, we present MMAS-8 results at week 24. Overall, 101 of 188 evaluable patients completed the questionnaire at every visit (full completers). Mean (±standard deviation) total MMAS-8 scores remained stable from week 4 to week 24 in the overall population (7.54 ± 0.77 and 7.67 ± 0.70, respectively) and full completers (7.53 ± 0.79 and 7.67 ± 0.73, respectively). Rates of low (MMAS-8 ˂6) or medium (MMAS-8 ≥ 6 to ˂8) adherence were 25-40% and 26-36%, respectively. Fifty-five full completers (54%) reported ≥1 change in adherence category (improvement and/or worsening), most of which were associated with unintentional behavior. The data suggest that one-third of patients receiving ruxolitinib may be undertreated due to non-adherence, potentially undermining disease control, and indicate a need for better interventions addressing noncompliance to oral therapies.