Ruxolitinib for myelofibrosis

Navigating 'grey areas' and challenges during evaluation of transplant eligibility in specific myelofibrosis populations: a perspective on behalf of the Chronic Malignancies Working Party of the EBMT

Significant efforts have been made to effectively select myelofibrosis (MF) patients who can benefit from allogeneic hematopoietic cell transplantation (allo-HCT), the only current cure for MF. The recent EBMT/ELN 2024 recommendations offer valuable guidance for hematologists and transplant physicians. However, several grey areas remain in day-to-day clinical practice regarding the feasibility and optimal preparation for transplantation in patients with this disease. Effective spleen size reduction, often achieved with JAK inhibitors, appears crucial for transplant success. For resistant cases, switching JAK inhibitors, splenectomy, or spleen irradiation may be considered, taking into account patient profiles, treatment availability and center preferences. Managing splanchnic vein thromboses, portal, and pulmonary hypertension is critical as these conditions may affect transplant outcomes. Cytopenias, particularly transfusion-dependent anemia and thrombocytopenia, complicate treatment and impact on outcomes, though new drugs show promise. Comorbidities play a significant role and tools like the Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) and frailty assessments are useful for evaluating transplant risks while allowing the implementation of corrective measures. Especially in low- and medium-income countries where access to novel therapies may be challenging, allo-HCT still represents an attractive therapeutic option for MF. Future directions include integrating new therapeutics into the transplant algorithm and leveraging artificial intelligence for more informed risk assessment, highlighting the need for tailored approaches to improve allo-HCT outcomes in such a setting.

Integrated bioinformatic analysis reveals the underlying molecular mechanism of and potential drugs for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating cardiovascular disease without a clear mechanism or drugs for treatment. Therefore, it is crucial to reveal the underlying molecular mechanism and identify potential drugs for PAH. In this study, we first integrated three human lung tissue datasets (GSE113439, GSE53408, GSE117261) from GEO. A total of 151 differentially expressed genes (DEGs) were screened, followed by KEGG and GO enrichment analyses and PPI network construction. Five hub genes (CSF3R, NT5E, ANGPT2, FGF7, and CXCL9) were identified by Cytoscape (Cytohubba). GSEA and GSVA were performed for each hub gene to uncover the potential mechanism. Moreover, to repurpose known and therapeutic drugs, the CMap database was retrieved, and nine candidate compounds (lypressin, ruxolitinib, triclabendazole, L-BSO, tiaprofenic acid, AT-9283, QL-X-138, huperzine-a, and L-741742) with a high level of confidence were obtained. Then ruxolitinib was selected to perform molecular docking simulations with ANGPT2, FGF7, NT5E, CSF3R, JAK1, JAK2, JAK3, TYK2. A certain concentration of ruxolitinib could inhibit the proliferation and migration of rat pulmonary artery smooth muscle cells (rPASMCs) in vitro. Together, these analyses principally identified CSF3R, NT5E, ANGPT2, FGF7 and CXCL9 as candidate biomarkers of PAH, and ruxolitinib might exert promising therapeutic action for PAH.

The impact of JAK/STAT inhibitor ruxolitinib on the genesis of lymphoproliferative diseases

Background/aim

Ruxolitinib, a JAK/STAT signaling pathway inhibitor targeted drug, has been approved for the controlling of disease symptoms and splenomegaly in patients with myeloproliferative neoplastic diseases. Recently, it has been proposed that ruxolitinib-induced JAK/STAT pathway inhibition in myelofibrosis is associated with an elevated frequency of aggressive B-cell lymphomas. However, the biological basis and significance of this pharmacobiological adverse event is unknown. The aim of this bioinformatics study is to detect any possible confounding effects of ruxolitinib on the genesis of lymphoproliferative disorders.

Materials and methods

The gene expression data were retrieved from the E-MTAB-783 Cancer Genome Project database. Gene expression data for all available genes in 26 cell lines belonging to various types of lymphomas were chosen for use in this in silico analysis.

Results

We identified genes that were significant in developing resistance to ruxolitinib in lymphoma cell lines.

Conclusion

Based on the results of our present study, ruxolitinib may potentially lead to the pathological expression of the transcription factors important in lymphoma genesis, neoplastic commitment on the progenitor lymphoid cells, inhibition of repressor transcriptions protective for lymphoma development, inhibition of apoptosis, promotion of neoplastic proliferation, transcriptional activation, and proliferation of malignant neoplastic B cells.

Safety and efficacy of ruxolitinib in splanchnic vein thrombosis associated with myeloproliferative neoplasms

Splanchnic vein thrombosis (SVT) is one of the vascular complications of myeloproliferative neoplasms (MPN). We designed a phase 2 clinical trial to evaluate safety and efficacy of ruxolitinib in reducing splenomegaly and improving disease-related symptoms in patients with MPN-associated SVT. Patients diagnosed with myelofibrosis (12 cases), polycythemia vera (5 cases) and essential thrombocythemia (4 cases) received ruxolitinib for 24 weeks in the core study period. Spleen volume was assessed by magnetic resonance imaging (MRI) and splanchnic vein circulation by echo-Doppler analysis. Nineteen patients carried JAK2V617F, one had MPLW515L, and one CALRL367fs*46 mutation. Eighteen patients had spleno-portal-mesenteric thrombosis, two had Budd-Chiari syndrome, and one had both sites involved; 16 patients had esophageal varices. Ruxolitinib was well tolerated with hematological toxicities consistent with those of patients without SVT and no hemorrhagic adverse events were recorded. After 24 weeks of treatment, spleen volume reduction ≥35% by MRI was achieved by 6/21 (29%) patients, and a ≥50% spleen length reduction by palpation at any time up to week 24 was obtained by 13/21 (62%) patients. At week 72, 8 of the 13 (62%) patients maintained the spleen response by palpation. No significant effect of treatment on esophageal varices or in splanchnic circulation was observed. MPN-related symptoms, evaluated by MPN-symptom assessment form (SAF) TSS questionnaire, improved significantly during the first 4 weeks and remained stable up to week 24. In conclusion, this trial shows that ruxolitinib is safe in patients with MPN-associated SVT, and effective in reducing spleen size and disease-related symptoms.

Pharmacobiological Approach for the Clinical Development of Ruxolitinib in Myeloproliferative Neoplasms

Ruxolitinib, a JAK1 and JAK2 inhibitor drug, has recently been approved for the treatment of patients with high- or intermediate-risk myelofibrosis with symptomatic splenomegaly. Ruxolitinib is the first clinically useful targeted therapy in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs). The aim of this paper is to indicate pharmacobiological aspects of ruxolitinib within the potential context of MPNs. Pharmacobiological assessments, in addition to knowledge of the risk profile for ruxolitinib in MPNs, are required. We propose hypotheses based on our experience in a splenectomized MPN patient with hyperproliferative bone marrow and moderate fibrosis receiving ruxolitinib. We believe that a true clinical development approach for this drug should include pharmacobiological assessments for ruxolitinib in addition to the disease risk profile of MPNs.

Diagnosis, prevention, and management of bleeding episodes in Philadelphia-negative myeloproliferative neoplasms: recommendations by the Hemostasis Working Party of the German Society of Hematology and Medical Oncology (DGHO) and the Society of Thrombosis and Hemostasis Research (GTH)

Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPN) comprise a heterogeneous group of chronic hematologic malignancies. The quality of life, morbidity, and mortality of patients with MPN are primarily affected by disease-related symptoms, thromboembolic and hemorrhagic complications, and progression to myelofibrosis and acute leukemia. Major bleeding represents a common and important complication in MPN, and the incidence of such bleeding events will become even more relevant in the future due to the increasing disease prevalence and survival of MPN patients. This review discusses the causes, differential diagnoses, prevention, and management of bleeding episodes in patients with MPN, aiming at defining updated standards of care in these often challenging situations.

How I treat myelofibrosis

Myelofibrosis (MF) is a BCR-ABL1-negative myeloproliferative neoplasm characterized by clonal myeloproliferation, dysregulated kinase signaling, and release of abnormal cytokines. In recent years, important progress has been made in the knowledge of the molecular biology and the prognostic assessment of MF. Conventional treatment has limited impact on the patients' survival; it includes a wait-and-see approach for asymptomatic patients, erythropoiesis-stimulating agents, androgens, or immunomodulatory agents for anemia, cytoreductive drugs such as hydroxyurea for the splenomegaly and constitutional symptoms, and splenectomy or radiotherapy in selected patients. The discovery of the Janus kinase (JAK)2 mutation triggered the development of molecular targeted therapy of MF. The JAK inhibitors are effective in both JAK2-positive and JAK2-negative MF; one of them, ruxolitinib, is the current best available therapy for MF splenomegaly and constitutional symptoms. However, although ruxolitinib has changed the therapeutic scenario of MF, there is no clear indication of a disease-modifying effect. Allogeneic stem cell transplantation remains the only curative therapy of MF, but due to its associated morbidity and mortality, it is usually restricted to eligible high- and intermediate-2-risk MF patients. To improve current therapeutic results, the combination of JAK inhibitors with other agents is currently being tested, and newer drugs are being investigated.

Clinical features of patients with Philadelphia-negative myeloproliferative neoplasms complicated by portal hypertension

BACKGROUND

Portal hypertension has been reported to afflict 7% to 18% of patients with Philadelphia-negative MPNs, with complications of variceal bleeding and ascites. The clinical features and outcomes of these patients are unclear.

PATIENTS AND METHODS

In this multicenter retrospective study, we evaluated the clinical features of 51 patients with MPNs complicated by PHTN.

RESULTS

The diagnosis of underlying MPN was most frequently PV (39%) and primary MF (35%), followed by post-PV MF (18%), ET (4%), and post-ET MF (4%). Frequency of Janus Kinase 2 V617F mutation appears as expected in the underlying MPN. Thrombosis within the splanchnic circulation was prevalent in patients with polycythemia compared with other MPNs (76% vs. 26%; P = .0007).

CONCLUSION

PV and MF patients have a greater incidence of PHTN in our population, with thrombosis contributing to PHTN development in PV patients. Patients with splanchnic circulation thrombosis are potential candidates for screening for PHTN. These data might be useful for developing screening strategies for early detection of PHTN in patients with MPN.

Biochemical and functional analyses of gp130 mutants unveil JAK1 as a novel therapeutic target in human inflammatory hepatocellular adenoma

Inflammatory hepatocellular adenomas (IHCAs) are benign liver lesions that can be characterized histologically by the presence of an inflammatory infiltrate and at the molecular level by the overexpression of acute phase inflammatory response genes. Recurrent somatic mutations of the interleukin-6 (IL-6) signal transducer (IL6ST) locus, encoding the critical component of the IL-6 signal transduction machinery gp130, are present in 60% of IHCAs and in a subset (2%) of hepatocellular carcinoma (HCCs). By screening of 256 human hepatic adenoma specimens (the largest genetic analysis of IL6ST performed to date in this setting), we identified 24 distinct somatic IL6ST mutations among 66 mutant adenomas. The functional analysis of nine different gp130 mutants expressed in hepatic cancer cell lines consistently revealed the constitutive and IL-6-independent activation of the JAK/STAT signaling pathway. We further demonstrated that the signaling activity of mutant gp130 in IHCA remains responsive to suppressor of cytokine signaling 3 (SOCS3), a physiological gp130 inhibitor. Specifically, cells expressing a double mutant variant of gp130 with a disrupted SOCS3-binding site at residue 759 (Y186/Y759F) displayed a hyperactivation of signal transducer and activator of transcription 3 (STAT3) as compared with cells expressing the endogenous IHCA-associated Y186 gp130 mutant. Notably, we identified that constitutive signaling via gp130 in IHCA requires the Janus kinase family member JAK1, but not JAK2 or tyrosine kinase 2. In support of this notion, AG490, a tyrosine kinase inhibitor that selectively blocks JAK2, had no effect on gp130 activity. In stark contrast, we showed that ruxolitinib, a JAK1/JAK2-selective tyrosine kinase inhibitor used to treat patients with myelofibrosis, dramatically impaired JAK1-STAT signaling downstream of all IHCA-associated gp130 mutants. In conclusion, our findings provide a rationale for the use of JAK1 inhibitors for the treatment of HCAs expressing mutant gp130 as well as a subset of HCCs that bear similar mutations.

Practical management of patients with myelofibrosis receiving ruxolitinib

Myelofibrosis (MF) is characterized by bone marrow fibrosis, progressive anemia and extramedullary hematopoiesis, primarily manifested as splenomegaly. Patients also experience debilitating constitutional symptoms, including sequelae of splenomegaly, night sweats and fatigue. Ruxolitinib (INC424, INCB18424, Jakafi, Jakavi), a JAK1 and JAK2 inhibitor, was approved in November 2011 by the US FDA for the treatment of intermediate- or high-risk MF, and more recently in Europe and Canada for the treatment of MF-related splenomegaly or symptoms. These approvals were based on data from two randomized Phase III studies: COMFORT-I randomized against placebo, and COMFORT-II randomized against best available therapy. In these studies, ruxolitinib rapidly improved multiple disease manifestations of MF, reducing splenomegaly and improving quality of life of patients and potentially prolonging survival. However, as with other chemotherapies, ruxolitinib therapy is associated with some adverse events, such as anemia and thrombocytopenia. The aims of this article are to provide a brief overview of ruxolitinib therapy, to discuss some common adverse events associated with ruxolitinib therapy and to provide clinical management recommendations to maximize patients' benefit from ruxolitinib.

The therapeutic goals of essential thrombocythemia under the clouds of over-treatment and under-treatment

INTRODUCTION

Therapeutic stratification after the accurate essential thrombocythemia (ET) diagnosis is made based on the medical history (age, previous thrombosis), clinical assessments (cardiovascular [CV] risk factors, comorbidities, systemic diseases), laboratory examinations (leukocytosis, extreme thrombocytosis, anemia) and if available further sophistical analyses (CD34 count, JAK2V617F homozygosity, and mutant allele burden).

AREAS COVERED

Current conventional therapeutic tools for reaching those goals are observation, low-dose aspirin, hydroxyurea, anegrelide and interferon alpha. Those treatment modalities are used alone or in combination to get the therapeutic goals in ET patients. The ET literature search was made in PubMed with particular focus on the clinical trials, recommendations, guidelines and expert opinions.

EXPERT OPINION

The most important step for the therapeutic decision of ET in the clinic is the risk assessments. Clinical decision making starts with the detection of the age and the prior thrombosis history of the ET patient. Treatment goals in ET are to avoid thrombosis and bleeding, to treat ET-related symptoms, improve quality of life and to minimize risk of malignant transformation and/or post-ET myelofibrosis.

Ruxolitinib: an oral Janus kinase 1 and Janus kinase 2 inhibitor in the management of myelofibrosis

Myelofibrosis (MF), polycythemia vera (PV), and essential thrombocythemia (ET) are referred to as the classic Philadelphia chromosome (BCR-ABL1)-negative myeloproliferative neoplasms. Although each has distinct pathologic features, all 3 display alterations in Janus kinase (JAK) signal transduction activator of transcription signaling. Myelofibrosis is the most serious of the 3, associated with shortened survival (median survival, 5-7 years); bone marrow failure with anemia; progressive splenomegaly; and chronic, burdensome symptoms, including fatigue, night sweats, itching, abdominal discomfort, loss of appetite/early satiety, unintentional weight loss, and bone, chest, and abdominal pain. Treatments for MF have been mainly palliative, with the exception of allogeneic stem cell transplantation, which, although potentially curative, is feasible only in a small subpopulation of patients. In November 2011, ruxolitinib, an inhibitor of JAK1 and JAK2, was approved by the US Food and Drug Administration for the treatment of intermediate- or high-risk MF, including primary MF, post-PV MF, and post-ET MF. In clinical trials, ruxolitinib was shown to reduce spleen volume and improve MF-related symptoms and quality-of-life measures. Evidence also suggests that ruxolitinib therapy has a survival advantage over placebo and best available therapy. Thrombocytopenia and anemia were the most common adverse events with treatment. Ongoing trials are assessing the efficacy and safety of ruxolitinib therapy in patients with PV and ET.

Primary myelofibrosis: risk stratification by IPSS identifies patients with poor clinical outcome

OBJECTIVES

To evaluate whether risk scores used to classify patients with primary myelofibrosis and JAK-2 V617F mutation status can predict clinical outcome.

METHODS

A review of clinical and laboratory data from 74 patients with primary myelofibrosis diagnosed between 1992 and 2011. The IPSS and Lille scores were calculated for risk stratification and correlated with overall survival.

RESULTS

A V617F JAK2 mutation was detected in 32 cases (47%), with no significant correlation with overall survival. The patients were classified according to the scores: Lille - low, 53 (73.%); intermediate, 13 (18%); and high, 5 (7%); and IPSS- low, 15 (26%); intermediate-1, 23 (32%); intermediate-2, 19 (26%); and high, 15 (31%). Those patients presenting a higher risk according to the IPSS (high and intermediate-2) had a significantly shorter overall survival relative to the low risk groups (intermediate-1 and low) (p = 0.02).

CONCLUSIONS

These results emphasize the importance of the IPSS prognostic score for risk assessment in predicting the clinical outcome of primary myelofibrosis patients.