A Phase 1/2 Study of the Oral Janus Kinase 1 Inhibitors INCB052793 and Itacitinib Alone or in Combination With Standard Therapies for Advanced Hematologic Malignancies

A phase 2 study of itacitinib alone or in combination with low-dose ruxolitinib in patients with myelofibrosis

BACKGROUND

The Janus kinase (JAK) 1/JAK2 inhibitor ruxolitinib has demonstrated efficacy/safety in patients with myelofibrosis; however, not all patients experience optimal and/or stable response, in part owing to dose-limiting toxicities. This phase 2 study evaluated itacitinib (JAK1-selective inhibitor) efficacy/safety alone or combined with low-dose ruxolitinib.

METHODS

Cohort A received itacitinib 200 mg once daily (QD) plus ruxolitinib at a previous stable dose (≤15 mg total daily dose). Cohort B (previously ruxolitinib-treated) received itacitinib 600 mg QD alone. The primary endpoint was baseline-to-week 24 spleen volume reduction (SVR).

RESULTS

Twenty-three patients were enrolled (median age, 71.0 years; intermediate-1/-2 risk, 73.9 %; Cohort A, n = 13; Cohort B, n = 10). Mean (standard deviation) percentage SVR from baseline was +6.9 % (27.5 %) and -3.0 % (34.7 %) in Cohorts A and B at week 24 (primary endpoint), and -1.6 % (14.7 %) and -24.6 % (21.7 %) in Cohorts A and B at week 12. SVR from baseline was achieved by 5 and 3 patients in Cohorts A and B at week 24, and by 9 and 7 patients in Cohorts A and B at week 12. Most common treatment-emergent adverse events (TEAEs) were anemia, diarrhea, and fatigue (each n = 8); most common grade ≥ 3 TEAEs were anemia (n = 6), thrombocytopenia (n = 5), fatigue (n = 3), and diarrhea (n = 2).

CONCLUSIONS

Overall, 8 of 23 patients enrolled achieved SVR at week 24; larger average changes in SVR at week 12 were observed for itacitinib monotherapy vs. the combination. No unexpected safety signals were observed.

Investigation into biased signaling, glycosylation, and drug vulnerability of acute myeloid leukemia

Understanding and harnessing biased signaling offers significant potential for developing novel therapeutic strategies or enhancing existing treatments. By managing biased signaling, it is possible to minimize adverse effects, including toxicity, and to optimize therapeutic outcomes by selectively targeting beneficial pathways. In the context of acute myeloid leukemia (AML), a highly aggressive blood cancer characterized by the rapid proliferation of abnormal myeloid cells in the bone marrow and blood, the dysregulation of these signaling pathways, particularly those involving G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs), significantly contributes to disease progression and therapeutic resistance. Traditional therapies for AML often struggle with resistance and toxicity, leading to poor patient outcomes. However, by exploiting the concept of biased signaling, researchers may be able to design drugs that selectively activate pathways that inhibit cancer cell growth while avoiding those that contribute to resistance or toxicity. Glycosylation, a key post-translational modification (PTM), plays a crucial role in biased signaling by altering receptor conformation and ligand-binding affinity, thereby affecting the outcome of biased signaling. Chemokine receptors like CXCR4, which are often overexpressed and heavily glycosylated in AML, serve as targets for therapeutic intervention. By externally inducing or inhibiting specific PTMs, it may be possible to further refine therapeutic strategies, unlocking new possibilities for developing more effective and less toxic treatments. This review highlights the importance of understanding the dynamic relationship between glycosylation and biased signaling in AML, which is essential for the development of more effective treatments and overcoming drug resistance, ultimately leading to better patient outcomes.

SOCS1 Protects Acute Myeloid Leukemia against Allogeneic T Cell-Mediated Cytotoxicity

SIGNIFICANCE

Our investigation of the SOCS1 pathway in AML and T-cell interactions provides insights into potential mechanisms of resistance of AML to allogeneic hematopoietic stem cell transplantation and demonstrates the potential of targeting SOCS1 and its downstream mediators to enhance antileukemic T-cell activity. See related commentary by Fry, p. 157.

Canonical and noncanonical NOTCH signaling in the nongenetic resistance of cancer: distinct and concerted control

Therapeutic resistance in cancer is responsible for numerous cancer deaths in clinical practice. While target mutations are well recognized as the basis of genetic resistance to targeted therapy, nontarget mutation resistance (or nongenetic resistance) remains poorly characterized. Despite its complex and unintegrated mechanisms in the literature, nongenetic resistance is considered from our perspective to be a collective response of innate or acquired resistant subpopulations in heterogeneous tumors to therapy. These subpopulations, e.g., cancer stem-like cells, cancer cells with epithelial-to-mesenchymal transition, and drug-tolerant persisters, are protected by their resistance traits at cellular and molecular levels. This review summarizes recent advances in the research on resistant populations and their resistance traits. NOTCH signaling, as a central regulator of nongenetic resistance, is discussed with a special focus on its canonical maintenance of resistant cancer cells and noncanonical regulation of their resistance traits. This novel view of canonical and noncanonical NOTCH signaling pathways is translated into our proposal of reshaping therapeutic strategies targeting NOTCH signaling in resistant cancer cells. We hope that this review will lead researchers to study the canonical and noncanonical arms of NOTCH signaling as an integrated resistant mechanism, thus promoting the development of innovative therapeutic strategies.

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

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

Preclinical and clinical evaluation of the Janus Kinase inhibitor ruxolitinib in multiple myeloma

Multiple myeloma (MM) is the most common primary malignancy of the bone marrow. No established curative treatment is currently available for patients diagnosed with MM. In recent years, new and more effective drugs have become available for the treatment of this B-cell malignancy. These new drugs have often been evaluated together and in combination with older agents. However, even these novel combinations eventually become ineffective; and, thus, novel therapeutic approaches are necessary to help overcome resistance to these treatments. Recently, the Janus Kinase (JAK) family of tyrosine kinases, specifically JAK1 and JAK2, has been shown to have a role in the pathogenesis of MM. Preclinical studies have demonstrated a role for JAK signaling in direct and indirect growth of MM and downregulation of anti-tumor immune responses in these patients. Also, inhibition of JAK proteins enhances the anti-MM effects of other drugs used to treat MM. These findings have been confirmed in clinical studies which have further demonstrated the safety and efficacy of JAK inhibition as a means to overcome resistance to currently available anti-MM therapies. Additional studies will provide further support for this promising new therapeutic approach for treating patients with MM.

The Use of JAK/STAT Inhibitors in Chronic Inflammatory Disorders

The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a critical role in orchestrating immune and inflammatory responses, and it is essential for a wide range of cellular processes, including differentiation, cell growth, and apoptosis. Over the years, this pathway has been heavily investigated due to its key role in the pathogeneses of several chronic inflammatory conditions, e.g., psoriasis, atopic dermatitis (AD), and inflammatory bowel diseases (IBDs). Nevertheless, the impact of this pathway on the pathogenesis of inflammatory conditions remains unclear. This review describes the role of the JAK/STAT signaling pathway in the pathogenesis of inflammatory diseases such as psoriasis (Pso), psoriatic arthritis (PsA), AD, and IBD with a focus on ulcerative colitis (UC) and briefly resumes the use of JAK inhibitors in their clinical management.

Kinase Inhibition in Multiple Myeloma: Current Scenario and Clinical Perspectives

Multiple myeloma (MM) is a blood cell neoplasm characterized by excessive production of malignant monoclonal plasma cells (activated B lymphocytes) by the bone marrow, which end up synthesizing antibodies or antibody fragments, called M proteins, in excess. The accumulation of this production, both cells themselves and of the immunoglobulins, causes a series of problems for the patient, of a systemic and local nature, such as blood hyperviscosity, renal failure, anemia, bone lesions, and infections due to compromised immunity. MM is the third most common hematological neoplasm, constituting 1% of all cancer cases, and is a disease that is difficult to treat, still being considered an incurable disease. The treatments currently available cannot cure the patient, but only extend their lifespan, and the main and most effective alternative is autologous hematopoietic stem cell transplantation, but not every patient is eligible, often due to age and pre-existing comorbidities. In this context, the search for new therapies that can bring better results to patients is of utmost importance. Protein tyrosine kinases (PTKs) are involved in several biological processes, such as cell growth regulation and proliferation, thus, mutations that affect their functionality can have a great impact on crucial molecular pathways in the cells, leading to tumorigenesis. In the past couple of decades, the use of small-molecule inhibitors, which include tyrosine kinase inhibitors (TKIs), has been a hallmark in the treatment of hematological malignancies, and MM patients may also benefit from TKI-based treatment strategies. In this review, we seek to understand the applicability of TKIs used in MM clinical trials in the last 10 years.