Preventive and Therapeutic Effects of a Novel JAK Inhibitor SHR0302 in Acute Graft-Versus-Host Disease

A Novel JAK1 Inhibitor SHR0302 Combined With Prednisone for First-Line Treatment of Chronic Graft-Versus-Host Disease: A Phase I Clinical Trial

Chronic graft-versus-host disease (cGVHD) is a potentially life-threatening complication after allogeneic hematopoietic stem cell transplantation. Standard steroid first-line treatment could not satisfy therapeutic needs due to limited efficacy. As a highly selective Janus kinase (JAK) 1 inhibitor, SHR0302 exhibits a reduced inhibition effect on JAK2 and might have less effect on hematopoiesis. This phase I clinical trial investigated the tolerability and safety of SHR0302 in combination with prednisone, and its early efficacy evidence as a potential first-line treatment to moderate/severe cGVHD. The standard 3 + 3 dose escalation was implemented to find the optimal dose of SHR0302. And prednisone was concurrently administrated with a dose of 1 mg/kg/d and then gradually tapered after 2 weeks. Eighteen patients were enrolled into the study. Grade ≥ 3 treatment-related adverse events were observed in 38.9% of patients. Only one patient developed DLT (grade ≥ 3 hypercholesterolemia) in the highest dose-level group who had pre-existing hypercholesterolemia. The maximum tolerated dose was not reached. No patient discontinued treatment due to AEs. Sixteen out of 18 patients were evaluable for responses, the ORR at week 4 and week 24 were 94.4 and 87.5%, respectively. Overall, the treatment of SHR0302 combined with prednisone was safe and well-tolerated, preliminary clinical results presented a high response for previously untreated cGVHD and a significant reduction in prednisone use in this study. A phase II trial will be conducted to further investigate its therapeutic effects clinically.

Effect of SHR0302 on the pharmacokinetics of CYP3A4, CYP2C8, CYP2C9 and CYP2C19 probe substrates in healthy volunteers: A cocktail analysis

AIMS

This study evaluated the effects of SHR0302 on the pharmacokinetics of cytochrome P450 (CYP) probe substrates.

METHODS

We performed a single-centre, open-label, three-period drug-drug interaction (DDI) study in 24 healthy subjects (NCT05392127). Subjects received a single oral dose of 5 mg warfarin (CYP2C9), 20 mg omeprazole (CYP2C19) and 15 mg midazolam (CYP3A4) on Days 1, 8 and 22, and received 0.5 mg repaglinide (CYP2C8) on Days 7, 14 and 28. Multiple oral doses of 8 mg SHR0302 were administered once daily from Day 8 to Day 28.

RESULTS

The exposure of S-warfarin and repaglinide were comparable before and after SHR0302 administration. AUC of midazolam was not affected by SHR0302, whereas the administration of SHR0302 slightly decreased the Cmax of midazolam by 7.6% (single dose) and 15.7% (once daily for 14 days). The AUC0-t , AUC0-inf , and Cmax of omeprazole were slightly decreased after a single dose of SHR0302 by 19.2%, 21.8% and 23.5%, respectively. In the presence of SHR0302 for 14 days, the AUC0-t , AUC0-inf , and Cmax of omeprazole were marginally reduced by 3.0%, 16.4% and 8.3%, respectively. According to the induction mechanism of the CYP enzyme, for the investigation of the induction effect, the results of multiple administrations of the perpetrator were more reliable than those of the single dose.

CONCLUSIONS

The results demonstrated that co-administration of SHR0302 8 mg once daily is unlikely to have a clinically meaningful effect on the exposure of drugs metabolized by CYP3A4, CYP2C8, CYP2C9 and CYP2C19 in healthy subjects.

Evolving cognition of the JAK-STAT signaling pathway: autoimmune disorders and cancer

The Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathway is an evolutionarily conserved mechanism of transmembrane signal transduction that enables cells to communicate with the exterior environment. Various cytokines, interferons, growth factors, and other specific molecules activate JAK-STAT signaling to drive a series of physiological and pathological processes, including proliferation, metabolism, immune response, inflammation, and malignancy. Dysregulated JAK-STAT signaling and related genetic mutations are strongly associated with immune activation and cancer progression. Insights into the structures and functions of the JAK-STAT pathway have led to the development and approval of diverse drugs for the clinical treatment of diseases. Currently, drugs have been developed to mainly target the JAK-STAT pathway and are commonly divided into three subtypes: cytokine or receptor antibodies, JAK inhibitors, and STAT inhibitors. And novel agents also continue to be developed and tested in preclinical and clinical studies. The effectiveness and safety of each kind of drug also warrant further scientific trials before put into being clinical applications. Here, we review the current understanding of the fundamental composition and function of the JAK-STAT signaling pathway. We also discuss advancements in the understanding of JAK-STAT-related pathogenic mechanisms; targeted JAK-STAT therapies for various diseases, especially immune disorders, and cancers; newly developed JAK inhibitors; and current challenges and directions in the field.

Selective JAK1 inhibitors for the treatment of inflammatory bowel disease

Janus kinase (JAK) inhibitors, also known as jakinibs, are third-generation oral small molecules that have expanded the therapeutic options for the management of chronic inflammatory diseases, including inflammatory bowel disease (IBD). Tofacitinib, a pan-JAK inhibitor, has spearheaded the new JAK class for IBD treatment. Unfortunately, serious adverse effects, including cardiovascular complications such as pulmonary embolism and venous thromboembolism or even death from any cause, have been reported for tofacitinib. However, it is anticipated that next-generation selective JAK inhibitors may limit the development of serious adverse events, leading to a safer treatment course with these novel targeted therapies. Nevertheless, although this drug class was recently introduced, following the launch of second-generation biologics in the late 1990s, it is breaking new ground and has been shown to efficiently modulate complex cytokine-driven inflammation in both preclinical models and human studies. Herein, we review the clinical opportunities for targeting JAK1 signaling in the pathophysiology of IBD, the biology and chemistry underpinning these target-selective compounds, and their mechanisms of actions. We also discuss the potential for these inhibitors in efforts to balance their benefits and harms.

Mass balance study of [14C]SHR0302, a selective and potent JAK1 inhibitor in humans

SHR0302, a selective JAK1 inhibitor developed by Jiangsu Hengrui Pharmaceutical Co., was intended for the treatment of rheumatoid arthritis. In this study, we evaluated the pharmacokinetics, mass balance, and metabolism of SHR0302 in six healthy Chinese male subjects after a single 8 mg (80 µCi) oral dose of [¹⁴C]SHR0302.SHR0302 was absorbed rapidly (T_max = 0.505 h), and the average t_1/2 of the SHR0302-related components in plasma was approximately 9.18 h. After an oral dose was administered, the average cumulative excretion of the radioactive components was 100.56% ± 1.51%, including 60.95% ± 11.62% in urine and 39.61% ± 10.52% in faeces.A total of 16 metabolites were identified. In plasma, the parent drug SHR0302 accounted for 90.42% of the total plasma radioactivity. In urine, SHR161279 was the main metabolite, accounting for 33.61% of the dose, whereas the parent drug SHR0302 only accounted for 5.1% of the dose. In faeces, the parent drug SHR0302 accounted for 23.73% of the dose, and SHR161279 was the significant metabolite, accounting for 5.67% of the dose. In conclusion, SHR0302-related radioactivity was mainly excreted through urine (60.95%) and secondarily through faeces (39.61%).The metabolic reaction of SHR0302 in the human body is mainly through mono-oxidation and glucuronidation. The main metabolic location of SHR0302 in the human body is the pyrrolopyrimidine ring.

Jakinibs of All Trades: Inhibiting Cytokine Signaling in Immune-Mediated Pathologies

Over the last 25 years, inhibition of Janus kinases (JAKs) has been pursued as a modality for treating various immune and inflammatory disorders. While the clinical development of JAK inhibitors (jakinibs) began with the investigation of their use in allogeneic transplantation, their widest successful application came in autoimmune and allergic diseases. Multiple molecules have now been approved for diseases ranging from rheumatoid and juvenile arthritis to ulcerative colitis, atopic dermatitis, graft-versus-host-disease (GVHD) and other inflammatory pathologies in 80 countries around the world. Moreover, two jakinibs have also shown surprising efficacy in the treatment of hospitalized coronavirus disease-19 (COVID-19) patients, indicating additional roles for jakinibs in infectious diseases, cytokine storms and other hyperinflammatory syndromes. Jakinibs, as a class of pharmaceutics, continue to expand in clinical applications and with the development of more selective JAK-targeting and organ-selective delivery. Importantly, jakinib safety and pharmacokinetics have been investigated alongside clinical development, further cementing the potential benefits and limits of jakinib use. This review covers jakinibs that are approved or are under late phase investigation, focusing on clinical applications, pharmacokinetic and safety profiles, and future opportunities and challenges.

Translational Clinical Strategies for the Prevention of Gastrointestinal Tract Graft Versus Host Disease

Graft versus host disease (GVHD) is the major non-relapse complication associated with allogeneic hematopoietic stem cell transplantation (HSCT). Unfortunately, GVHD occurs in roughly half of patients following this therapy and can induce severe life-threatening side effects and premature mortality. The pathophysiology of GVHD is driven by alloreactive donor T cells that induce a proinflammatory environment to cause pathological damage in the skin, gastrointestinal (GI) tract, lung, and liver during the acute phase of this disease. Recent work has demonstrated that the GI tract is a pivotal target organ and a primary driver of morbidity and mortality in patients. Prevention of this complication has therefore emerged as an important goal of prophylaxis strategies given the primacy of this tissue site in GVHD pathophysiology. In this review, we summarize foundational pre-clinical studies that have been conducted in animal models to prevent GI tract GVHD and examine the efficacy of these approaches upon subsequent translation into the clinic. Specifically, we focus on therapies designed to block inflammatory cytokine pathways, inhibit cellular trafficking of alloreactive donor T cells to the GI tract, and reconstitute impaired regulatory networks for the prevention of GVHD in the GI tract.