Novel Non-biologic Targets for Inflammatory Bowel Disease

[Application of advanced treatment in chronic inflammatory bowel diseases]

BACKGROUND

The treatment options for chronic inflammatory bowel diseases (IBD) have been greatly expanded due to a better understanding of the underlying pathogenesis. A total of five classes of advanced treatment are available.

OBJECTIVE

A practical overview of advanced treatment of IBD.

METHODS

Narrative review.

RESULTS AND DISCUSSION

Advanced treatments are indicated for moderate to severe IBD. A timely use is recommended to achieve better response rates and to avoid irreversible bowel damage. Tumor necrosis factor (TNF) inhibitors and Janus kinase (JAK) inhibitors have a broad efficacy, also for extraintestinal disease manifestations. The risk of reactivation of varicella zoster virus is increased with JAK inhibitors. In high-risk patients and an age >65 years there is possibly a moderately elevated cardiovascular risk and neoplastic side effects. The integrin alpha4beta7 inhibitor vedolizumab and the interleukin (IL) 12 and 23 inhibitor ustekinumab have very good safety profiles. Selective IL-23 inhibitors are sometimes superior to ustekinumab with comparable safety profiles with respect to efficacy. The sphingosine-1-phosphate receptor modulators ozanimod and etrasimod are approved for oral treatment of ulcerative colitis. The treatment success of the medications remains still limited and a minority of patients will not respond to every individual treatment. Thus, sequential administration of several treatments is often needed. Due to the lack of comparative studies, the personalized choice, sequence and decision for treatments are usually based on personal experience and should take patient preferences, efficacy, safety and individual patient profiles into consideration.

Small molecule agents in clinical management of inflammatory bowel disease: Current status and future prospects

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is a chronic non-specific inflammatory disorder affecting the intestines. It is characterized by a protracted course with frequent relapses, potentially resulting in disability, heightened surgical risk, diminished patient quality of life, and increased familial and societal economic burden. Current understanding posits that genetic, immune, and environmental factors, as well as the intestinal microbiota, collectively contribute to the pathogenesis and progression of these diseases. Notably, the prevalence of IBD in China has exhibited a gradual rise in recent years. The inadequate effectiveness and adverse effects of conventional medications, including 5-aminosalicylic acid (5-ASA), corticosteroids, and immunosuppressants, have hindered the effective management of certain patients with IBD. In the realm of biological agents, anti-tumor necrosis factor (TNF) antagonists have emerged as the pioneering targeted therapy, extensively employed for an extended period. However, extensive data analysis spanning several decades reveals a notable proportion of primary and secondary loss of response to these agents. Hence, the ongoing introduction of novel targeted therapy medications, including small molecule agents, has presented a new avenue for individuals who have experienced inadequate response to conventional treatment and anti-TNF therapy. Nevertheless, additional investigation and research are required to determine the optimal role of small molecule agents as initial treatment options. This article provides a comprehensive overview of the efficacy and safety of small molecular agents in recent clinical trials for the treatment of IBD, and explores the treatment decision-making process to identify optimal subsequent treatment drugs and guide the selection of appropriate first-line targeted therapy drugs.

Use of Mesenchymal Stem Cells in Crohn's Disease and Perianal Fistulas: A Narrative Review

Crohn's Disease (CD), which usually leads to anal fistulas among patients, is the most important inflammatory bowel disease that causes morbidity in many people around the world. This review article proposes using MSCs as a hopeful therapeutic strategy for CD and anal fistula treatment in both preclinical and clinical conditions. Finally, darvadstrocel, a cell-based medication to treat complex anal fistulas in adults, as the only European Medicines Agency (EMA)-approved product for the treatment of anal fistulas in CD is addressed. Although several common therapies, such as surgery and anti-tumor necrosis factor-alpha (TNF-α) drugs as well as a combination of these methods is used to improve this disease, however, due to the low effectiveness of these treatments, the use of new strategies with higher efficiency is still recommended. Cell therapy is among the new emerging therapeutic strategies that have attracted great attention from clinicians due to its unique capabilities. One of the most widely used cell sources administrated in cell therapy is mesenchymal stem cell (MSC). This review article will discuss preclinical and clinical studies about MSCs as a potent and promising therapeutic option in the treatment of CD and anal fistula.

Evaluating Upadacitinib in the Treatment of Moderate-to-Severe Active Ulcerative Colitis: Design, Development, and Potential Position in Therapy

Upadacitinib is a selective small molecule that inhibits Janus kinase (JAK) type 1. This molecule is administrated orally and is currently approved for the treatment of rheumatoid arthritis, atopic dermatitis, and psoriatic arthritis. Upadacitinib has been approved by the United States Food and Drug Administration for the induction and maintenance therapy of moderate-to-severe ulcerative colitis (UC) and is under investigation by the European Medicines Agency. Data from two induction and two maintenance Phase III randomized controlled trials (RCTs) proved the efficacy of upadacitinib in achieving clinical and endoscopic remission in patients with moderate-to-severe UC, regardless of previous inadequate response to other biologic therapies. The most frequently reported adverse events in the induction trials were acne, creatine phosphokinase increase, nasopharyngitis, headache, and anemia, while in the maintenance studies nasopharyngitis, elevation of creatine phosphokinase, UC exacerbation, upper respiratory tract infection, arthralgia, and anemia were reported. A limited proportion of upadacitinib-treated patients experienced adverse events of special interest, like herpes zoster infections or thromboembolic events, indicating a reliable safety profile. The aim of this review is to summarize the available evidence on upadacitinib in UC providing useful insights about the positioning of this drug in the therapeutic algorithm.

Emerging Treatment Options in Inflammatory Bowel Disease: Janus Kinases, Stem Cells, and More

BACKGROUND

Treatment of inflammatory bowel diseases (IBD) has tremendously improved during the last 20 years; however, a substantial fraction of patients does not respond to available therapies or lose response, and new strategies are needed.

SUMMARY

Two pharmacological principles have been successfully used for IBD treatment: inhibition of cellular signaling and interference with leukocyte trafficking. Besides tumor necrosis factor, interleukin (IL)-23 is a promising drug target, and antibodies for the combined inhibition of IL-23 and IL-12 (ustekinumab and briakinumab) or selective IL-23 inhibition (brazikumab, risankizumab, and mirikizumab) seem to be effective in Crohn's disease (CD) with emerging evidence also for ulcerative colitis (UC). Janus kinase (JAK) mediates intracellular signaling of a large number of cytokines. Tofacitinib is the first JAK inhibitor approved for UC, and the JAK inhibitors filgotinib and upadacitinib showed potential in CD. Leukocyte trafficking can be inhibited by interference with lymphocyte integrin-α4β7 or endothelial MadCAM-1. The α4β7 integrin inhibitor vedolizumab is an established treatment in IBD, and long-term data of pivotal studies are now available. Additional molecules with therapeutic potential are α4β7-specific abrilumab, β7-specific etrolizumab, and the α4-specific small molecule AJM300. PF-00547659, an antibody against endothelial MadCAM-1, also showed therapeutic potential in UC. Modulation of sphingosine-1-phosphate receptor (S1PR) activity is necessary for the egress of lymphocytes into the circulation, and S1PR modulation results in lymphocyte trapping in lymphatic organs. Ozanimod, an S1PR1 and S1PR5 inhibitor, has been successfully tested in initial studies in UC. Mesenchymal stem cell therapy has been approved for the treatment of complex, active CD fistula, and mesenchymal stem cell therapy might be a paradigm shift for this condition. Autologous stem cell transplantation (ASCT) has been successfully used in CD case series; however, in a randomized trial, a highly stringent endpoint was not met. However, considering positive effects in secondary endpoints, ASCT might be a future treatment of last resort in severe, refractory CD cases, provided that safer protocols can be provided. Key messages: New IBD treatments are successful for a significant fraction of patients. However, new strategies for patient selection, treatment combinations, and/or additional therapies must be developed to serve the need of all IBD patients.

Targeting JAK/STAT signaling pathways in treatment of inflammatory bowel disease

Janus kinase/signal transduction and transcriptional activator (JAK/STAT) signaling pathway is a transport hub for cytokine secretion and exerts its effects. The activation of JAK/STAT signaling pathway is essential for the regulation of inflammatory responses. Inappropriate activation or deletion of JAK/STAT signaling pathway is the initiator of the inflammatory response. JAK/STAT signaling pathway has been demonstrated to be involved in the process of innate and adaptive immune response to inflammatory bowel disease (IBD). In this review, we discuss the role of the JAK/STAT signaling pathway in the regulation of different cells in IBD, as well as new findings on the involvement of the JAK/STAT signaling pathway in the regulation of the intestinal immune response. The current status of JAK inhibitors in the treatment of IBD is summarized as well. This review highlights natural remedies that can serve as potential JAK inhibitors. These phytochemicals may be useful in the identification of precursor compounds in the process of designing and developing novel JAK inhibitors.

Biosimilar Interchangeability and Emerging Treatment Strategies for Inflammatory Bowel Diseases: A Commentary

This commentary summarizes a collection of key references published within the last ten years, and identifies pharmacologic research directions to improve treatment access and success through greater biosimilar or “follow-on” biologic utilization combined with other targeted small molecule agents that possess unique pathophysiologic mechanisms for inflammatory bowel diseases (IBD) in adult and pediatric patients. Since they are not identical to the originator or reference biologic agent, all biosimilars are not generically equivalent. However, in the US and other countries, they are considered therapeutically interchangeable if the manufacturer has demonstrated no clinically meaningful differences from the reference product. Comparisons of different clinical initiation and switching scenarios are discussed with reference to interchangeability, immunogenicity, nocebo effect, cost effectiveness, and time courses for discontinuation rates.

Will mesenchymal stem cells be future directions for treating radiation-induced skin injury?

Radiation-induced skin injury (RISI) is one of the common serious side effects of radiotherapy (RT) for patients with malignant tumors. Mesenchymal stem cells (MSCs) are applied to RISI repair in some clinical cases series except some traditional options. Though direct replacement of damaged cells may be achieved through differentiation capacity of MSCs, more recent data indicate that various cytokines and chemokines secreted by MSCs are involved in synergetic therapy of RISI by anti-inflammatory, immunomodulation, antioxidant, revascularization, and anti-apoptotic activity. In this paper, we not only discussed different sources of MSCs on the treatment of RISI both in preclinical studies and clinical trials, but also summarized the applications and mechanisms of MSCs in other related regenerative fields.

New Therapeutics for Ulcerative Colitis

Ulcerative colitis (UC) is a relapsing and remitting inflammatory disease of the colon with a variable course. Despite advances in treatment, only approximately 40% of patients achieve clinical remission at the end of a year, prompting the exploration of new treatment modalities. This review explores novel therapeutic approaches to UC, including promising drugs in various stages of development, efforts to maximize the efficacy of currently available treatment options, and non-medication-based modalities. Treatment approaches which show promise in impacting the future of UC management are highlighted.

Current Status of Medical Therapy for Inflammatory Bowel Disease: The Wealth of Medications

Previously, the natural history of Crohn's disease and ulcerative colitis included significant morbidity due to limited treatment options that were not without serious side effects. Early treatment options included corticosteroids as well as mesalamine, thiopurines, and methotrexate. In 1998, monoclonal antibodies to a key inflammatory cytokine, TNFα, became available. Over the next 22 years, the field of gastroenterology has seen multiple new treatments emerging for inflammatory bowel disease (IBD) that target different aspects of the inflammatory cascade, significantly changing the therapeutic landscape. Additional monoclonal antibodies are available that target the integrins, which are adhesion proteins that traffic inflammatory leukocytes. Small molecule inhibitors block the inflammatory signals of several cytokines. New therapies that modulate lymphocyte escape from lymphoid tissue are promising. Lastly, stem cell technology has emerged as a platform to successfully treat perianal fistulizing disease. Our aim is to summarize the currently available therapies for IBD beyond steroids, mesalamine, and immune modulators. We highlight the most important clinical trials that have brought these treatments to clinical practice, and we discuss the ongoing clinical trials of novel therapies that have a high probability of eventual regulatory approval.

Small molecule drugs in the treatment of inflammatory bowel diseases: which one, when and why? - a systematic review

In the 'treat-to-target' era of inflammatory bowel disease (IBD) management, small molecule drugs (SMDs) represent a promising alternative to biomolecular drugs. Moreover, increasing failure rates of anti-tumor necrosis factor α agents have contributed to the development of new molecules with different mechanisms of action and bioavailability. This review focuses on the positioning of new, orally targeted therapies in the treatment algorithm of both Crohn's disease (CD) and ulcerative colitis (UC), with special consideration to their efficacy and safety. We performed a comprehensive search of PubMed and clinical trial registries to identify randomized controlled trials assessing SMDs in adult patients with moderate-to-severe IBD, irrespective of previous exposure to other biologics. In this review, we included 15 double-blind, placebo-controlled trials that assessed the efficacy and safety of Janus kinase inhibitors, sphingosine-1-phosphate modulators (S1P), SMAD blockers, phosphodiesterase 4 inhibitors and α-4 antagonists. The primary endpoints in UC were achieved for tofacitinib in the phase III OCTAVE study and AJM-300, with a favorable safety profile. S1P receptor agonists, such as etrasimod and ozanimod, demonstrated favorable results in induction studies. For CD, filgotinib and upadacitinib also met the primary outcome criteria. Available data have demonstrated so far that SMDs have an advantageous safety and efficacy profile. However, their use in a clinical setting will eventually require a personalized, mechanism-based therapeutic approach.