Safety issues with biological therapies for inflammatory bowel disease

Discovery of WD-890: A novel allosteric TYK2 inhibitor for the treatment of multiple autoimmune diseases

Tyrosine kinase 2 (TYK2) as a member of Janus kinase (JAK) family, mainly mediates the signaling of type I interferons (IFN), interleukin-12 (IL-12) and interleukin-23 (IL-23), which has become an attractive target for treatment of immune and inflammatory diseases. However, the development of selective TYK2 inhibitors is challenging due to the high homology of the catalytic kinase domain among the JAK family members. Here, we report a novel and potent allosteric inhibitor, WD-890, which binds to the pseudokinase domain of TYK2 with high selectivity and inhibits its function. We accomplished a series of preclinical studies to demonstrate the therapeutic efficacy of WD-890 in four animal models: systemic lupus erythematosus (SLE), psoriasis, psoriatic arthritis (PsA), and inflammatory bowel disease (IBD). The pharmacokinetic and toxicology results further indicate that WD-890 has favorable absorption, distribution, metabolism, and excretion (ADME) properties and tolerable toxicity. In conclusion, our study shows that WD-890 could be a promising oral TYK2 inhibitor for future treatment of autoimmune diseases.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.

Nanotechnology in the Treatment of Inflammatory Bowel Disease

Due to the lack of cure for inflammatory bowel disease (IBD) and failure of current medical therapies in many patients with IBD, a need exists in finding novel ways to treat inflammation with a high benefit and the lowest risk possible. With current medical therapies, adverse events or risks of cancer/lymphoma and infections prevent patients-and sometimes providers-in using effective therapies for treatment. Some patients develop systemic side effects that preclude them from continuing a therapy that may have been efficacious, or in other cases, current medical therapies are not adequate to control disease. Nanotechnology is an emerging field where particles, in the size of nanometers, can be used to deliver medications directly to the area of inflammation thus avoiding drug-associated systemic side effects. When using nanoparticles (NPs), only a small amount of the drug is needed, and it can be delivered directly to the inflamed site without exposure to the rest of the body. Here we review conventional and unconventional therapies applied in the treatment of IBD underlying how the introduction of NPs has improved their safety and efficacy.

Remicade® (infliximab): 20 years of contributions to science and medicine

On August 24, 1998, Remicade^® (infliximab), the first tumor necrosis factor-α (TNF) inhibitor, received its initial marketing approval from the US Food and Drug Administration for the treatment of Crohn’s disease. Subsequently, Remicade was approved in another five adult and two pediatric indications both in the USA and across the globe. In the 20 years since this first approval, Remicade has made several important contributions to the advancement of science and medicine: 1) clinical trials with Remicade established the proof of concept that targeted therapy can be effective in immune-mediated inflammatory diseases; 2) as the first monoclonal antibody approved for use in a chronic condition, Remicade helped in identifying methods of administering large, foreign proteins repeatedly while limiting the body’s immune response to them; 3) the need to establish Remicade’s safety profile required developing new methods and setting new standards for postmarketing safety studies, specifically in the real-world setting, in terms of approach, size, and duration of follow-up; 4) the study of Remicade has improved our understanding of TNF’s role in the immune system, as well as our understanding of the pathophysiology of a range of diseases characterized by chronic inflammation; and 5) Remicade and other TNF inhibitors have transformed treatment practices in these chronic inflammatory diseases: remission has become a realistic goal of therapy and long-term disability resulting from structural damage can be prevented. This paper reviews how, over the course of its development and 20 years of use in clinical practice, Remicade was able to make these contributions.

Review article: The pharmacokinetics and pharmacodynamics of drugs used in inflammatory bowel disease treatment

BACKGROUND

The following review is a compilation of the recent advances and knowledge on the behaviour of the most frequently used compounds to treat inflammatory bowel disease in an organism.

RESULTS

It considers clinical aspects of each entity and the pharmacokinetic/pharmacodynamic relationship supported by the use of plasma monitoring, tissue concentrations, and certain aspects derived from pharmacogenetics.

Potential prospects of nanomedicine for targeted therapeutics in inflammatory bowel diseases

Inflammatory bowel diseases (IBDs) such as Crohn’s disease are highly debilitating. There are inconsistencies in response to and side effects in the current conventional medications, failures in adequate drug delivery, and the lack of therapeutics to offer complete remission in the presently available treatments of IBD. This suggests the need to explore beyond the horizons of conventional approaches in IBD therapeutics. This review examines the arena of the evolving IBD nanomedicine, studied so far in animal and in vitro models, before comprehensive clinical testing in humans. The investigations carried out so far in IBD models have provided substantial evidence of the nanotherapeutic approach as having the potential to overcome some of the current drawbacks to conventional IBD therapy. We analyze the pros and cons of nanotechnology in IBD therapies studied in different models, aimed at different targets and mechanisms of IBD pathogenesis, in an attempt to predict its possible impact in humans.

Oral administration of Parabacteroides distasonis antigens attenuates experimental murine colitis through modulation of immunity and microbiota composition

Commensal bacteria have been shown to modulate the host mucosal immune system. Here, we report that oral treatment of BALB/c mice with components from the commensal, Parabacteroides distasonis, significantly reduces the severity of intestinal inflammation in murine models of acute and chronic colitis induced by dextran sulphate sodium (DSS). The membranous fraction of P. distasonis (mPd) prevented DSS-induced increases in several proinflammatory cytokines, increased mPd-specific serum antibodies and stabilized the intestinal microbial ecology. The anti-colitic effect of oral mPd was not observed in severe combined immunodeficient mice and probably involved induction of specific antibody responses and stabilization of the intestinal microbiota. Our results suggest that specific bacterial components derived from the commensal bacterium, P. distasonis, may be useful in the development of new therapeutic strategies for chronic inflammatory disorders such as inflammatory bowel disease.

Positioning biologic agents in the treatment of Crohn's disease

One decade after the emergence of biologic therapy for Crohn's disease (CD), our treatment algorithms are beginning to change. Once reserved for patients with refractory disease, disease unresponsive to conventional therapies, or those requiring multiple courses of corticosteroids, there is increasing evidence that early, aggressive interventions with immunosuppressants or biologic therapies targeting tumor necrosis factor-alpha or alpha-4 integrins can alter the natural history of CD by reducing the transmural complications of structuring and fistulization and the nearly inevitable requisite for surgical resections. More recent trials are beginning to suggest that intervention with combination therapy for selected patients with a poor prognosis may modify the long-term course of CD. Selection of patients with features predicting a complex or progressive course and early, combined intervention is now possible. Future studies are still needed to best identify predictors of response to individual agents with differing mechanisms of action, as well as to optimize the risk-benefit of long-term maintenance therapy.

Management of Crohn's disease in adults

Guidelines for clinical practice are intended to suggest preferable approaches to particular medical problems as established by interpretation and collation of scientifically valid research, derived from extensive review of published literature. When data that will withstand objective scrutiny are not available, a recommendation may be made based on a consensus of experts. Guidelines are intended to apply to the clinical situation for all physicians without regard to specialty. Guidelines are intended to be flexible, not necessarily indicating the only acceptable approach, and should be distinguished from standards of care that are inflexible and rarely violated. Given the wide range of choices in any health-care problem, the physician should select the course best suited to the individual patient and the clinical situation presented. These guidelines are developed under the auspices of the American College of Gastroenterology and its Practice Parameters Committee. Expert opinion is solicited from the outset for the document. The quality of evidence upon which a specific recommendation is based is as follows: Grade A: Homogeneous evidence from multiple well-designed randomized (therapeutic) or cohort (descriptive) controlled trials, each involving a number of participants to be of sufficient statistical power. Grade B: Evidence from at least one large well-designed clinical trial with or without randomization, from cohort or case-control analytic studies, or well-designed meta-analysis. Grade C: Evidence based on clinical experience, descriptive studies, or reports of expert committees. The Committee reviews guidelines in depth, with participation from experienced clinicians and others in related fields. The final recommendations are based on the data available at the time of the production of the document and may be updated with pertinent scientific developments at a later time.

Infliximab for pediatric ulcerative colitis: a retrospective Italian multicenter study

BACKGROUND

Infliximab (IFX), the chimeric anti TNFalpha antibody, an established treatment for Crohn's disease in adults and in children, is used less frequently in ulcerative colitis (UC).

AIM OF THE STUDY

To report the clinical course of pediatric patients with active UC receiving IFX.

PATIENTS AND METHODS

Charts of 22 patients were reviewed (13 male, 9 female): 4 with a severe UC attack refractory to systemic corticosteroids (CS); 18 with a protracted course, of which 16 CS-dependent and 2 CS-resistant. The baseline therapeutic program consisted of 3 consecutive intravenous infusions (0, 2, 6 weeks) of IFX (5 mg/kg), followed by a retreatment schedule (infusion every 8 weeks); azathioprine (AZA) was administered chronically in all. Clinical evaluation was done with the Lichtiger Colitis Activity Index (LCAI). Follow-up was performed until week 54. LCAI >/= 9 was considered treatment failure; a LCAI

RESULTS

All 22 patients began the study with a LCAI > 9: 12 had a full response and were on remission at week 54 and did not receive CS (8 on IFX re-treatment and AZA, 4 on AZA alone); 6 had a partial response; 4 were non responders. Colectomy was performed in 7 patients, beyond the period of the acute attack in all but one.

CONCLUSIONS

In children with severe ulcerative colitis IFX is a valuable treatment for inducing remission, avoiding emergency colectomy; retreatment may be offered to maintain remission.

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MESH Headings

• Adolescent
• Antibodies, Monoclonal/therapeutic use
• Azathioprine/therapeutic use
• Child
• Colitis, Ulcerative/drug therapy
• Drug Therapy, Combination
• Female
• Humans
• Immunosuppressive Agents/therapeutic use
• Infliximab
• Italy
• Male
• Remission Induction
• Retrospective Studies
• Salvage Therapy

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Affiliation(s)

S Cucchiara Division Pediatric Gastroenterology and Hepatology, Department of Pediatrics, University of Rome "La Sapienza", Rome, Italy.
E Romeo
F Viola
M Cottone
M Fontana
G Lombardi
V Rutigliano
G L de'Angelis
T Federici

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Collaborators Collapse

Minimizing infliximab toxicity in the treatment of inflammatory bowel disease

BACKGROUND

Infliximab is a widely used biological agent for the treatment of inflammatory bowel disease, and has a favorable risk/benefit ratio.

AIM

It is useful to know that patients treated with infliximab are exposed to developing adverse events that could be reduced with a prudent and a rational clinical approach and by optimizing the treatment protocol.

METHODS

PubMed (including Epub) was searched in October 2006 and again in March 2007.

RESULTS

The high immunogenic potential of infliximab determines the antibodies that inhibit the effect of infliximab and the appearance of subsequent acute and delayed infusion reactions. Infliximab has an immunomodulatory effect, thus increasing the risk of serious and latent infections. Screening for tuberculosis, HBV, opportunistic or latent infections, heart failure, and haematological, neurological and hepatological disorders must be performed before infliximab therapy. There is no definitive evidence that infliximab increases the risk of neoplasia. Mortality in infliximab-treated patients does not appear increased compared to the controls.

CONCLUSIONS

Infliximab safety is similar to that of conventional immunomodulators and patients treated had similar rates of mortality, neoplasm and lymphoma as patients not treated with infliximab. Patients treated with infliximab have an increased risk of serious infections but it is not related to infliximab therapy.

Infliximab for the treatment of ulcerative colitis: outcomes in Oxford from 2000 to 2006

BACKGROUND

Infliximab has been shown to be of benefit in the treatment of ulcerative colitis but long-term colectomy rates remain unknown.

AIMS

To review the rate of colectomy after infliximab for ulcerative colitis and to identify factors that might predict the need for colectomy.

METHODS

We conducted a retrospective cohort study of patients with active ulcerative colitis treated with infliximab between 2000 and 2006. The primary outcome was colectomy-free survival. Disease and treatment characteristics and complications were documented.

RESULTS

Thirty patients were treated with infliximab for refractory ulcerative colitis. Sixteen (53%) came to colectomy a median of 140 days after their first infusion (range 4-607). There was no difference in colectomy between those receiving infliximab for acute severe ulcerative colitis failing intravenous steroids (8/14) and out-patients with steroid-refractory ulcerative colitis (8/16). Only 17% (5/30) achieved a steroid-free remission after a median follow-up of 13 months (range 2-72). Univariate analysis showed that a younger age at diagnosis of colitis was significantly associated with an increased rate of colectomy (27.5 years vs. 38.7 years, P = 0.016).

CONCLUSION

Over half the patients studied came to colectomy. Of those avoiding colectomy, only five (17%) sustained a steroid-free remission.