Adalimumab for maintenance of clinical response and remission in patients with Crohn's disease: the CHARM trial

Biological therapies for inflammatory bowel diseases

Crohn's disease and ulcerative colitis are chronic disabling inflammatory bowel diseases (IBDs). Although the causes of IBD are unknown, defects in innate and adaptive immune pathways have been identified and biological therapies that target key molecules have been designed. Infliximab, a chimeric immunoglobulin (Ig)G1 monoclonal antibody to tumor necrosis factor, dramatically improved treatment of patients with Crohn's disease and ulcerative colitis. Infliximab has achieved treatment goals such as mucosal healing and decreasing the need for hospitalizations and surgeries. Although several anti-tumor necrosis factor therapies have been developed, there is a great need for drugs that target other pathways. Natalizumab, an antibody against the integrin alpha4 subunit, blocks leukocyte adhesion and has reached the clinic in the United States but has not been approved in the European Union; other anti-adhesion molecules currently are under development. Additional approaches under clinical development include therapeutics that target cytokines, such as interleukin-12/23, as well as those that block T-cell signaling. The use of recombinant human proteins, including immunoregulatory cytokines and growth factors, has not been successful so far. The efficacy of each therapy must be shown in carefully designed clinical programs. Biological therapies carry a definite safety risk, so their place in treatment algorithms must be defined carefully.

Meta-analysis: the efficacy and safety of certolizumab pegol in Crohn's disease

BACKGROUND

Certolizumab pegol is the third anti-TNF-alpha agent approved by the Food and Drug Administration of the United States.

AIM

To provide a comprehensive up-to-date review of the efficacy and safety of certolizumab in Crohn's disease (CD).

METHODS

Electronic databases, including PubMed, EMBASE, the Cochrane library and the Science Citation Index, were searched to retrieve relevant trials. In addition, meeting abstracts and the reference lists of retrieved articles were reviewed for further relevant studies.

RESULTS

Three trials, enrolling a total of 1040 patients, are included in the meta-analysis to evaluate the short-term efficacy of certolizumab, which is effective for rapid induction and long-term maintenance of clinical response or remission and can improve quality of life in patients with Crohn's disease. Certolizumab is also effective for patients who have lost response to infliximab. However, its efficacy in infliximab-exposed patients is probably less than in infliximab-naive patients. Re-induction with certolizumab in patients who have flared on maintenance therapy can rescue a significant proportion of patients. There is no significant association between the efficacy of certolizumab and the baseline C-reactive protein level. In comparison with placebo, certolizumab does not increase the risk of serious adverse events.

CONCLUSIONS

Certolizumab is effective and safe in treating Crohn's disease. Further studies are still required to assess its full safety profile.

Pediatric inflammatory bowel diseases and the risk of lymphoma: should we revise our treatment strategies?

Inflammatory bowel diseases (IBDs) are lifelong inflammatory gastrointestinal diseases starting in about one third of patients during childhood. Treatment strategies aim to control this chronic inflammatory process. Owing to recent advances in the understanding of IBD, immunosuppressive agents (mainly against TNFalpha directed) as well as biological drugs are more and more often used. This therapeutic approach clearly improved the clinical condition of the majority of patients with IBD. However, with this more aggressive treatment strategy, safety concerns clearly arise. Recently, the description of a series of a particularly severe form of T cell lymphoma in pediatric and young adult patients with IBD under immunomodulator and biological combination therapy raised the question of the risks of treatment-induced side effects or complications. As reviewed in the present article, there is a slightly increased risk of not only lymphoma development in IBD patients, potentially related to the inflammatory process, but also to the use of immunosuppressive therapies. On the basis of the literature data, were analyzed current treatment strategies for children with moderate-to-severe IBD, who are candidates to receive immunomodulator and/or biological agents potentially accelerating the risk of lymphoma development. Comparative clinical studies in IBD are still missing; however, it is prudent to think about adapting immunosuppressive therapies to the inflammatory process of the underlying disorder and if possible to reduce them to monotherapy. Alternative treatment strategies for heavy immunosuppression exist (eg, enteral nutrition in Crohn disease or colectomy in patients with ulcerative colitis) and should be considered whenever appropriate. There is a major need for comparative studies before evidence-based guidelines can be established for safest and best treatment strategies of pediatric patients with IBD.

Loss of response and requirement of infliximab dose intensification in Crohn's disease: a review

OBJECTIVES

To review the frequency with which infliximabloses its effect and dose "intensification" is required for Crohn's disease treatment.

METHODS

Bibliographical searches were performed in MEDLINE, and European (ECCO) and American (DDW) Congresses. Studies evaluating loss of efficacy and requirement of infliximab dose intensification-defined either as an increase of the infliximab dose (generally from 5 mg/kg to 10 mg/kg) or as a decrease in the frequency of infusion (to as often as every 4 weeks)-in Crohn's disease patients were included.

RESULTS

Sixteen studies evaluating the incidence of loss of response to infliximab in Crohn's disease patients were found. A total of 2,236 patients were included (the majority of them receiving a three-dose induction regimen at weeks 0, 2, and 6, followed by maintenance therapy every 8 weeks), providing 6,284 patient-years of follow-up. The mean percentage of patients with loss of infliximab response was 37%. However, as the follow-up time varied markedly among studies, the risk of losing response to infliximab is better expressed as the incidence of this complication per patient-year of follow-up. Therefore, the annual risk for loss of infliximab response was calculated to be 13% per patient-year.

CONCLUSIONS

A variable but relevant proportion of Crohn's disease patients on long-term infliximab treatment lose response. This may be interpreted in two different but compatible ways: a positive view, highlighting that infliximab therapy is relatively durable, with the majority of patients predicted to continue infliximab treatment at least during the first year; or a negative view, interpreting that a significant proportion of Crohn's disease patients-more than 10% per patient-year of infliximab treatment-on long term will lose response and will require an increase in dose and/or decrease in infusion interval.

Canadian Association of Gastroenterology Clinical Practice Guidelines: The use of tumour necrosis factor-alpha antagonist therapy in Crohn's disease

BACKGROUND

Guidelines regarding the use of infliximab in Crohn's disease were previously published by the Canadian Association of Gastroenterology in 2004. However, recent clinical findings and drug developments warrant a review and update of these guidelines.

OBJECTIVE

To review and update Canadian guidelines regarding the use of tumour necrosis factor-alpha antibody therapy in both luminal and fistulizing Crohn's disease.

METHODS

A consensus group of 25 voting participants developed a series of recommendation statements that addressed pertinent clinical questions and gaps in existing knowledge. An iterative voting and feedback process was used in advance of the consensus meeting in conjunction with a systematic literature review to refine the voting statements. These statements were brought to a formal consensus meeting held in Montreal, Quebec (March 2008), wherein each statement underwent discussion, reformulation, voting and subsequent revision until group consensus was obtained (at least 80% agreement).

OUTCOME

The 47 voting statements addressed three themes: induction therapy, maintenance therapy and safety issues. As a result of the iterative process, 23 statements achieved consensus and were submitted for publication.

CONCLUSION

In the past five years, tumour necrosis factor-alpha antagonist therapy has become a cornerstone in the management of moderate-to-severe Crohn's disease refractory to conventional treatment algorithms. The evidentiary base supporting the use of these drugs in Crohn's disease is substantial and strengthened by results from longterm clinical and molecular studies. However, significant gaps in knowledge exist, particularly with regard to treatment failure. Confidence in the safety of these drugs is increasing, provided that therapy is administered in a clinical setting in which potential complications can be readily recognized and treated.

Azathioprine is superior to budesonide in achieving and maintaining mucosal healing and histologic remission in steroid-dependent Crohn's disease

BACKGROUND

The effects of azathioprine (AZA) and budesonide (BUD) on mucosal healing and histologic remission of Crohn's disease (CD) are insufficiently studied. In this prospective study we evaluated the comparative effects of AZA and BUD on endoscopic and histologic activity in patients with steroid-dependent Crohn's ileocolitis or proximal colitis who had achieved clinical remission on conventional steroids.

METHODS

Patients were randomized to AZA (2.0-2.5 mg/kg a day) or BUD (6-9 mg a day) for 1 year. The study protocol included clinical examination, laboratory tests, calculation of the Crohn's Disease Activity Index (CDAI), completion of the Inflammatory Bowel Disease Questionnaire (IBDQ), at baseline and then every 2 months for 1 year. Ileocolonoscopy with regional biopsies was performed at baseline and then at the end of the study to assess mucosal healing and the histologic activity of CD.

RESULTS

Thirty-eight patients were randomized to AZA and 39 to BUD. At the end of the study 32 and 25 patients in the AZA and BUD groups, respectively, were in clinical remission (P = 0.07). The Crohn's Disease Endoscopic Index of Severity (CDEIS) score fell significantly only in the AZA group (P < 0.0001). Complete or near complete healing was achieved in 83% of AZA-treated patients compared with only 24% of BUD-treated patients (P < 0.0001). Histologic activity as assessed by an average histology score (AHS) fell significantly only in the AZA group (P < 0.001 versus baseline) and was significantly lower than in the BUD group at the end of the study (P < 0.001). Eight patients in the AZA group were withdrawn for adverse events (n = 6) or relapse of disease compared with 14 patients in the BUD group who were withdrawn for relapse of disease.

CONCLUSIONS

In patients with steroid-dependent inflammatory Crohn's ileocolitis or proximal colitis who achieve clinical remission with conventional steroids, a 1-year treatment with AZA was superior to BUD in achieving and maintaining mucosal healing and histologic remission.

Efficacy and complications of adalimumab treatment for medically-refractory Crohn's disease: analysis of nationwide experience in Scotland (2004-2008)

BACKGROUND

Adalimumab is a second generation humanized anti-tumour necrosis factor (TNF) monoclonal antibody with established efficacy in Crohn's disease (CD).

AIMS

To evaluate the efficacy and safety of adalimumab on a nationwide clinical setting.

METHODS

We used the Scottish Society of Gastroenterology network to identify and follow up the clinical outcomes of patients with CD treated with adalimumab over a 4-year period (2004-2008).

RESULTS

A total of 98 patients received adalimumab - 100.5 patient follow-up years were recorded (64.3% females; median age at diagnosis of 20.7 years; 88.8% treated with 80/40 mg induction regimen. Eighty eight (89.8%) had previous infliximab with 29 (32.9%) primary nonresponders; 32 (32.6%) were corticosteroid-dependent; 47 (47.9%) were intolerant/resistant to most immunosuppressive therapies (two or more). In all, 60% of patients were in clinical remission at 1-year follow-up, with 30% and 55% requiring dose escalation to weekly therapy at 1-and 2-year follow-up respectively. Overall, 29 (29.6%) patients developed complications with eight nonfatal serious (8.2%) adverse events and 2 (2.0%) case fatalities (sepsis following perforation and disseminated colorectal cancer, respectively).

CONCLUSIONS

Adalimumab is efficacious in severe and refractory CD in the clinical setting, although there remain significant therapy- and disease-related risks of serious complications.

Adalimumab for Crohn's disease with intolerance or lost response to infliximab: a 3-year single-centre experience

BACKGROUND

Adalimumab is effective in inducing clinical remission in patients with Crohn's disease who lost response or became intolerant to infliximab.

AIM

To evaluate long-term efficacy and safety of adalimumab as a second line therapy in luminal and fistulizing Crohn's disease.

METHODS

We report our single-centre experience in 53 patients. We evaluated maintenance of clinical response defined as the absence of adverse events leading to drug withdrawal, no major abdominal surgery and no loss of clinical response in initial responders. Major abdominal surgery, steroid sparing, complete fistula closure and safety were also assessed.

RESULTS

The probability of maintaining clinical response was 77.2%, 67.8% and 50.8% at 26, 52 and 130 weeks respectively. The probability of remaining major abdominal surgery-free was 82.3% at 26, 52 and 130 weeks. Complete fistula closure occurred in six of 10 patients, and eight of 10 patients were able to taper steroid therapy. Adverse events occurred in 31 patients (58.5%) leading to adalimumab withdrawal in nine patients (17%).

CONCLUSION

Adalimumab therapy may be effective in the long term in both luminal and fistulizing Crohn's disease in infliximab-failure patients, half of patients maintaining clinical response and potentially avoiding major abdominal surgery in 80% of cases.

Early clinical experience with adalimumab in treatment of inflammatory bowel disease with infliximab-treated and naïve patients

BACKGROUND

Adalimumab, at an induction dose of 160/80 mg followed by 40 mg every other week is approved for treatment of refractory Crohn's disease (CD) and for patients with loss of response to infliximab.

AIM

To evaluate the indications for adalimumab, the proportion of inflammatory bowel disease patients who require dose escalation and to identify whether this strategy is effective in inducing or maintaining remission.

METHODS

Patients prescribed adalimumab for CD were identified and included for analysis, if they had follow-up of at least 6 weeks. Adalimumab dose was escalated if patients had return of symptoms prior to next dose. Clinical judgment was used to determine severity of disease. A second GI physician confirmed disease severity as determined by the first physician.

RESULTS

A total of 48 out of 60 patients met inclusion criteria. Adalimumab was used to treat CD in 47/48 (98%) and ulcerative colitis in one (2%). Most patients had moderate 30/48 (63%) or severe 17/48 (35%) disease. Prior infliximab exposure was present in 42/48 (88%). Adalimumab dose escalation occurred in 14/48 (29%) within an average time of 2.2 months (s.d. 1.5 months). A majority of patients who required dose escalation, nine of 14 (64%) did not improve clinically. Steroids could be discontinued in three of 16 (18.8%). Clinical improvement was noted in 21/48 (43.8%) and one of 48 (2%) patients achieved clinical remission. Adverse drug reactions necessitated drug discontinuation in four of 48 (8%) of patients.

CONCLUSIONS

This retrospective review from a single academic medical centre suggests that a minority of patients, who cannot be maintained on 40 mg every other week, of adalimumab benefit from an increased dose. This suggests the need for a treatment with an alternative mode of action in anti-TNF failures.

The safety profile of anti-tumour necrosis factor therapy in inflammatory bowel disease in clinical practice: analysis of 620 patient-years follow-up

BACKGROUND

Anti-TNF agents are now widely used in Crohn's disease (CD), and in ulcerative colitis (UC).

AIM

To review the safety profile of anti-TNF agents in all patients treated with infliximab in Edinburgh from 1999 to 2007.

METHODS

Complete data were available on 202/207 patients comprising 157 CD, 42 UC and three coeliac disease. Median follow-up was 2.4 years (1.0-4.9) with a total of 620 patient-years follow-up. About 19.1% of CD patients were subsequently treated with adalimumab.

RESULTS

Seven deaths (3.3%) occurred in follow-up; only one death was <1 year post-infliximab (at day 72, from lung cancer). A total of six malignancies (three haematological, three bronchogenic) and six cases of suspected demyelination (three with confirmed neurological disease) were reported. In the 90 days following infliximab, 95 adverse events (36 serious) occurred in 58/202 (28.7%) patients. In all, 42/202 (20.8%) had an infectious event (22 serious) and 27/202 (13.4%) of patients had an infusion reaction: 19 acute (four serious) and eight delayed (three serious).

CONCLUSIONS

Serious infections, malignancies and neurological disease complicate anti-TNF use in clinical practice. Although evidence for causality is unclear, potential mechanisms and predisposing factors need to be explored. In individual patients, the risk/benefit analysis needs to be carefully assessed and discussed prior to commencement of 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.

Serum sickness, encephalitis and other complications of anti-cytokine therapy

The introduction of biological therapies has greatly advanced the therapeutic armamentarium of the inflammatory bowel diseases Crohn's disease and ulcerative colitis. At present, three anti-tumour necrosis factor (TNF) agents (infliximab, adalimumab and certolizumab pegol) and one anti-adhesion cytokine (natalizumab) have been approved and have shown efficacy in luminal and/or fistulizing Crohn's disease and/or in ulcerative colitis. Although the overall benefit/risk ratio for the anti-TNF agents is positive, of particular concern has been the problem of immunogenicity ascribed to the formation of antibodies to these molecules. Antibody formation is associated with allergic reactions and loss of response through decreased trough serum concentrations. Ways to reduce antibody formation include maintenance therapy, the use of concomitant immunomodulators and pre-treatment with corticosteroids. Other safety concerns include the occurrence of opportunistic infections, skin manifestations, and the rare but often lethal hepatosplenic T-cell lymphoma. The alpha-4 integrin natalizumab has been associated with three cases of progressive multifocal leucoencephalopathy and was the reason for which the drug was not approved in Europe, and is available only through a specialised programme in the US. We discuss the safety aspects of the biological agents in this chapter and, where available, give ways to prevent and/or treat them.

Diagnosis and management of fistulizing Crohn's disease

The transmural inflammation characteristic of Crohn's disease predisposes patients to the formation of fistulas. Up to 50% of patients with Crohn's disease are affected by fistulas, which is a major problem given the considerable morbidity associated with this complication. Appropriate treatment of fistulas requires knowledge of specific pharmacological and surgical therapies. Treatment options depend on the severity of symptoms, fistula location, the number and complexity of fistula tracts, and the presence of rectal complications. Internal fistulas, such as ileoileal or ileocecal fistulas, are mostly asymptomatic and do not require intervention. By contrast, perianal fistulas can be painful and abscesses may develop that require surgical drainage with or without seton placement, transient ileostomy, or in severe cases, proctectomy. This Review describes the epidemiology and pathology of fistulizing Crohn's disease. Particular focus is given to external and perianal fistulas, for which treatment options are well established. Available therapeutic options, including novel therapies, are discussed. Wherever possible, practical and evidence-based treatment regimens for Crohn's disease-associated fistulas are provided.

Cost utility of adalimumab versus infliximab maintenance therapies in the United States for moderately to severely active Crohn's disease

OBJECTIVE

To determine and compare the cost utilities of the tumour necrosis factor (TNF) antagonists adalimumab and infliximab as maintenance therapies for patients in the US with moderately to severely active Crohn's disease.

METHODS

Maintenance regimens of adalimumab (40 mg every other week) and infliximab (5 mg/kg) were compared using primary data from the CHARM and published data from the ACCENT I clinical trials. Differences in study samples were minimized by matching and weighting baseline characteristics (Crohn's Disease Activity Index score, age and sex) between the patient groups using the primary clinical trial data. Utilization data were estimated from trial data. Unit costs of TNF antagonists (year 2007 values), hospitalizations (year 2006 values), and other medical costs (year 2006 values) were derived from a systematic literature search. Standard gamble-calculated primary data were used to derive health-utility estimates. Data were analysed in a cost-utility framework from a private payer perspective over a 56-week time horizon. Univariate and probabilistic sensitivity analyses were used to explore uncertainty related to the base-case cost-utility analysis. Given the time horizon, costs and effects were not discounted.

RESULTS

Adalimumab- and infliximab-treated patients were in remission for 47.2% and 37.1% of the 56-week period, respectively. Hospital admissions were 34-40% lower for adalimumab than for infliximab, based on the model and observed data, respectively. Patients treated with adalimumab accrued greater expected QALYs (0.014; 95% CI 0.000, 0.022) and lower costs (-$US4852; 95% CI -6758, 491) in the first year of therapy than patients treated with infliximab. Compared with infliximab maintenance therapy, adalimumab had lower drug and administration costs, less drug waste, and lower hospitalization rates. Univariate and multivariate probabilistic sensitivity analyses suggested that these results were robust.

CONCLUSIONS

This analysis suggests that adalimumab maintenance therapy is a dominant strategy versus infliximab maintenance therapy for patients with moderate to severe Crohn's disease. Adalimumab appeared more effective and less costly than infliximab.

Optimizing treatment of inflammatory bowel diseases with biologic agents

Despite more than a decade of clinical experience in the treatment of inflammatory bowel disease with biologic agents, particularly anti-tumor necrosis factor (TNF) antibodies, optimal treatment strategies are still debated. Secondary loss of response due to immuno-genicity is intrinsic to the use of therapeutic antibodies and has important implications. With the chimeric anti-TNF antibody, infliximab, scheduled maintenance therapy minimizes the risk of loss of response, and there is no clear evidence that concomitant immunosuppressives have added value in this setting. More humanized anti-TNF antibodies have entered clinical practice, opening new perspectives to patients with inflammatory bowel disease, but interventions in the dosing regimen remain necessary for more than one third of patients. Because biologics, like other immune therapies, carry the risk of infections and possibly of some malignancies, selecting the right patient for therapy and assessing disease activity beyond clinical symptoms aids in optimizing the benefit-to-risk ratio of our treatment approach.

Short-term response to adalimumab in childhood inflammatory bowel disease

BACKGROUND

Adalimumab is effective for adults with moderate to severe Crohn's disease (CD). Data in children with inflammatory bowel disease (IBD) is sparse. We aim to evaluate pediatric IBD response to adalimumab.

METHODS

We conducted a retrospective chart review of pediatric IBD patients treated with adalimumab. We defined response as either a decrease in the disease activity index severity or remission after 3-6 months of treatment.

RESULTS

Ten patients were identified. Seven had CD, three had ulcerative colitis (UC). All had colonic disease and disease in either the esophagus, stomach, or duodenum. Eight patients initially responded to infliximab, 5 with CD and 3 with UC; 2 CD patients had incomplete data for evaluation. The mean and median times between initial infliximab and initial adalimumab were 29.5 and 24 months, respectively. Eight patients responded to adalimumab 40 mg or 80 mg biweekly, or 80 mg initial dose followed by 40 mg biweekly. The mean Pediatric Crohn's Disease Activity Index (PCDAI) in CD patients before and after adalimumab were 12 and 4.2, respectively (normal <or=10). The mean Lichtiger Colitis Activity Index (LCAI) in UC patients before and after adalimumab were 9 and 5.1, respectively (normal <10). Corticosteroids were weaned off in 4/7 patients at 1 to 10 months after initiation of adalimumab. One patient with CD and 1 patient with UC failed adalimumab, required surgery, and remained on corticosteroids.

CONCLUSIONS

Adalimumab is useful in pediatric IBD patients who become intolerant of infliximab.

Defining the optimal response criteria for the Crohn's disease activity index for induction studies in patients with mildly to moderately active Crohn's disease

OBJECTIVES

The Crohn's Disease Activity Index (CDAI) is used to judge efficacy in clinical trials. We explored the effect of CDAI response definitions for induction on study efficiency.

METHODS

We analyzed primary CDAI data from induction studies in patients with mildly to moderately active Crohn's disease, not receiving concomitant aminosalicylates, corticosteroids, or immunomodulator therapy, and without fistulizing or stricturing complications. The 12 definitions of clinical response included: CDAI decrease from baseline by 50, 70, 100, or 150 points; decrease by 25% from baseline and by 70 or 100 points; CDAI <100 or 150 points; CDAI <150 points plus decrease by 70 or 100 points; CDAI <150 points at any time sustained for the duration of the trial; or decrease in the CDAI by 70 points for the last two consecutive visits. Response definitions were ranked according to ability to optimize the effect difference between treatment arms. The effect of time, baseline disease activity (CDAI 200-299 or > or =300 points), and previous surgical resections on response definitions were evaluated and ranked. Multivariate analysis on additional factors of age (<40 or > or =40 yr), gender and duration of disease (<2 or > or =2 yr) were performed to determine predictors of response when applied to these CDAI definitions.

RESULTS

Treatment effect differences in placebo-controlled studies were maximized by response definitions that incorporated either a decrease CDAI > or =70 points for the last two consecutive visits or decrease in baseline CDAI > or =100 points, and remained optimal when evaluated for the composite effect of time, baseline activity, and prior resections. A decrease in baseline CDAI > or =100 points had some advantages over a decrease CDAI > or =70 points over two visits in terms of study efficiency, as it produced a lower control response rate and was not influenced by any of the baseline factors.

CONCLUSION

Clinical trial efficiency for induction studies in patients with mildly to moderately active Crohn's disease can be improved by using either a decrease in CDAI by > or =70 points for the last two consecutive visits or a decrease in baseline CDAI by > or =100 points as the primary end point for the trial. These findings are valid for patients with ileocecal Crohn's disease not refractory to aminosalicylates, corticosteroids, immunomodulators, and biologics, and patients who do not have stricturing or penetrating complications. It is unclear if these CDAI response criteria would similarly increase study efficiency in trials that recruited patients with moderately to severely active disease, patients refractory to aminosalicylates, corticosteroids, immunomodulators, and biologics, and patients with stricturing or penetrating complications.

Effects of fistula on healthcare costs and utilization for patients with Crohn's disease treated in a managed care environment

BACKGROUND

Fistulas are a common complication of Crohn's disease (CD) and are difficult to treat effectively. This study aimed to assess the effects of fistula on annual costs of healthcare and resource utilization for patients with CD.

METHODS

A retrospective analysis, using the PharMetrics database, of patients with a diagnosis of CD from January 1, 2000 through June 30, 2005 was conducted. Using paid claim amounts, healthcare costs and resource utilization were compared for patients with and without fistula in the year following diagnosis. Further analysis compared costs for adult, pediatric, and older adult patients with and without fistula.

RESULTS

This analysis included 13,454 patients with CD, of whom 12,683 (94.3%) had no diagnosis of fistula. The total median (range) cost per patient was higher for the fistula cohort ($10,863 [$0-$1,307,019]) than the nonfistula cohort ($6268 [$0-$1,181,485]), driven mainly by higher hospital and surgery costs. Median healthcare costs and resource utilization rates were generally higher for patients with fistula compared with those without fistula in all 3 age groups, with some of the largest differences observed in the pediatric cohort.

CONCLUSIONS

Fistulas are often a difficult and costly complication of CD. This study determined that patients with fistulizing CD have higher healthcare costs and resource consumption than patients without fistula. Use of therapies that heal fistulas may help deter some of the high costs and intensive resource utilization found in this study. Economic analyses need to account for these issues when assessing the cost-effectiveness of therapies targeting fistulizing disease.

Treatment of active Crohn's disease with MLN0002, a humanized antibody to the alpha4beta7 integrin

BACKGROUND & AIMS

Selective blockade of lymphocyte-vascular endothelium interactions in the gastrointestinal tract is a promising therapeutic strategy for inflammatory bowel disease. This randomized, double-blind, controlled trial assessed the efficacy and safety of MLN0002, a monoclonal antibody targeting the alpha4beta7 integrin, in patients with active Crohn's disease.

METHODS

Patients were randomized to receive MLN0002 2.0 mg/kg (n = 65), MLN0002 0.5 mg/kg (n = 62), or placebo (n = 58) by intravenous infusion on days 1 and 29. The primary efficacy end point was clinical response (>or=70-point decrement in the Crohn's Disease Activity Index [CDAI] score) on day 57. Secondary end points were the proportions of patients with clinical remission (CDAI score <or=150) and with an enhanced clinical response (>or=100-point decrement in CDAI). Human anti-human antibody levels were measured.

RESULTS

Clinical response rates at day 57 were 53%, 49%, and 41% in the MLN0002 2.0 mg/kg, MLN0002 0.5 mg/kg, and placebo groups. Clinical remission rates at day 57 were 37%, 30%, and 21%, respectively (P = .04 for the 2.0 mg/kg vs placebo comparison). At day 57, 12% and 34% of patients in the 2.0- and 0.5-mg/kg groups had clinically significant human anti-human antibody levels (titers > 1:125). There was one infusion-related hypersensitivity reaction. The most common serious adverse event was worsening of Crohn's disease.

CONCLUSIONS

This phase 2 study was suggestive of a dose-dependent beneficial effect of MLN0002 therapy on clinical remission. MLN0002 was well tolerated in patients with active Crohn's disease.

Effects of adalimumab maintenance therapy on health-related quality of life of patients with Crohn's disease: patient-reported outcomes of the CHARM trial

OBJECTIVES

We evaluated the effects of adalimumab maintenance therapy on health-related quality of life (HRQOL) in patients with moderate to severe Crohn's disease.

METHODS

In a Phase III, randomized, double-blind clinical trial (CHARM) of moderate to severe Crohn's disease patients, HRQOL outcomes were compared between the adalimumab maintenance treatment groups (every other week and weekly injection) and the adalimumab induction-only group. The Zung Self-Rating Depression Scale, functional assessment of chronic illness therapy (FACIT)-Fatigue, visual analog pain scales, Inflammatory Bowel Disease questionnaire (IBDQ), and Medical Outcomes Study 36-item Short Form Health Survey (SF-36) were analyzed for 499 randomized responders (a decrease of > or =70 points from baseline in the Crohn's Disease Activity Index [CDAI]) at baseline and weeks 4, 12, 26, and 56.

RESULTS

CHARM patients' HRQOL was substantially impaired at baseline. Following a 4-week adalimumab induction therapy, patients experienced statistically significant improvements in all HRQOL measures (P < 0.0001). Compared with patients who were assigned to placebo after induction therapy, patients who continued adalimumab at 40 mg every other week maintenance therapy reported less depression (P < 0.01), fewer fatigue symptoms (P < 0.001), greater improvements in the IBDQ (P < 0.05), greater SF-36 physical component summary scores (P < 0.05), and less abdominal pain (P < 0.05) from weeks 12 to 56. They also had greater SF-36 mental component summary scores at week 56 (P < 0.05). Patients who continued adalimumab at 40-mg weekly maintenance therapy reported less depression and fewer fatigue symptoms at week 56, greater improvement in IBDQ, and less abdominal pain from weeks 12 to 56 (all P < 0.05 vs. placebo).

CONCLUSIONS

Adalimumab maintenance therapy provided sustained improvements in HRQOL for patients with moderate to severe Crohn's disease through week 56.

[Anti-TNF biologics in the treatment of chronic inflammatory bowel disease]

The utility of infliximab as a therapy for complicated inflammatory bowel disease (Crohn's disease, ulcerative colitis) has been established through large prospective trials in the last decade. With approval of adalimumab physicians and patients now have the choice between two different anti-TNF agents. In addition to control of inflammation, the avoidance of chronic exposure to glucocorticoids has become a primary reason to use anti-TNF therapy. Early use of anti-TNF therapy in the course of disease is a potential new indication. The increasingly critical appreciation of side effects promotes mono-therapy with anti-TNF agents.

Molecular pathogenesis of inflammatory bowel disease: relevance for novel therapies

The immense load of microorganisms within the gastrointestinal tract is a great challenge for the mucosal immune system. Whereas the vast majority of commensal bacteria should be tolerated, pathogenic organisms have to be attacked. During inflammatory bowel disease, the balanced interaction between the mucosal flora and the intestinal immune system is disturbed. Various defective components of this complex interaction have been described, such as different susceptibility genes, impaired innate immune responses and environmental factors, suggesting that inflammatory bowel diseases are multifactorial diseases. Based on new insights into the pathogenesis of inflammatory bowel disease, various targets for future drugs have been identified and new substances are emerging. The following article will review the current understanding of inflammatory bowel disease pathogenesis in context with genetic risk factors, imbalanced innate and acquired immune responses, and altered barrier function. Clinical treatment of the diseases will be summarized and emerging therapies as well as individual management based on recent insights into pathogenesis will be discussed.

Immunogenicity negatively influences the outcome of adalimumab treatment in Crohn's disease

BACKGROUND

Adalimumab is an effective treatment in patients with Crohn's disease; as it is a humanized anti-tumour necrosis factor monoclonal antibody, immunogenicity is thought not to be of any significance.

AIM

To assess whether antibodies to adalimumab (ATAs) affect adalimumab treatment outcome in patients with Crohn's disease previously treated with infliximab.

METHODS

A retrospective study was performed. Patients with active Crohn's disease and who had lost response or were intolerant to infliximab were treated with adalimumab. Clinical response and side effects were assessed as were serum ATAs and antibodies to infliximab (ATIs).

RESULTS

In total 30 patients [M/F (7/23)], median age 36 years (range 21-73) were treated with adalimumab for 318 days (median range 83-632). Clinical response was 77% (23/30), a dose escalation was necessary in eight (27%) patients and side effects were observed in 47% (14/30). In five patients (17%) ATAs were detected; of these patients, four were nonresponders. The presence of ATAs was related to nonresponse to adalimumab (P = 0.006). ATIs were positive in 57% of patients (17/30) and serum levels were significantly increased in adalimumab nonresponders (P = 0.01).

CONCLUSION

Immunogenicity plays a role in adalimumab treatment because of the development of ATAs.

Effects of adalimumab therapy on incidence of hospitalization and surgery in Crohn's disease: results from the CHARM study

BACKGROUND & AIMS

We determined the effects of adalimumab maintenance treatment on the risks of hospitalization and surgery in Crohn's disease (CD).

METHODS

A total of 778 patients with CD were randomized to placebo, adalimumab 40 mg every other week or adalimumab 40 mg weekly, all after an 80-mg/40-mg adalimumab induction regimen. All-cause and CD-related hospitalizations and major CD-related surgeries were compared between the placebo and adalimumab groups (every other week, weekly, and both combined) using Kaplan-Meier analysis and Cox proportional hazard models.

RESULTS

Both 3- and 12-month hospitalization risks were significantly lower for patients who received adalimumab. Hazard ratios for all-cause hospitalization were 0.45, 0.36, and 0.40 for the adalimumab every other week, weekly, and combined groups, respectively (all P < .01 vs placebo). Hazard ratios for CD-related hospitalization were 0.50, 0.34, and 0.42, respectively (all P < .05). Cox model estimates demonstrated adalimumab every other week and weekly maintenance therapies were associated with 52% and 60% relative reductions in 12-month, all-cause hospitalization risk, and 48% and 64% reductions in 12-month risk of CD-related hospitalization. The combined adalimumab group was associated with 56% reductions in both all-cause and CD-related hospitalization risks. Fewer CD-related surgeries occurred in the adalimumab every other week, weekly, and combined groups compared with placebo (0.4, 0.8, and 0.6 vs 3.8 per 100 patients; all P < .05).

CONCLUSIONS

Patients with moderate-to-severe CD treated with adalimumab had lower 1-year risks of hospitalization and surgery than placebo patients.

Long-term outcome of adalimumab therapy for ulcerative colitis with intolerance or lost response to infliximab: a single-centre experience

BACKGROUND

Adalimumab may be effective in inducing remission in patients with mild-to-moderate ulcerative colitis who had secondary failure to infliximab.

AIM

To evaluate long-term efficacy and safety of adalimumab in patients with ulcerative colitis who previously responded to infliximab, and then lost response or became intolerant.

METHODS

We report our single-centre experience in 13 patients. The patients received a loading dose of 160 mg of adalimumab subcutaneously in week 0, followed by 80 mg at week 2 and then 40 mg every other week starting at week 4. The primary efficacy measure was the proportion of patients on adalimumab therapy during the study.

RESULTS

Median duration of follow-up was 42 weeks (range, 10-100). The mean number of adalimumab infusions was 21 (range, 5-50). The probability of maintaining adalimumab was 92.3%, 84.6%, 60.6% and 32.5% at 1, 3, 6 and 23 months respectively. Six of 13 patients (46.2%) underwent colectomy during the study. No serious toxicities occurred in the study.

CONCLUSION

Adalimumab is well-tolerated and may be effective in maintaining clinical remission in a subgroup of patients with ulcerative colitis and lost response or intolerance to infliximab, potentially avoiding colectomy in about half of the patients.

Interaction of ribavirin with azathioprine metabolism potentially induces myelosuppression

BACKGROUND

The interaction of ribavirin, an inosine monophosphate dehydrogenase inhibitor, with azathioprine metabolism, potentially leading to myelotoxicity, remains unexplored.

AIM

To underline the interaction of ribavirin, an inosine monophosphate dehydrogenase inhibitor, with azathioprine metabolism, potentially leading to myelotoxicity.

METHODS

The medical records of eight patients who developed severe pancytopenia following concomitant use of azathioprine and ribavirin were retrospectively reviewed.

RESULTS

Bone marrow suppression reached nadir after a mean interval of 4.6 +/- 1.6 weeks following HCV therapy initiation in seven patients. At the time of pancytopenia, the mean platelet count was 69.75 +/- 82.8 x 10(-3)/mm(3), mean haemoglobin level 7.75 +/- 1.3 g/dL and mean neutrophil count 0.45 +/- 0.26 x 10(-3)/mm(3). All patients had normal thiopurine methyltransferase genotype. In two patients, a prospective monitoring of azathioprine metabolites was available. Myelotoxicity was accompanied by elevated total methylated metabolite levels (16,500 and 15,000 pmol/8 x 10(8) erythrocytes) with a concomitant decrease in 6-tioguanine nucleotide levels; 1 month after azathioprine, pegylated interferon alfa and ribavirin were discontinued and full blood count returned to normal in both patients. No haematological toxicity occurred after the reintroduction of peginterferon plus ribarivin or azathioprine alone in eight patients.

CONCLUSION

Collectively, the benefit/risk ratio favours avoidance of inosine monophosphate dehydrogenase inhibitors in purine analogue-treated patients with normal thiopurine methyltransferase activity, a situation frequently encountered in clinical practice.

A randomized trial of Ustekinumab, a human interleukin-12/23 monoclonal antibody, in patients with moderate-to-severe Crohn's disease

BACKGROUND & AIMS

Interleukin-12 and interleukin-23 are inflammatory cytokines implicated in Crohn's disease pathophysiology. Ustekinumab is a monoclonal antibody against the p40 subunit of interleukin-12/23.

METHODS

We performed a double-blind, cross-over trial of the clinical effects of ustekinumab in 104 patients with moderate-to-severe Crohn's disease (population 1). Patients were given subcutaneous placebo at weeks 0-3, then ustekinumab at weeks 8-11; subcutaneous ustekinumab at weeks 0-3, then placebo at weeks 8-11; intravenous placebo at week 0, then ustekinumab at week 8; or intravenous ustekinumab at week 0, then placebo at week 8. Furthermore, an open-label trial evaluated the effects of 4 weekly subcutaneous injections or 1 intravenous infusion of ustekinumab in 27 patients who were primary or secondary nonresponders to infliximab (population 2).

RESULTS

In population 1, clinical response rates for the combined groups given ustekinumab and placebo were 53% and 30% (P = .02), respectively at weeks 4 and 6, and 49% and 40% (P = .34), respectively at week 8. In a subgroup of 49 patients who were previously given infliximab (neither primary nor secondary nonresponders), clinical response to ustekinumab was significantly greater than the group given placebo (P < .05) through week 8. In population 2, the clinical responses at week 8 to subcutaneous and intravenous ustekinumab were 43% and 54%, respectively. There was no increase in the number of adverse or serious adverse events in patients given ustekinumab through week 8 compared with placebo.

CONCLUSIONS

Ustekinumab induced a clinical response in patients with moderate-to-severe Crohn's disease, especially in patients previously given infliximab.

Are we giving biologics too late? The case for early versus late use

Corticosteroids and immunomodulators have been the mainstay therapies for Crohn’s disease. Corticosteroids are highly effective to control symptoms in the short-term, but they are not effective in maintaining remission, they heal the mucosa in a reduced proportion of cases, and long-time exposure is associated with an increased risk of infections and mortality. Immunomodulators, azathioprine and methotrexate, heal the mucosa in a higher proportion of patients that corticosteroids but their onset of action is slow and they benefit less than half of patients with Crohn’s disease. In the last decade, medical therapy for Crohn’s disease has experienced a remarkable change due to the introduction of biologic therapy, and particularly the use of anti-tumour necrosis factor-alpha agents. Infliximab, adalimumab, and certolizumab pegol have demonstrated efficacy for induction and maintenance of remission in active Crohn’s disease. These agents have raised the bar for what is a suitable symptomatic response in Crohn’s disease and modification of the natural history of the disease has become a major goal in the treatment of Crohn’s disease. There are several data in the literature that suggest that early use of biologic therapy and achievement of mucosal healing contribute to disease course modification. However, many questions on early biological therapy for Crohn’s disease remain still unanswered.

Are we giving biologics too much time? When should we stop treatment?

The optimal duration of biological treatment, particularly anti-TNF, in inflammatory bowel disease (IBD) is a very important question both for patients and physicians. There is no published evidence to clearly and definitely answer this question. However data on natural history of IBD, long term safety of biologics, immunosuppressors (IS) cessation and some preliminary studies on biologics cessation may help us to discuss this topic. The decision to stop a biological treatment is currently based on a compromise between the benefits and risks associated with the prolongation of this treatment. IBD, more particularly CD, are characterized by the development of complications and the need for recurrent hospitalizations and surgeries in approximately 2/3 of cases. In these patients potentially in need of biological treatments, it is probable that, as it has been demonstrated for IS, the longer a stable remission has be achieved under treatment, the lower the risk of relapse is after treatment cessation. Further prospective studies should now aim at disclosing patient characteristics associated with a low risk of relapse to implement this strategy.

Review article: treatment algorithms to maximize remission and minimize corticosteroid dependence in patients with inflammatory bowel disease

BACKGROUND

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the intestine, which frequently require surgery for complications or failure of medical therapy.

AIM

To seek evidence and provide direction for clinicians on optimal strategies to enable steroid free remission in inflammatory bowel disease.

METHODS

Scientific literature was reviewed using MEDLINIE with a specific focus on medical therapies for inducing and maintaining remission of CD and UC. The results were discussed at a roundtable meeting to reach a consensus on key issues.

RESULTS

Several therapies have demonstrated efficacy for the treatment of active, moderate-to-severe CD and UC. These include agents, which induce remission [corticosteroids, infliximab and adalimumab (CD only)] or maintain remission and spare corticosteroids [azathioprine, mercaptopurine, methotrexate (CD only), infliximab and adalimumab (CD only)]. Wide variability exists in the use of these agents.

CONCLUSION

Treatment strategy algorithms are developed for use of these therapies that maximize remission and minimize corticosteroid dependence in patients with moderate-to-severe CD and UC.

Adalimumab for the treatment of Crohn's disease

The advent of biologic therapy for Crohn's disease has revolutionized our approach to disease management and redefined our goals. Infliximab (Remicade), an intravenously delivered murine-chimeric monoclonal antibody against TNF-alpha was released in 1998 and shown to have significant benefits in patients with refractory luminal and fistulizing Crohn's disease. Since then other anti-TNF strategies have undergone investigation with variable results. Adalimumab (Humira), a self administered, subcutaneous, fully human monoclonal antibody against TNF-alpha represents the next generation of therapy. It has demonstrated efficacy for induction and maintenance of remission in patients with moderate-to-severe Crohn's in three large double-blind, placebo-controlled, randomized trials. In addition it has demonstrated steroid-sparing properties and the ability to reduce hospitalizations and improve quality of life. It is anticipated, given its clinical efficacy, its fully human nature, and the convenience of self administration that it will have a significant effect on the management of Crohn's disease.

Recent advances in the management of Crohn's disease

In the last 10 years many advances have been achieved in the treatment of patients with Crohn's disease, particularly in the field of biological agents. Infliximab, a tumour necrosis factor alpha antagonist, has been recently added to the therapeutic armamentarium for Crohn's disease and has greatly improved our treatment options. Infliximab has demonstrated efficacy in the induction and maintenance of remission in luminal and fistulizing Crohn's disease both in adults and children. However, the potential development of autoantibodies and the risk of serious adverse events limit the possibility of a wider use of infliximab. Searching for less immunogenicity and higher effectiveness in the last years a number of biological agents have been developed. Adalimumab, a fully human monoclonal antibody anti tumour necrosis factor alpha, has resulted effective and safe in patients with Crohn's disease, both naive and refractory to infliximab, presenting also the advantage of subcutaneous way of administration. Natalizumab also showed promising results in terms of efficacy but its safety is still under investigation. To date no particular advances have been recently appeared in the literature concerning conventional immunosuppressive drugs. Surgery remains a valid resort for refractory patients. Autologous stem cell transplantation represents a new hope as rescue treatment for patients with severe refractory Crohn's disease.

Laparoscopic ileocolic resection versus infliximab treatment of distal ileitis in Crohn's disease: a randomized multicenter trial (LIR!C-trial)

Background

With the availability of infliximab, nowadays recurrent Crohn's disease, defined as disease refractory to immunomodulatory agents that has been treated with steroids, is generally treated with infliximab. Infliximab is an effective but expensive treatment and once started it is unclear when therapy can be discontinued. Surgical resection has been the golden standard in recurrent Crohn's disease. Laparoscopic ileocolic resection proved to be safe and is characterized by a quick symptom reduction.

The objective of this study is to compare infliximab treatment with laparoscopic ileocolic resection in patients with recurrent Crohn's disease of the distal ileum with respect to quality of life and costs.

Methods/design

The study is designed as a multicenter randomized clinical trial including patients with Crohn's disease located in the terminal ileum that require infliximab treatment following recent consensus statements on inflammatory bowel disease treatment: moderate to severe disease activity in patients that fail to respond to steroid therapy or immunomodulatory therapy. Patients will be randomized to receive either infliximab or undergo a laparoscopic ileocolic resection. Primary outcomes are quality of life and costs. Secondary outcomes are hospital stay, early and late morbidity, sick leave and surgical recurrence. In order to detect an effect size of 0.5 on the Inflammatory Bowel Disease Questionnaire at a 5% two sided significance level with a power of 80%, a sample size of 65 patients per treatment group can be calculated. An economic evaluation will be performed by assessing the marginal direct medical, non-medical and time costs and the costs per Quality Adjusted Life Year (QALY) will be calculated. For both treatment strategies a cost-utility ratio will be calculated. Patients will be included from December 2007.

Discussion

The LIR!C-trial is a randomized multicenter trial that will provide evidence whether infliximab treatment or surgery is the best treatment for recurrent distal ileitis in Crohn's disease.

Trial registration

Nederlands Trial Register NTR1150

Galectin-4 controls intestinal inflammation by selective regulation of peripheral and mucosal T cell apoptosis and cell cycle

Galectin-4 is a carbohydrate-binding protein belonging to the galectin family. Here we provide novel evidence that galectin-4 is selectively expressed and secreted by intestinal epithelial cells and binds potently to activated peripheral and mucosal lamina propria T-cells at the CD3 epitope. The carbohydrate-dependent binding of galectin-4 at the CD3 epitope is fully functional and inhibited T cell activation, cycling and expansion. Galectin-4 induced apoptosis of activated peripheral and mucosal lamina propria T cells via calpain-, but not caspase-dependent, pathways. Providing further evidence for its important role in regulating T cell function, galectin-4 blockade by antisense oligonucleotides reduced TNF-alpha inhibitor induced T cell death. Furthermore, in T cells, galectin-4 reduced pro-inflammatory cytokine secretion including IL-17. In a model of experimental colitis, galectin-4 ameliorated mucosal inflammation, induced apoptosis of mucosal T-cells and decreased the secretion of pro-inflammatory cytokines. Our results show that galectin-4 plays a unique role in the intestine and assign a novel role of this protein in controlling intestinal inflammation by a selective induction of T cell apoptosis and cell cycle restriction. Conclusively, after defining its biological role, we propose Galectin-4 is a novel anti-inflammatory agent that could be therapeutically effective in diseases with a disturbed T cell expansion and apoptosis such as inflammatory bowel disease.

Crohn's disease: beyond antagonists of tumour necrosis factor

In the past few years, antagonists of tumour necrosis factor have resulted in unforetold therapeutic benefits in Crohn's disease, but the magnitude and duration of responses are variable. New agents are therefore needed. Their development has benefited from advances in the understanding of the pathophysiology of this disease. Uncontrolled activation of the acquired immune system has an important role, and lymphocytes, cytokines, and adhesion molecules are broadly targeted for therapeutic intervention. With increasing evidence of an implication of the innate immune system and the intestinal epithelium, the therapeutic paradigm is also shifting from mere immunosuppression to the reinforcement of the intestinal barrier. We review mechanisms of actions of new drugs and the efficacy and adverse events from data from clinical trials. We discuss future directions, including new strategies with optimum endpoints.

Health-economic analysis: cost-effectiveness of scheduled maintenance treatment with infliximab for Crohn's disease--modelling outcomes in active luminal and fistulizing disease in adults

BACKGROUND

Infliximab has been shown to be efficacious in moderate-to-severe Crohn's disease (CD).

AIM

To evaluate the cost-effectiveness of scheduled maintenance treatment with infliximab in luminal and fistulizing CD patients.

METHODS

Markov models were constructed to simulate the progression of adult CD patients with and without fistulae during treatment with infliximab (5 mg/kg). Transitions were estimated from published clinical trials of infliximab. Standard care, comprising immunomodulators and/or corticosteroids was used as a comparator. An average weight of 60 kg was used to estimate the dose of infliximab. The costs and outcomes were discounted at 3.5% over 5 years. The primary effectiveness measurement was quality-adjusted life years (QALYs) estimated using EQ-5D. One-way and probabilistic sensitivity analyses were performed by varying the infliximab efficacy estimates, costs and utilities.

RESULTS

The incremental cost per QALY gained was pound 26,128 in luminal CD and pound 29,752 in fistulizing CD at 5 years. Results were robust and remained in the range of pound 23,752- pound 38,848 for luminal CD and pound 27,047- pound 44,206 for fistulizing CD. Patient body weight was the most important factor affecting cost-effectiveness.

CONCLUSION

Eight-week scheduled maintenance treatment with infliximab is a cost-effective treatment for adult patients suffering from active luminal or fistulizing CD.

Pharmacogenetics of Crohn’s disease

The considerable interindividual differences in efficacy and side effects of commonly used medications in Crohn’s disease are partly owing to genetic polymorphisms. Many genetic variants have been studied in genes possibly involved in the metabolism or mechanism of action of therapeutic agents such as glucocorticosteroids, azathioprine/6-mercaptopurine, methotrexate, calcineurin inhibitors or anti-TNF agents. However, the only test translated into clinical practice is thiopurine S-methyltransferase (TPMT) genotyping for hematological toxicity of thiopurine treatment. To date, there are no other meaningful applications for pharmacogenomics in clinical practice of Crohn’s disease. In the future, designed therapeutic trials should possibly permit the development of predictive models including genotypic markers, such as that proposed for the clinical outcome after infliximab therapy, which includes an apoptotic pharmacogenetic index. The recent identification of new susceptibility genes provides additional candidate markers that have possible effects on the outcomes of therapies, and prioritizes new therapeutic targets, such as the IL-23 pathway. Futher innovative approaches might be relevant for the pharmacogenetic investigation of gene variants implied in innate immune pattern recognition and autophagy.

Infliximab in Crohn's disease: early and long-term treatment

The natural history of Crohn's disease is characterized by a remitting and relapsing course that progresses to complications and surgery in the majority of patients. Current treatment guidelines advocate a stepwise approach according to disease location and severity at presentation, with goals mainly aimed at inducing and maintaining clinical remission. Major advances in the understanding of the pathogenesis of Crohn's disease offered significant opportunities for the development of new therapies over the past years. Infliximab and other biologic agents have shown impressive results in Crohn's disease patients refractory to standard therapy, suggesting a potential disease course-modifying action. These led to the proposal to reverse the traditional therapeutic algorithms using these agents early in the course of the disease. Preliminary data suggest that early intervention may be a more effective treatment strategy in some Crohn's disease patients. As yet, early and indiscriminate use of biologics remains to be supported by convincing evidence. Data on long-term treatment of Crohn's disease with infliximab or other biologics are even more scarce. Future studies aimed to identify predictors of complicated disease and long-term randomized studies aimed to compare "step-up" and "top-down" strategies in high-risk groups should help to answer if early introduction of biological therapy alters the natural history of Crohn's disease.