Practical guidelines for treating inflammatory bowel disease safely with anti-tumour necrosis factor therapy in Australia

Secondary Loss of Response to Infliximab in Pediatric Crohn Disease: Does It Matter How and When We Start?

OBJECTIVES

A significant proportion of children with Crohn disease develop a secondary loss of response (LOR) to infliximab. Our aim was to study the impact of initial treatment strategies on secondary LOR.

METHODS

We reviewed the medical records of children with Crohn disease who received scheduled maintenance infliximab therapy for at least 12 months. We compared children who developed LOR with those who did not; with regards to their clinical and laboratory parameters, disease phenotype, and treatment strategy before developing LOR.

RESULTS

A total of 73 children (median age at diagnosis 11 (2-16) years, 41 boys) who had received a median duration of 33 (13-110) months of infliximab therapy were included in the final analysis. LOR was seen in 25(34.2%). Demographic variables, disease phenotype (age, disease location, and behavior), inflammatory parameters, and pediatric Crohn disease activity index at induction with infliximab were similar between both groups. Children with LOR had a significantly greater number of flares of the disease when compared to those who did not have LOR (4 [1-8] vs 2 [1-5] P = 0.03). The choice of the concomitant immunomodulator-methotrexate (11/29 [37.9%]) versus azathioprine (11/36 [30.5%]) (P = 0.6) did not affect LOR rates. The median time-lag between diagnosis and induction with infliximab was significantly longer in children with LOR as compared to those who did not have an LOR (28 [4-90] months vs 12.5 [1-121] months, P = 0.004).

CONCLUSION

Early use of infliximab in pediatric Crohn disease is associated with a decrease in secondary LOR. The type of concomitant immunomodulator used does not make a difference to LOR rates.

Asia-Pacific consensus statements on Crohn's disease. Part 2: Management

The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology (APAGE) with the goal of developing best management practices, coordinating research and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis (UC) with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis and management of Crohn's disease (CD). The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses and treatment availability. It does not intend to be all-comprehensive and future revisions are likely to be required in this ever-changing field.

Loss of response to long-term infliximab therapy in children with Crohn's disease

Secondary loss of response (LoR) often precludes further use of infliximab in children with Crohn’s disease. Immunomodulators may reduce the incidence of LoR but their combination with infliximab presents safety concerns. We aimed to determine the long-term durability of infliximab response in paediatric Crohn’s, effect of immunomodulators on LoR, and secondarily the effect of infliximab on growth. We retrospectively audited patients on maintenance infliximab at a single centre. Data included height and weight, Paediatric Crohn’s Disease Activity Index (PCDAI), and immunomodulator use. 71 children (32% female, mean age 14.4 years) had been commenced on maintenance infliximab before July 2011. 89% had been on immunomodulators concurrently with infliximab. LoR occurred in 20 (28%), with a median time to LoR of 4.31 years. LoR was significantly increased in children who did not enter remission (PCDAI ≤ 10) after induction (p < 0.05). LoR occurred more frequently in the 72% who ceased immunomodulators, but this failed to reach statistical significance (p = 0.300). Height and weight SDS improved significantly on infliximab. Infliximab is a durable long-term therapy for paediatric Crohn’s refractory to conventional therapy. A large-magnitude increase in the rate of loss of response after immunomodulator cessation was not observed.

Modifiable factors associated with nonadherence to maintenance medication for inflammatory bowel disease

BACKGROUND

Poor adherence frequently impaired the efficacy of therapy to maintain remission from inflammatory bowel diseases (IBD). There is a lack of practical and effective interventions to improve adherence. This study aimed to identify modifiable risk factors, which may yield targets for new interventions.

METHODS

Participants with IBD were recruited from hospital outpatient clinics and office-based gastroenterologists. Demographic and disease-related data were recorded by means of self-administered questionnaires. Modifiable risk factors were assessed with the validated Belief about Medicine Questionnaire, Hospital Anxiety and Depression Score, and short inflammatory bowel disease questionnaire. Adherence was assessed separately for 5-aminosalicylates, thiopurines, and biological agents using the validated Medicine Adherence Report Scale (good adherence defined as >16).

RESULTS

Nonadherence occurred in 102 of 356 participants (28.7%). Adherence increased significantly with more aggressive therapies (median Medicine Adherence Report Scale: 5-aminosalicylates 18, thiopurines 19, biological 20; P < 0.0001). Nonadherence was not associated with anxiety and depression or disease-related patient knowledge. Adherent patients had significantly higher belief of necessity for medication (P < 0.0001) and a trend toward lower concerns about medication (P = 0.08). Membership of an IBD patient organization was associated with better adherence (P < 0.0001). Concerns about medication rose significantly with more aggressive therapies (P = 0.009), but belief of necessity was similar for all medications.

CONCLUSIONS

Nonadherence occurs most frequently with 5-aminosalicylates. Belief of necessity may prove the key target for future interventions, although general IBD education is unlikely to yield an adherence benefit. Patient organization membership should be encouraged.

A survey of applications of biological products for drug interference of immunogenicity assays

PURPOSE

Biological drugs in circulation can interfere with anti-drug antibody (ADA) assays and cause false ADA negatives. We surveyed the applications of biological products approved by FDA during 2005-2011 for prevalence of drug interferences and proposed approaches to address this issue scientifically.

METHODS

The immunogenicity assay drug tolerance, steady-state drug concentrations, and immunogenicity rates were reviewed for 26 BLA/NDA and 2 sBLA.

RESULTS

Many FDA approved biologics had higher steady-state drug concentrations than the drug tolerance of ADA assays, by 1.2- to 800-fold. Reported immunogenicity rates may be negatively impacted. Some sponsors triaged immunogenicity samples according to the drug tolerance, leaving some samples un-assayed or reporting them as inconclusive ADA; but these samples were interpreted as ADA- for calculating immunogenicity rates.

CONCLUSIONS

Implementation of ADA assays that can tolerate therapeutic drug concentrations is imperative. Given drug interferences, we propose in this paper the following practices: (i) to measure drug concentrations in ADA samples, (ii) to explicitly list all ADA status, including inconclusive ADA and un-assayed samples, (iii) to calculate population immunogenicity rates based on only subjects with confirmed ADA+ and ADA-, and (iv) to make available ADA assay specifics relevant to the use of ADA data in disease management.

When to use biological agents in inflammatory bowel disease

The use of biological agents in inflammatory bowel diseases across the Asia-Pacific region is increasing. As new molecules and targets are identified, knowledge regarding the indications, utility, optimization and adverse effects of biological agents grows. Careful patient selection, attention to communication and patient education will maximize the benefit of these drugs. Tertiary referral centers with specific interest in inflammatory bowel diseases and experience play an important role in their use. There is enormous opportunity for patients to benefit from biological agents in the therapy of Crohn's disease and ulcerative colitis. Use of these agents has been studied across a variety of indications and populations, and at different stages in the disease course. Failure to respond or loss of response can result from different causes, and can be medically managed in many cases. More research on the pleiotropic effects, safety of biological agents and biomarkers in the prediction of response will provide a sounder basis for individually directing therapy. Adverse events such as opportunistic infection and malignancy can occur, and screening prior to therapy and discussion on risk-benefit of the various management options are important. Cost of these medications especially with maintenance therapy remains an important issue in many Asia-Pacific countries. New and more specific agents will better target therapy and minimize adverse events.