Abatacept for Crohn's disease and ulcerative colitis

Review article: a clinician's guide for therapeutic drug monitoring of infliximab in inflammatory bowel disease

BACKGROUND

Tumour necrosis factor (TNF)-antagonists have an established role in the treatment of inflammatory bowel diseases (IBDs), however, subtherapeutic drug levels and the formation of anti-drug antibodies (ADAs) may decrease their efficacy.

AIM

The evidence supporting the use of therapeutic drug monitoring (TDM) based clinical algorithms for infliximab (IFX) and their role in clinical practice will be discussed.

METHODS

The literature was reviewed to identify relevant articles on the measurement of IFX levels and antibodies-to-infliximab.

RESULTS

Treatment algorithms for IBD have evolved from episodic monotherapy used in patients refractory to all other treatments, to long-term combination therapy initiated early in the disease course. Improved remission rates have been observed with this paradigm shift, nevertheless many patients ultimately lose response to therapy. Although empiric dose optimization or switching agents constitute the current standard of care for secondary failure, these interventions have not been applied in an evidence-based manner and are probably not cost-effective. Multiple TDM-based algorithms have been developed to identify patients that may benefit from measurement of IFX and ADA levels to guide adjustments to therapy.

CONCLUSIONS

Therapeutic drug monitoring offers a rational approach to the management of secondary failure to IFX. This concept has gained momentum based on evidence from case series, cohort studies and post-hoc analyses of randomised controlled trials.

Ulcerative colitis: current and future treatment strategies

Since the incidence of inflammatory bowel diseases including ulcerative colitis is continuously increasing worldwide, there is a strong need for effective treatment strategies. However, there is no therapy allowing for healing ulcerative colitis; consequently, the available medications will have to be applied at their best. The preferred option for mild pan- or left-sided colitis is still mesalazine. One can only emphasize that the formulations allowing for once daily dosing are not only equally effective, but even facilitate the implication of long-term therapy in daily life. In case steroids are frequently required to control disease, further immunosuppressive therapy should be introduced in order to minimize steroid exposure. Thiopurines represent the first-choice immunosuppressive medication. In more severe cases, early escalation to combinatory therapies with anti-TNF antibodies should be considered with the possibility of therapy deescalation after induction of remission. Major difficulties arise with steroid-refractory acute flares. Here cyclosporine as well as anti-TNF strategies can be initiated. However, in case of severe disease, the high 1-year colectomy rate of about 50% should be considered. If short-term surgery is an option due to disease severity, cyclosporine might be advantageous since the half-life is short compared to infliximab or adalimumab. The central problem of all therapeutic approaches is that because we chase after the disease, solid markers that allow for prediction of the future disease course are desirable. In fact, the CD8+ transcriptome might fill this gap and will potentially lead to the classification of patients in low- and high-risk groups.