Cost-Effectiveness of Anti-TNF Therapy for the Management of Inflammatory Bowel Disease

  • Author / Creator
    Beilman, Candace L
  • Anti-TNF therapy is effective for the induction and maintenance of remission in patients with inflammatory bowel disease (IBD). The benefits of anti-TNF therapy include improved quality of life, steroid discontinuation, and reduced hospitalization and surgery rates. Due to their high costs and potential serious adverse side effects, anti-TNF agents are generally prescribed once patients have failed to respond to less aggressive medical therapies, such as 5-ASAs, steroids, and immunosuppressants. Recently, it has been suggested that early initiation of anti-TNF therapy reduces rates of surgery and loss of response by minimizing irreversible, structural changes to the bowel. However, the costly nature of these medications gives rise to concerns regarding their usage. Also, the introduction of anti-TNF biosimilars has resulted in a need to assess how the economic burden of IBD will be affected by these agents. The aim of this study was to determine the cost-effectiveness of anti-TNF therapy for patients with moderate to severe IBD in several novel areas. First, we aimed to determine if adalimumab is cost-effective for the management of ulcerative colitis (UC), compared to patients who choose to remain on chronic steroids, opposed to undergoing surgery. Secondly, we wanted to determine when anti-TNF therapy initiation is most cost-effective for the management of Crohn’s disease (CD) comparing early (≤2 years after diagnosis) versus late (>2 years after diagnosis) initiation. Lastly, we aimed to determine the impact of the lower price of biosimilars on CD treatment cost efficacy, while making necessary assumptions regarding their efficacy, cost, and safety. In all three studies, a Markov model was constructed that simulated the progression of a hypothetical cohort of patients with moderate to severe IBD upon initiation of either infliximab or adalimumab. Transition probabilities were obtained from randomized controlled trials and real-life rates published by expert IBD centres. Costs and utility values were obtained using a variety of sources, including literature searches, cost estimators, and provincial databases. Sensitivity analysis was conducted to characterize uncertainty related to outputs. The first study revealed an incremental cost-effectiveness ratio (ICER) of $59,000 per quality-adjusted life year (QALY) for adalimumab therapy compared to ongoing steroid therapy, at a 10-year time horizon for patients with moderate to severe UC. For patients needing to be dose escalated, we calculated an ICER of $102,000 per QALY, above currently accepted willingness-to-pay (WTP) thresholds. The second study revealed that early initiation of infliximab (≤2 years of diagnosis) resulted in a lifetime savings of $18,054 and a gain of 1.02 QALYs compared to late initiation of anti-TNF therapy for patients with CD. Similarly, early initiation of adalimumab resulted in a savings of $18,526 and an increase of 0.74 QALYs. Sensitivity analysis revealed that early initiation of both infliximab and adalimumab had a 68% chance of being cost-effective at a WTP threshold of $50,000 per QALY. Our final study found that an infliximab biosimilar would result in a lifetime savings of $120,889 to $241,800 for patients with CD compared to the originator biologic. Similarly, an adalimumab biosimilar would result in a cost savings of $277,260 to $344,565 over a patient’s lifetime. In conclusion, anti-TNF therapy is very expensive and represents a large proportion of the financial burden of IBD. We concluded that anti-TNF therapy, particularly its early usage, is cost-effective for the management of IBD, however, adalimumab use in UC becomes costly in patients requiring escalated dosing. Anti-TNF biosimilars represent a promising way to reduce costs associated with IBD, although further research is needed to assess the true efficacy and cost of these agents.

  • Subjects / Keywords
  • Graduation date
    Fall 2016
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.