Rectification of miscalculation of adalimumab costs

Abstract

Response to: Eshuis EJ, Stokkers PC, Bemelman WA. Decision-making in ileocecal Crohn’s disease management: surgery versus pharmacotherapy. Expert Rev. Gastroenterol. Hepatol. 4(2), 181–189 (2010).

Figure 1. Costs of anti-TNF therapy and ileocolic resection.

IFX costs were calculated for a person weighing 60–80 kg.

^†Data taken from [101].

^‡Data taken from [1].

ADA: Adalimumab; IFX: Infliximab.

In the April 2010 issue of Expert Review of Gastroenterology and Hepatology, we published an article regarding the decision-making in the management of Crohn’s disease (CD) in the terminal ileum, with the question whether to treat medically or surgically. One of the parameters we used for this decision-making process was the costs of the various medical and surgical treatment options. Our conclusion was that surgical therapy is much less expensive compared with biological therapy. Furthermore, although this was not the subject of this article, we argued that adalimumab (Humira) therapy may be more expensive compared with infliximab (Remicade^®) therapy when the costs are calculated based on the prices of both drugs in The Netherlands.

Recently, however, we were approached by Abbott, the manufacturer of adalimumab, and they made us aware of a miscalculation with regard to the costs of their product. With this letter we would like to rectify this and apologize for our mistake.

With regard to those costs, the surgical treatment options costs were derived from a published randomized trial comparing laparoscopic to open ileocolic resection [1]. The costs of regular medical treatment options for moderate-to-severe CD, being infliximab or adalimumab, were calculated from data derived from the website of the Dutch pharmacotherapeutical compass [101].

For adalimumab, we mistakenly based our initial cost calculation on a unit price of €1084 per 40 mg. This was incorrect; on the website the costs were presented as costs per month of treatment. Adalimumab is administered every other week, meaning that per month, two doses of 40 mg are administered. This means that the calculated costs were twice as high as the actual costs.

With this rectification letter we hope to set this mistake right by presenting the correct current costs.

Cost of adalimumab

The first two administrations of adalimumab are ‘loading’ doses of 160 mg (four injections) at week 0 and 80 mg (two injections) at week 2. After this, 40 mg (one injection) of adalimumab is administered once every 2 weeks. The price per injection is €496.94. This means that in the first year, costs mount up to €14,908.20.

The cost of every following year, without necessity of loading doses, is €12,920.44. Only in the case of dose intensification, which means that adalimumab is administered every week, do the costs double.

Cost of infliximab

Infliximab is supplied in ampoules of 100 mg and should be administered as a dosage of 5 mg/kg of bodyweight during daycare admission. Therefore, one ampoule represents 20 kg of bodyweight. In most cases, four ampoules are required (for patients weighing 60–80 kg).

One ampoule costs €591.88; therefore, one infusion for a patient weighing 60–80 kg costs €2367.52.

In the first year of therapy, three loading doses are administered in weeks 0, 2 and 6; thereafter infliximab is administered every 8 weeks. This means that in the first year, eight infusions are administered, costing €18,940.16.

The costs of every subsequent year, without the loading doses, are €16,572.64. When patients are treated for shorter intervals or double doses, the cost increases equivalently.

It is important to realize that this cost calculation of infliximab is based only on the cost of the drug itself, separate from daycare costs at the hospital, estimated at €500 per infusion.

These estimates are based on prices of the drugs in The Netherlands and rough estimates of dose and dose intervals would imply that adalimumab is less expensive compared with infliximab (also see rectified Figure 1). We would like to stress that these calculations cannot be used as a cost–effectiveness analysis of both drugs. The important message of our paper remains unaffected: anti-TNF therapies are very expensive treatments compared with ileocolic resection. Since both ileocolic resection and anti-TNF treatment are reasonably safe strategies for the treatment of CD in the ileocecal region, clinical trials comparing both strategies at the level of cost–effectiveness, safety and quality of life are eagerly awaited [2].

Disclaimer

This work is the opinion of the author and does not represent the views of Expert Reviews Ltd or its employees.

Financial & competing interests disclosure

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