Anti-TNF re-induction may be an effective and less costly strategy to manage secondary loss of response to therapy than dose interval shortening in patients with Crohn’s disease.

A retrospective study of 423 Victorian patients with Crohn’s disease found 19% developed secondary loss of response to either infliximab or adalimumab.

Just over a third of patients were subsequently managed with anti-TNF re-induction while almost two thirds had their dose interval shortened.

The study found treatment outcomes were similar in both groups of patients at 12 and 24 months. There was no significant difference in median time to treatment failure or rates of clinical remission at the end of follow-up.

However the costs of the two treatment strategies were significantly different. Re-induction required an extra two doses of the anti-TNF at a cost of about $4,839, while dose interval shortening required 6.5 doses at a cost of about $13,190.

Researcher Dr Daniel van Langenberg, head of IBD at Eastern Health, told the limbic it was important to consider cost effectiveness.

“We have a responsibility to try and be smart with the way we use these drugs.”

“Nothing is lost in trying a re-induction and then if it fails, you’ve obviously got the other option of dose interval shortening.”

He said one of the problems with dose interval shortening was it typically became a long-term strategy when long-term escalation may not be necessary.

“Dose interval shortening is the method most often employed but the problem is it doesn’t have any exit strategy and people tend to give indefinitely.”

He said there was no consensus on the optimal time period for dose interval shortening before reverting to normal dosing.

“The short-term strategy to regain response may be just as effective as long-term escalation. It is worthwhile trying this first,” he said.

“If someone is failing a biologic, we can also can switch to another biologic but the problem in IBD is we have only got three or four agents so for a young person in their 20s with Crohn’s disease who have 50 to 60 years of disease ahead of them, we don’t want to be exhausting biologic options too quickly.”

Dr van Langenberg said re-inductions were covered by the PBS but the three strikes in five years rule meant that clinicians would often try to avoid a strike by applying to the pharmaceutical company for compassionate access to the extra doses.

He added that prospective randomised trials of the different strategies were required.