Gastroenterologists look set to enjoy an increase in their treatment options for patients with Crohn’s disease over the next couple of years, with a crop of new biologic therapies for the disease.

At this week’s American College of Gastroenterology conference, encouraging results from trials of three biologic drugs – Abbott Laboratories’ Humira (adalimumab), UCB’s Cimzia (certolizumab pegol, CDP870) and Schering AG’s Leukine (sargramostim) – suggest these agents could join Schering-Plough’s Remicade (infliximab) in the treatment of CD.

And this could help increase the number of CD patients who receive biologic treatment. At present, is estimated that just 15% of Crohn's sufferers in the USA - and 8% in Europe - receive this type of treatment.

Abbott presented results at the ACG from an extension of its Phase III CLASSIC 1 study of Humira in CD which showed that the anti-tumour necrosis factor alpha antibody, given every other week, kept 74% of patients in remission after a year’s treatment. If Humira was given every week, the remission rate went up to 83%, said Abbott.

The trial involved 55 patients who had achieved clinical remission in the CLASSIC 1 study. The 221 patients who did not meet this clinical objective in the initial study were entered into an open-label extension, receiving Humira every other week. 43% of them had gone into clinical remission after a year.

Humira is already approved for rheumatoid arthritis and psoriatic arthritis, and is Abbott’s biggest-selling product, bringing in sales of $356 million dollars in the third quarter of this year [[20/10/05e]].

Meanwhile, another company with aspirations in the CD category, Belgium’s UCB, gave the first view of its PRECiSE 2 clinical data, first presented at the United European Gastroenterology Week conference last month [[19/10/05d]], to an audience in the USA. This study is one of two that will be submitted to support a marketing application for Cimzia in CD, expected in the first quarter of 2006. The other, PRECiSE 1, is ongoing.

In PRECiSE 2, the anti-TNF agent demonstrated a 48% clinical remission rate at six months. It is given once a month after an initial induction regimen.

Both Humira and Cimzia can be given by subcutaneous injection, while Remicade requires an intravenous infusion.

Meanwhile, a biologic therapy of a different kind also showed promising results in a trial presented at the ACG conference. Schering’s Leukine, marketed in the USA by Berlex, was associated with improved and maintained quality-of-life in patients with moderately to severely active Crohn's disease, according to the results of the NOVEL 1 study.

This Phase II trial showed that patients treated with Leukine had a 20%-plus improvement in symptoms compared to those on placebo, measured using the Inflammatory Bowel Disease Questionnaire, as well as improvements on a battery of other measures that equated to ‘moderate to large improvements in QoL’, according to the German firm.

Schering believes Leukine may act by a different mechanism to the anti-TNF agents in CD. One hypothesis is that CD may arise from a breakdown in intestinal barrier function by several layers of cells that protect the gastrointestinal tract. This breakdown may precede secondary inflammatory processes associated with CD.

This suggests sargramostim may address a primary defect of Crohn's disease by helping to improve immune cell function within the intestinal barrier, unlike anti-NF therapies that broadly suppress immune response and inflammatory symptoms, according to the company.