Sales of drugs to treat ulcerative colitis will nearly double from $1.2 billion in 2008 to $2.1 billion by 2018 in the US, France, Germany, Italy, Spain, the UK and Japan, according to a new study.

During this period, the primary drivers of market growth will be the uptake of Abbott/Eisai’s blockbuster Humira (adalimumab) and Johnson & Johnson/Merck & Co/Mitsubishi Tanabe’s Simponi (golimumab), as well as an increase in the diagnosed prevalent population in the US, according to the study, published by Decision Resources.

Moreover, there continue to be significant opportunities for the development of more effective maintenance therapies with sustained long-term efficacy, new agents for the treatment of severe and refractory disease and also for new therapiess that can compete with potent corticosteroids such as prednisone, say the report authors. Emerging therapies such as Humira and Simponi - both tumour necrosis factor (TNF)-alpha inhibitors - could prove to be effective alternatives to currently-available maintenance therapies for patients who have moderate to severe disease, they say, but also caution that the high price of these emerging biologics is likely to limit their overall uptake in the market.

Sales of Abbott’s Humira, which is also approved for conditions including rheumatoid arthritis, Crohn’s disease and psoriasis, soared 23.8% to $1.49 billion for the third quarter of last year, the company reported in October.

Also that month, Simponi received approval in the European Union (EU) for the treatment of three rheumatic conditions - rheumatoid arthritis, psoriatic arthritis and ankylosing spondilitis - following US approval in April. The drug is also expected to be a big earner, with analysts forecasting $3 billion in sales over the next three years.

__Meantime, the Decision Resources report goes on to note that patients with severe, treatment-refractory ulcerative colitis requiring hospitalisation are treated with intravenous corticosteroids, cyclosporine (Novartis’s Sandimmune or generic versions), and/or J&J/Merck & Co/Mitsubishi Tanabe’s Remicade (infliximab).

__“However, the short-term nature of corticosteroid treatment and the waning efficacy observed with immunosuppressants and TNF-alpha inhibitors highlight the shortcomings of marketed products for ulcerative colitis both in induction and maintenance regimens,” comments Kathryn Benton, an analyst with the firm.

“Additionally, although colectomy represents a curative treatment for the most severe forms of the disease for patients who do not respond to corticosteroids, cyclosporine or Remicade, many patients elect not to undergo surgery and seek more-effective alternatives to last-line pharmacological treatments,” she notes.