New data presented at the European League Against Rheumatism meeting in Paris show UCB’s anti tumour necrosis factor agent Cimzia, added to standard methotrexate, may have a leading edge over competitors in the same class when treating rheumatoid arthritis.

Cimzia (certolizumab pegol) claims to be the fastest-acting anti-TNF on the basis of new data, including X-ray evidence, from further analyses of the RAPID studies. RAPID 1 and 2 are two large double-blind placebo-controlled trials of 24 weeks and one year which tested two doses of Cimzia, 200 and 400mg, or placebo, with 10 to 30mg methotrexate, in various sequencing schedules.

RAPID 1 was a year-long, large randomised double-blind placebo-controlled study of 982 subjects. Patients adding Cimzia to methotrexate reported significantly greater improvements in RA symptom relief and physical function than patients adding placebo, within a week of receiving their first dose. By the end of week one approximately half of patients had also achieved the American College of Rheumatology ACR 20 criterion which equates to at least a 20% reduction in core RA symptoms.

X ray proof of Cimzia’s added effects on joint preservation was apparent from 16 weeks. Patients receiving the Cimzia/methotrexate regimen scored significantly better than those adding placebo to methotrexate on key measures of joint changes (joint-space narrowing and bone erosion). This is the earliest reported time for an RA drug regimen to show efficacy and represents a considerable treatment advance, say experts.

Rheumatologists are repeatedly emphasising the need to begin treatment that will inhibit the rheumatoid disease process effectively as early as possible if structural damage to joints and deformity are to be avoided. Effective early treatment also gives patients their best chance of being able to carry on working. Achieving a response to treatment within 10 to 12 weeks is the recommended window of opportunity to get patients’ disease into remission or a state of low disease activity over a one-year period.

For this reason patients are assessed frequently to ensure treatment is working and if necessary to change dosage, add in, or change to new therapy. Professor Desiree van der Heijde of Leiden University Medical Centre, The Netherlands, stressed: “Early in the course of the disease poor functional capacity is primarily associated with increased structural joint damage. Therapies that both inhibit progression of joint damage and improve physical function may help prevent long-term disability.”

There are several anti-TNF drugs in development, but Cimzia is the first and only PEGylated type of anti-TNF. PEGylation gives the product a longer half life and enables dosing intervals to be every four weeks. The product has been licensed in Switzerland from 2007, and from April 2008 in the USA, for Crohns Disease.

The FDA is now considering a Biologics Licence Application for Cimzia in rheumatoid arthritis and UCB plans to submit an application to European regulators imminently. By Olwen Glynn Owen