Sirukumab meets both co-primary endpoints in rheumatoid arthritis study

Sirukumab is being co-developed by GlaxoSmithKline (GSK) and Janssen Biologics in a partnership that startesd in December 2011.

It is a human monoclonal IgG kappa antibody that binds to interleukin-6 (IL-6), a cytokine that plays an important role in autoimmune conditions.

The SIRROUND-D study randomized 1,670 patients with moderately to severely active RA who had an inadequate response to disease-modifying antirheumatic drugs.

Patients received either sirukumab 50mg every 4 weeks, sirukumab 100mg every 2 weeks or placebo.

Results from the study demonstrated that patients treated with sirukumab experienced significantly less joint destruction than placebo (p<0.001) from baseline to week 52 as measured by a method called Sharp van der Heijde Score which is used to measure joint damage observed in X-ray images.

There was a minimum 20% improvement in RA symptoms for more than half of patients by week 16.

All major secondary endpoints were also met. Regulatory applications for sirukumab for RA are expected in the third quarter of this year.

Sirukumab has not been approved as a treatment for any indication anywhere in the world.

The agreement between GSK and Janssen gives both companies the option to evaluate sirukumab for other indications beyond RA.

Last November, GSK initiated a phase III study of sirukumab for patients with Giant Cell Arteritis.

Image: GlaxoSmithKline head office, London. Photo: courtesy of Ian Wilson.