GSK and J&J file rheumatoid arthritis treatment sirukumab in EU

GlaxoSmithKline and partner Johnson & Johnson’s Janssen Biologics unit have filed for approval of rheumatoid arthritis (RA) treatment sirukumab in Europe in an attempt to compete with Roche’s $1.5 billion Actemra.

Sirukumab is an anti-interleukin (IL)-6 monoclonal antibody that selectively binds with high affinity to the IL-6 cytokine, a naturally occurring protein that plays a role in autoimmune conditions, and is designed to interrupt the autoimmune process in RA.

The two companies are seeking its EMA approval in combination with methotrexate in patients who have failed or are intolerant to disease-modifying anti-rheumatic drugs (DMARDs) including TNF inhibitors, and additionally as a single-agent therapy for those who cannot take methotrexate.

The subcutaneously-administered antibody is designed to be available both as a single-dose prefilled syringe or a single-dose autoinjector and could allow treatment once-monthly, an advantage over rival Sanofi’s sarilumab which is injected every two weeks.

This new filing is based on the results of the SIRROUND phase III trials programme, which suggest that around 55% patients on the antibody achieve an ACR 20 response - a 20% improvement in signs and symptoms of RA - compared to a placebo response rate of around 26%. 

However, this is a drop from the 84% improvement seen in Phase II testing, and lower than sarilumab’s 56-60% improvement average in Phase III testing.

GSK is also reportedly planning a US filing this year.

Matt Fellows