Johnson & Johnson and Schering-Plough have posted some very promising data from three late-stage rheumatoid arthritis trials of their investigational anti-tumour necrosis factor therapy golimumab.

The data, which was presented at the European League Against Rheumatism congress in Paris, shows that patients in all three Phase III trials of golimumab, a once-monthly injectable, experienced improvements in symptoms of rheumatoid arthritis as well as in physical function.

The first of those, called GO-FORWARD, included 444 patients with active RA despite ongoing treatment with methotrexate. At week 14, 55% of patients receiving golimumab 50mg plus MTX and 56% receiving 100mg of the drug plus MTX achieved at least 20% improvement in signs and symptoms of RA, compared to 33% who received placebo and MTX. Improvements were seen as early as the first clinical assessment, which was four weeks after the first golimumab injection.

GO-BEFORE, one of the other Phase III trials, included 637 MTX-naive adults with RA treated with golimumab 50 mg or 100 mg in combination with MTX and they experienced improvement in the signs and symptoms of arthritis as well as in disease activity.

Edward Keystone, of the Rebecca MacDonald Centre for Arthritis & Autoimmune Disease in Toronto, and lead investigator of GO-FORWARD, said the data demonstrate that golimumab is beneficial in “improving numerous disease parameters, including inducing remission, in patients whose disease was active despite ongoing treatment with MTX”. Since some patients do not respond adequately to the latter drug alone, “this combination therapy could prove to be a highly valuable treatment option”, he added.

Perhaps most striking was the data from the 461-patient GO-AFTER study which showed that patients with moderately-to-severely active rheumatoid arthritis previously treated with anti-TNF-alpha agents experienced significant improvements in signs and symptoms and physical function after receiving every four-week subcutaneous injections of golimumab.

Some 35% and 38% of patients receiving golimumab 50mg and 100mg, respectively, achieved the primary endpoint of at least 20% improvement in symptoms at week 14, compared with 18% on placebo. Importantly, among the 58% of patients whose prior anti-TNF-alpha therapy had been discontinued due to lack of efficacy, 36% receiving golimumab 50mg and 43% on 100mg achieved the 20% improvement level compared with 18% of patients on placebo.

The data means that golimumab, if approved, would be in a good position to compete with other injectable anti-TNF-alpha drugs agents, such as Amgen/Wyeth’s Enbrel (etanercept), which needs to be injected every week and Abbott’s every-other-week jab Humira (adalimumab). J&J and S-P already market Remicade (infliximab), which is administered by intravenous infusion every eight weeks.

In March, the firms sought permission to market golimumab for RA, psoriatic arthritis and ankylosing spondylitis in Europe and an application for the three indications is expected to be submitted in the USA before the month is out. If approved, analysts estimate the drug could comfortably top annual sales of $1 billion by 2012.