Schering-Plough, Johnson & Johnson and Centocor were celebrating this week after the US Food and Drug Administration approved the firm’s inflammatory drug, Remicade (infliximab), to reduce the signs and symptoms of active arthritis in patients with psoriatic arthritis.

Approval was primarily based on data from the so-called Impact 2 trial, in which Remicade-treated patients showed significant disease improvements. At week 14, 58% of those receiving Remicade experienced at least 20% improvement in arthritis symptoms, according to the American College of Rheumatology scoring criteria (ACR 20), versus 11% of those treated with placebo. At week 24, 27% of Remicade receivers experienced at least a 70% percent improvement compared to just 2% in the placebo group. Additionally, at week 24, 60% of Remicade-treated patients experienced at least a 75% percent improvement from baseline in psoriasis, as assessed by Psoriasis Area Severity Index (PASI 75), compared to 1% in the placebo group, with more than one third of the Remicade receivers achieving a PASI 90 score at week 24. No patients receiving placebo achieved a PASI 90 response at week 24.

Importantly, patients in the Remicade group also experienced decreased symptoms of dactylitis (swelling of digits in the hands or feet) and enthesopathy (inflammation of a tendon, or ligament insertion to the bone), two common disease manifestations causing pain and swelling, which are estimated to affect more than one-third of people with psoriatic arthritis.

This is the drug’s ninth US approval since first winning the green light back in 1998 for the treatment of Crohn’s disease. It is also available to treat inflammatory diseases such as rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis. Psoriatic arthritis involves joint pain and swelling that can lead to debilitation coupled with inflamed, scaly, red patches of psoriasis. Approximately one million people in the US alone psoriatic arthritis, and the disease affects both men and women equally, most commonly between the ages of 30 and 50.