FDA ( Food and Drug Administration ) has approved Remicade ( Infliximab ) to reduce the signs and symptoms of active arthritis in patients with psoriatic arthritis.

Psoriatic arthritis affects approximately one million men and women in the U.S. and is often characterized by the complex symptoms of joint inflammation and skin lesions.

Data from the Induction and Maintenance of Psoriatic Arthritis Clinical Trial 2 ( IMPACT 2 ) served as the primary basis for the approval.

Significant improvements in both ACR 20 and PASI 75 were observed in patients treated with Infliximab as early as week two, with further improvements through 24 weeks.
At week 14, 58 percent of patients treated with Infliximab experienced at least 20 percent improvement in arthritis symptoms, according to the American College of Rheumatology scoring criteria ( ACR 20 ) versus 11 percent of placebo-treated patients ( P < 0.001 ).
At week 24, 27 percent of patients treated with Infliximab experienced at least 70 percent improvement ( ACR 70 ) versus two percent of placebo-treated patients ( P < 0.001 ).
Additionally, at week 24, 60 percent of patients treated with Infliximab experienced at least 75 percent improvement from baseline in psoriasis, as assessed by Psoriasis Area Severity Index ( PASI 75 ), versus one percent of placebo-treated patients.
At week 24, more than one-third ( 39 percent ) of patients receiving Infliximab achieved PASI 90, a dramatic improvement in psoriasis symptoms. No patients receiving placebo achieved a PASI 90 response at week 24.

Patients in the Infliximab group also experienced decreased symptoms of dactylitis and enthesopathy, two common disease manifestations causing pain and swelling.

Dactylitis, swelling of digits in the hands or feet, and enthesopathy, inflammation of a tendon, or ligament insertion to the bone, are estimated to affect more than one-third of people with psoriatic arthritis.

In the study, 40 percent of Infliximab patients and 41 percent of patients in the placebo group had dactylitis in at least one digit at baseline.
After 24 weeks of treatment, only 15 percent of Infliximab patients continued to experience symptoms, compared to 33 percent of patients receiving placebo ( P greater than or equal to 0.05 ).

At baseline, enthesopathy was observed in 42 percent of patients in the Infliximab group and 35 percent of patients receiving placebo.
At week 24, only 22 percent of Infliximab patients still experienced enthesopathy, compared to 36 percent in the placebo group ( P = 0.004 ).

IMPACT 2 was a Phase III randomized, double-blind, placebo-controlled study of 200 patients with active psoriatic arthritis ( defined as affecting at least five joints ).
The study evaluated the safety and efficacy of Infliximab in patients who had an inadequate response to DMARDs or nonsteroidal anti- inflammatory drugs ( NSAIDs ). Patients received Infliximab ( 5mg/kg ) or placebo at weeks zero, two, six and every eight weeks until week 22.

Patients treated with Infliximab also experienced significant improvement in the physical component summary ( PCS ) and mental component summary ( MCS ) scores of the short form 36 ( SF-36 ).

The SF-36 is a 36-item questionnaire that assesses impact in eight areas, including physical functioning, pain, vitality, social functioning, psychological functioning, general health perceptions and role limitations due to physical and emotional problems. SF- 36 scores range from zero to 100, and lower scores indicate poorer functioning and well-being.

At week 14, Infliximab patients experienced an average increase in PCS score of 9.1 units, compared to an average 1.1-unit increase in patients receiving placebo ( P < 0.001 ).
Additionally, patients in the Inflixiamb group experienced an average 3.8-unit increase in MCS score, while patients receiving placebo averaged a decrease of 1.2 units ( P = 0.001 ).

Through 24 weeks, a similar number of patients experienced adverse events in each treatment group. No deaths, cases of tuberculosis or other opportunistic infections, or serious infusion reactions were reported and serious infections were uncommon. Also, with the exception of one case of basal cell carcinoma in the placebo group, no malignancies were reported.
Significant laboratory abnormalities were unusual, with an elevation in liver function tests being the most common abnormality.
There were more patients with serious adverse events in the Infliximab group ( 8.7 percent ) than in the placebo group ( 6.2 percent ).

Source: Centocor, 2005


XagenaMedicine2005