Natalizumab in the Treatment of Rheumatoid Arthritis in Subjects Receiving Methotrexate

Altoona Center for Clinical Research, Duncansville

Rheumatic Disease Associates, Willow Grove

Jacksonville Center for Clinical Research, Jacksonville

University of Alabama at Birmingham, Birmingham

Justus Fiechtner, MD, PC, Lansing

Radiant Research, Dallas

Clinical Research Unit / University of Arizona, Tucson

Arthritis Medical Clinic of North County, Inc., Escondido

Massachusetts General Hospital, Boston

Clinical Pharmacology Study Group, Worcester

St. Clare's Mercy Hospital, St. John's

The Arthritis Program Research Group Inc., Newmarket