Positive Safety Results for IV Stem-Cell Therapy in Rheumatoid Arthritis
Few serious adverse events after 3 months of treatment (Dec. 19)
Positive interim safety results have been reported from a phase IIa study of Cx611 (TiGenix) in rheumatoid arthritis (RA). Cx611 is an intravenously injected suspension of expanded allogeneic adult stem cells derived from human adipose (fat) tissue.
The ongoing placebo-controlled study is evaluating the safety, feasibility, tolerance, and optimal dosing of Cx611 in 53 patients with RA. All of the patients had failed treatment with at least two biological agents. The study is based on a three-step dose-finding protocol, in which each step starts with a safety review of the first three patients after 40 days of dosing.
The interim safety results cover the first 3 months of the trial’s 6-month follow-up. The study’s primary endpoint is safety, and the data collected so far indicate a positive safety profile for three dosing regimens of Cx611: 1) 1 million stem cells/kg administered on days 1, 8, and 15; 2) 2 million stem cells/kg administered on days 1, 8, and 15; and 3) 4 million stem cells/kg administered on days 1, 8 and 15.
Only two patients (4%) experienced serious adverse events (AEs), and one patient discontinued treatment. All other AEs were mild and transient.
Final study results are expected no later than April 2013.
Traditionally, RA is treated with nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, and non-biologic DMARDs. Only non-biologic DMARDs and, to a lesser extent, glucocorticoids have been shown to prevent or inhibit the inflammatory and destructive effects of RA. Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that can differentiate into mesenchymal tissues, such as bone, cartilage, muscle, ligament, tendon, and fat. MSCs also have immunosuppressive and anti-inflammatory properties, and have the potential to improve angiogenesis and prevent fibrosis.
MSCs can be isolated from bone marrow or adipose tissue and rapidly grown in culture. Researchers are working to adapt the immunosuppressive and anti-inflammatory properties of these cells for the treatment of various disorders, including RA, osteoarthritis (OA), genetic bone and cartilage diseases, and cancer metastasis to bone.