Corixa (formerly Anergen), in collaboration with Organon, is developing AnergiX.RA, a complex of solubilized HLA DRB1-0401(a) together with a specific peptide from the human cartilage glycoprotein HCgp39, for the potential treatment of rheumatoid arthritis (RA) [307156]. Phase I/II trials were completed in April 2000 and the final results from the randomized, blinded, placebo-controlled dose-escalation study are expected later this year [363409]. The product utilizes Anergen's AnergiX technology, and combines an MHC-derived protein with an Organon autoantigen peptide, derived from myelin basic protein and involved in the development of RA [212659,363409]. Engagement of T-cell receptors with AnergiX.RA induces apoptosis in autoreactive T-cells [227421]. Researchers at Organon identified the central component in AnergiX.RA; results from preclinical studies identifying this target protein were published in June 1997 in Arthritis & Rheumatism. Researchers demonstrated that HC (human cartilage) gp39 is recognized by T-cells from RA patients and has the potential to block arthritis in the mouse model [248543,354821].