Rheumatoid Arthritis: Meijerink J

Eming R, Visconti K, Hall F, Sekine C, Kobayashi K, Chen Q, Cope A, Kanazawa S, Peterlin M, Rijnders A, Boots A, Meijerink J, Sønderstrup G. · Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305, USA. · Arthritis Res. · Pubmed #12110132 No free full text.

Abstract: Genetic susceptibility to rheumatoid arthritis (RA), a common autoimmune disease, is associated with certain HLA-DR4 alleles. Treatments are rarely curative and are often tied to major side effects. We describe the development of a humanized mouse model wherein new, less toxic, vaccine-like treatments for RA might be pretested. This model includes four separate transgenes: HLA-DR*0401 and human CD4 molecules, a RA-related human autoantigenic protein (HCgp-39), and a T-cell receptor (TCRalphabeta) transgene specific for an important HCgp-39 epitope, eliciting strong Th1 responses in the context of HLA-DR*0401.

Zandbelt MM, Houbiers JG, van den Hoogen FH, Meijerink J, van Riel PL, in't Hout J, van de Putte LB. · Department of Rheumatic Diseases, Radboud University Medical Center, Nijmegen, The Netherlands. · J Rheumatol. · Pubmed #16960935 No free full text.

Abstract: OBJECTIVE: To investigate safety and tolerability and pilot efficacy of repeated single doses of Org39141 in patients with active rheumatoid arthritis (RA). Org 39141 is recombinant human cartilage glycoprotein-39, intended to induce mucosal tolerance upon intranasal administration. METHODS: RA patients with moderate disease activity were treated for 4 weeks and followed for another 8 weeks. The trial had a sequential cohort design: RA patients in the first cohort received 4 intranasal doses (one per week) of either 25 microg Org 39141 or placebo; in subsequent cohorts, treatment with 125microg, 625 microg, or 3125 microg Org39141 was compared to placebo. Safety was evaluated by means of reporting adverse events, standard laboratory testing, and nose examination. The primary efficacy endpoint was RA disease activity as measured by the Disease Activity Score 28 (DAS28). RESULTS: A total of 36 patients were randomized. Org39141 was well tolerated, and no severe or serious adverse events (AE) were reported. In the pooled placebo group, a decrease in DAS28 was observed, but to a lesser extent than in the Org 39141 treatment groups. After 4 weeks of treatment, the mean decrease in DAS in the 625 microg Org 39141 treatment group (-24%) was statistically (p = 0.02) and clinically (EULAR criteria) significantly larger than in the pooled placebo group (-3%). Once-weekly intranasal treatment with Org39141 was well tolerated, and no serious or severe AE were reported. A trend towards efficacy was observed. Our results are encouraging for further clinical development of Org39141.

Kavanaugh A, Genovese M, Baughman J, Kivitz A, Bulpitt K, Olsen N, Weisman M, Matteson E, Furst D, van Vollenhoven R, Anderson J, Cohen S, Wei N, Meijerink J, Jacobs C, Mocci S. · Division of Rheumatology, Allergy and Immunology, University of California, San Diego, San Diego, CA 92037-0943, USA. · J Rheumatol. · Pubmed #12610799 No free full text.

Abstract: OBJECTIVE: Human cartilage glycoprotein 39 (HC gp-39) appears to be a relevant autoantigen in patients with rheumatoid arthritis (RA). Administration of major histocompatibility complex (MHC) Class II complexed antigens without requisite costimulatory signals can induce immunologic tolerance. We evaluated the safety, pharmacokinetics, and preliminary efficacy of AG4263 in patients with RA. AG4263 is a soluble complex of native HLA-DR4 (beta*0401) complexed to Org 36601, a 13-mer peptide derived from HC gp-39 (also referred to as CDP263). METHODS: Thirty-one HLA-DRB1*0401 positive patients with persistent RA disease activity despite concurrent methotrexate were randomized to 7 infusions of AG4263 (n = 24) or placebo (n = 7) over 6 weeks. The initial dose of 0.5 micro g/kg was escalated in subsequent cohorts to a maximum of 150 micro g/kg. Safety analyses included recording of adverse events and measurement of CD4/CD8 counts, reactivity to recall antigens, and development of antibodies to HLA-DR4. Efficacy was assessed using the Paulus 20 criteria. RESULTS: Treatment was well tolerated, with injection site reaction the most common adverse event. There was no loss of reactivity to recall antigens, change in cell counts, or antibodies to HLA-DR. The mean half-life of AG4263 was 12.5 h. Some evidence of clinical response was seen; responses were more common among patients receiving the highest doses of AG4263 and among those with baseline T cell reactivity to CDP263. CONCLUSION: AG4263 was safe, well tolerated, and without evidence of generalized immune suppression. Along with the observed trend toward clinical efficacy, the results suggest that this therapeutic approach warrants further investigation in patients with RA.

Steenbakkers PG, Baeten D, Rovers E, Veys EM, Rijnders AW, Meijerink J, De Keyser F, Boots AM. · Department of Pharmacology, N. V. Organon, Oss, The Netherlands. · J Immunol. · Pubmed #12759455 links to  free full text

Abstract: Recently human cartilage gp-39 (HC gp-39) was identified as a candidate autoantigen in rheumatoid arthritis (RA). To further investigate the relevance of this Ag in RA, we have generated a set of five mAbs to a combination epitope of complexes of HC gp-39(263-275) and the RA-associated DR alpha beta 1*0401 HLA class II molecules. FACS studies revealed that these mAb recognize specific complexes on homozygous DR alpha beta 1*0401-positive B lymphoblastoid cells pulsed with HC gp-39(263-275). The best mAb, 12A, was further characterized using a set of irrelevant DR alpha beta 1*0401-binding peptides and truncated/elongated versions of HC gp-39(263-275) itself. The minimal epitope recognized in combination with DR alpha beta 1*0401 was HC gp-39(263-273). Peptides not encompassing HC gp-39(263-273) were not recognized. Three of five mAb were able to inhibit (up to 90%) the response of HC gp-39(263-275)-specific DR alpha beta 1*0401-restricted T cell hybridomas to peptide-pulsed APC or purified complexes. Using mAb 12A, we have been able to identify and localize dendritic cells that present DR alpha beta 1*0401/HC gp-39(263-275) complexes in synovial tissue of DR alpha beta 1*0401-positive RA patients, indicating local presentation of the HC gp-39(263-275) epitope in the inflamed target tissue by professional APC. These data support a role of HC gp-39 in the local autoimmune response that leads to chronic inflammation and joint destruction.