SuppreMol Taps Protagen’s Biomarker Expertise for Phase IIa Systemic Lupus Erythematosus Study

SuppreMol is teaming up with Protagen to identify biomarkers of response to SuppreMol’s clinical-stage systemic lupus erythematosus (SLE) candidate SM101. The firms’ collaboration will exploit Protagen’s UNIarray™ platform to identify serum autoantibody signatures that indicate which patients enrolled in SuppreMol’s Phase IIa SM101 study are most likely to benefit from treatment.

SuppreMol says the work may in addition allow the classification of patients into subgroups of SLE. The collaboration and the Phase IIa trial are being supported by the German Federal Ministry for Education and Research (BMBF).

The production of autoantibodies reflects the immune response to chronic autoimmune diseases such as SLE and rheumatoid arthritis as well as neurodegenerative diseases and cancer, Protagen explains. The firm’s UNIarray platform has been designed to identify such autoantibody signatures in blood for the development of in vitro diagnostics and companion diagnostics for patient stratification and therapy selection.

It claims identifying serum or plasma autoantibody signatures has a number of advantages over genomic signature-based approaches. The autoantibody technology allows the multiplexed assessment of thousands of proteins, requires little sample, and can be used with archived samples. In addition, the IgG analyte is highly stable in patient samples, present at high levels, and binds to target antigens with high specificity and affinity, negating the need for enrichment steps or elaborated sample preparation, Protagen claims.

Protagen is exploiting the UNIarray platform both in house and through diagnostics and biomarker discovery and validation collaborations. In April the firm inked a collaboration with Biogen Idec focused on the discovery of treatment response biomarkers in relapsing-remitting multiple sclerosis.

SuppreMol is developing soluble Fc gamma receptors (sFcgRs) for the treatment of autoimmune diseases including primary immune thrombocytopenia (ITP), SLE, and rheumatoid arthritis. Lead candidate SM101 is a recombinant, soluble, nonglycosylated version of the human Fcγ receptor FcγRIIb, which is designed to bind autoantibody/autoantigen complexes and block the triggering of Fcγ receptors on the surface of immune cells.

A Phase Ib/IIa multicenter trial evaluating SM101 in the treatment of ITP was initiated during early 2010. The Phase IIa placebo-control study in SME was initiated just last month and will enroll 50 SLE patients with or without a history of lupus nephritis.

SuppreMol is in addition developing a mAb targeting FcγRIIb, for the treatment of subtypes of autoimmune diseases that cannot be treated with SM101. The firm says the antibody does not interfere with the IgG-binding of the Fcγ receptor and therefore acts as a nonblocking antibody that still allows the receptor to bind to immune complexes and send inhibitory signals that amplify a negative regulating effect on the autoantibody production. Additional preclinical research is focused on the development of sFcRs for the treatment of SLE and rheumatoid arthritis.

In May SuppreMol licensed an IL-3 antibody developed by the molecular immunology research group at the University of Regensburg. The firm says an antibody-based IL-3 inhibitor may provide a new approach to treating rheumatoid arthritis, either during the early stages of the disease or during flares or exacerbations.