A Phase I/Ii Study Of Atacicept (Taci-Ig) To Neutralize April And Blys In Patients With Refractory Or Relapsed Multiple Myeloma (Mm) Or Active Previously Treated Waldenstrom'S Macroglobulinemia (Wm).

Background: Atacicept (formerly referred to as TACI-Ig) is a soluble receptor fusion protein comprised of the extracellular domain of TACI and the Fc portion of a human IgG. Atacicept binds to APRIL (A Proliferation-Inducing Ligand) and BLyS (B Lymphocyte Stimulator), which are potent survival factors for normal B cells and are over-expressed in plasma cell malignancies. APRIL and BLyS are produced by MM cellsand other cells within the tumor environment, resulting in the enhanced survival of malignant cells via both autocrine and paracrine loops. The aim of this trial was to determine the tolerability, PK, PD and biological activity of atacicept in patients with MM or WM.