Design and preclinical characterization of ALXN1210: A novel anti-C5 antibody with extended duration of action.

Eculizumab, a monoclonal antibody (mAb) directed against complement protein C5, is considered to be the current standard of care for patients with paroxysmal nocturnal hemoglobinuria (PNH) and atypical hemolytic uremic syndrome. This study describes the generation and preclinical attributes of ALXN1210, a new long-acting anti-C5 mAb, obtained through select modifications to eculizumab to both largely abolish target-mediated drug disposition (TMDD) and increase recycling efficiency via the neonatal Fc receptor (FcRn). To attenuate the effect of TMDD on plasma terminal half-life (t1/2), histidine substitutions were engineered into the complementarity-determining regions of eculizumab to enhance the dissociation rate of the mAb:C5 complex in the acidic early endosome relative to the slightly basic pH of blood.

Complement system activation contributes to the ependymal damage induced by microbial neuraminidase.

Background: In the rat brain, a single intracerebroventricular injection of neuraminidase from Clostridium perfringens induces ependymal detachment and death. This injury occurs before the infiltration of inflammatory blood cells; some reports implicate the complement system as a cause of these injuries. Here, we set out to test the role of complement.

Genetic variants in C5 and poor response to eculizumab.

Background: Eculizumab is a humanized monoclonal antibody that targets complement protein C5 and inhibits terminal complement-mediated hemolysis associated with paroxysmal nocturnal hemoglobinuria (PNH). The molecular basis for the poor response to eculizumab in a small population of Japanese patients is unclear.

Methods: We assessed the sequences of the gene encoding C5 in patients with PNH who had either a good or poor response to eculizumab.

C3 glomerulopathy: consensus report.

C3 glomerulopathy is a recently introduced pathological entity whose original definition was glomerular pathology characterized by C3 accumulation with absent or scanty immunoglobulin deposition. In August 2012, an invited group of experts (comprising the authors of this document) in renal pathology, nephrology, complement biology, and complement therapeutics met to discuss C3 glomerulopathy in the first C3 Glomerulopathy Meeting. The objectives were to reach a consensus on: the definition of C3 glomerulopathy, appropriate complement investigations that should be performed in these patients, and how complement therapeutics should be explored in the condition.

Therapeutic mechanism and efficacy of the antibody-drug conjugate BAY 79-4620 targeting human carbonic anhydrase 9.

Carbonic anhydrase IX (CAIX) is a cell surface glycoprotein that is expressed in many different tumors and yet restricted in normal tissues to the gastrointestinal tract. It is upregulated by hypoxia and correlates with tumor grade and poor survival in several tumor indications. Monoclonal antibodies (mAb) with single digit nanomolar binding affinity for CAIX were derived by panning with the recombinant ectodomain of CAIX against the MorphoSys HUCAL Gold library of human Fabs.

A TPO receptor agonist, ALXN4100TPO, mitigates radiation-induced lethality and stimulates hematopoiesis in CD2F1 mice.

Thrombopoietin (TPO) receptor agonists lacking sequence homology to TPO were designed by grafting a known peptide sequence into the hinge and/or kappa constant regions of a human anti-anthrax antibody. Some of these proteins were equipotent to TPO in stimulating cMpl-r activity in vitro and in increasing platelet levels in vivo. ALXN4100TPO (4100TPO), the best agonist in this series with a K(d) of 30 nM for cMpl-r, exhibited potent activity as a radiation countermeasure in CD2F1 mice exposed to lethal total-body radiation from a cobalt-60 γ-ray source.