Ra Pharmaceuticals Announces Initiation of First-in-Human Clinical Trial of Novel Complement C5 Inhibitor

-- Presentation of Data Supporting In Vivo Efficacy and Novel Mechanism of Action of Synthetic C5 Inhibitor at 2015 ASH Annual Meeting --

CAMBRIDGE, Mass.--()--Ra Pharmaceuticals announced today that it has launched a Phase 1 study of its synthetic peptide C5 inhibitor, RA101495. The Phase 1 trial is a randomized, double-blind study designed to test the safety of single, escalating doses of RA101495 and to establish the pharmacokinetics and pharmacodynamics after subcutaneous administration in healthy volunteers.

“This study is the first step in the clinical development of RA101495 and will allow us to determine a dose suitable for treating patients with a range of complement-mediated disorders including our lead indication, paroxysmal nocturnal hemoglobinuria (PNH), a rare acquired hematologic syndrome in which red blood cells are destroyed by the complement system,” said Debasish Roychowdhury, M.D., Acting Chief Medical Officer of Ra Pharmaceuticals. “In this study we will be monitoring both safety as well as complement inhibitory activity in plasma samples from treated subjects. The data being presented at ASH highlights the novel mechanism of action and the in vivo pharmacokinetics and pharmacodynamics of RA101495. Our in vivo studies have demonstrated that RA101495 can potently and durably suppress complement activity, which is known to be a critical factor in the treatment of PNH”, added Dr. Roychowdhury.

Preclinical data demonstrating potent C5 inhibition suitable for a broad range of complement-mediated diseases will be presented at the 57th American Society of Hematology Annual Meeting and Exposition (ASH), taking place December 5-8, 2014 in Orlando, FL. Details on the presentations at ASH are as follows:

Abstract Title: Preclinical Evaluation of RA101495, a Potent Cyclic Peptide Inhibitor of C5 for the Treatment of Paroxysmal Nocturnal Hemoglobinuria (#939)

  • Session: 101. Red Cells and Erythropoiesis, Structure and Function, Metabolism, and Survival, Excluding Iron: Poster I
  • Date: Saturday, December 5, 2015
  • Time: 5:30 PM-7:30 PM ET
  • Location: Hall A, Level 2 (Orange County Convention Center)

Abstract Title: Complement C5 Inhibition Blocks the Cytokine Storm and Consumptive Coagulopathy By Decreasing Lipopolysaccharide (LPS) Release in E. coli Sepsis (#765)

  • Session: 331. Pathophysiology of Thrombosis: Procoagulant States – Assessment and Risks
  • Date: Monday, December 7, 2015
  • Time: 5:00 PM ET (Oral presentation)
  • Location: W311ABCD, Level 3 (Orange County Convention Center)

About RA101495

Ra Pharma is developing RA101495 for paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), and other debilitating conditions. The product is designed for convenient, subcutaneous self-administration. RA101495 is a synthetic, macrocyclic peptide discovered by Ra’s Proprietary Extreme Diversity™ platform. The peptide binds complement C5 with subnanomolar affinity and allosterically inhibits its cleavage into C5a and C5b upon activation of the classical, alternative or lectin pathways. In vitro studies demonstrate that RA101495 disrupts the interaction between C5b and C6 and prevents assembly of the membrane attack complex (MAC), defining a new mechanism for the inhibition of C5 function. Repeat dosing in vivo demonstrated sustained and predictable inhibition of complement activity with an excellent safety profile.

About Ra Pharmaceuticals

Ra Pharma combines novel insights into innate immunity with leadership in macrocycle technology to transform the lives of patients with life-threatening disorders. Our proprietary Extreme Diversity™ peptide chemistry platform delivers drugs with the diversity and specificity of antibodies, coupled with the pharmacological properties of small molecules. Our primary clinical focus is on diseases of complement dysregulation and orphan indications defined by validated biomarkers. For more information, please visit: www.rapharma.com.


MacDougall Biomedical Communications
Douglas MacDougall, 781-235-3060

Release Summary

Ra Pharmaceuticals announced today that it has launched a Phase 1 study of its synthetic peptide C5 inhibitor, RA101495.


MacDougall Biomedical Communications
Douglas MacDougall, 781-235-3060