CAMBRIDGE, MA, USA I January 8, 2018 I Ra Pharmaceuticals, Inc. (NASDAQ:RARX) today announced that it has initiated dosing in the Company’s Phase 1b clinical trial evaluating RA101495 SC in patients with renal impairment. This trial is designed to characterize the pharmacokinetics (PK) of RA101495 SC in these patients, thereby enabling the evaluation of RA101495 SC in complement-mediated renal diseases, such as atypical hemolytic uremic disorder (aHUS) and lupus nephritis (LN). Ra Pharma is a clinical stage biopharmaceutical company focusing on the development of next-generation therapeutics for the treatment of complement-mediated diseases and is developing RA101495 as a novel, subcutaneously-administered (SC) inhibitor of complement component 5 (C5). RA101495 SC is currently in Phase 2 clinical development for the treatment of paroxysmal nocturnal hemoglobinuria (PNH) and generalized myasthenia gravis (gMG).

“Building on the clinical data collected to date from which we observed the favorable PK and pharmacodynamic (PD) profile of RA101495, this Phase 1b trial is designed to evaluate RA101495 in a subset of patients with renal impairment, with the aim of expanding the range of indications for RA101495 as a potential therapy for patients with complement-mediated disorders,” said Ramin Farzaneh-Far, MD, Chief Medical Officer of Ra Pharma. “C5 is a clinically-validated target for multiple complement-mediated renal disorders, including aHUS, and this trial is designed to provide the necessary PK data to support the future evaluation of RA101495 in renal disorders.”

The Phase 1b, multi-center, open-label trial is designed to evaluate the PK profile of RA101495 SC in patients with renal impairment. The trial is planned to enroll approximately 16 subjects, including eight patients with severe renal impairment matched with eight healthy control subjects with normal renal function. Each patient will receive a single, SC dose of 0.3 mg/kg of RA101495. The trial will compare the PK profile in patients with renal impairment with subjects with normal renal function.

“The initiation of dosing in this Phase 1b trial is a meaningful step for advancing RA101495 in multiple complement-mediated renal indications,” said Doug Treco, PhD, President and Chief Executive Officer. “The convenient, once-daily, SC, self-administration dosing profile of RA101495 provides a compelling alternative to currently available, intravenously-administered (IV) therapies, and we continue to work toward providing a differentiated treatment option for these patients and addressing this significant unmet need. Following our recently reported positive interim data from the RA101495 Phase 2 program in PNH, we look forward to expanding the scope of RA101495 with the goal of maximizing its potential as a safe, well-tolerated, convenient, and efficacious C5 inhibitor for patients with complement-mediated disorders.”

About RA101495 SC

Ra Pharma is developing RA101495 SC for paroxysmal nocturnal hemoglobinuria (PNH), generalized myasthenia gravis (gMG), atypical hemolytic uremic syndrome (aHUS), and lupus nephritis (LN). The product is designed for convenient, once-daily, subcutaneous (SC) self-administration. RA101495 SC is a synthetic, macrocyclic peptide discovered using Ra Pharma’s powerful proprietary drug discovery technology. The peptide binds complement component 5 (C5) with sub-nanomolar affinity and allosterically inhibits its cleavage into C5a and C5b upon activation of the classical, alternative, or lectin pathways. By binding to a region of C5 corresponding to C5b, RA101495 SC also disrupts the interaction between C5b and C6 and prevents assembly of the membrane attack complex (MAC). This activity defines an additional, novel mechanism for the inhibition of C5 function. To learn more about RA101495 SC, please visit: http://rapharma.com/pipeline/ra101495/.

About Ra Pharmaceuticals

Ra Pharmaceuticals is a clinical stage biopharmaceutical company focusing on the development of next-generation therapeutics for complement-mediated diseases. The Company discovers and develops peptides and small molecules to target key components of the complement cascade. For more information, please visit: www.rapharma.com.

SOURCE: Ra Pharmaceuticals