Ra Pharmaceuticals, Inc. (Nasdaq:RARX) today presented pre-clinical data for an extended release (XR) formulation of zilucoplan at the 6th Annual Peptides Congress, taking place April 24-25, 2019, in London, UK.

This XR formulation of zilucoplan employs poly(D,L-lactic-co-glycolic acid) (PLGA) technology, an established delivery platform for sustained release of peptides. The PLGA XR formulation of zilucoplan is designed to produce uniform particles with homogenous distribution of zilucoplan and a predictable release profile. In pre-clinical studies, the PLGA XR formulation of zilucoplan achieved and maintained therapeutic drug levels necessary to treat complement-mediated diseases, including generalized myasthenia gravis.

“We’re excited to present data for the PLGA XR formulation of zilucoplan, in which target drug concentrations were achieved and maintained with once-weekly subcutaneous dosing,” said Simon Read, Ph.D., Chief Scientific Officer of Ra Pharma. “Our XR development program allows for simple administration of a low drug volume without the need for intravenous loading, on-body infusion devices, tissue-degrading enzymes, or permeation enhancers. We look forward to sharing our continued progress in this and other XR formulations that form part of the zilucoplan life-cycle extension program, and we remain on track to advance the zilucoplan XR program into the clinic in the first half of 2020.”

Weekly subcutaneous doses of the PLGA XR formulation of zilucoplan in non-human primates rapidly achieved and maintained target drug concentrations for 14 days. Near-complete inhibition of complement component 5 (C5) in an ex vivo hemolysis assay was sustained throughout this 14 day period.

“Consistent with our patient-centric approach to drug development, the progress of the PLGA XR formulation of zilucoplan is an important step in our efforts to develop and expand patient access to simple and convenient treatment options for a wide range of C5-mediated diseases,” said Doug Treco, Ph.D., President and Chief Executive Officer of Ra Pharma.

The presentation from the 6th Annual Peptides Congress can be accessed by visiting the “Presentations and Publications” section of the Ra Pharma website: www.rapharma.com.

About Zilucoplan

Ra Pharma is developing zilucoplan for generalized myasthenia gravis (gMG) and other tissue-based, complement-mediated disorders with high unmet medical need. The product candidate is designed for convenient, once-daily, subcutaneous (SC) self-administration. Zilucoplan 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.

About Ra Pharmaceuticals

Ra Pharmaceuticals is a clinical-stage biopharmaceutical company focused on leading the field of complement biology to bring innovative and accessible therapies to patients with rare 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.

Forward-Looking Statements

This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding the potential and progress of the PLGA XR formulation of zilucoplan and other XR formulations, our expectations surrounding the initiation of clinical trials of the XR formulation of zilucoplan and timing thereof, our efforts to develop and expand patient access to treatment options for a wide range of C5-mediated diseases, and bringing innovative and accessible therapies to patients with rare diseases. All such forward-looking statements are based on management’s current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include the risks that Ra Pharma's product candidates, including zilucoplan, will not successfully be developed or commercialized, in the timeframe we expect or at all; as well as the other factors discussed in the “Risk Factors” section in Ra Pharma’s most recently filed Annual Report on Form 10-K, as well as other risks detailed in Ra Pharma’s subsequent filings with the Securities and Exchange Commission. There can be no assurance that the actual results or developments anticipated by Ra Pharma will be realized or, even if substantially realized, that they will have the expected consequences to, or effects on, Ra Pharma. All information in this press release is as of the date of the release, and Ra Pharma undertakes no duty to update this information unless required by law.