Ra Pharmaceuticals to Present at the 4th Congress of the European Academy of Neurology

- Phase 2 Trial in Generalized Myasthenia Gravis Over 50% Enrolled

CAMBRIDGE, Mass.--()--Ra Pharmaceuticals, Inc. (NASDAQ:RARX) today announced that the design of its Phase 2 clinical trial of RA101495 SC for the treatment of generalized myasthenia gravis (gMG) will be presented at the 4th Congress of the European Academy of Neurology (EAN), taking place June 16-19, 2018 in Lisbon, Portugal. The Phase 2 trial design will be presented along with previously detailed Phase 1 clinical trial results evaluating the safety, tolerability, pharmacokinetics, and pharmacodynamics of RA101495 SC in healthy volunteers.

“Complement C5 is a validated target for treating gMG, but currently available options are difficult to access, and the need for high-volume intravenous infusions places a burden on patients suffering with this lifelong disease. This creates an opportunity to deliver a more convenient, accessible therapy such as RA101495 SC to benefit a larger population of patients with gMG,” said Ramin Farzaneh-Far, MD, Chief Medical Officer of Ra Pharma. “As a once-daily, low-volume, subcutaneous (SC), self-administered therapy, we believe RA101495 SC has the potential to transform complement therapeutics in gMG.”

Initiated in December 2017, the Phase 2, multicenter, randomized, double-blind, placebo-controlled trial is designed to evaluate the safety, tolerability, and preliminary efficacy of RA101495 SC in approximately 36 patients with gMG. At the outset of a 12-week treatment period, patients are randomized in a 1:1:1 ratio and receive daily, SC doses of 0.1 mg/kg of RA101495, 0.3 mg/kg of RA101495, or matching placebo. The primary efficacy endpoint is change in Quantitative Myasthenia Gravis (QMG) score from baseline to week 12. All patients will have the opportunity to receive RA101495 SC in a long-term extension study.

To date, 19 patients, over 50% of target enrollment, have been dosed in the trial, and the Company remains on track to report data from the study in the first half of 2019.

Details of the poster presentations are as follows:

Title: Baseline Characteristics and Disease Burden in the Myasthenia Gravis Foundation of America (MGFA) Registry
Session Title: Muscle and Neuromuscular Junction Disease 1
Date/Time: Saturday, June 16, 12:30-13:15 WEST
Location: Poster Area, Screen C1
Abstract Code: 777

Title: Complement C5 Inhibitor RA101495 for the Treatment of Myasthenia Gravis
Session Title: Muscle and Neuromuscular Junction Disease 1
Date/Time: Saturday, June 16, 13:30-14:15 WEST
Location: Poster Area, Screen C1
Abstract Code: 933

About gMG

Myasthenia gravis (MG) is a chronic, autoimmune, neuromuscular disease characterized by weakness and fatigue of skeletal muscles. Patients with MG present with muscle weakness that becomes increasingly severe with repeated use and recovers with rest. Weakness can be localized to specific muscles, such as those responsible for eye movements, but often progresses to affect a broader range, including head, limb, and respiratory muscles. This progression is often described as the generalized, or severe, form of the disease. gMG is estimated to affect over 80,000 individuals worldwide.

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 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 is designed to disrupt the interaction between C5b and C6 and prevent assembly of the membrane attack complex (MAC). This activity may define an additional, novel mechanism for the inhibition of C5 function.

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.

Forward-Looking Statement

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 safety, efficacy and regulatory and clinical progress of our product candidates, including RA101495 SC, and statements regarding trial design, timeline and enrollment of our ongoing and planned clinical programs. 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 RA101495 SC, will not successfully be developed or commercialized; the risk that topline results as of February 7, 2017 from the Company's global Phase 2 clinical program evaluating RA101495 SC for the treatment of PNH may not be indicative of final study results; 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.

Contacts

Investors:
Ra Pharmaceuticals, Inc.
Jennifer Robinson, 617-674-9873
jrobinson@rapharma.com
or
Media:
Argot Partners
David Rosen, 212-600-1902
david.rosen@argotpartners.com

Contacts

Investors:
Ra Pharmaceuticals, Inc.
Jennifer Robinson, 617-674-9873
jrobinson@rapharma.com
or
Media:
Argot Partners
David Rosen, 212-600-1902
david.rosen@argotpartners.com