Ra Pharmaceuticals Announces Publication of Zilucoplan Phase 2 gMG Trial Results in JAMA Neurology

Pivotal Phase 3 trial of zilucoplan in gMG ongoing, with top-line results expected in early 2021

CAMBRIDGE, Mass.–(BUSINESS WIRE)–Ra Pharmaceuticals, Inc. (Nasdaq:RARX) today announced that full results from its Phase 2 clinical trial of zilucoplan in patients with generalized myasthenia gravis (gMG) were published online in JAMA Neurology. The JAMA Neurology publication can be accessed here.

“This publication in JAMA Neurology recognizes the impact and significance of the findings from our Phase 2 clinical trial demonstrating zilucoplan’s potential in gMG, a chronic and debilitating neuromuscular disease that affects more than 60,000 patients in the U.S.,” said Doug Treco, Ph.D., President and Chief Executive Officer of Ra Pharma. “These results support our further evaluation of zilucoplan in the ongoing RAISE study, a pivotal Phase 3 trial of zilucoplan in gMG, with top-line results expected in early 2021. If successfully developed and approved, zilucoplan has the potential to expand access to convenient and effective complement inhibition therapy to a broad range of patients with gMG.”

As reported in the JAMA Neurology article, “Clinical Effects of the Self-administered Subcutaneous Complement Inhibitor Zilucoplan in Patients with Moderate to Severe Generalized Myasthenia Gravis: Results of a Phase 2 Randomized, Double-Blind, Placebo-Controlled, Multicenter Clinical Trial,” the study demonstrated that zilucoplan resulted in rapid, clinically meaningful, statistically significant, and sustained improvements in the primary and key secondary endpoints, namely, change from baseline to week 12 in Quantitative Myasthenia Gravis (QMG) and MG Activities of Daily Living (MG-ADL) scores, respectively. Further, near-complete complement inhibition was associated with a faster onset and greater magnitude of benefit than submaximal complement inhibition, with a favorable safety and tolerability profile.

Ra Pharma is currently evaluating zilucoplan in the RAISE study, a single, global, pivotal, randomized, double-blind, placebo-controlled, Phase 3 clinical trial, for the treatment of gMG. The trial, which incorporates feedback from the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and Japan’s Pharmaceuticals and Medical Devices Agency (PMDA), is designed to evaluate the efficacy of a once-daily, subcutaneously (SC) self-administered dose of 0.3 mg/kg of zilucoplan versus placebo. Top-line results from the RAISE study are expected in early 2021.

About Zilucoplan Phase 2 gMG Clinical Trial

The Phase 2, multi-center, randomized, double-blind, placebo-controlled trial was designed to evaluate the safety, tolerability, and preliminary efficacy of zilucoplan in patients with generalized myasthenia gravis (gMG), regardless of prior therapies, who had an MGFA Disease Class of II-IVa at screening and a Quantitative Myasthenia Gravis (QMG) score, a physician-administered assessment of MG-related muscle weakness, of ≥ 12 at screening and randomization. The trial enrolled 44 patients in the U.S. and Canada. At the outset of the 12-week treatment period, patients were randomized in a 1:1:1 ratio to receive daily, subcutaneous (SC) doses of 0.1 mg/kg of zilucoplan, 0.3 mg/kg of zilucoplan, or matching placebo. The pre-specified primary efficacy endpoint was the change in QMG score from baseline to week 12. The key secondary efficacy endpoint was the change in MG Activities of Daily Living (MG-ADL) score, a patient-reported outcome measure, from baseline to week 12. Significance testing was pre-specified at a 1-sided alpha of 0.1. All 44 patients completed the 12-week study and, of these, 42 (95%) entered a long-term extension to receive active study drug.

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 approximately 60,000 people in the U.S. alone.

About Zilucoplan

Ra Pharma is developing zilucoplan and zilucoplan extended release (XR) for generalized myasthenia gravis (gMG), immune-mediated necrotizing myopathy (IMNM), amyotrophic lateral sclerosis (ALS), and other tissue-based complement-mediated disorders with high unmet medical need. The product candidate is designed for convenient subcutaneous (SC) self-administration. Zilucoplan is an investigational, synthetic, macrocyclic peptide discovered using Ra Pharma’s powerful proprietary drug discovery technology. The peptide is designed to bind complement component 5 (C5) with sub-nanomolar affinity and allosterically inhibit its cleavage into C5a and C5b upon activation of the classical, alternative, or lectin pathways. The U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to zilucoplan for the treatment of MG.

About Ra Pharmaceuticals, Inc.

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 Ra Pharma’s ability to expand patient access to important therapies, the safety, efficacy, regulatory and clinical progress, and therapeutic potential of Ra Pharma’s product candidates, including without limitation zilucoplan and zilucoplan XR, statements regarding trial design, timeline, and enrollment of Ra Pharma’s ongoing and planned clinical programs, including without limitation the Phase 3 trial of zilucoplan for the treatment of gMG, and plans and timing for the presentation of and beliefs regarding clinical trial data, including top-line results for the RAISE study. 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 and zilucoplan XR, will not successfully be developed or commercialized, in the timeframe we expect or at all; the risk that Ra Pharma may fail to enroll patients in its clinical trials, which may cause delays or other adverse effects; the risk that Ra Pharma may fail to obtain additional financing on favorable terms or at all; risks relating to the Merger, including: that Ra Pharma may be unable to obtain stockholder approval as required for the Merger; conditions to the closing of the Merger may not be satisfied and required regulatory approvals may be delayed or not be obtained; the Merger may involve unexpected costs, liabilities or delays; the business of Ra Pharma may suffer as a result of uncertainty surrounding the Merger; the outcome of any legal proceedings related to the Merger; Ra Pharma may be adversely affected by other economic, business, and/or competitive factors; the occurrence of any event, change or other circumstances that could give rise to the termination of the Merger Agreement; and other risks to the consummation of the Merger, including the risk that the Merger will not be consummated within the expected time period or at all. If the Merger is consummated, Ra Pharma stockholders will cease to have any equity interest in Ra Pharma and will have no right to participate in its earnings and future growth. Additional factors that may affect the future results of Ra Pharma are discussed in the “Risk Factors” section in Ra Pharma’s most recently filed Annual Report on Form 10-K and Quarterly Report on Form 10-Q for the period ending September 30, 2019, 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.

Natalie Wildenradt, 617-674-9874

[email protected]

Media:

Argot Partners

David Rosen, 212-600-1902

[email protected]