Ra Pharma Announces FDA Orphan Drug Designation for Zilucoplan in Generalized Myasthenia Gravis

On September 6, 2019, VCBeat (WeChat ID: vcbeat) learned via Business Wire that biotechnology and pharmaceutical company Ra Pharmaceuticals (Ra Pharma) announced that its therapeutic drug Zilucoplan for generalized myasthenia gravis (gMG) had received orphan drug designation from the U.S. Food and Drug Administration (FDA).

gMG is a chronic, autoimmune neuromuscular disorder. Patients primarily present with skeletal muscle weakness and fatigability, with symptoms worsening after frequent activity and alleviating after rest. gMG may initially be confined to localized areas such as the eyes, but it typically progresses to involve the respiratory muscles, as well as the muscles of the head and limbs. The disease has a low prevalence, and female patients are more commonly affected than males.

Like other complement-mediated rare diseases, gMG is caused by abnormal complement levels in patients. Therefore, the R&D team at Ra Pharmaceuticals is dedicated to developing drugs that regulate complement expression levels.

Ra Pharmaceuticals, founded in 2008 and headquartered in Massachusetts, USA, is a clinical-stage biopharmaceutical company. The company is dedicated to advancing the field of complement biology and providing new therapeutic options for patients with rare diseases. Ra Pharmaceuticals went public on the NASDAQ Stock Market on October 27, 2016, under the ticker symbol RARX.

Ra Pharmaceuticals developed zilucoplan, a treatment for generalized myasthenia gravis (gMG), leveraging its robust proprietary drug discovery platform. This synthetic macrocyclic peptide binds to complement component C5, inhibiting its cleavage into C5a and C5b, thereby reducing the risk of autoimmune disease exacerbation. Zilucoplan offers patients a convenient and highly effective subcutaneous therapy regimen. The drug was poised to initiate a 12-week Phase III clinical trial in the second half of 2019.

Ra Pharmaceuticals has also developed a new biologic based on zilucoplan by leveraging targeted complement technology. Like zilucoplan, this drug can be used to treat gMG, immune-mediated necrotizing myopathy (IMNM), and other complement-mediated diseases.

The FDA established the Office of Orphan Products Development primarily to support the development of drugs for rare diseases, providing safe and effective methods for prevention, diagnosis, and treatment to patients with rare diseases worldwide. In addition to FDA orphan drug designation, Zilucoplan will also receive incentive supports such as tax credits for qualified clinical testing expenses.

Dr. Doug Treco, President and Chief Executive Officer of Ra Pharmaceuticals, stated, “gMG is a debilitating neuromuscular disorder affecting more than 60,000 patients in the United States. We developed Zilucoplan, a macrocyclic peptide inhibitor, to improve therapeutic outcomes for patients. By targeting and modulating complement levels to treat gMG, this medication facilitates patient self-management and provides a convenient and effective subcutaneous treatment option.”

(Compiled by Xu Xiaoxue)