aTyr Pharma Announces FDA Orphan Drug Designation for Efzofitimod (ATYR1923) for Treatment of Systemic Sclerosis

aTyr Pharma, Inc. announced that the U.S. Food and Drug Administration (FDA) has granted the company orphan drug designation for its lead therapeutic candidate, efzofitimod, for the treatment of systemic sclerosis (SSc, also known as scleroderma).

Efzofitimod is a potential first-in-class immunomodulator that downregulates innate and adaptive immune responses in uncontrolled inflammatory disease states via selective modulation of neuropilin-2 (NRP2). Clinical proof-of-concept was recently established for efzofitimod in a Phase 1b/2a study in patients with pulmonary sarcoidosis, a major form of interstitial lung disease (ILD). Many patients with SSc may develop associated ILD, known as SSc-ILD. The pathology of SSc-ILD is driven by the same immune cells that are central to sarcoidosis pathology, and NRP2 is upregulated on these cells, particularly on macrophages. Furthermore, efzofitimod has been shown to reduce lung and skin fibrosis in animal models of SSc and idiopathic pulmonary fibrosis, where it matched or outperformed known anti-fibrotic agents, including nintedanib and pirfenidone.

“We are very pleased to receive orphan drug designation for efzofitimod for SSc, which marks the second such designation for our efzofitimod clinical program,” said Sanjay S. Shukla, M.D., M.S., President and CEO of aTyr. “The data we have presented in animal models of SSc along with the positive findings reported from our recent Phase 1b/2a study in pulmonary sarcoidosis patients suggest that efzofitimod has the potential to be a new treatment option that resolves inflammation and subsequent fibrosis in those living with SSc-ILD. We look forward to exploring the potential expansion of our efzofitimod clinical program into other forms of ILD with high unmet need where this novel therapeutic may be able to improve patient outcomes.”

The FDA’s Office of Orphan Drug Products grants orphan status to support the development of medicines for patients with unmet needs for rare disorders affecting fewer than 200,000 people in the United States. Orphan drug designation provides certain benefits, including the potential for seven years of market exclusivity following regulatory approval, exemption from FDA application fees and tax credits for qualified clinical trials.

Systemic sclerosis is a chronic, progressive, autoimmune disease characterized by inflammation and fibrosis of connective tissues throughout the body, including the skin and other internal organs. SSc that occurs in the lungs is called SSc-ILD. It is estimated that approximately 100,000 people in the U.S. are affected by SSc and 55-65% may develop ILD. SSc-ILD causes inflammation in the lungs and, if left untreated, can result in scarring that causes permanent loss of lung function. ILD is the primary cause of death in patients with SSc. Current treatment options for SSc-ILD are limited, mainly focus on slowing disease progression and are associated with significant toxicity.